Method for producing compound encoded by oligonucleotide, and application thereof

Abstract

The purpose of the present invention is to provide a new method for producing a compound encoded by an oligonucleotide. Provided according to the present invention is a method for producing a compound encoded by an oligonucleotide, the method including phosphodiester bonding of oligonucleotide chains to each other by chemical ligation under prescribed conditions.

Description

Methods for producing oligonucleotide-encoded compounds and their applications

[0001] The present invention relates to a method for producing a compound encoded by an oligonucleotide, and its applications.

[0002] DELs (DNA Encoded Libraries) are compound libraries containing millions to hundreds of millions of compounds, each linked to a DNA barcode that encodes the compound's structure. By selecting compounds that bind to a target molecule and sequencing the DNA barcode that encodes the compound's structure, it is possible to identify the structure of a small molecule compound that has binding activity to the target molecule from the DNA sequence. Because DELs occupy a very large chemical space, it is possible to screen a wider range of compounds in a single run, potentially leading to more efficient identification of superior hit compounds.

[0003] High-throughput screening (HTS) is a well-known compound screening method. HTS is a random screening method with a high processing capacity per unit time, and involves biochemical evaluation of tens of thousands to hundreds of thousands of compounds to identify hit compounds. In contrast, DELs are small to medium-sized molecules with DNA barcodes that encode their structures, allowing them to be handled as a mixture, making it easy to select target molecules. DELs have many advantages over HTS, including lower operating costs, and are therefore expected to become a new compound library.

[0004] The basic structure of the compounds that make up DELs includes a complex in which an oligonucleotide tag and a building block having a chemical structure encoded by the oligonucleotide tag are bound to a bifunctional molecular headpiece (Patent Documents 1-4, Non-Patent Documents 1, 2, and 14).

[0005] The Split & Pool method is generally used to prepare compounds that make up DELs (Patent Documents 1-4, Non-Patent Documents 1 and 2). The Split & Pool method involves (1) aliquoting a compound mixture into multiple aliquots, (2) attaching different building blocks and corresponding tags to each aliquot, and (3) pooling and mixing the resulting mixtures. This method involves repeating steps (1) to (3) multiple times. For example, if steps (1) to (3) are repeated three times, each using x, y, and z building blocks (x, y, and z are natural numbers) and corresponding tags, respectively, a library containing x x y x z compounds is prepared.

[0006] Enzymatic ligation using an enzyme is a common method for attaching an oligonucleotide tag to a compound constituting DELs. In enzymatic ligation, the ends of the nucleotide chains of the compound constituting DELs and the ends of the oligonucleotide tag are linked by an enzymatic reaction. Patent documents 1-4, Non-Patent Document 1, and Non-Patent Document 14 describe methods for attaching an oligonucleotide tag to a compound constituting DELs using a ligase or polymerase.

[0007] In recent years, non-enzymatic ligation methods have been developed as alternatives to enzymatic ligation in order to increase the variety of methods for attaching oligonucleotide tags. Examples of such methods include a ligation method using a photochemical cycloaddition reaction using psoralen and thymidine (Patent Document 5, Non-Patent Documents 3-4), a ligation method using an alkyne-azide cycloaddition reaction using a copper catalyst (Patent Document 6, Non-Patent Documents 3-4, 8), and a Zn 2+ , Mn 2+ , Mg 2+ Ligation methods using condensing agents such as cyanoimidazole and cyanogen bromide in the presence of a metal source such as thiazolinone (Patent Documents 7-8, Non-Patent Documents 3, 9-13) are known. These methods are generally referred to as chemical ligation.

[0008] On the other hand, Non-Patent Document 8 reports that polymerase cannot synthesize cDNA (complementary DNA) with the correct sequence around the triazole bond formed by chemical ligation.

[0009] It is believed that natural phosphodiester bonds are preferable for correct cDNA synthesis by polymerase. 2+ It has been described that chemical ligation using metal salts of the formula (I) results in the formation of phosphodiester bonds in oligonucleotide pairs having 5'-monophospho and 3'-hydroxy termini and in oligonucleotide pairs having 5'-hydroxy and 3'-monophospho termini.

[0010] However, the method described in Patent Document 7 has been shown to yield a one-sided ligation product in which the chemical ligation reaction stops midway. In the synthesis of compounds constituting DELs, the next ligation reaction does not proceed from the one-sided ligation product, leading to a decrease in the yield of the compounds constituting DELs.

[0011] International Publication No. 1993 / 020242, International Publication No. 2004 / 039825, International Publication No. 2005 / 058479, International Publication No. 2006 / 135786, International Publication No. 2014 / 012010, International Publication No. 2013 / 036810, International Publication No. 2016 / 109423, Chinese Publication No. 109868268

[0012] Matthew A Clark et al. Design, synthesis and selection of DNA-encoded small-molecule libraries. Nature Chemical Biology 5, 647-654 (2009)Robert A. Goodnow Jr, Christoph E. Dumelin and Anthony D. Keefe, DNA-encoded chemistry: enabling the deeper sampling of chemical space. Nature Reviews Drug Discovery 16, 131-147 (2017)Anthony D Keefe, Matthew A Clark, Christopher D Hupp, Alexander Litovchick and Ying Zhang, Chemical ligation methods for the tagging of DNA-encoded chemical libraries. Curr. Opin. Chem. Biol. 2015 Jun;26:80-8Alexander Litovchick, Matthew A Clark and Anthony D Keefe, Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags. Artificial DNA: PNA & XNA 2014;5(1):e27896Chiamaka Obianyor, Gary Newnam, Bryce E. Clifton, Martha A. Grover and Nicholas V. Hud, Towards Efficient Nonenzymatic DNA Ligation: Comparing Key Parameters for Maximizing Ligation Rates and Yields with Carbodiimide Activation.ChemBioChem 21, 3359-3370 (2020)E Kanaya and H Yanagawa, Template-directed polymerization of oligoadenylates using cyanogen bromide. Biochemistry 1986 Nov 18;25(23):7423-30.J P Ferris, C H Huang, W J Hagan Jr., N-cyanoimidazole and diimidazole imine: water-soluble condensing agents for the formation of the phosphodiester bond. Nucleosides Nucleotides 1989;8(3):407-14.Alexander Litovchick, Christoph E. Dumelin, Sevan Habeshian, Diana Gikunju, Marie-Aude Guiee, Paolo Centrella, Ying Zhang, Eric A. Sigel, John W. Cuozzo, Anthony D. Keefe & Matthew A. Clark, Encoded Library Synthesis Using Chemical Ligation and the Discovery of sEH Inhibitors from a 334-Million Member Library. Scientific Reports volume 5, 10916 (2015)Haodong Chen, Feng Du, Gangyi Chen, Frank Streckenbach, Afshan Yasmeen, Yun Zhao, Zhuo Tang, Template-directed chemical ligation to obtain 3'-3' and 5'-5' phosphodiester DNA linkages. Sci Rep. 2014 Apr 4;4:4595.Sandra Carriero and Masad J.Damha, Synthesis of Lariat-DNA via the Chemical Ligation of a Dumbbell Complex. Org. Lett. 2003, 5, 3, 273-276Keiji Murayama, Hikari Okita, Takumi Kuriki & Hiroyuki Asanuma, Nonenzymatic polymerase-like template-directed synthesis of acyclic L-threoninol nucleic acid. Nature Communications 12, 804 (2021)N.I. Sokolova,D.T. Ashirbekova,N.G. Dolinnaya,Z.A. Shabarova, Chemical reactions within DNA duplexes Cyanogen bromide as an effective oligodeoxyribonucleotide coupling agent. FEBS Lett. 1988 May 9;232(1):153-5.Kevin J. Luebke, Peter B. Dervan, Nonenzymatic ligation of double-helical DNA by alternate-strand triple helix formation. Nucleic Acids Res. 1992 Jun 25;20(12):3005-9.Andrew B MacConnell, Patrick J McEnaney, Valerie J Cavett, Brian M Paegel, DNA-Encoded Solid-Phase Synthesis: Encoding Language Design and Complex Oligomer Library Synthesis. ACS Comb Sci. 2015 Sep 14;17(9):518-34.

[0013] An object of the present invention is to provide a new method for producing compounds encoded by oligonucleotides, a new ligation method, or a new compound suitable for synthesizing DELs by chemical ligation.

[0014] The present invention relates to the following: [1] A method for producing a compound encoded with an oligonucleotide, comprising: (a) preparing a headpiece, the headpiece having a chemical reaction site and an oligonucleotide, the headpiece oligonucleotide having a phosphate group at its 3'-end and a hydroxy group at its 5'-end; (b) phosphodiester-linking a double-stranded oligonucleotide tag to the headpiece oligonucleotide by chemical ligation, the double-stranded oligonucleotide tag consisting of at least one double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the headpiece oligonucleotide, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the headpiece oligonucleotide, respectively; and (c) directly or indirectly binding at least one building block to a chemical reaction site of the headpiece; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag encodes the building block. [2] The method of [1], wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative. [3] The method of [1] or [2], wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt. [4] The method of [1] or [2], wherein the divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+[5] The method according to any one of [1] to [4], wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being 4 to 7. [6] The method according to any one of [1] to [5], wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long. [7] The method according to [6], wherein the overhang is 5 bases long. [8] The method according to [6] or [7], wherein the headpiece oligonucleotide has an overhang at the 3'-end. [9] The method according to [8], wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[10] The method according to [1], wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[11] The method according to

[10] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[12] A method for producing an oligonucleotide-encoded compound, comprising the steps of: (a) preparing a headpiece, wherein the headpiece has a chemical reaction site and an oligonucleotide, and the oligonucleotide of the headpiece contains a phosphate group at the 3'-end and a hydroxy group at the 5'-end;(b) phosphodiester-linking a double-stranded oligonucleotide tag to an oligonucleotide of a headpiece by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece; (c) directly or indirectly linking at least one building block to a chemical reaction site of the headpiece; (b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in an encoded compound (m-1), wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); and (c') directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block;wherein step (b) and step (c) are carried out once, and then step (b') and step (c') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times step (b') and step (c') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[13] The method according to

[12] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[14] The method according to

[12] or

[13] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[15] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[14] The method according to

[14] , wherein the oligonucleotide is a metal salt of the formula (I).

[16] The method according to any one of

[12] to

[15] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[17] The method according to any one of

[12] to

[16] , wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long.

[18] The method according to

[17] , wherein the overhang is 5 bases long.

[19] The method according to

[17] or

[18] , wherein the headpiece oligonucleotide has an overhang at the 3'-end.

[20] The method of

[19] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag and / or double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag and / or double-stranded oligonucleotide tag (m).

[21] The method of

[12] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[22] The method of

[21] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[23] A method for producing a compound encoded with an oligonucleotide, comprising: (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end; and (b) in each of the reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotides of the headpieces by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, and the first strand has a hydroxy group at the 5'-end and a phosphate group at the 3'-end, and the second strand has a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel. (c) directly or indirectly binding at least one building block to a chemical reaction site on the headpiece in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; and (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[24] The method according to

[23] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

[25] The method according to

[23] or

[24] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[26] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[25] The method according to

[26] , wherein the first strand of the double-stranded oligonucleotide tag has an overhang at its 3'-end, and the chemical ligation is carried out in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang at the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[27] The method according to any one of

[23] to

[26] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being 4 to 7.

[28] The method according to any one of

[23] to

[27] , wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long.

[29] The method according to

[28] , wherein the overhang is 5 bases long.

[30] The method according to

[28] or

[29] , wherein the headpiece oligonucleotide has an overhang at its 3'-end.

[31] The method according to

[30] , wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on its 3'-end, and the chemical ligation is carried out in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[32] The method according to

[23] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[33] The method according to

[32] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the pH of the buffer solution is 4 to 8.

[34] A method for producing an oligonucleotide-encoded compound, comprising the steps of: (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end;(b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel, and the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece; (c) in each of the dispensed reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block and may be different for each reaction vessel; and (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[35] The method according to

[34] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[36] The method according to

[34] or

[35] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[37] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[36] The method according to

[36] , wherein the oligonucleotide is a metal salt of the formula (I).

[38] The method according to any one of

[34] to

[37] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[39] The method according to any one of

[34] to

[38] , wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long.

[40] The method according to

[39] , wherein the overhang is 5 bases long.

[41] The method according to

[39] or

[40] , wherein the headpiece oligonucleotide has an overhang at the 3'-end.

[42] The method of

[41] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m).

[43] The method of

[34] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[44] The method of

[43] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[45] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing headpieces into two or more reaction vessels, each headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece containing a phosphate group at the 3'-end and a hydroxyl group at the 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation;The double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) phosphodiester-linking the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece; (d) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel;(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof; and (e) ligating a Closing Primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond, wherein the Closing Primer is a Closing Primer. the primer has a phosphate group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a hydroxy group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and the method comprises the step of phosphodiester-linking the phosphate group at the 5'-end of the first strand of the closing primer to the hydroxy group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the closing primer to the phosphate group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');Step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and mth time represent the number of times steps (a') to (d') are carried out; only in the nth time, the double-stranded oligonucleotide tag (m) in step (b') has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand), and then step (e) is carried out; step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel;

[46] The method according to

[45] , wherein the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and in the mth time, binds to an oligonucleotide contained in the encoded compound (m-1), and the building block (m) in the mth time directly or indirectly binds to the chemical reaction site of the encoded compound (m-1).

[46] The method according to

[45] , wherein in step (e), the closing primer is phosphodiester-linked by ligation, and then the protruding end is blunted with an enzyme, and the second strand of the closing primer contains a modified nucleotide.

[47] The method according to

[45] or

[46] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[48] ​​The method according to any one of

[45] to

[47] , wherein step (b) and / or step (b') further comprises chemical ligation in the presence of a divalent metal salt to form a phosphodiester bond.

[49] The method according to any one of

[45] to

[47] , wherein the divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+

[50] The method according to any one of

[45] to

[49] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[51] The method according to any one of

[45] to

[50] , wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long.

[52] The method according to

[51] , wherein the overhang is 5 bases long.

[53] The method according to

[51] or

[52] , wherein the headpiece oligonucleotide has an overhang at the 3'-end.

[54] The method according to

[53] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that the nth chemical ligation is performed in the absence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m).

[55] The method according to

[45] or

[46] , wherein step (b) and / or step (b') is performed in the presence of a condensing agent to form a phosphodiester bond by chemical ligation, wherein the condensing agent is a carbodiimide derivative.

[56] The method according to

[55] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 8.

[57] A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and the double-stranded oligonucleotide tag (p) is bound to the headpiece, and the double-stranded oligonucleotide tag (p) consists of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and having a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand; (c) linking, via phosphodiester bonds, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; and (c) linking, directly or indirectly, at least one building block to a chemical reaction site contained in the complex; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c).

[58] The method according to

[57] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[59] The method according to

[57] or

[58] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[60] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[61] The method according to any one of

[57] to

[60] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being 4 to 7.

[62] The method according to any one of

[57] to

[61] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[63] The method according to

[62] , wherein the overhang is 5 bases long.

[64] The method according to

[62] or

[63] , wherein the oligonucleotide contained in the complex has an overhang at its 3'-end.

[65] The method according to

[64] , wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide containing a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[66] The method according to

[57] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[67] The method according to

[66] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[68] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p);(b) phosphodiester-linking a double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex; (b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1), wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); and (c') directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block;wherein step (b) and step (c) are carried out once, and then step (b') and step (c') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times step (b') and step (c') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[69] The method according to

[68] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[70] The method according to

[68] or

[69] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[71] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[70] The method according to

[70] , wherein the oligonucleotide is a metal salt of the formula (I).

[72] The method according to any one of

[68] to

[71] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[73] The method according to any one of

[68] to

[72] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[74] The method according to

[73] , wherein the overhang is 5 bases long.

[75] The method according to

[73] or

[74] , wherein the oligonucleotide contained in the complex has an overhang at its 3'-end.

[76] The method of

[75] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m).

[77] The method of

[68] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[78] The method of

[77] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[79] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and the double-stranded oligonucleotide tag (p) is bound to the headpiece;(b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, has a hydroxy group at the 5'-end of the first strand and a phosphate group at the 3'-end of the second strand, and is bound to a headpiece at the 5'-end of the first strand and the 3'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, has a hydroxy group at the 5'-end of the first strand and a phosphate group at the 3'-end, and has a phosphate group at the 3'-end of the second strand and a hydroxy group at the 5'-end, and the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel, (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; and (d) pooling the contents of each of the reaction vessels, each containing the compounds encoded in steps (b) and (c), to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[80] The method according to

[79] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[81] The method according to

[79] or

[80] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[82] The method according to

[79] or

[80] , wherein the divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+

[81] The method according to

[81] , wherein the metal salt of the compound is a metal salt of the compound.

[83] The method according to any one of

[79] to

[82] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[84] The method according to any one of

[79] to

[83] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[85] The method according to

[84] , wherein the overhang is 5 bases long.

[86] The method according to

[84] or

[85] , wherein the oligonucleotide contained in the complex has an overhang at the 3'-end.

[87] The method according to

[86] , wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide containing a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[88] The method according to

[79] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[89] The method according to

[88] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[90] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p);(b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel, and the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) in each of the dispensed reaction vessels, directly or indirectly linking at least one building block to a chemical reaction site contained in the complex, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block and may be different for each reaction vessel; and (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[91] The method according to

[90] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[92] The method according to

[90] or

[91] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[93] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[92] The method according to any one of

[90] to

[93] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being 4 to 7.

[95] The method according to any one of

[90] to

[93] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[96] The method according to

[95] , wherein the overhang is 5 bases long.

[97] The method according to

[95] or

[96] , wherein the oligonucleotide contained in the complex has an overhang at its 3'-end.

[98] The method according to

[97] , wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide containing a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[99] The method according to

[90] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a carbodiimide derivative.

[100] The method according to

[99] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, wherein the buffer solution has a pH of 4 to 8.

[101] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p);(b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel, and the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) in each of the dispensed reaction vessels, directly or indirectly linking at least one building block to a chemical reaction site contained in the complex, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) consists of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel;(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof; and (e) ligating a Closing Primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond, wherein the Closing Primer is a Closing Primer. the primer has a phosphate group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a hydroxy group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and the method comprises the step of phosphodiester-linking the phosphate group at the 5'-end of the first strand of the closing primer to the hydroxy group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the closing primer to the phosphate group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');Step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and mth time represent the number of times steps (a') to (d') are carried out; only in the nth time, the double-stranded oligonucleotide tag (m) in step (b') has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand), and then step (e) is carried out; step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a double-stranded oligonucleotide tag (m) or a building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and in the mth time, binds to an oligonucleotide contained in the encoded compound (m-1), and the building block (m) in the mth time binds directly or indirectly to the chemical reaction site of the encoded compound (m-1).

[102] The method according to

[101] , wherein in step (e), the closing primer is phosphodiester-linked by ligation, and then the protruding end is blunted with an enzyme, and the second strand of the closing primer contains a modified nucleotide.

[103] The method according to

[101] or

[102] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[104] The method according to any one of

[101] to

[103] , wherein step (b) and / or step (b') further comprises chemical ligation in the presence of a divalent metal salt to form a phosphodiester bond.

[105] The method according to any one of

[101] to

[103] , wherein the divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+

[104] The method according to

[104] , wherein the oligonucleotide is a metal salt of the formula (I).

[106] The method according to any one of

[101] to

[105] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[107] The method according to any one of

[101] to

[106] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[108] The method according to

[107] , wherein the overhang is 5 bases long.

[109] The method according to

[107] or

[108] , wherein the oligonucleotide contained in the complex has an overhang at its 3'-end.

[110] The method according to

[109] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that the nth chemical ligation is performed in the absence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m).

[111] The method according to

[101] or

[102] , wherein step (b) and / or step (b') is performed in the presence of a condensing agent to form a phosphodiester bond by chemical ligation, wherein the condensing agent is a carbodiimide derivative.

[112] The method according to

[111] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 8.

[113] A compound consisting of the following formula I: A compound in which A is a chemical reaction site; L is a linker; C and D are each independently a spacer; B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-end of G; F is a functional group which forms a bond with the 3'-end of H; G is an oligonucleotide moiety having a phosphate group at the 3'-end; H is an oligonucleotide moiety having a hydroxy group at the 5'-end; and j is 0 or 1 (when j is 0, A and B are directly bonded, and when j is 1, a linker L is present between A and B).

[114] A compound having the following formula II: A compound in which A' represents one or more building blocks; L represents a linker; C and D each independently represent a spacer; B represents a trivalent molecular backbone which may have a substituent; E represents a functional group which forms a bond with the 5'-end of G'; F represents a functional group which forms a bond with the 3'-end of H'; G' represents an oligonucleotide having a phosphate group at the 3'-end; H' represents an oligonucleotide having a hydroxy group at the 5'-end; G' and H' comprise a sequence which encodes A'; and j represents 0 or 1 (when j is 0, A and B are directly bonded, and when j is 1, A and B are separated by a linker L).

[115] The compound according to

[113] or

[114] , in which C and D comprise dSpacer (Formula IV).

[116] A compound of formula III: A' is one or more building blocks; L is a linker; C' and D' are independent spacers each containing 1 to 5 dSpacers (Formula IV); A compound in which B is a trivalent molecular skeleton which may have a substituent; E is a functional group which forms a bond with the 5'-end of G"; F is a functional group which forms a bond with the 3'-end of H"; G" is an oligonucleotide having a hydroxy group at the 3'-end; H" is an oligonucleotide having a phosphate group at the 5'-end; G" and H" comprise a sequence which encodes A', and j is 0 or 1 (when j is 0, A' and B are directly bonded, and when j is 1, there is a linker L between A' and B).

[117] A composition comprising the compound according to any one of

[113] to

[116] .

[118] A method for ligating an initiator oligonucleotide and a double-stranded oligonucleotide having an overhang, wherein a first strand of the double-stranded oligonucleotide has an overhang, and a second strand of the double-stranded oligonucleotide has an overhang complementary to that of the initiator oligonucleotide, and the method comprises ligating the initiator oligonucleotide and the double-stranded oligonucleotide in the presence of a dummy oligonucleotide having a sequence complementary to the overhang of the first strand of the double-stranded oligonucleotide.

[119] The method according to

[118] , wherein the ligation is chemical ligation.

[120] The method according to

[118] or

[119] , wherein the bond is a phosphodiester bond.

[121] The method of

[120] , wherein the initiator oligonucleotide contains a phosphate group at its 3'-end, and the first strand of the double-stranded oligonucleotide has a hydroxy group at its 5'-end and a phosphate group at its 3'-end, and the method comprises chemically ligating the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide to the phosphate group at the 3'-end of the initiator oligonucleotide via a phosphodiester bond.

[122] The method of any one of

[118] to

[121] , wherein the overhang of the double-stranded oligonucleotide is 4 to 6 bases long.

[123] A method for ligating a double-stranded oligonucleotide tag to a headpiece comprising an oligonucleotide having an overhang, wherein the first strand of the double-stranded oligonucleotide tag has an overhang, and the second strand of the double-stranded oligonucleotide tag has an overhang complementary to the overhang of the oligonucleotide contained in the headpiece, the method comprising ligating in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang of the first strand of the double-stranded oligonucleotide tag.

[124] The method according to

[123] , wherein the ligation is chemical ligation.

[125] The method according to

[123] or

[124] , wherein the bond is a phosphodiester bond.

[126] The method of

[125] , wherein the oligonucleotide of the headpiece has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, the first strand of the double-stranded oligonucleotide tag has a hydroxy group at its 5'-end and a phosphate group at its 3'-end, the second strand has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the second strand of the double-stranded oligonucleotide tag has an overhang complementary to the overhang of the headpiece, and the method comprises chemically ligating the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece via phosphodiester linkage.

[127] The method of any one of

[123] to

[126] , wherein the overhang of the double-stranded oligonucleotide tag is 4 to 6 bases long.

[128] A method for selecting a compound encoded by an oligonucleotide, comprising: (a) contacting a compound encoded by one oligonucleotide obtained by the method according to any one of [1] to

[112] , preferably the method according to [1],

[12] ,

[23] ,

[34] ,

[45] ,

[57] ,

[68] ,

[79] ,

[90] or

[101] , or a library containing a plurality of compounds encoded by oligonucleotides obtained by the method according to any one of [1] to

[112] , preferably the method according to [1],

[12] ,

[23] ,

[34] ,

[45] ,

[57] ,

[68] ,

[79] ,

[90] or

[101] , with a biological target under conditions suitable for the compound encoded by the one oligonucleotide or at least one compound encoded by an oligonucleotide contained in the library to bind to the biological target; and (b) identifying the compound encoded by the oligonucleotide that bound to the biological target in step (a).

[129] The method according to

[128] , further comprising the following steps (1) and (2): (1) determining the structure of a building block encoded by an oligonucleotide contained in a compound encoded by an oligonucleotide selected by the method according to

[128] ; and (2) preparing the building block whose structure has been determined in step (1).

[130] A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a headpiece, wherein the headpiece has a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxy group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece by chemical ligation in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; and (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag encodes the building block.

[131] The method according to

[130] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative.

[132] The method according to

[130] or

[131] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[133] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[134] The method according to any one of

[130] to

[133] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[135] A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a headpiece, wherein the headpiece has a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxy group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; and (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to the single-stranded oligonucleotide contained in the encoded compound (m-1) in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and (c') a step of directly or indirectly binding the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1) via a phosphodiester bond; and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; wherein steps (b) and (c) are carried out once, and then a set of steps (b') and (c') is carried out n times (n is a natural number from 1 to 10, m is a natural number up to n, and the mth time refers to the number of times steps (b') and (c') are carried out).), steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the m-th time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, the sequence of the single-stranded oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to the single-stranded oligonucleotide contained in the encoded compound (m-1) in the m-th time; The method according to

[135] , wherein the building block (m) is directly or indirectly bound to a chemical reaction site of the encoded compound (m-1) in the mth time.

[136] The method according to

[135] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative.

[137] The method according to

[135] or

[136] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[138] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[139] The method according to any one of

[135] to

[138] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[140] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, the single-stranded oligonucleotides of the headpieces having a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece; (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each of the reaction vessels, the building block may differ between reaction vessels; and (d) pooling the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) into one to obtain a mixture thereof; wherein step (b) and step (c) can be performed in any order, and the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[141] The method according to

[140] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[142] The method according to

[140] or

[141] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[143] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[144] The method according to any one of

[140] to

[143] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[145] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, the single-stranded oligonucleotides of the headpieces having a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; (c) in each of the reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, the building block may differ between reaction vessels; (d) pooling the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a single-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in an encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may be different for each reaction vessel, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of a single-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[146] The method according to

[145] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[147] The method according to

[145] or

[146] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[148] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[149] The method according to any one of

[145] to

[148] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[150] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, the single-stranded oligonucleotides of the headpieces having a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; (c) in each of the reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, the building block may differ between reaction vessels; (d) pooling the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a single-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in an encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may be different for each of the reaction vessels, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may be different for each of the reaction vessels; (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof; and (e) ligating a closing primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond;carrying out step (b) and step (c) once, followed by step (d), and then carrying out a set of steps (a') to (d') n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been carried out), and then carrying out step (e); step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of a single-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[151] The method according to

[150] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[152] The method according to

[150] or

[151] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[153] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[154] The method according to any one of

[150] to

[153] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[155] A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a complex comprising a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to a single-stranded oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; and (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c).

[156] The method of

[150] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative.

[157] The method of

[155] or

[156] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[158] The method of

[159] , wherein the divalent metal salt is Co 2+ , Cu2+ , Zn 2+ or Mn 2+

[159] The method according to any one of

[155] to

[158] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[160] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the hydroxy group at the 5'-end of the oligonucleotide contained in the complex and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag are phosphodiester-linked; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1);and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; wherein steps (b) and (c) are carried out once, and then steps (b') and (c') are carried out as a set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times steps (b') and (c') are carried out), wherein steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c), the encoded compound (m-1) comprises a chemical reaction site, a sequence of a single-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the single-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[161] The method according to

[160] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[162] The method according to

[160] or

[161] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[163] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn2+

[164] The method according to any one of

[160] to

[164] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[165] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels dispensed, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between the reaction vessels, (c) directly or indirectly attaching at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; and (d) pooling the contents of each reaction vessel, containing the compounds encoded in steps (b) and (c), to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[166] The method according to

[165] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative.

[167] The method according to

[165] or

[166] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[168] The divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[169] The method according to any one of

[165] to

[168] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[170] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a step of phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and a step of phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block and the building block (m) may differ from reaction vessel to reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a single-stranded oligonucleotide tag (m) or a building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[171] The method according to

[170] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[172] The method according to

[170] or

[171] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[173] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[174] The method according to any one of

[170] to

[173] , wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the buffer solution has a pH of 4 to 7.

[175] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels dispensed, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between the reaction vessels, (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a single-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may differ from reaction vessel to reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof; and (e) ligating a closing primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond;carrying out step (b) and step (c) once, followed by step (d), and then carrying out a set of steps (a') to (d') n times (where n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a single-stranded oligonucleotide tag (m) or a building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[176] The method according to

[175] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[177] The method according to

[175] or

[176] , wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[178] The divalent metal salt is Co; 2+ , Cu 2+ , Zn 2+ or Mn 2+

[179] The method according to any one of

[175] to

[178] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[180] A compound having the following formula XII: A compound in which A is a chemical reaction site; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-end of H; H is an oligonucleotide moiety having a hydroxy group at the 5'-end; and j is 0 or 1 (when j is 0, A and D are directly bonded, and when j is 1, A and D are connected by a linker L).

[181] A compound having the following formula XIII: A compound in which A' is one or more building blocks; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-end of H'; H' is an oligonucleotide having a hydroxy group at the 5'-end; H' comprises a sequence that encodes A', and j is 0 or 1 (when j is 0, A and D are directly bonded, and when j is 1, A' and D are connected by a linker L).

[182] A composition comprising the compound according to

[180] or

[181] .

[183] ​​A method for selecting an oligonucleotide-encoded compound, comprising: (a) contacting a biological target with one oligonucleotide-encoded compound or a library containing a plurality of oligonucleotide-encoded compounds obtained by the method of any one of

[130] to

[179] under conditions suitable for the one oligonucleotide-encoded compound or at least one oligonucleotide-encoded compound contained in the library to bind to the biological target; and (b) identifying the oligonucleotide-encoded compound that bound to the biological target in step (a).

[184] The method of

[183] , further comprising the following steps (1) and (2): (1) determining the structure of an oligonucleotide-encoded building block contained in the oligonucleotide-encoded compound selected by the method of

[183] ; and (2) preparing the building block whose structure has been determined in step (1).

[185] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing headpieces into two or more reaction vessels, each headpiece having a chemical reaction site and an oligonucleotide, the headpiece oligonucleotide containing a phosphate group at its 3'-end and a hydroxyl group at its 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the headpiece oligonucleotide by chemical ligation;The double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) phosphodiester-linking the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece; (d) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel;(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof; and (e) ligating a Closing Primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond, wherein the Closing Primer is a Closing Primer. the primer has a hydroxy group at the 5'-end of the first strand and a hydroxy group at the 3'-end, and a phosphate group at the 3'-end of the second strand and a hydroxy group at the 5'-end; and the method comprises the step of phosphodiester-linking, by chemical ligation, the hydroxy group at the 5'-end of the first strand of the closing primer to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the phosphate group at the 3'-end of the second strand of the closing primer to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), Step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times step (a') to step (d') are carried out), and then step (e) is carried out;Steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, the sequence of the oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and in the mth time, binds to the oligonucleotide contained in the encoded compound (m-1); The method according to

[185] , wherein the building block (m) is directly or indirectly bound to a chemical reaction site of the encoded compound (m-1) in the mth time.

[186] The method according to

[185] , wherein in step (e), the Closing Primer is ligated to form a phosphodiester bond, and then the protruding end is blunted with an enzyme, and the second strand of the Closing Primer contains a modified nucleotide.

[187] The method according to

[185] or

[186] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, wherein the condensing agent is a cyano derivative or an imidazole derivative.

[188] The method according to

[185] or

[186] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[189] The method according to

[189] , wherein the divalent metal salt is Co. 2+ , Cu 2+ , Zn 2+ or Mn 2+

[190] The method according to any one of

[185] to

[189] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[191] The method according to any one of

[185] to

[190] , wherein the headpiece oligonucleotide has an overhang, and the overhang is 4 to 6 bases long.

[192] The method according to

[191] , wherein the overhang is 5 bases long.

[193] The method according to

[191] or

[192] , wherein the headpiece oligonucleotide has an overhang at the 3'-end.

[194] The method according to any one of

[191] to

[193] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that the nth chemical ligation is performed in the absence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m).

[195] The method according to any one of

[185] to

[194] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

[196] The method according to any one of

[185] to

[195] , wherein step (b) and / or step (b') and / or step (e) are steps of forming phosphodiester bonds by chemical ligation in the presence of a buffer solution, wherein the pH of the buffer solution is 4 to 8.

[197] A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels;(b) in each of the reaction vessels dispensed, at least one building block (p) is directly or indirectly bound to a headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, wherein the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each reaction vessel, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation,the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, wherein the sequence of the double-stranded oligonucleotide tag (m) may differ for each reaction vessel; a step of phosphodiester-linking the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof; and (e) phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture by ligation, wherein the Closing Primer has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and wherein the Closing Primer is linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'). The hydroxy group at the 5'-end of the first strand of the primer is connected to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d').a step of forming a phosphodiester bond between the 3'-terminal phosphate groups of the second strands of the primers by chemical ligation; performing step (d) after performing step (b) and step (c) once, and then performing step (d) as a set of steps (a') to (d') n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been performed), and then performing step (e); step (b) and step (c) can be performed in any order, and step (b') and step (c') can be performed in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a double-stranded oligonucleotide tag (m) or a building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively), the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

[198] The method according to

[197] , wherein in step (e), the closing primer is phosphodiester-linked by ligation, and then the protruding end is blunted with an enzyme, and the second strand of the closing primer contains a modified nucleotide.

[199] The method according to

[197] or

[198] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

[200] The method according to any one of

[197] to

[199] , wherein step (b) and / or step (b') and / or step (e) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

[201] The method according to any one of

[197] to

[199] , wherein the divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+

[200] The method according to

[200] , wherein the oligonucleotide is a metal salt of the formula (I).

[202] The method according to any one of

[197] to

[201] , wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 7.

[203] The method according to any one of

[197] to

[202] , wherein the oligonucleotide contained in the complex has an overhang, and the overhang is 4 to 6 bases long.

[204] The method according to

[203] , wherein the overhang is 5 bases long.

[205] The method according to

[203] or

[204] , wherein the oligonucleotide contained in the complex has an overhang at the 3'-end.

[206] The method according to any one of

[203] to

[205] , wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that the nth chemical ligation is performed in the absence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m).

[207] The method according to any one of

[197] to

[206] , wherein step (b) and / or step (b') and / or step (e) are steps of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

[208] The method according to any one of

[197] to

[207] , wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, and the pH of the buffer solution is 4 to 8.

[209] The method according to any one of [1] to [9],

[12] to

[20] ,

[23] to

[31] ,

[34] to

[42] ,

[45] to

[54] ,

[57] to

[65] ,

[68] to

[76] ,

[79] to

[87] ,

[90] to

[98] ,

[101] to

[110] ,

[130] to

[179] ,

[185] to

[194] , or

[197] to

[206] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is 1-cyano-2-methylimidazole.

[210] The method according to any one of [1] to [9],

[12] to

[20] ,

[23] to

[31] ,

[34] to

[42] ,

[45] to

[54] ,

[57] to

[65] ,

[68] to

[76] ,

[79] to

[87] ,

[90] to

[98] ,

[101] to

[110] ,

[130] to

[179] ,

[185] to

[194] , or

[197] to

[206] , wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being 1-cyano-2-methylimidazole, and the reaction temperature of step (b) and / or step (b') is 20°C to 30°C.

[211] The method according to any one of

[197] to

[208] , wherein step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being 1-cyano-2-methylimidazole.

[212] The method according to any one of

[197] to

[208] , wherein step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being 1-cyano-2-methylimidazole, and the reaction temperature in step (e) is 20°C to 30°C.

[213] A method for selecting an oligonucleotide-encoded compound, comprising: (a) contacting a biological target with one oligonucleotide-encoded compound or a library containing a plurality of oligonucleotide-encoded compounds obtained by the method of any one of

[185] to

[212] under conditions suitable for the one oligonucleotide-encoded compound or at least one oligonucleotide-encoded compound contained in the library to bind to the biological target; and (b) identifying the oligonucleotide-encoded compound that bound to the biological target in step (a).

[214] The method of

[213] , further comprising the following steps (1) and (2): (1) determining the structure of an oligonucleotide-encoded building block contained in the oligonucleotide-encoded compound selected by the method of

[213] ; and (2) preparing the building block whose structure has been determined in step (1).

[0015] Through extensive research, the inventors have found that the yield (conversion rate) of chemical ligation can be improved by employing the steps of the present invention in the synthesis of DELs or the binding mode of the present invention with oligonucleotide tags. Furthermore, they have found that the additives of the present invention (metal salts, etc.), the pH of the buffer solution, the addition of dummy oligos, etc. contribute to the improvement of the yield (conversion rate), and have thus completed the present invention.

[0016] According to the present invention, a new method for producing a compound encoded by an oligonucleotide, a new ligation method using a dummy oligo, or a new compound suitable for synthesizing DELs by chemical ligation is provided.

[0017] Figures 1-1 to 1-5 show the conversion rates observed in chemical ligation using various divalent metal salts under pH conditions ranging from 4.0 to 8.0 in Example 1. The plots in Figures 1-1 to 1-5 are defined as follows: X: starting material (1-1); Circle: full-length ligation product (1-3); Upward triangle: upper half ligation product (1-4); Downward triangle: lower half ligation product (1-5); X axis: reaction time (hours); Y axis: conversion rate (%). Figure 1-1 shows the results when CoCl2 was used. Figure 1-2 shows the results when CuCl2 was used. Figure 1-3 shows the results when ZnCl2 was used. Figure 1-4 shows the results when MnCl2 was used. Figure 1-5 shows the results when MgCl2 was used. Figure 2 shows the results of compound selection performed in Example 7 using compounds encoded with oligonucleotides produced using the method of the present invention. The size of the dots in the figure indicates the UMI counts of the DNA sequence calculated from the results of amplicon sequence analysis. Figures 3-1 and 3-2 show the results of compound selection performed in Example 11, 11-A using compounds encoded with oligonucleotides produced using the method of the present invention. The size of the dots in the figure indicates the counts of the DNA sequence calculated from the results of amplicon sequence analysis. Figure 3-1 shows the results of selection using streptavidin beads or carboxylic acid beads. Figure 3-2 shows the results of the control. Figures 4-1 and 4-2 show the results of compound selection performed in Example 11, 11-B using compounds encoded with oligonucleotides produced using the method of the present invention. The size of the dots in the figure indicates the counts of the DNA sequence calculated from the results of amplicon sequence analysis. Figure 4-1 shows the results when the concentration of the oligonucleotide-encoded compound was 0.3 μM or 0.003 μM, and Figure 4-2 shows the results when the concentration of the oligonucleotide-encoded compound was 0.00003 μM.5 shows the results of electrophoresis using samples 12-9 (lane 2) obtained in step D, 12-13 (lane 3) obtained in step E, 12-16 (lane 4) obtained in step F, and 12-17 (lane 5) obtained in step G in Example 12. Lane 1 shows the results of electrophoresis using a 20 bp DNA ladder as a molecular weight marker.

[0018] In the present invention, when "and / or" is used, it means that either "and" or "or" is acceptable.

[0019] [Method for producing a compound encoded by an oligonucleotide] According to some aspects of the present invention, a method for producing a compound encoded by an oligonucleotide (hereinafter sometimes referred to as the production method of the present invention) is provided.

[0020] <First Aspect> According to the first aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c): (a) preparing a headpiece, the headpiece having a chemical reaction site and an oligonucleotide, the headpiece oligonucleotide having a phosphate group at its 3'-end and a hydroxy group at its 5'-end; (b) phosphodiester-linking a double-stranded oligonucleotide tag to the headpiece oligonucleotide by chemical ligation, the double-stranded oligonucleotide tag consisting of at least one double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the headpiece oligonucleotide, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the headpiece oligonucleotide, respectively; and (c) directly or indirectly attaching at least one building block to a chemically reactive site on the headpiece; wherein steps (b) and (c) can be performed in any order, and wherein the double-stranded oligonucleotide tag encodes the building block.

[0021] <Second Aspect> According to a second aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c): (a) preparing a headpiece, wherein the headpiece has a single-stranded oligonucleotide, wherein the single-stranded oligonucleotide of the headpiece has a chemical reaction site at its 3'-end via a spacer and a hydroxy group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece; and (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag encodes the building block.

[0022] In the present invention, "code" refers to the base sequence of an oligonucleotide tag that identifies a building block. "Encoding" refers to a situation in which an oligonucleotide tag that identifies a building block is contained in a compound, and the structure of the building block contained in the compound and the base sequence of the oligonucleotide tag have a one-to-one relationship. "An oligonucleotide tag encodes a building block" refers to a situation in which the structure of the building block corresponding to the base sequence can be identified by analyzing the base sequence of the oligonucleotide tag.

[0023] In some embodiments of the production method of the present invention, the phrase "step (b) and step (c) can be performed in any order" means that step (b) and step (c) can be performed in any order from step (b) to step (c), or from step (c) to step (b).

[0024] (Headpiece) A "headpiece" is a starting material for producing a compound encoded by an oligonucleotide. A headpiece has a chemically reactive site and an oligonucleotide. As shown in Scheme 1, a headpiece in the present invention is: i) a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site; ii) a double-stranded structure in which one of the two complementary oligonucleotide strands has a chemically reactive site via a spacer; iii) a single-stranded structure in which a chemically reactive site is located on the 3'-end via a spacer; or iv) a single-stranded structure in which a chemically reactive site is located on the 5'-end via a spacer.

[0025]

[0026] The headpiece is preferably i) a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site, or iii) a single-stranded structure having a chemically reactive site on the 3'-end side via a spacer. i) A single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site is more preferred. iii) In another embodiment, a single-stranded structure having a chemically reactive site on the 3'-end side via a spacer is also preferred. Two complementary oligonucleotides included in i) of Scheme 1, or two complementary oligonucleotides included in ii) of Scheme 1, can be linked to a double-stranded oligonucleotide tag by a ligation reaction to obtain a compound containing a double-stranded oligonucleotide tag. On the other hand, a single oligonucleotide included in iii) of Scheme 1, or a single oligonucleotide included in iv) of Scheme 1, can be linked to a single-stranded oligonucleotide tag by a ligation reaction to obtain a compound containing a single-stranded oligonucleotide tag.

[0027] The chemically reactive site in the headpiece is a functional group having at least one site that has the ability to bind to a building block, linker, or scaffold compound. As shown in Scheme 1, the chemically reactive site in the headpiece is bound to the oligonucleotide via a spacer, and is not particularly limited as long as it is a functional group that can form a covalent bond with a functional group in the building block, linker, or scaffold compound. For example, if the chemically reactive site in the headpiece is an amino group, it can react with a halogeno group, a carboxy group, a sulfonic acid group, etc. Other chemically reactive sites in the headpiece may be, for example, a carboxy group, a thiol group, an aldehyde group, a hydroxy group, an azide group, an alkynyl group, etc. These functional groups may be substituted with one or more substituents as long as they have binding ability. Examples of the substituent include, for example, C １－５ Alkyl group, C １－５ Alkoxy group, halogen, C substituted with one or more halogens １－５ alkyl group, C substituted with one or more halogens １－５ Examples thereof include an alkoxy group.

[0028] In a preferred embodiment, the chemically reactive site is an amino group.

[0029] In some embodiments of the manufacturing method of the present invention, (a) the "step of preparing a headpiece" refers to putting the headpiece in a state in which it can be subjected to steps (b) and (c), and does not necessarily include manufacturing the headpiece. The "step of preparing a headpiece" may be, for example, placing a pre-made headpiece in a reaction vessel.

[0030] (Oligonucleotide) A "nucleotide" is generally a substance in which a phosphate group is bound to a nucleoside. Nucleotides and nucleosides are the building blocks of DNA, RNA, etc. Nucleotides can form and bind to the sequence of an oligonucleotide, and each nucleotide monomer usually consists of two parts: a nucleobase part and a backbone. In some cases, the backbone may be divided into a sugar part and an internucleoside linker. The nucleobase part may be selected from naturally occurring nucleobases and artificial nucleobases that do not occur in nature. Therefore, nucleobases include not only naturally occurring purine and pyrimidine heterocycles, but also heterocycle analogs and their tautomers. Nucleobases are defined in The Chemical Biology of Nucleic Acids (Gunter Mayer, John Wiley & Sons, 2010) and other publications, and examples thereof include adenine, guanine, thymine, cytosine, uracil, purine, inosine, isoguanine, isocytosine, xanthine, diaminopurine, 5-methylcytosine, 5-fluorouracil, 5-bromouracil, 5-iodouracil, 7-deazaguanine, 7-deazaadenine, pseudouracil, 3-methyluracil, dihydrouracil, 5-ethyluracil, 6-azapyrimidine, 6-methyluracil, 2-thiouracil, 4-thiouracil, 4-acetylcytosine, Examples of suitable cytosine include, but are not limited to, cytosine, 5-(carboxyhydroxymethyl)uracil, 5-carboxymethylaminomethyluracil, 1-methyladenine, 2,2-dimethylguanine, 3-methylcytosine, 2-methyladenine, 2-methylguanine, 7-methylguanine, 5-methoxyaminomethyl-2-thiouracil, 5-methylaminomethyluracil, 5-methylcarbonylmethyluracil, 5-methyloxyuracil, 5-methyl-2-thiouracil, 2-thiocytosine, etc. The sugar portion of the backbone may be a pentose, PNA, or part of a six-membered ring.Examples of pentoses include, but are not limited to, 2'-deoxyribose, ribose, 2'-O-methylribose, 2'-O-methoxyethylribose, 2'-fluororibose, 2'-4'-O-methyleneribose (LNA), and 2'-4'-O-C-ethyleneribose (ENA). The nucleobase is attached to the 1' position of the pentose. When the sugar moiety of the backbone is a pentose such as 2'-deoxyribose or ribose, the internucleoside linker connects the 3' end of the previous monomer to the 5' end of the next monomer. Examples of internucleoside linkers are described in Non-Patent Document 3, etc., and include phosphodiester bonds, phosphorothioate bonds, etc.

[0031] In preferred embodiments, the nucleotide monomers include deoxyadenosine, thymidine, deoxyguanosine, deoxycytidine, adenosine, guanosine, uridine, cytidine, and inosine, linked via phosphodiester bonds, and in particularly preferred embodiments, deoxyadenosine, thymidine, deoxyguanosine, and deoxycytidine.

[0032] The oligonucleotide in the headpiece can be bound to a single-stranded or double-stranded oligonucleotide tag. The oligonucleotide in the headpiece can be any base length, for example, 1 to 200 bases, 10 to 180 bases, 30 to 160 bases, 50 to 140 bases, 70 to 120 bases, and preferably 80 to 100 bases. In another embodiment, a length of 10 to 30 bases is preferred. The oligonucleotide in the headpiece preferably includes a primer oligonucleotide. In the present invention, a primer oligonucleotide is a single-stranded or double-stranded oligonucleotide having a fixed sequence necessary for binding to a primer used to amplify a region containing a tag by polymerase chain reaction (PCR).

[0033] In some preferred embodiments, the oligonucleotide in the headpiece has a phosphate group at the 3'-end and a hydroxy group at the 5'-end in a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemical reaction site, as shown in Scheme 1. In another preferred embodiment, the oligonucleotide in the headpiece has a hydroxy group at the 5'-end in a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemical reaction site on the 3'-end side, as shown in Scheme 1.

[0034] (Chemical Reactive Site) The term "chemically reactive site" refers to a functional group having at least one site capable of binding to a building block, linker, or scaffold compound. The chemically reactive site is not particularly limited as long as it is a functional group capable of forming a covalent bond with a building block, linker, or scaffold compound.

[0035] In the present invention, when a building block is "directly bound" to a headpiece, it means that the building block is directly bound to a chemical reaction site on the headpiece without the intervention of a scaffolding compound, linker, etc. On the other hand, in the present invention, when a building block is "indirectly bound" to a headpiece, it means that the building block is bound to a chemical reaction site on the headpiece via a scaffolding compound, linker, etc. In some embodiments of the production method of the present invention, step (c) may be a step of directly or indirectly binding at least one building block to a chemical reaction site on the headpiece or a chemical reaction site on a linker bound to the headpiece.

[0036] The reaction for binding the building block to the chemical reaction site is not particularly limited and can be carried out according to methods known to those skilled in the art, for example, as described in DNA-Encoded Chemical Libraries, Methods and Protocols (David Israel, Yun Ding John, Springer Nature, 2022).

[0037] (Building Block) A "building block" refers to a small to medium molecular compound having a functional group, or a structural unit having one or more functional groups in a part of the structure of a small to medium molecular compound. A building block can bond to a chemically reactive site in a headpiece. Furthermore, when a building block bonded to a headpiece (here, referred to as building block 1) has a chemically reactive site, another building block (here, referred to as building block 2) can also bond to the chemically reactive site of building block 1. In the present invention, when a building block is separate from other building blocks, such as the relationship between building block 1 and building block 2, it may be referred to as an independent building block.

[0038] Building blocks can also be bonded to chemical reaction sites on headpieces, linkers, or other building blocks bonded to headpieces or linkers via scaffold compounds. A "scaffold" is a molecular framework having two or more functional groups for bonding to chemical reaction sites or building blocks contained in a headpiece. Examples of scaffold compounds include compounds having a cycloalkyl group, a cycloalkenyl group, a heterocycloalkyl group, a heterocycloalkenyl group, an aryl group, or a heteroaryl group, and having multiple functional groups. An example of a scaffold compound is cyanuric chloride. Cyanuric chloride is a heteroaryl compound having three replaceable chloro groups. For example, one chloro group can react with a chemical reaction site on a headpiece or linker, and the other two chloro groups can bond to building blocks.

[0039] (Protecting Group) One or more functional groups in a chemically reactive site, a scaffold compound bonded to a chemically reactive site, a scaffold compound bonded to a building block, a linker, or a building block may be protected with a deprotectable protecting group. Commonly used protecting groups are not particularly limited as long as they can be protected and deprotected as described in Greene's Protective Groups in Organic Synthesis, 5th Edition (John Wiley & Sons, 2014), etc. For example, when the functional group is an amino group, the protecting group may be a tert-butoxycarbonyl group (Boc group), a benzyloxycarbonyl group (Cbz group), a 9-fluorenylmethyloxycarbonyl group (Fmoc group), a 2,2,2-trichloroethoxycarbonyl group (Troc group), an allyloxycarbonyl group (Alloc group), a phthaloyl group (Pht group), a p-toluenesulfonyl group (Ts group), a 2-nitrobenzenesulfonyl group (Ns group), an allyl group, etc. When the functional group is an amino group, the protecting group is preferably an Fmoc group. When the functional group is a thiol group, the protecting group can be, for example, a trimethylphenyl group (Trt group), an acetamidomethyl group (Acm group), a tert-butyl group (tBu group), or the like. When the functional group is an aldehyde group, the protecting group can be, for example, an acetal-based protecting group. An acetal-based protecting group can be generated using a method known to those skilled in the art, for example, a method of converting a carbonyl group to an acetal using dimethyl acetal under an acid catalyst, or the like. When the functional group is a hydroxy group, the protecting group can be, for example, a C protecting group such as a methyl group or a tBu group. １－６ the alkyl group listed above, aralkyl groups such as benzyl group (Bn group) and p-methoxybenzyl group (PMB group), acyl groups such as acetyl group (Ac group) and benzoyl group (Bz group), and silyl groups such as trimethylsilyl group (TMS group), triethylsilyl group (TES group), tert-butyldimethylsilyl group (TBS group), and tert-butyldiphenylsilyl group (TBDPS group).

[0040] Deprotection can be carried out according to methods known to those skilled in the art, such as those described in Greene's Protective Groups in Organic Synthesis, 5th Edition (John Wiley & Sons, 2014). For example, a method of deprotecting a Boc group by heating in a buffer solution is known. A method of deprotecting an Fmoc group by using a secondary amine such as piperidine is known.

[0041] (Linker) The building block or scaffold compound and the headpiece may be linked via a linker. In some embodiments of the production method of the present invention, in the step (a) of preparing the headpiece, a headpiece or a headpiece linked to a linker can be used.

[0042] A "linker" is a linking group that connects a building block or scaffold compound to a headpiece. The structure of the linker is not particularly limited, except that it has a functional group for binding to the headpiece and a functional group for binding to the building block. The linker may include a resin that can perform a chemical ligation reaction, an enzymatic ligation reaction, or a chemical reaction with the building block in a solid phase. The linker can be, for example, a C １－１００ , preferably C ５－９０ , more preferably C １０－８０ , more preferably C １５－７０ , particularly preferably C ２０－６０ , most preferably C ３０－５０ The alkyl group may have a linear or branched chain aliphatic or aromatic hydrocarbon, which may be substituted with one or more substituents. Examples of the substituent include C １－５ Alkyl group, C １－５ an alkoxy group, a carbonyl group, an amino group, a halogen, or a C substituted with these substituents; １－５ The linker may include a polyalkylene chain or a polyalkylene glycol chain, and is preferably —(CH2CH2O) n-, and more preferably an ethylene glycol chain. Here, n is an integer of 2 to 10, preferably 2 to 8, and more preferably 3 to 7. Furthermore, the polyethylene glycol chain or the ethylene glycol chain may have 1 to 5, preferably 1 to 4, and more preferably 1 to 3 amide bonds. When the linker contains a resin, the type of resin is not particularly limited, and resins of the type known to those skilled in the art, such as those described in Andrew B. MacConnell et al., DNA-Encoded Solid-Phase Synthesis: Encoding Language Design and Complex Oligomer Library Synthesis, ACS Comb Sci. 17, 518-534 (2015) and DNA-Encoded Chemical Libraries, Methods and Protocols (David Israel, Yun Ding John, Springer Nature, 2022), can be used. Furthermore, the resin may contain a linker (cleavable linker) that is cleaved from the resin at an appropriate time and at an appropriate location. Examples of such linkers include cleavable linkers known to those skilled in the art, such as those described in Andrew B. MacConnell et al., An Integrated Microfluidic Processor for DNA-Encoded Combinatorial Library Functional Screening, ACS Comb Sci. 19, 181-192 (2017).

[0043] In a preferred embodiment, the linker comprises an ethylene glycol chain with an amide bond such as -OCH2CH2OCH2CONHCH2CH2OCH2CH2O-.

[0044] (Spacer) A "spacer" is a linking group that connects molecular backbones. The spacer can link an oligonucleotide to a chemically reactive site in the headpiece, or can link an oligonucleotide to a trivalent molecular backbone containing a chemically reactive site. The oligonucleotide in the headpiece can be bound to a single-stranded or double-stranded oligonucleotide tag via the spacer.

[0045] When the headpiece i) has a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site, in a preferred embodiment, the spacer comprises an optionally substituted trivalent group, an optionally substituted alkylene chain, an optionally substituted oligoethylene glycol chain, an optionally substituted saturated alkyl ring, or an optionally substituted saturated heterocycle. In a more preferred embodiment, the spacer comprises an optionally substituted AminoC7 or an optionally substituted dSpacer. In a particularly preferred embodiment, the spacer comprises AminoC7 and dSpacer. Examples of optionally substituted saturated heterocycles include C １ ~C ６ Examples of suitable dSpacers include 5- or 6-membered saturated heterocycles containing at least one heteroatom (such as an oxygen atom, nitrogen atom, or sulfur atom) substituted with an alkylene or hydroxyl group. dSpacers have a structure such as Formula IV below, and the hydroxyl groups form phosphodiester bonds, allowing them to bond with each other, other spacers, or oligonucleotides. For example, dSpacers can form a phosphodiester bond via a phosphate group between the hydroxyl group at the 3' position and the hydroxyl group at the 5' position. The number of dSpacers contained in a spacer is not particularly limited, but may be, for example, 1 to 5, preferably 2 to 4, more preferably 2 to 3, and even more preferably 2.

[0046]

[0047] AminoC7 has a structure as shown in Formula V below, and its hydroxy group can form a phosphodiester bond to bind to another spacer or oligonucleotide. For example, AminoC7 can bind to a dSpacer via a phosphodiester bond between the hydroxy group of AminoC7 and the hydroxy group at the 3' or 5' position of the dSpacer via a phosphate group. The amino group of AminoC7 can be bound to a linker, building block, scaffold compound, or the like.

[0048]

[0049] Furthermore, when the headpiece has iii) a single-stranded structure having a chemical reaction site on the 3'-end side via a spacer, the spacer is preferably an alkylene chain which may have a substituent or an oligoethylene glycol chain which may have a substituent, with AminoC6 being particularly preferred. AminoC6 has a structure such as Formula VI below, and its hydroxy group can form a phosphodiester bond to bind to an oligonucleotide. The amino group of AminoC6 can be bound to a linker, building block, scaffold compound, or the like.

[0050]

[0051] Note that even when a spacer has a phosphodiester bond in its structure, the phosphodiester bond may be omitted. For example, the hydroxy groups of dSpacer and AminoC7 can form a phosphodiester bond with a hydroxy group in an oligonucleotide, but the phosphodiester bond may be omitted and represented as -O-, as in Formula IV and Formula V, respectively. Furthermore, AminoC6 may have a phosphodiester bond at the end opposite the amino group, but the phosphodiester bond may be omitted and represented as -O-, as in Formula VI. Note that the term "hydroxy group" in relation to a spacer not only refers to a group capable of forming a phosphodiester bond with a hydroxy group in another compound or an oligonucleotide, but also refers to the group (end) represented as -O-, omitting the phosphodiester bond, as described above.

[0052] (Oligonucleotide tag) An "oligonucleotide tag" is a single-stranded or double-stranded oligonucleotide that encodes a structural unit of a building block and functions as a label for each chemical structure. The sequence and base length of the oligonucleotide in the tag are not particularly limited as long as they encode the structural unit of the building block.

[0053] An oligonucleotide tag can be a double-stranded oligonucleotide when the headpiece has i) a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site, or ii) a double-stranded structure in which one of the two complementary oligonucleotide strands has a chemically reactive site via a spacer, as shown in Scheme 1. Alternatively, an oligonucleotide tag can be a single-stranded oligonucleotide when the headpiece has iii) a single-stranded oligonucleotide structure in which a chemically reactive site is located on the 3'-end side via a spacer, or iv) a single-stranded oligonucleotide structure in which a chemically reactive site is located on the 5'-end side via a spacer.

[0054] (Ligation) The manufacturing method of the present invention includes (b) a step of ligating a single-stranded or double-stranded oligonucleotide tag to a headpiece oligonucleotide. "Ligation" refers to the binding and linking of two nucleic acids via a functional group, spacer, or linker. A preferred embodiment of ligation involves forming a phosphodiester bond between the hydroxyl group and the phosphate group at the end of the two nucleic acids. The single-stranded or double-stranded oligonucleotide tag can be linked to the headpiece oligonucleotide by enzymatic or chemical ligation.

[0055] "Enzymatic ligation" refers to the formation of a phosphodiester bond between the ends of nucleic acids by an enzymatic reaction. Enzymatic ligation uses an enzyme such as DNA ligase. DNA ligase forms a phosphodiester bond between the phosphate group at the 5'-end and the hydroxyl group at the 3'-end of DNA, joining the ends together.

[0056] "Chemical ligation" refers to a method for joining the ends of nucleic acids without using enzymes. In chemical ligation, for example, a condensing agent can be used to form a phosphodiester bond between the phosphate group at the 5'-end of a nucleic acid and the hydroxyl group at the 3'-end, or between the phosphate group at the 3'-end and the hydroxyl group at the 5'-end. In chemical ligation, the reaction can be optimized by adjusting the condensing agent and reaction conditions, making it possible to improve the yield of the desired product by ligation.

[0057] In the present invention, the double-stranded oligonucleotide carried by the double-stranded oligonucleotide tag may be a double-stranded oligonucleotide that is hybridized before being ligated to the headpiece oligonucleotide, or an oligonucleotide in which each oligonucleotide strand is ligated to the headpiece oligonucleotide, and the double strand hybridizes when ligated.

[0058] (Condensing Agent) In some embodiments of the manufacturing method of the present invention, step (b) may be a step of phosphodiester-linking a double-stranded oligonucleotide tag to a headpiece oligonucleotide or an oligonucleotide contained in an encoded compound by chemical ligation in the presence of a condensing agent. In other embodiments of the method of the present invention, step (b) may be a step of phosphodiester-linking a single-stranded oligonucleotide tag to a headpiece single-stranded oligonucleotide by chemical ligation in the presence of a condensing agent.

[0059] As the condensing agent, a cyano derivative, an imidazole derivative, or a carbodiimide derivative can be used. As the cyano derivative, 1-cyanoazole, cyanogen chloride, cyanogen bromide, etc. can be used. As the imidazole derivative, 1-cyanoimidazole, 1-cyano-2-methylimidazole, 1,1'-carbimidoylbis-1H-imidazole, 1,1'-carbonyldiimidazole, 1,1'-thiocarbonyldiimidazole, etc. can be used. As the carbodiimide derivative, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and its salt, N,N'-diisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide, etc. can be used. The condensing agent is preferably 1-cyanoimidazole, 1-cyano-2-methylimidazole, or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride, with 1-cyanoimidazole or 1-cyano-2-methylimidazole being more preferred. 1-cyano-2-methylimidazole can improve the conversion rate to a full-length ligation product in chemical ligation. 1-cyano-2-methylimidazole can improve the conversion rate of a product obtained by chemical ligation of a single-stranded oligonucleotide tag to a headpiece single-stranded oligonucleotide via a phosphodiester bond. The conversion rate can be evaluated by analyzing the reaction solution after ultrafiltration and desalting, or the product after ultrafiltration and desalting following treatment with a chelating agent, by LC / MS. For example, the conversion rate can be calculated by dividing the peak area of ​​the target product by (peak area of ​​the starting material + peak area of ​​the target product + peak area of ​​the by-product). 1-Cyano-2-methylimidazole can improve the yield of full-length ligation products in chemical ligation. 1-Cyano-2-methylimidazole can improve the yield of products obtained by chemical ligation of a single-stranded oligonucleotide tag to a headpiece single-stranded oligonucleotide via a phosphodiester bond.When 1-cyano-2-methylimidazole is used as the condensing agent, the reaction temperature for chemical ligation can be selected from 20°C to 30°C, specifically 20°C or higher, 21°C or higher, 22°C or higher, 23°C or higher, 24°C or higher, 25°C or higher, 26°C or lower, 27°C or lower, 28°C or lower, 29°C or lower, and 30°C or lower, with 25°C being preferred. In addition to the condensing agent, imidazole, 1-methylimidazole, 2-methylimidazole, etc. can also be added. Commercially available condensing agents can be purchased and used. Purchased reagents can also be purified and used. Alternatively, the condensing agent can be produced by a known method. For example, 1-cyanoimidazole can be produced and used by a method known to those skilled in the art, such as that reported in Luebke KJ and Dervan PB., Nucleic Acids Research, 1992, 20, 3005-3009.

[0060] A product may be obtained in which a condensation agent or a component derived from the condensation agent is added to the ligation product with dehydration. For example, a product in which 1H-imidazole, a component derived from the condensation agent 1-cyanoimidazole, is added to the full-length ligation product with dehydration. A product in which a condensation agent or a component derived from the condensation agent is added to the ligation product with dehydration can be converted to the original ligation product by post-treatment under acidic or basic conditions, a method known to those skilled in the art, such as that reported in Kanavarioti A, Bernasconi CF, Doodokyan DL, Alberas DJ., J. Am. Chem. Soc., 1989, 111, 7247-7257.

[0061] (Divalent Metal Salt) In some embodiments of the production method of the present invention, step (b) may be a step of phosphodiester-linking a double-stranded oligonucleotide tag to a headpiece oligonucleotide or an oligonucleotide contained in an encoded compound by chemical ligation in the presence of a divalent metal salt. In other embodiments of the production method of the present invention, step (b) may be a step of phosphodiester-linking a single-stranded oligonucleotide tag to a headpiece single-stranded oligonucleotide by chemical ligation in the presence of a divalent metal salt.

[0062] In chemical ligation, the reaction can be optimized using a divalent metal salt that is effective in chemical ligation reactions. By performing chemical ligation in the presence of a divalent metal salt, the formation of a one-sided ligation product can be suppressed and the formation of a full-length ligation product can be promoted.

[0063] Divalent metal salts include Co 2+ salts (e.g., soluble Co such as CoCl2, CoBr2, Co(NO3)2, CoSO4, etc. 2+ source), Cu 2+ salts (e.g., CuF2, CuCl2, CuBr2, CuI2, Cu(NO3)2, CuSO4, etc.) 2+ source), Zn 2+ salts (e.g., soluble Zn such as ZnF2, ZnCl2, ZnBr2, ZnI2, Zn(NO3)2, Zn(ClO3)2, ZnSO4, Zn(O2CCH3)2, Zn(OSOCF3)2, Zn(SO2CF3)2, etc. 2+ source) or in situ oxidized elemental zinc, Mn 2+ salts (e.g., soluble Mn such as MnSO4, MnCl2, MnBr2, etc.) 2+ The divalent metal salts include Co, 2+ , Cu 2+ , Zn 2+ , or Mn 2+ The salts of Co are preferred. 2+ , Cu 2+ Or Zn 2+ The salts of Co are more preferred. 2+or Cu 2+ More preferred are salts of Co 2+ Most preferred are salts of Cu, e.g., CoCl2. 2+ salts such as CuCl2 or Zn 2+ In another embodiment, a divalent metal salt such as ZnCl2 is preferred. In the present invention, a divalent metal salt that can be used in chemical ligation may be referred to as a divalent metal salt that is effective in a chemical ligation reaction.

[0064] In chemical ligation, the condensing agent and divalent metal salt are cyano derivatives or imidazole derivatives and Co 2+ , Cu 2+ , Zn 2+ , Mn 2+ Combinations of salts such as cyano derivatives or imidazole derivatives with Co 2+ , Cu 2+ or Zn 2+ A combination of a cyano derivative or an imidazole derivative with a salt of Co is preferred. 2+ or Cu 2+ More preferred is a combination of a cyano derivative or an imidazole derivative with a salt of Co 2+ The combination of cyano or imidazole derivatives with Cu salts, such as CoCl2, is particularly preferred. 2+ salts such as CuCl2 or Zn 2+ In another embodiment, a combination with a salt of, for example, ZnCl2 is preferred. In these combinations, the cyano derivative or imidazole derivative is preferably 1-cyanoimidazole or 1-cyano-2-methylimidazole.

[0065] Chemical ligation may be performed in the presence of other additives to the extent that the ligation efficiency is not reduced, unintended products are not increased, etc. Examples of other additives include sodium salts such as sodium chloride.

[0066] (Buffer Solution) In some embodiments of the manufacturing method of the present invention, step (b) may be a step of phosphodiester-linking a double-stranded oligonucleotide tag to a headpiece oligonucleotide or an oligonucleotide contained in an encoded compound by chemical ligation in the presence of a buffer solution. In other embodiments of the method of the present invention, step (b) may be a step of phosphodiester-linking a single-stranded oligonucleotide tag to a headpiece single-stranded oligonucleotide by chemical ligation in the presence of a buffer solution.

[0067] In chemical ligation, the ligation reaction can be optimized by adjusting the pH of the reaction solution using a buffer. Chemical ligation using a buffer with a specific pH can suppress the formation of one-sided ligation products and promote the formation of full-length ligation products. A one-sided ligation product is one in which an oligonucleotide tag is bound to only the 3'-end or 5'-end of an oligonucleotide in a headpiece, when the headpiece is either i) a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemically reactive site, or ii) a double-stranded structure in which one of the two complementary oligonucleotide strands has a chemically reactive site via a spacer. In contrast, a full-length ligation product refers to a product in which tags are attached to both the 3'-end and 5'-end of an oligonucleotide in a headpiece when the headpiece is i) a single-stranded structure in which two complementary oligonucleotide strands are connected by a spacer containing a chemical reaction site, or ii) a double-stranded structure in which one of the two complementary oligonucleotide strands has a chemical reaction site via a spacer, or a product in which a single-stranded oligonucleotide tag is attached to an oligonucleotide in a headpiece when the headpiece is iii) a single-stranded structure in which a chemical reaction site is attached via a spacer on the 3'-end side, or iv) a single-stranded structure in which a chemical reaction site is attached via a spacer on the 5'-end side.

[0068] The pH of the buffer solution may be 7.5 or less, with the upper limit being, for example, 7.5, 7.0, 6.5, or 6.0, and the lower limit being, for example, 4.0, 4.5, 5.0, or 5.5. The upper and lower limits described above can be used in combination and expressed as the pH range of the buffer solution. The pH of the buffer solution is preferably 4.0 to 7.0, more preferably 4.5 to 6.5, and even more preferably 5.0 to 6.0. In another embodiment, the pH is preferably 4.5 to 5.5.

[0069] Co 2+ When chemical ligation is performed using a salt such as CoCl2, the pH of the buffer solution is preferably 4.0 to 7.0, more preferably 4.0 to 6.0. 2+ When chemical ligation is performed using a salt of Zn, for example, CuCl2, the pH of the buffer solution is preferably 4.0 to 7.0, more preferably 4.0 to 6.0, and particularly preferably 4.0 to 4.5. 2+ When chemical ligation is performed using a salt of Mn, for example, ZnCl2, the pH of the buffer is preferably 4.0 to 7.0, more preferably 5.0 to 6.0. 2+ When chemical ligation is performed using a salt such as MnCl2, the pH of the buffer solution is preferably 4.0 to 7.0, more preferably 6.0 to 7.0.

[0070] When a cyano derivative or an imidazole derivative, such as 1-cyanoimidazole, is used as the condensing agent, the pH of the buffer solution can be 4.0 to 7.0, preferably 4.0 to 6.0, and particularly preferably 4.0 to 5.0. In other embodiments, a pH of 4.0 to 4.5 or 4.5 to 5.5 is preferred.

[0071] When a carbodiimide derivative, such as 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride, is used as the condensing agent, the pH of the buffer solution can be 4.0 to 8.0, preferably 5.0 to 7.0, and particularly preferably 5.0 to 6.0. In another embodiment, the pH is preferably 6.0 to 7.0.

[0072] The buffer solution used may be any commonly used one that can be adjusted to the above pH range, such as acetate buffer, phosphate buffer, citrate buffer, borate buffer, tartrate buffer, MES (2-morpholinoethanesulfonic acid), bistrismethane, ADA (N-(2-acetamido)-iminodiacetic acid), PIPES (piperazine-2,4-bis(2-ethanesulfonic acid)), ACES (N-(2-acetamido)-aminoethanesulfonic acid), MOPSO (2-hydroxy-3-morpholinopropanesulfonic acid), cholamine hydrochloride, MOPS (3-morpholinopropanesulfonic acid), BES (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), TES (N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid), Acid), HEPES (N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid)), acetamidoglycine, TAPSO (N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid), TEA (triethanolamine), POPSO (piperazine-1,4-bis(2-hydroxypropanesulfonic acid)), HEPPSO (tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid), EPPS (4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid), HEPPS (4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid), Tricine, Tris (trishydroxymethylaminomethane), glycineamide, bicine, Good's buffer such as TAPS, etc. Preferably, MES or MOPS can be used.

[0073] The reaction time for chemical ligation is not particularly limited, but may be 0.5 to 72 hours, preferably 1 to 50 hours, more preferably 2 to 24 hours, and particularly preferably 3 to 20 hours.

[0074] The reaction temperature for chemical ligation may be, for example, 0 to 50°C, preferably 0 to 25°C, more preferably 0 to 10°C, and most preferably 0 to 5°C. In another embodiment, 20 to 30°C is preferred. When 1-cyano-2-methylimidazole is used as the condensing agent, the reaction temperature may be selected from 20 to 30°C. When 1-cyanoimidazole is used as the condensing agent, the reaction temperature may be selected from 0 to 5°C.

[0075] The ligation reaction is preferably carried out in the absence of nucleases such as deoxyribonuclease, which is a DNA degrading enzyme, or ribonuclease, which is an RNA degrading enzyme.

[0076] (Overhang) "Overhang" refers to a protruding end with a single strand protruding from the end of a hybridized oligonucleotide chain. The headpiece oligonucleotide may have an overhang, and if the overhang and the overhang of the double-stranded oligonucleotide tag are complementary, the reaction site can be brought closer during ligation, resulting in a structure suitable for ligation. When the oligonucleotide in the headpiece has an overhang, the overhang may be at the 3'-end or 5'-end of the oligonucleotide chain, but the 3'-end is preferred. That is, in some embodiments of the production method of the present invention, the headpiece oligonucleotide preferably has an overhang at the 3'-end. The base length of the overhang of the oligonucleotide in the headpiece can be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. In other embodiments, a 4-base or 6-base length is preferred.

[0077] In some embodiments of the production method of the present invention, the double-stranded oligonucleotide tag may have an overhang, and if the overhang is complementary to the overhang of the oligonucleotide in the headpiece, the reaction site can be brought close to each other during ligation, resulting in a structure suitable for ligation. In the present invention, when a double-stranded oligonucleotide tag has an overhang, this encompasses both the double-stranded oligonucleotide of the double-stranded oligonucleotide tag that hybridizes before ligation to the headpiece having an overhang, and the double-stranded oligonucleotide of the double-stranded oligonucleotide tag that is ligated to the headpiece one strand at a time and hybridizes to the headpiece having an overhang. In some embodiments of the production method of the present invention, the double-stranded oligonucleotide tag preferably has an overhang at its 3' end. The base length of the overhang of the double-stranded oligonucleotide tag may be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. In other embodiments, a length of 4 or 6 bases is preferred.

[0078] (Dummy Oligo) In the present invention, a "dummy oligo" refers to a single-stranded oligonucleotide comprising a sequence complementary to the sequence of the overhang of the first strand of double-stranded oligonucleotide B (the side opposite to the terminal base involved in ligation), as shown in Scheme 2, for example. The method of performing ligation by adding a dummy oligo involves ligating double-stranded oligonucleotide A and double-stranded oligonucleotide B in the presence of a dummy oligo comprising a sequence complementary to the overhang of the first strand of double-stranded oligonucleotide B, as shown in Scheme 2, for example.

[0079]

[0080] The dummy oligo is preferably a single-stranded oligonucleotide having a sequence complementary to the overhang sequence of the first strand of the double-stranded oligonucleotide tag, as shown in Scheme 3. The dummy oligo may have a phosphate group or a hydroxy group at the 3'-end or a phosphate group or a hydroxy group at the 5'-end, and preferably has a hydroxy group at each of the 3'-end and 5'-end. The presence of the dummy oligo can suppress the formation of an overhang cyclized form of the double-stranded oligonucleotide tag when the double-stranded oligonucleotide tag is ligated to the headpiece oligonucleotide. An overhang cyclized product is, for example, as shown in Scheme 4, an overhang cyclized product (1), i.e., when the oligonucleotide in the headpiece has an overhang, the overhang portion is bonded to the other end of the oligonucleotide in the headpiece to form a circular product, or an overhang cyclized product (2), i.e., when the oligonucleotide in the headpiece is bonded to the double-stranded oligonucleotide tag, the overhang portion of the double-stranded oligonucleotide tag bonded to the oligonucleotide in the headpiece is bonded to the other end of the oligonucleotide tag strand to form a circular product.

[0081]

[0082]

[0083] In some embodiments of the production method of the present invention, in step (b), the first strand of the double-stranded oligonucleotide tag, i.e., the strand that binds to the 3'-end of the headpiece oligonucleotide, may have an overhang on the 3'-end, and further, the chemical ligation in step (b) may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag. In some preferred embodiments of the production method of the present invention, in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[0084] The amount of the dummy oligo is not particularly limited, but from the viewpoint of suppressing the formation of overhang cyclized products, the molar equivalent of the dummy oligo is preferably 0.5 or more relative to the headpiece, more preferably 1.0 or more, even more preferably 1.5 or more, particularly preferably 2.0 or more, more preferably 3.0 or more, and most preferably 7.5 or more. In another embodiment, the molar equivalent of the dummy oligo is preferably 0.5 or more relative to the double-stranded oligonucleotide or double-stranded oligonucleotide tag, more preferably 1.0 or more, even more preferably 1.3 or more, particularly preferably 2.0 or more, and most preferably 5 or more.

[0085] When chemical ligation is performed in the presence of a dummy oligo, the reaction time for chemical ligation may be 0.5 to 72 hours, preferably 1 to 50 hours, more preferably 2 to 24 hours, and particularly preferably 3 to 20 hours. This is because a reaction time within these ranges can prevent the formation of overhang cyclized products by chemical ligation. When chemical ligation is performed in the absence of a dummy oligo, the reaction time is preferably 0.5 to 20 hours.

[0086] In the present invention, the term "complementary sequence" refers to a sequence of nucleotides that can form a complementary base pair between two nucleic acid oligonucleotides by forming a specific combination of adenine and thymine (or uracil) or guanine and cytosine and interacting with each other through hydrogen bonds. The formation of a complementary base pair is also called hybridization. The base pair may be a Watson-Crick base pair, a Hoogsteen base pair, or a base pair formed by other hydrogen-bonding motifs (e.g., artificial nucleobases described in *The Chemical Biology of Nucleic Acids* (Gunter Mayer, John Wiley & Sons, 2010)). There are no limitations on the complementary sequences between the two oligonucleotides that can form a double-stranded chain, and there are also no limitations on the homology between the two sequences. Homology is preferably 99% or more, 98% or more, 95% or more, 90% or more, 80% or more, 70% or more, 60% or more, or 50% or more.

[0087] "PCR" refers to polymerase chain reaction. PCR is a method for amplifying oligonucleotide chains and is a technique well known to those skilled in the art. In PCR, (1) the double-stranded oligonucleotide chain to be amplified is dissociated into single strands by heat treatment or other means, and (2) the temperature is adjusted to a suitable temperature for enzymatic reaction. Then, an enzyme (e.g., DNA polymerase) contained in the reaction system synthesizes complementary strands to each single strand. In other words, one double-stranded oligonucleotide can be amplified into two. In PCR, steps (1) and (2) are repeated by adjusting the temperature, allowing for highly efficient amplification of oligonucleotide chains.

[0088] In the present invention, the term "primer" refers to an oligonucleotide that anneals to a template oligonucleotide strand and is extended by an enzyme (such as DNA polymerase) in a template-dependent manner.

[0089] In the present invention, the term "primer oligonucleotide sequence for PCR" refers to the sequence of the portion of an oligonucleotide chain to which a primer anneals, and is preferably a sequence suitable for PCR as known in the art.

[0090] In some embodiments of the present invention, a single-stranded oligonucleotide tag can be linked to a headpiece single-stranded oligonucleotide via a phosphodiester bond by chemical ligation in the presence of a splint oligonucleotide. Ligation methods using a splint oligonucleotide are preferably used to link a single-stranded oligonucleotide to a headpiece single-stranded oligonucleotide having either iii) a single-stranded oligonucleotide structure having a chemical reactive site at the 3'-end via a spacer, or iv) a single-stranded oligonucleotide structure having a chemical reactive site at the 5'-end via a spacer.

[0091] A "splint oligonucleotide" is a single-stranded oligonucleotide having a sequence complementary to the base sequence of a headpiece having either iii) a single-stranded structure with a chemically reactive site at the 3'-end via a spacer, or iv) a single-stranded structure with a chemically reactive site at the 5'-end via a spacer, as shown in Scheme 5, in order to bring the reactive site at which a single-stranded oligonucleotide tag is linked closer to the headpiece. The splint oligonucleotide can be any base length, as long as it is a single-stranded oligonucleotide having a sequence complementary to the base sequence of a headpiece with a reactive site at either end, for example, 6 to 50 bases, 8 to 40 bases, 10 to 30 bases, or preferably 15 to 25 bases. The splint oligonucleotide may have a phosphate or hydroxy group at the 3'-end or a phosphate or hydroxy group at the 5'-end, and preferably has a hydroxy group at each of the 3'-end and 5'-end.

[0092]

[0093] <Third Aspect> According to the third aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c) and (b') and (c'): (a) preparing a headpiece, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece having a phosphate group at its 3'-end and a hydroxy group at its 5'-end; (b) phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag consisting of at least one double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide included in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide included in the headpiece; (c) directly or indirectly binding at least one building block to the chemical reaction site of the headpiece; (b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group and a hydroxy group at the 3'-end of the second strand, and the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1);and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; wherein, after performing steps (b) and (c) once, a set of steps (b') and (c') is performed n times, steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order from step (b') to step (c') or from step (c') to step (b') in the mth time, respectively, the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c), and the double-stranded oligonucleotide tag (m) encodes the building block (m) and binds to the oligonucleotide contained in the encoded compound (m-1) in the mth time, The building block (m) is directly or indirectly attached to the chemical reactive site of the encoded compound (m-1) at the mth time;

[0094] In some embodiments of the production method of the present invention, n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth represents the number of times step (b') and step (c') are performed. The upper limit of n may be, for example, any natural number from 1 to 10, and is preferably 8, more preferably 6, even more preferably 4, and most preferably 3. There is also another preferred embodiment in which the upper limit of n is 2.

[0095] In some embodiments of the production method of the present invention, the encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and the double-stranded oligonucleotide tag (m) and the building block (m) may not be bonded together. Furthermore, the oligonucleotide contained in the encoded compound (m-1) may have an overhang. Complementarity between the overhang of the oligonucleotide contained in the encoded compound (m-1) and the overhang of the double-stranded oligonucleotide tag (m) allows the reaction site to approach each other during ligation, resulting in a structure suitable for ligation. When the oligonucleotide contained in the encoded compound (m-1) has an overhang, the overhang may be at the 3'-end or the 5'-end of the oligonucleotide chain, but preferably at the 3'-end. That is, in some embodiments of the production method of the present invention, the oligonucleotide contained in the encoded compound (m-1) preferably has an overhang at the 3'-end. The base length of the oligonucleotide overhang contained in the encoded compound (m-1) can be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. There is also another embodiment in which a 4-base or 6-base length is preferred.

[0096] In some embodiments of the production method of the present invention, when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively.

[0097] In some embodiments of the production method of the present invention, "(b') phosphodiester-linking the double-stranded oligonucleotide tag (m) to the oligonucleotide contained in the encoded compound (m-1) by chemical ligation" may mean binding the double-stranded oligonucleotide tag (m) to the double-stranded oligonucleotide tag (m-1) contained in the encoded compound (m-1).

[0098] In some embodiments of the production method of the present invention, the "chemically reactive site" in "(c') directly or indirectly binding at least one building block (m) to a chemically reactive site of the encoded compound (m-1)" may be any chemically reactive site of the headpiece, linker, building block, or scaffold compound contained in the encoded compound (m-1).

[0099] In some embodiments of the production method of the present invention, the phrase "step (b') and step (c') can be performed in any order in the mth iteration" means that step (b') and step (c') can be performed in any order from step (b') to step (c') or from step (c') to step (b') in the mth iteration.

[0100] In some embodiments of the manufacturing method of the present invention, step (b) and / or step (b') may be a step of phosphodiester-linking the double-stranded oligonucleotide tag to the headpiece oligonucleotide or the oligonucleotide contained in the encoded compound by chemical ligation in the presence of a condensing agent.

[0101] In some embodiments of the manufacturing method of the present invention, step (b) and / or step (b') may be a step of phosphodiester-linking a double-stranded oligonucleotide tag to a headpiece oligonucleotide or an oligonucleotide contained in an encoded compound by chemical ligation in the presence of a divalent metal salt.

[0102] In some embodiments of the manufacturing method of the present invention, step (b) and / or step (b') may be a step of phosphodiester linking the double-stranded oligonucleotide tag to the headpiece oligonucleotide or the oligonucleotide contained in the encoded compound by chemical ligation in the presence of a buffer.

[0103] In some embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag may have an overhang on the 3'-end, and further, the chemical ligation in step (b) and / or step (b') may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag. In some preferred embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag may have an overhang on the 3'-end, and the chemical ligation may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[0104] In some embodiments of the production method of the present invention, as shown in Scheme 6, ligation of an oligonucleotide contained in an encoded compound (m-1) to a double-stranded oligonucleotide tag (m) can be performed in the presence of a dummy oligonucleotide. The presence of a dummy oligonucleotide can suppress the formation of an overhang cyclized product when ligating the double-stranded oligonucleotide tag (m) to the oligonucleotide contained in the encoded compound (m-1). Examples of overhang cyclized products include, as shown in Scheme 6, overhang cyclized products (3), i.e., when the oligonucleotide contained in the encoded compound (m-1) has an overhang, the overhang portion is bonded to the other end of the oligonucleotide contained in the encoded compound (m-1) to form a cyclized product; and overhang cyclized products (4), i.e., when the oligonucleotide contained in the encoded compound (m-1) and the double-stranded oligonucleotide tag (m) are bonded, the overhang portion of the double-stranded oligonucleotide tag (m) bonded to the oligonucleotide contained in the encoded compound (m-1) is bonded to the other end of the oligonucleotide tag strand to form a cyclized product.

[0105]

[0106] <Fourth Aspect> According to the fourth aspect of the present invention, there is provided a method for producing an oligonucleotide-encoded compound, the method comprising the following steps (a) to (d): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end; (b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotides of the headpieces by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of a first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) directly or indirectly binding at least one building block to a chemical reaction site on the headpiece in each of the reaction vessels, wherein the building block may be different for each reaction vessel; and (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c); wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[0107] (Split & Pool Method) The Split & Pool method can generally be used to produce compounds encoded with oligonucleotides. The Split & Pool method involves (1) dispensing a headpiece or encoded compound into multiple aliquots, (2) attaching a different building block and a corresponding oligonucleotide tag to each of the aliquots, and (3) pooling and mixing the resulting aliquots. Repeating steps (1) to (3) multiple times is thus achieved. For example, if steps (1) to (3) are repeated using x, y, and z (x, y, and z are natural numbers) building blocks and their corresponding oligonucleotide tags, x x y x z types of oligonucleotide-encoded compounds can be produced. The Split & Pool method is used in the production methods of the fourth aspect of the present invention, as well as the fifth, sixth, ninth, eleventh, eighteenth, twentieth, and twenty-second, twenty-seventh, and twenty-seventh aspects described below.

[0108] (Dispensing step) In some embodiments of the production method of the present invention, the reaction vessel may be any vessel capable of carrying out each reaction in the production method of the present invention, such as a test tube, a tube, or a 96-well plate. The number of reaction vessels is not particularly limited as long as it is two or more, and can be determined appropriately depending on the type of building block or tag used. The proportion of headpieces dispensed into each reaction vessel is not particularly limited, and may be equal or uneven.

[0109] In some embodiments of the manufacturing method of the present invention, in step (a) of dispensing the headpieces into two or more reaction vessels, a linker may be attached to the headpieces.

[0110] (Pooling Step) In some embodiments of the production method of the present invention, the step (d) of pooling the dispensed contents into one can be performed using any container such as an Eppendorf tube. Pooling the contents into one means mixing multiple contents into one, and the form of this is not particularly limited.

[0111] <Fifth Aspect> A fifth aspect of the present invention provides a method for producing an oligonucleotide-encoded compound, comprising the following steps (a) to (d) and (a') to (d'): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotides of the headpieces by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of a first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and the sequence of the double-stranded oligonucleotide tag may differ between the reaction vessels; (c) directly or indirectly binding at least one building block to a chemical reaction site on the headpiece in each of the reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation in the presence of a condensing agent and a buffer solution and / or an additive, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') a step of pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;wherein step (b) and step (c) are carried out once, followed by step (d), and then steps (a') to (d') are carried out n times as a set; step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; and the encoded compound (m-1) comprises a chemical reaction site, the sequence of the oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); The double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time, and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time;

[0112] In some embodiments of the production method of the present invention, in the step (a') of dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels, a linker may be bound to the encoded compounds (m-1) in the mixture.

[0113] In some embodiments of the production method of the present invention, ligation of the double-stranded oligonucleotide tag (m) to the oligonucleotide of the encoded compound (m-1) or a mixture obtained by pooling contents containing the encoded compound can be carried out in the presence of a dummy oligonucleotide, as in Scheme 6. The presence of a dummy oligonucleotide can suppress the formation of an overhang cyclized form of the double-stranded oligonucleotide tag (m) when the double-stranded oligonucleotide tag (m) is ligated to the oligonucleotide of the encoded compound (m-1).

[0114] In some embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) may have an overhang on the 3'-end, and further, the chemical ligation in step (b) and / or step (b') may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag. In some preferred embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) may have an overhang on the 3'-end, and may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

[0115] <Sixth Aspect> A sixth aspect of the present invention provides a method for producing an oligonucleotide-encoded compound, comprising the following steps (a) to (d), (a') to (d'), and (e): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end; (b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotides of the headpieces by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of a first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and the sequence of the double-stranded oligonucleotide tag may differ between reaction vessels; (c) directly or indirectly binding at least one building block to a chemical reaction site on the headpiece in each of the reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') a step of pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, wherein the Closing Primer has a phosphate group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a hydroxy group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and wherein the phosphate group at the 5'-end of the first strand of the Closing Primer is phosphodiester-linked to the hydroxy group at the 3'-end of the oligonucleotide contained in the mixture of encoded compounds obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the Closing Primer is phosphodiester-linked to the phosphate group at the 5'-end of the oligonucleotide contained in the mixture of encoded compounds obtained in step (d'); wherein step (d) is carried out after step (b) and step (c) are carried out once, and then a set of steps (a') to (d') is carried out n times, and then step (e) is carried out; Step (b) and step (c) can be performed in any order from step (b) to step (c) or from step (c) to step (b), and step (b') and step (c') can be performed in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of the oligonucleotide tag (m-1), and a structural unit of the building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to the oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time;

[0116] (Closing Primer) In the present invention, the term "closing primer" refers to an oligonucleotide consisting of a single-stranded or double-stranded oligonucleotide, having a fixed sequence required for binding to a primer used in amplifying a tag-containing region by PCR. When the closing primer consists of a double-stranded oligonucleotide, the closing primer has a fixed sequence required for binding to a primer used in amplifying a tag-containing region by PCR, in the strand opposite to the primer oligonucleotide. The closing primer may contain modified nucleotides known to those skilled in the art, for example, as described in Non-Patent Document 1. When the closing primer is a double-stranded oligonucleotide, it is preferable that the closing primer contains a modified nucleotide in the second strand, i.e., the strand that binds to the 5'-end of the oligonucleotide encoding the compound. The modified nucleotide refers to a variable nucleotide, and in the case of DNA, for example, examples include modified nucleotides containing a mixture of the four nucleobases adenine, guanine, thymine, and cytosine. The modified nucleotides may be oligonucleotides consisting of multiple consecutive modified nucleotides. For example, a 12-base-long oligonucleotide containing a mixture of the four types of modified nucleotides (adenine, guanine, thymine, and cytosine) allows for 4 to the power of 12 (16,777,216) different sequences. The oligonucleotides consisting of modified nucleotides may be, for example, 5 to 30 bases long, preferably 8 to 20 bases long. The oligonucleotides consisting of modified nucleotides are called UMIs (Unique Molecular Identifiers) and are used to determine whether a sequence is the result of PCR duplication (identical sequence) or an independent occurrence of a molecule (different sequence). In other words, the UMI can reduce the potential number of false positives in amplicon sequencing analysis performed after selection of the encoded compound against the biological target.

[0117] In the step (e) of ligating the Closing Primer to the oligonucleotide of the encoded compound via a phosphodiester bond, the ligation may be either enzymatic ligation or chemical ligation. Unless otherwise specified, the type of ligation is not limited. However, in some embodiments of the production method of the present invention, enzymatic ligation is preferred, and in other embodiments of the production method of the present invention, chemical ligation is preferred.

[0118] For example, ligation can be enzymatic ligation when the phosphate group at the 5' end of a closing primer is ligated to the hydroxy group at the 3' end of an oligonucleotide contained in the encoded compound, and when the hydroxy group at the 3' end of a closing primer is ligated to the phosphate group at the 5' end of an oligonucleotide contained in the encoded compound. Ligation can also be chemical ligation when the hydroxy group at the 5' end of a closing primer is ligated to the phosphate group at the 3' end of an oligonucleotide contained in the encoded compound, and when the phosphate group at the 3' end of a closing primer is ligated to the hydroxy group at the 5' end of an oligonucleotide contained in the encoded compound.

[0119] The enzyme used in enzymatic ligation may be, for example, DNA ligase. DNA ligase forms a phosphodiester bond between the phosphate group at the 5'-end and the hydroxyl group at the 3'-end of DNA. Therefore, when DNA ligase is used in step (e), it is desirable to make the ends of the encoded compound oligonucleotide a 5'-phosphate group and a 3'-hydroxyl group. That is, in the methods of the sixth aspect of the present invention and the eleventh aspect described below, it is preferred that the double-stranded oligonucleotide tag (m) in step (b') has a hydroxyl group at the 5'-end and a hydroxyl group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand only in the nth iteration (the nth iteration refers to the number of times steps (a') to (d') are performed).

[0120] In step (e), if a protruding end remains after ligating the closing primer to form a phosphodiester bond, the end can be blunted by a method known to those skilled in the art, such as that described in Sambrook, J., Fritsch, E. F., and Maniatis, T. (1989) Molecular Cloning, A Laboratory Manual, 2nd ed., pp. 5. 40-5. 43. That is, the method according to the sixth aspect of the present invention may include a step of enzymatically blunting the protruding end after ligating the closing primer to form a phosphodiester bond in step (e). For example, if a 5'-protruding end is formed by ligating the closing primer, the blunt end can be formed using Klenow Fragment derived from Escherichia coli DNA polymerase I.

[0121] In some embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) may have an overhang on the 3'-end, and further, the chemical ligation in step (b) and / or step (b') may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag. In some preferred embodiments of the production method of the present invention, in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) may have an overhang on the 3'-end, and further, the chemical ligation in step (b) and / or step (b') may be performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag. However, in some embodiments of the production method of the present invention, which includes a step of binding a closing primer, it is preferable that the nth round is carried out in the absence of a dummy oligonucleotide containing a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m).

[0122] <Seventh Aspect> According to the seventh aspect of the present invention, there is provided a method for producing an oligonucleotide-encoded compound, the method comprising the following steps (a) to (c): (a) preparing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and the double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand and a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and having a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; and (c) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c).

[0123] In some embodiments of the production method of the present invention, a "complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p)" (hereinafter sometimes simply referred to as a "complex") is a compound in which at least one building block (p) is directly or indirectly bound to a headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece. In these embodiments, the double-stranded oligonucleotide tag (p) consists of at least one double-stranded oligonucleotide and is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand. The bond between the double-stranded oligonucleotide tag (p) and the headpiece may be a covalent bond, preferably a phosphodiester bond.

[0124] The double-stranded oligonucleotide tag (p) bound to the complex has a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, and its structure is not particularly limited except that it encodes the building block (p) bound to the complex.

[0125] (a) "The step of preparing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p)" does not necessarily involve producing the complex. (a) "The step of preparing a complex" may be, for example, placing a pre-made complex into a reaction vessel. On the other hand, the "complex" may be produced by any method. In one aspect, the "complex" may be an encoded compound produced by the production method of the present invention. In another aspect, the "complex" may be produced by a method other than the production method of the present invention. The method other than the production method of the present invention may be, for example, a method using enzymatic ligation.

[0126] In some embodiments of the production method of the present invention, "(b) phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation" may mean binding the double-stranded oligonucleotide tag to the double-stranded oligonucleotide tag (p) contained in the complex.

[0127] In some embodiments of the production method of the present invention, the "chemically reactive site" in "(c) directly or indirectly binding at least one building block to a chemically reactive site contained in the complex" may be a chemically reactive site of any of the headpiece, linker, building block, and scaffold compound contained in the complex.

[0128] In some embodiments of the production method of the present invention, the oligonucleotide contained in the complex may have an overhang. In this case, the 3'-end or the 5'-end of the oligonucleotide chain may be overhanging, but the 3'-end is preferred. That is, in some embodiments of the production method of the present invention, the oligonucleotide contained in the complex preferably has an overhang at the 3'-end. The base length of the overhang of the oligonucleotide contained in the complex can be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. In other embodiments, a 4-base or 6-base length is preferred.

[0129] <Eighth Aspect> According to the eighth aspect of the present invention, there is provided a method for producing an oligonucleotide-encoded compound, the method comprising the following steps (a) to (c) and (b') and (c'): (a) preparing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and the double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand and a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end and a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxy group at the 5'-end, wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex;(b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group and a hydroxy group at the 3'-end of the second strand, and wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); and (c') directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1), building block (m) is an independent building block;wherein step (b) and step (c) are carried out once, and then step (b') and step (c') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times step (b') and step (c') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c); The encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0130] <Ninth Aspect> According to the ninth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d):(a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, wherein the double-stranded oligonucleotide tag (p) consists of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) phosphodiester-linking the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; and (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; wherein Steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[0131] <Tenth Aspect> According to the tenth aspect of the present invention, there is provided a method for producing an oligonucleotide-encoded compound, the method comprising the following steps (a) to (d): (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) is composed of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof;(a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block and may be different for each reaction vessel; and (d') pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time;

[0132] <Eleventh Aspect> According to the eleventh aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d) and (a') to (d'): (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, wherein the double-stranded oligonucleotide tag (p) consists of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof;(a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') a step of pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, wherein the Closing Primer has a phosphate group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a hydroxy group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and wherein the phosphate group at the 5'-end of the first strand of the Closing Primer is phosphodiester-linked to the hydroxy group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the Closing Primer is phosphodiester-linked to the phosphate group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out n times as a set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and mth time represent the number of times steps (a') to (d') are carried out; only in the nth time, the double-stranded oligonucleotide tag (m) in step (b') has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand), and then step (e) is carried out; step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0133] <18th Aspect> According to the 18th aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c) and (b') and (c'): (a) preparing a headpiece, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxy group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; and (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to the single-stranded oligonucleotide contained in the encoded compound (m-1) in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and (c') a step of directly or indirectly binding the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1) via a phosphodiester bond; and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; wherein steps (b) and (c) are carried out once, and then a set of steps (b') and (c') is carried out n times (n is a natural number from 1 to 10, m is a natural number up to n, and the mth time refers to the number of times steps (b') and (c') are carried out).), steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the m-th time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, the sequence of the single-stranded oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to the single-stranded oligonucleotide contained in the encoded compound (m-1) in the m-th time; The building block (m) is attached directly or indirectly to the chemical reactive site of the encoded compound (m-1) at the mth time.

[0134] <19th Aspect> According to the 19th aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, and the single-stranded oligonucleotides of the headpieces have a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the dispensed reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece; (c) in each of the dispensed reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, wherein the building block may differ between reaction vessels; and (d) pooling together the contents of each reaction vessel containing the compounds encoded in step (b) and step (c) to obtain a mixture thereof; wherein step (b) and step (c) can be performed in any order, and wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[0135] <Twentieth Aspect> According to the twentieth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d) and (a') to (d'): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, and the single-stranded oligonucleotides of the headpieces have a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; (c) in each of the reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, wherein the building block may differ between reaction vessels; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in encoded compound (m-1) via phosphodiester linkage;(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the dispensed reaction vessels, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; and (d') pooling the contents of each reaction vessel, containing the compounds encoded in steps (b') and (c'), into one to obtain a mixture; wherein steps (b) and (c) are performed once, followed by step (d), and then steps (a') to (d') are performed n times as a set (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are performed), and steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the mth time, the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, the sequence of the single-stranded oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to the oligonucleotide contained in the encoded compound (m-1) at the mth time, and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time;

[0136] <Twenty-first aspect> According to the twenty-first aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d), (a') to (d'), and (e): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have single-stranded oligonucleotides, and the single-stranded oligonucleotides of the headpieces have a chemical reaction site at their 3'-end via a spacer and a hydroxy group at their 5'-end; (b) in each of the reaction vessels, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece via a phosphodiester bond; (c) in each of the reaction vessels, directly or indirectly linking at least one building block to the chemical reaction site of the headpiece, wherein the building block may differ between reaction vessels; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ between reaction vessels, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in encoded compound (m-1) via phosphodiester linkage;(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the dispensed reaction vessels, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel, including the compounds encoded in steps (b') and (c'), into one to obtain a mixture thereof; and (e) ligating a closing primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond; wherein steps (b) and (c) are performed once, followed by performing step (d), and then performing a set of steps (a') to (d') n times (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are performed), and then step (e), Steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, the sequence of the single-stranded oligonucleotide tag (m-1), and the structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and in the mth time, binds to the oligonucleotide contained in the encoded compound (m-1); The building block (m) is directly or indirectly attached to the chemical reactive site of the encoded compound (m-1) at the mth time;

[0137] <Twenty-Second Aspect> According to the twenty-second aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c): (a) preparing a complex comprising a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to a single-stranded oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; and (c) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex; Steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c).

[0138] <Twenty-third Aspect> According to the twenty-third aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (c) and (b') and (c'): (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the hydroxy group at the 5'-end of the oligonucleotide contained in the complex and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag are phosphodiester-linked; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1);and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; wherein steps (b) and (c) are carried out once, and then steps (b') and (c') are carried out as a set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times steps (b') and (c') are carried out), wherein steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c), The encoded compound (m-1) comprises a chemical reaction site, a sequence of a single-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0139] <Twenty-Fourth Aspect> According to the twenty-fourth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d): (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and phosphodiester-linking the phosphate group to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex at the 3'-end of the single-stranded oligonucleotide tag; (c) directly or indirectly attaching at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; and (d) pooling the contents of each reaction vessel, including the compounds encoded in steps (b) and (c), to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

[0140] <Twenty-fifth Aspect> According to the twenty-fifth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d) and (a') to (d'): (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex, respectively; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a step of phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and a step of phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block and the building block (m) may differ from reaction vessel to reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof;wherein step (b) and step (c) are carried out once, followed by step (d), and then step (a') to step (d') are carried out as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0141] <Twenty-sixth Aspect> According to the twenty-sixth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d), (a') to (d'), and (e): (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may differ between reaction vessels, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the reaction vessels dispensed, a single-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the reaction vessels dispensed, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may differ from reaction vessel to reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in step (b') and step (c') into one to obtain a mixture thereof; and (e) ligating a closing primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond;carrying out step (b) and step (c) once, followed by step (d), and then carrying out a set of steps (a') to (d') n times (where n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0142] <27th Aspect> According to the 27th aspect of the present invention, there is provided a method for producing an oligonucleotide-encoded compound, the method comprising the following steps (a) to (d), (a') to (d'), and (e): (a) dispensing headpieces into two or more reaction vessels, wherein the headpieces have a chemical reaction site and an oligonucleotide, and the oligonucleotides of the headpieces contain a phosphate group at the 3'-end and a hydroxy group at the 5'-end; (b) in each of the dispensed reaction vessels, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotides of the headpieces by chemical ligation, wherein the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of a first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and the sequence of the double-stranded oligonucleotide tag may differ between the reaction vessels; (c) directly or indirectly binding at least one building block to a chemical reaction site on the headpiece in each of the reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') a step of pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, wherein the Closing Primer has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and wherein the hydroxy group at the 5'-end of the first strand of the Closing Primer is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the phosphate group at the 3'-end of the second strand of the Closing Primer is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');carrying out step (b) and step (c) once, followed by step (d), and then carrying out a set of steps (a') to (d') n times (where n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0143] <Twenty-eighth Aspect> According to the twenty-eighth aspect of the present invention, there is provided a method for producing a compound encoded by an oligonucleotide, the method comprising the following steps (a) to (d), (a') to (d'), and (e): (a) dispensing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is bound directly or indirectly to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, wherein the double-stranded oligonucleotide tag (p) consists of at least one double-stranded oligonucleotide, is bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, has a phosphate group at the 3'-end of the first strand, and has a hydroxy group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the dispensed reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of the first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of the second strand, and a hydroxy group at the 5'-end, wherein the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, wherein the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof;(a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel; (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in each of the reaction vessels dispensed, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') a step of pooling the contents of each of the reaction vessels containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, wherein the Closing Primer has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, and wherein the hydroxy group at the 5'-end of the first strand of the Closing Primer is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the phosphate group at the 3'-end of the second strand of the Closing Primer is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');carrying out step (b) and step (c) once, followed by step (d), and then carrying out a set of steps (a') to (d') n times (where n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') have been carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; The encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to the oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

[0144] In step (e) of the production methods according to the 27th and 28th aspects of the present invention, the closing primer is bound to the encoded compound by chemical ligation. The conditions for chemical ligation in step (e) of the production methods according to the 27th and 28th aspects of the present invention can be selected from the same conditions for chemical ligation in step (b) or (b') of the same production methods.

[0145] [New compounds suitable for synthesizing DELs by chemical ligation and compounds obtained by chemical ligation] According to some aspects of the present invention, new compounds suitable for synthesizing DELs by chemical ligation and new compounds obtained by chemical ligation (hereinafter, these may be referred to as the compounds of the present invention) are provided.

[0146] <Twelfth Aspect> According to the twelfth aspect of the present invention, there is provided a compound represented by the following formula (I): A is a chemical reaction site; L is a linker; C and D are each independently a spacer; B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-end of G; F is a functional group which forms a bond with the 3'-end of H; G is an oligonucleotide moiety having a phosphate group at the 3'-end; H is an oligonucleotide moiety having a hydroxy group at the 5'-end; and j is 0 or 1 (when j is 0, A and B are directly bonded, and when j is 1, a linker L is present between A and B).

[0147] Each element of the compound will be described below. When a specific notation is used to represent a specific element, the notation represents the same specific element in all of the compounds listed below. For example, "A" represents a chemically reactive site in the following description, but the notation "A" represents a chemically reactive site in the twelfth aspect, the twenty-eighth aspect, and other cases described below.

[0148] (Chemical Reactive Site A) The chemical reactive site A is a functional group in the headpiece or linker that has at least one site capable of binding to a building block or scaffold compound. The chemical reactive site A can be linked to the linker L or molecular framework B. The chemical reactive site A is not particularly limited as long as it is a functional group that can form a covalent bond with a functional group in the building block or scaffold compound. For example, when the chemical reactive site A in the headpiece is an amino group, it can react with a halogeno group, a carboxy group, a sulfonic acid group, etc. Alternatively, the chemical reactive site A may be, for example, a carboxy group, a thiol group, an aldehyde group, a hydroxy group, an azide group, or an alkynyl group. These functional groups may be substituted with one or more substituents. Examples of the substituent include C １－５ Alkyl group, C １－５ Alkoxy group, halogen, C substituted with one or more halogens １－５ alkyl group, C substituted with one or more halogens １－５ Examples thereof include an alkoxy group.

[0149] In a preferred embodiment, the chemically reactive site A is an amino group.

[0150] The chemically reactive site A may be protected with a deprotectable protecting group. Protecting groups that are commonly used are not particularly limited as long as they are capable of protection and deprotection as described in Greene's Protective Groups in Organic Synthesis, 5th Edition (John Wiley & Sons, 2014), etc.; for example, when A is an amino group, the protecting group may be a tert-butoxycarbonyl group (Boc group), a benzyloxycarbonyl group (Cbz group), a 9-fluorenylmethyloxycarbonyl group (Fmoc group), a 2,2,2-trichloroethoxycarbonyl group (Troc group), an allyloxycarbonyl group (Alloc group), a phthaloyl group (Pht group), a p-toluenesulfonyl group (Ts group), a 2-nitrobenzenesulfonyl group (Ns group), an allyl group, etc. When A is an amino group, the protecting group is preferably an Fmoc group. When A is a thiol group, its protecting group can be, for example, a trimethylphenyl group (Trt group), an acetamidomethyl group (Acm group), a tert-butyl group (tBu group), etc. When A is an aldehyde group, its protection can be, for example, an acetal-based protecting group. An acetal-based protecting group can be generated using a method known to those skilled in the art, for example, a method of converting a carbonyl group to an acetal using dimethyl acetal under an acid catalyst, etc. When A is a hydroxy group, its protecting group can be, for example, a C-type protecting group such as a methyl group, a tBu group, etc. １～６ the alkyl group mentioned above, aralkyl groups such as benzyl group (Bn group) and p-methoxybenzyl group (PMB group), acyl groups such as acetyl group (Ac group) and benzoyl group (Bz group), and silyl groups such as trimethylsilyl group (TMS group), triethylsilyl group (TES group), tert-butyldimethylsilyl group (TBS group), and tert-butyldiphenylsilyl group (TBDPS group).

[0151] (Linker L) In the compound of the present invention, the linker L is a linking group that links the chemically reactive site A and the trivalent molecular skeleton B, which may have a substituent. The structure of the linker L is not particularly limited except that it has an atom or functional group for bonding to the chemically reactive site A and an atom or functional group for bonding to the trivalent molecular skeleton B, which may have a substituent. The linker can be, for example, C １－１００ , preferably C ５－９０ , more preferably C １０－８０ , more preferably C １５－７０ , particularly preferably C ２０－６０ , most preferably C ３０－５０ The alkyl group may have a linear or branched chain aliphatic or aromatic hydrocarbon, which may be substituted with one or more substituents. Examples of the substituent include C １－５ Alkyl group, C １－５ an alkoxy group, a carbonyl group, an amino group, a halogen, or a C substituted with these substituents; １－５ The linker may include a polyalkylene chain or a polyalkylene glycol chain, and is preferably —(CH2CH2O) n -, more preferably an ethylene glycol chain, in which n is an integer of 2 to 10, preferably 2 to 8, more preferably 3 to 7. Furthermore, the polyethylene glycol chain or the ethylene glycol chain may have 1 to 5, preferably 1 to 4, more preferably 1 to 3 amide bonds.

[0152] In a preferred embodiment, the linker L comprises an ethylene glycol chain having an amide bond such as -OCH2CH2OCH2CONHCH2CH2OCH2CH2O-, and is more preferably represented by the following formula L-1, where k in the following formula L-1 is 0 or 1.

[0153]

[0154] (Spacers C, D) In ​​some embodiments of the compound of the present invention, spacers C and D are linking groups that link functional group E and functional group F to the optionally substituted trivalent group B, respectively. In preferred embodiments of C and D, the spacer comprises an optionally substituted alkylene chain, an optionally substituted oligoethylene glycol chain, or an optionally substituted saturated alkyl ring, or an optionally substituted saturated heterocycle, and in preferred embodiments, the spacer comprises an optionally substituted dSpacer, and in particularly preferred embodiments, the spacer comprises a dSpacer. The optionally substituted saturated heterocycle can be, for example, C １ ~C ６ Examples of suitable dSpacers include 5- or 6-membered saturated heterocycles containing at least one heteroatom (such as an oxygen atom, nitrogen atom, or sulfur atom) substituted with an alkylene or hydroxyl group. The dSpacer has a structure as shown in Formula IV below, where the hydroxy group forms a phosphodiester bond via a phosphate group, which can bond to an optionally substituted trivalent group B, other dSpacers, or other spacers. In another embodiment, the hydroxy group of the dSpacer can bond to functional group E or functional group F. The hydroxy group at the 3' position and the hydroxy group at the 5' position of the dSpacer can form a phosphodiester bond via a phosphate group. The number of dSpacers contained in spacers C and D is not particularly limited, but may be, for example, 1 to 5, preferably 2 to 4, more preferably 2 to 3, and most preferably 2. Spacers C and D may have different structures. In the present invention, the fact that spacers C and D may have different structures is sometimes referred to as C and D being independent spacers.

[0155]

[0156] (Molecular Skeleton B) In the compound of the present invention, B is a trivalent molecular skeleton which may have a substituent, and when j is 1, B can be linked to the linker L, the spacer C, and the spacer D, and when j is 0, B can be linked to the chemical reaction site A, the spacer C, and the spacer D. In a preferred embodiment of B, C which may have a substituent １ ~C １４ and is preferably a group represented by the following general formula VII, and particularly preferably represented by the following formula VIII. In the following general formula VII, a, which represents the length of the alkylene, may be 1 to 10, preferably 2 to 8, more preferably 3 to 6, and particularly preferably 4 to 5. In the following general formula VII, b, which represents the length of the alkylene, may be 1 to 10, preferably 1 to 7, more preferably 1 to 4, and particularly preferably 1 to 2. In the following general formula VII, c, which represents the length of the alkylene, may be 1 to 10, preferably 1 to 7, more preferably 1 to 4, and particularly preferably 1 to 2. In the following general formula VII, R represents a hydrogen atom or a C １ ~C １０ The hydroxy group of the following general formula VII or the following formula VIII can form a phosphodiester bond with C and D.

[0157]

[0158]

[0159] (Functional Groups E and F) In the compounds of the present invention, functional group E is a functional group capable of forming a bond with the 5'-end of oligonucleotide moiety G, more specifically, a functional group capable of covalently bonding a substituent of spacer C to a substituent at the 5'-end of oligonucleotide moiety G. Functional group F is a functional group capable of forming a bond with the 3'-end of oligonucleotide moiety H, more specifically, a functional group capable of covalently bonding a substituent of spacer D to a substituent at the 3'-end of oligonucleotide moiety H. E is preferably a phosphate group, and F is preferably a phosphate group. In this case, in the compound of formula I, E can form a phosphodiester bond with the hydroxy group of spacer C and the hydroxy group at the 5'-end of oligonucleotide moiety G, and F can form a phosphodiester bond with the hydroxy group of spacer D and the hydroxy group at the 3'-end of oligonucleotide moiety H.

[0160] (Oligonucleotide Moieties G and H) In the present invention, the term "oligonucleotide moiety" refers to an oligonucleotide contained in a headpiece, and does not refer to an oligonucleotide tag, i.e., an oligonucleotide having a sequence encoding a structural unit of a building block. In other words, in the compounds of the present invention, the oligonucleotide moieties G and H are oligonucleotides contained in a headpiece and do not have a sequence encoding a structural unit of a building block. The oligonucleotide moieties G and H can each be a nucleotide chain consisting of any base length, for example, 1 to 200 bases long, 5 to 100 bases long, 10 to 90 bases long, 15 to 80 bases long, 20 to 70 bases long, 20 to 60 bases long, 20 to 50 bases long, 20 to 40 bases long, 20 to 30 bases long, 30 to 60 bases long, and preferably 40 to 50 bases long. The oligonucleotide moiety G has a phosphate group at the 3'-end, and the oligonucleotide moiety H has a hydroxy group at the 5'-end.

[0161] Preferably, the oligonucleotide portion G or H contains a primer oligonucleotide. In the present invention, the term "primer oligonucleotide" refers to an oligonucleotide having a fixed sequence necessary for binding to a primer used in amplifying a tag-containing region by PCR. In a preferred embodiment, the oligonucleotide portion H contains a primer oligonucleotide, and the primer used in amplifying a tag-containing region by PCR binds to the primer oligonucleotide. Furthermore, each nucleotide monomer constituting the oligonucleotide portions G and H usually consists of two parts: a nucleobase portion and a backbone. In some cases, the backbone may be divided into a sugar portion and an internucleoside linker. The nucleobase portion may be selected from naturally occurring nucleobases and non-naturally occurring artificial nucleobases. Thus, nucleobases include not only naturally occurring purine and pyrimidine heterocycles, but also heterocycle analogs and their tautomers. Nucleobases are defined in accordance with the principles of The Chemical Biology of Nucleic Acids (Gunter Mayer, John Wiley & Sons, 2010) and other publications, and examples thereof include adenine, guanine, thymine, cytosine, uracil, purine, inosine, isoguanine, isocytosine, xanthine, diaminopurine, 5-methylcytosine, 5-fluorouracil, 5-bromouracil, 5-iodouracil, 7-deazaguanine, 7-deazaadenine, pseudouracil, 3-methyluracil, dihydrouracil, 5-ethyluracil, 6-azapyrimidine, 6-methyluracil, 2-thiouracil, 4-thiouracil, 4-acetyluracil, and the like. These include, but are not limited to, cytosine, 5-(carboxyhydroxymethyl)uracil, 5-carboxymethylaminomethyluracil, 1-methyladenine, 2,2-dimethylguanine, 3-methylcytosine, 2-methyladenine, 2-methylguanine, 7-methylguanine, 5-methoxyaminomethyl-2-thiouracil, 5-methylaminomethyluracil, 5-methylcarbonylmethyluracil, 5-methyloxyuracil, 5-methyl-2-thiouracil, 2-thiocytosine, etc. The sugar portion of the backbone may be a pentose, PNA, or part of a six-membered ring.Examples of pentoses include, but are not limited to, 2'-deoxyribose, ribose, 2'-O-methylribose, 2'-O-methoxyethylribose, 2'-fluororibose, 2'-4'-O-methyleneribose (LNA), 2'-4'-O-C-ethyleneribose (ENA), etc. The nucleobase is attached to the 1'-position of the pentose. When the sugar moiety of the backbone is a pentose such as 2'-deoxyribose or ribose, the internucleoside linker connects the 3'-end of the previous monomer to the 5'-end of the next monomer. Examples of internucleoside linkers are described in Non-Patent Document 3, etc., and include phosphodiester bonds, phosphorothioate bonds, etc.

[0162] In preferred embodiments, the nucleotide monomers include deoxyadenosine, thymidine, deoxyguanosine, deoxycytidine, adenosine, guanosine, uridine, cytidine, and inosine, linked via phosphodiester bonds, and in particularly preferred embodiments, deoxyadenosine, thymidine, deoxyguanosine, and deoxycytidine.

[0163] The oligonucleotide moieties G and H may form an overhang. Complementarity between the overhang and the overhang of the double-stranded oligonucleotide tag allows the reaction sites to be closer together during ligation, resulting in a structure suitable for ligation. The 3'-end of G or the 5'-end of H may overhang, but the 3'-end of G is preferred. That is, in some embodiments of the compound of the present invention, the oligonucleotide moieties G and H preferably have an overhang at the 3'-end of G. The base length of the overhang may be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. In other embodiments, the overhang is preferably 4 or 6 bases long.

[0164] When j in Formula I is 0, it indicates that A and B are directly bonded. When j is 0, Formula I typically represents a headpiece. When j in Formula I is 1, it indicates that a linker L is present between A and B. j is preferably 0 or 1, and particularly preferably 1. There is also another embodiment in which j is preferably 0.

[0165] Preferred embodiments of the compound of formula I include the following formula IX, formula X, and formula XI, with formula X and formula XI being more preferred, and formula XI being particularly preferred. In formula IX, formula X, or formula XI, there is also another preferred embodiment in which j is 1.

[0166]

[0167]

[0168]

[0169] <Thirteenth Aspect> According to the thirteenth aspect of the present invention, there is provided a compound represented by the following formula (II): A' is one or more building blocks; L is a linker; C and D are each independently a spacer; B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-end of G'; F is a functional group which forms a bond with the 3'-end of H'; G' is an oligonucleotide having a phosphate group at the 3'-end; H' is an oligonucleotide having a hydroxy group at the 5'-end; G' and H' comprise a sequence which encodes A'; j is 0 or 1 (when j is 0, A' and B are directly bonded, and when j is 1, a linker L is present between A' and B).

[0170] (Building Block A') In some embodiments of the compounds of the present invention, A' is a building block, i.e., a small to medium molecular compound having a functional group, or a structural unit having one or more functional groups in a portion of the structure of a small to medium molecular compound. The building block A' can be bonded to a chemically reactive site of the linker L or the molecular scaffold B.

[0171] Furthermore, A' may be one or more building blocks. When A' is a plurality of building blocks, each building block may be an independent building block. That is, in this case, each building block may be a structural unit of a different small to medium molecular compound or a part thereof. In addition, in this case, each building block can be bonded to a chemical reaction site of a linker L, a molecular framework B, or another building block.

[0172] In one embodiment, A' may be a building block and a scaffold compound. In this embodiment, the building block can be bonded to a chemical reactive site of the linker L or the molecular skeleton B via the scaffold compound. In another embodiment, A' may be one or more building blocks and one or more scaffold compounds. In these embodiments, each building block may be an independent building block and can be bonded to a chemical reactive site of the linker L, the molecular skeleton B, or another building block directly or via a scaffold compound. A "scaffold" is a molecular skeleton having two or more functional groups for bonding to a chemical reactive site of the linker L, the molecular skeleton B, or another building block. Examples of scaffold compounds include compounds having a cycloalkyl group, a cycloalkenyl group, a heterocycloalkyl group, a heterocycloalkenyl group, an aryl group, or a heteroaryl group, and having multiple functional groups. An example of a scaffold compound is cyanuric chloride. Cyanuric chloride is a heteroaryl compound having three replaceable chloro groups, and for example, one chloro group can be bonded to a chemical reactive site of a linker L, a molecular framework B, or another building block, and the other two chloro groups can be bonded to other building blocks, respectively.

[0173] (Oligonucleotide G' having a phosphate group at the 3'-end and oligonucleotide H' having a hydroxy group at the 5'-end) Oligonucleotides G' and H' are oligonucleotides comprising an oligonucleotide contained in a headpiece and an oligonucleotide tag. That is, oligonucleotides G' and H' comprise a sequence encoding A', and preferably G' or H' further comprises a primer oligonucleotide, and more preferably H' comprises a primer oligonucleotide. Oligonucleotides G' and H' may each be a nucleotide chain consisting of any base length, and their base lengths are not particularly limited as long as they encode A'. Oligonucleotide G' has a phosphate group at the 3'-end, and oligonucleotide H' has a hydroxy group at the 5'-end.

[0174] The oligonucleotides G' and H' may form an overhang. Complementarity between the overhang and the overhang of the double-stranded oligonucleotide tag allows the reaction sites to be closer together during ligation, resulting in a structure suitable for ligation. The 3'-end of G' may overhang, or the 5'-end of H' may overhang, but the 3'-end of G' is preferred. That is, in a thirteenth aspect of the compound of the present invention, the oligonucleotides G' and H' preferably have an overhang at the 3'-end of G'. The base length of the overhang may be, for example, 1 to 7 bases, preferably 2 to 6 bases, more preferably 3 to 6 bases, even more preferably 4 to 6 bases, particularly preferably 4 to 5 bases, and most preferably 5 bases. In another aspect, the overhang is preferably 4 or 6 bases long.

[0175] <14th Aspect> According to the 14th aspect of the present invention, there is provided a compound represented by the following formula (III): A' is one or more building blocks; L is a linker; C' and D' are independent spacers each containing 1 to 5 dSpacers (Formula IV); B is a trivalent molecular skeleton which may have a substituent; E is a functional group which forms a bond with the 5'-end of G''; F is a functional group which forms a bond with the 3'-end of H''; G'' is an oligonucleotide having a hydroxy group at the 3'-end; H'' is an oligonucleotide having a phosphate group at the 5'-end; G'' and H'' comprise a sequence which encodes A'; and j is 0 or 1 (when j is 0, A' and B are directly bonded, and when j is 1, there is a linker L between A' and B).

[0176] (Spacers C', D') Spacers C' and D' each contain 1 to 5 dSpacers (Formula IV) and are linking groups connecting functional group E, functional group F, and optionally substituted trivalent group B. The hydroxyl group of a dSpacer can form a phosphodiester bond via a phosphate group to optionally substituted trivalent group B, to other dSpacers, or to other spacers. In another embodiment, the hydroxyl group of a dSpacer can bond to functional group E or functional group F. A phosphodiester bond can be formed between the hydroxyl group at the 3' position and the hydroxyl group at the 5' position of a dSpacer via a phosphate group. The number of dSpacers contained in spacers C' and D' may preferably be 2 to 4, more preferably 2 to 3, and most preferably 2. Spacers C' and D' may each further contain an optionally substituted alkylene chain, an optionally substituted oligoethylene glycol chain, or an optionally substituted saturated alkyl ring. The structures of spacers C' and D' may be different from each other, and in the present invention, when the structures of spacers C' and D' may be different from each other, C' and D' are sometimes referred to as independent spacers.

[0177] (Oligonucleotide G'' having a hydroxy group at the 3'-end and oligonucleotide H'' having a phosphate group at the 5'-end) Oligonucleotides G'' and H'' are oligonucleotides comprising the oligonucleotide contained in the headpiece and an oligonucleotide tag. That is, oligonucleotides G'' and H'' comprise a sequence encoding A', and preferably G'' or H'' further comprises a primer oligonucleotide, and more preferably H'' comprises a primer oligonucleotide. Oligonucleotides G'' and H'' may each be a nucleotide chain consisting of any base length, and their base lengths are not particularly limited as long as they encode A'. Oligonucleotide G'' has a hydroxy group at the 3'-end, and oligonucleotide H'' has a phosphate group at the 5'-end.

[0178] In a fourteenth aspect of the compound of the present invention, a closing primer may further be bound to the oligonucleotides G" and H". The closing primer consists of a double-stranded oligonucleotide and contains, in the strand opposite to the strand containing the primer oligonucleotide, a fixed sequence necessary for binding of a primer used in amplifying a region containing a tag by PCR. That is, when the oligonucleotide H" contains a primer oligonucleotide, G" contains a fixed sequence. In this case, it is preferable that G" and / or H" contain an oligonucleotide consisting of multiple consecutive modified nucleotides. In the modified nucleotides, the nucleobases are selected randomly, and in the case of DNA, the nucleobases are selected from adenine, guanine, thymine, and cytosine with equal probability. The oligonucleotide chain consisting of modified nucleotides may be, for example, 5 to 30 bases long, and preferably 8 to 20 bases long. In the oligonucleotide chain consisting of modified nucleotides, the nucleobases in each nucleotide are each selected randomly.

[0179] In a fourteenth aspect of the compound of the present invention, when a closing primer is bound, the end of the oligonucleotide chain containing the closing primer may be blunt. A blunt end means that no strand protrudes from the end of the hybridized oligonucleotide chain. The blunting of the oligonucleotide chain end, i.e., the blunting of the end of the oligonucleotide chain, can be achieved, for example, by a method using the Klenow Fragment derived from Escherichia coli DNA polymerase I.

[0180] <Twenty-ninth Aspect> According to the twenty-ninth aspect of the present invention, there is provided a compound represented by the following formula (XII): A is a chemical reaction site; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-end of H; H is an oligonucleotide moiety having a hydroxy group at the 5'-end; and j is 0 or 1 (when j is 0, A and D are directly bonded, and when j is 1, A and D are connected by a linker L).

[0181] <Thirtieth Aspect> According to the thirtieth aspect of the present invention, there is provided a compound represented by the following formula (XIII): A' is one or more building blocks; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-end of H'; H' is an oligonucleotide having a hydroxy group at the 5'-end; H' comprises a sequence that encodes A'; and j is 0 or 1 (when j is 0, A and D are directly bonded, and when j is 1, there is a linker L between A' and D).

[0182] <Composition> In one embodiment, the present invention relates to a composition comprising a compound of the present invention. In one embodiment, the composition of the present invention comprises a plurality of different types of compounds of the present invention. A plurality of different types of compounds of the present inventi...

Claims

1. A method for producing an oligonucleotide-encoded compound, comprising: (a) providing a headpiece, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at its 3'-end and a hydroxy group at its 5'-end; (b) phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the headpiece oligonucleotide, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the headpiece oligonucleotide; and (c) directly or indirectly attaching at least one building block to a chemically reactive site on the headpiece; and wherein steps (b) and (c) can be performed in any order, and wherein the double-stranded oligonucleotide tag encodes the building block.

2. The method according to claim 1, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

3. The method according to claim 1 or 2, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

4. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method according to claim 3, wherein the metal salt of 5. The method of claim 1, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

6. The method of claim 1, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

7. The method of claim 6, wherein the overhang is 5 bases long.

8. The method of claim 6 or claim 7, wherein the headpiece oligonucleotide has an overhang at the 3'-end.

9. The method according to claim 8, wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end side, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag.

10. The method of claim 1, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a carbodiimide derivative.

11. The method according to claim 10, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

12. A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a headpiece, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at its 3'-end and a hydroxy group at its 5'-end; (b) phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide included in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide included in the headpiece; (c) directly or indirectly binding at least one building block to the chemical reaction site of the headpiece; (b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is an independent double-stranded oligonucleotide having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of a second strand, and wherein the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1);and (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), wherein the building block (m) is an independent building block; and after carrying out steps (b) and (c) once, carrying out a set of steps (b') and (c') n times (n is a natural number from 1 to 10, m is a natural number up to n, and the mth time represents the number of times steps (b') and (c') are carried out), wherein steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, wherein the double-stranded oligonucleotide tag in step (b) codes for the building block in step (c), the encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

13. The method according to claim 12, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

14. The method according to claim 12 or 13, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

15. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 14, wherein the metal salt of 16. The method according to claim 12, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

17. The method of claim 12, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

18. The method of claim 17, wherein the overhang is 5 bases in length.

19. The method of claim 17 or 18, wherein the headpiece oligonucleotide has an overhang at the 3'-end.

20. The method according to claim 19, wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m).

21. The method according to claim 12, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

22. The method according to claim 21, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

23. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at the 3'-end and a hydroxyl group at the 5'-end; (b) in each reaction vessel, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide, the first strand having a hydroxyl group at the 5'-end and a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, the sequence of the double-stranded oligonucleotide tag being different for each reaction vessel, (c) linking, via phosphodiester linkage, at least one building block to a chemical reaction site on the headpiece in each of the dispensed reaction vessels, where the building block may be different for each reaction vessel; and (d) pooling together the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

24. The method according to claim 23, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

25. The method according to claim 23 or 24, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

26. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 25, wherein the metal salt of 27. The method of claim 23, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

28. The method of claim 23, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

29. The method of claim 28, wherein the overhang is 5 bases in length.

30. The method of claim 28 or claim 29, wherein the headpiece oligonucleotide has an overhang at the 3'-end.

31. The method according to claim 30, wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

32. The method of claim 23, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a carbodiimide derivative.

33. The method of claim 32, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

34. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at the 3'-end and a hydroxyl group at the 5'-end; (b) in each reaction vessel, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide, the first strand having a hydroxyl group at the 5'-end and a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, the sequence of the double-stranded oligonucleotide tag being different for each reaction vessel, (c) linking at least one building block directly or indirectly to a chemical reaction site of the headpiece in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof;carrying out step (b) and step (c) once, followed by carrying out step (d), and then carrying out step (a') to step (d') as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out); step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

35. The method according to claim 34, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

36. The method according to claim 34 or 35, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

37. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 36, wherein the metal salt of 38. The method according to claim 34, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

39. The method of claim 34, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

40. The method of claim 39, wherein the overhang is 5 bases in length.

41. The method of claim 39 or 40, wherein the headpiece oligonucleotide has an overhang at the 3' end.

42. The method according to claim 41, wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m).

43. The method according to claim 34, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

44. The method according to claim 43, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

45. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at the 3'-end and a hydroxyl group at the 5'-end; (b) in each reaction vessel, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide, the first strand having a hydroxyl group at the 5'-end and a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, the sequence of the double-stranded oligonucleotide tag being different for each reaction vessel, (c) linking at least one building block directly or indirectly to a chemical reaction site of the headpiece in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, the Closing Primer having a phosphate group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a hydroxy group at the 3'-end of the second strand, the phosphate group at the 5'-end of the first strand of the Closing Primer being phosphodiester-linked to the hydroxy group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the Closing Primer being phosphodiester-linked to the phosphate group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');carrying out step (d) after carrying out step (b) and step (c) once, and then carrying out step (d) as one set of steps (a') to (d') n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out. Only in the nth time, the double-stranded oligonucleotide tag (m) in step (b') has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

46. ​​The method of claim 45, wherein in step (e), after the Closing Primer is phosphodiester-linked by ligation, the protruding end is enzymatically blunted, and the second strand of the Closing Primer contains modified nucleotides.

47. The method according to claim 45 or 46, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

48. The method according to claim 45 or 46, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

49. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 48, wherein the metal salt of 50. The method according to claim 45, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

51. The method of claim 45, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

52. The method of claim 51, wherein the overhang is 5 bases in length.

53. The method of claim 51 or claim 52, wherein the headpiece oligonucleotide has an overhang at the 3' end.

54. The method according to claim 53, wherein in step (b) and / or step (b'), the double-stranded oligonucleotide tag (m-1) and / or the first strand of the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that in the nth time, the dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m) is not present.

55. The method according to claim 45, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

56. The method according to claim 55, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

57. A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a complex comprising a building block (p), a headpiece, and a double-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of a first strand and the 3'-end of a second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of a second strand, and having a hydroxy group at the 5'-end; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of an oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of an oligonucleotide contained in the complex; and (d) linking, directly or indirectly, at least one building block to a chemical reaction site contained in the complex; (e) linking, via phosphodiester linkage, at least one building block to a chemical reaction site contained in the complex; (f) linking, via phosphodiester linkage, at least one building block to a chemical reaction site contained in the complex; (g) linking, via phosphodiester linkage, at least one building block to a chemical reaction site contained in the complex; 58. The method of claim 57, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

59. The method according to claim 57 or 58, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

60. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 59, wherein the metal salt is 61. The method of claim 57, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

62. The method of claim 57, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

63. The method of claim 62, wherein the overhang is 5 bases in length.

64. The method of claim 62 or 63, wherein the oligonucleotide contained in the complex has an overhang at its 3' end.

65. The method of claim 64, wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

66. The method of claim 57, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a carbodiimide derivative.

67. The method of claim 66, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

68. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the double-stranded oligonucleotide tag to an oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end, a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxy group at the 5'-end, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag being phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (c) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex;(b') phosphodiester-linking a double-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) by chemical ligation, the double-stranded oligonucleotide tag (m) being composed of an independent double-stranded oligonucleotide, having a hydroxy group at the 5'-end of a first strand, a phosphate group at the 3'-end, and a phosphate group at the 3'-end of a second strand, and a hydroxy group at the 5'-end, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag (m) being phosphodiester-linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound (m-1), and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag (m) being phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); and (c') directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1), building block (m) is an independent building block;carrying out step (b) and step (c) once, and then carrying out step (b') and step (c') as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times steps (b') and (c') are carried out); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, a sequence of a double-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

69. The method according to claim 68, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

70. The method according to claim 68 or 69, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

71. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 70, wherein the metal salt of 72. The method according to claim 68, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

73. The method of claim 68, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

74. The method of claim 73, wherein the overhang is 5 bases in length.

75. The method of claim 73 or 74, wherein the oligonucleotide contained in the complex has an overhang at its 3' end.

76. The method according to claim 75, wherein in step (b) and / or step (b'), the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag and / or the double-stranded oligonucleotide tag (m).

77. The method according to claim 68, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

78. The method according to claim 77, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

79. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end, a phosphate group at the 3'-end, the second strand having a phosphate group at the 3'-end, and a hydroxy group at the 5'-end, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex, respectively, via phosphodiester bond; (d) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; and (e) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof;wherein steps (b) and (c) can be performed in any order, and the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; 80. The method of claim 79, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

81. The method of claim 79 or 80, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

82. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 81, wherein the metal salt is 83. The method of claim 79, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

84. The method of claim 79, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

85. The method of claim 84, wherein the overhang is 5 bases in length.

86. The method of claim 84 or 85, wherein the oligonucleotide contained in the complex has an overhang at its 3' end.

87. The method of claim 86, wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

88. The method of claim 79, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a carbodiimide derivative.

89. The method of claim 88, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

90. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end, a phosphate group at the 3'-end, the second strand having a phosphate group at the 3'-end, and a hydroxy group at the 5'-end, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture thereof;carrying out step (b) and step (c) once, followed by carrying out step (d), and then carrying out step (a') to step (d') as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out); step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

91. The method of claim 90, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

92. The method of claim 90 or 91, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

93. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 92, wherein the metal salt is 94. The method of claim 90, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

95. The method of claim 90, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

96. The method of claim 95, wherein the overhang is 5 bases in length.

97. The method of claim 95 or 96, wherein the oligonucleotide contained in the complex has an overhang at the 3' end.

98. The method of claim 97, wherein in step (b), the first strand of the double-stranded oligonucleotide tag has an overhang on the 3'-end, and the chemical ligation is ligation in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end of the first strand of the double-stranded oligonucleotide tag.

99. The method of claim 90, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a carbodiimide derivative.

100. The method of claim 99, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

101. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end, a phosphate group at the 3'-end, the second strand having a phosphate group at the 3'-end, and a hydroxy group at the 5'-end, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture, the Closing Primer having a phosphate group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a hydroxy group at the 3'-end of the second strand, the phosphate group at the 5'-end of the first strand of the Closing Primer being phosphodiester-linked to the hydroxy group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the hydroxy group at the 3'-end of the second strand of the Closing Primer being phosphodiester-linked to the phosphate group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d');carrying out step (d) after carrying out step (b) and step (c) once, and then carrying out step (d) as one set of steps (a') to (d') n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out. Only in the nth time, the double-stranded oligonucleotide tag (m) in step (b') has a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

102. The method of claim 101, wherein in step (e), after the Closing Primer is phosphodiester-linked by ligation, the protruding end is enzymatically blunted, and the second strand of the Closing Primer contains modified nucleotides.

103. The method according to claim 101 or 102, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

104. The method according to claim 101 or 102, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

105. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 104, wherein the metal salt is 106. The method of claim 101, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

107. The method of claim 101, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

108. The method of claim 107, wherein the overhang is 5 bases in length.

109. The method of claim 107 or 108, wherein the oligonucleotide contained in the complex has an overhang at its 3' end.

110. The method according to claim 109, wherein in step (b) and / or step (b'), the double-stranded oligonucleotide tag (m-1) and / or the first strand of the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that in the nth time, the dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m) is not present.

111. The method of claim 101, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

112. The method of claim 111, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 8.

113. A compound of formula I: A compound in which A is a chemical reaction site; L is a linker; C and D are each independently a spacer; B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-end of G; F is a functional group which forms a bond with the 3'-end of H; G is an oligonucleotide moiety having a phosphate group at the 3'-end; H is an oligonucleotide moiety having a hydroxyl group at the 5'-end; and j is 0 or 1 (when j is 0, A and B are directly bonded, and when j is 1, A and B are connected by a linker L).

114. A compound of formula II: A compound in which A' is one or more building blocks; L is a linker; C and D are each independently a spacer; B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-end of G'; F is a functional group which forms a bond with the 3'-end of H'; G' is an oligonucleotide having a phosphate group at the 3'-end; H' is an oligonucleotide having a hydroxyl group at the 5'-end; G' and H' comprise a sequence which codes for A'; and j is 0 or 1 (when j is 0, A and B are directly bonded, and when j is 1, A and B are connected via a linker L).

115. The compound of claim 113 or 114, wherein C and D comprise dSpacer (Formula IV).

116. A compound of formula III: A' is one or more building blocks; L is a linker; C' and D' are independent spacers each containing 1 to 5 dSpacers (Formula IV); A compound in which B is a trivalent molecular backbone which may have a substituent; E is a functional group which forms a bond with the 5'-terminus of G''; F is a functional group which forms a bond with the 3'-terminus of H''; G'' is an oligonucleotide having a hydroxy group at the 3'-terminus; H'' is an oligonucleotide having a phosphate group at the 5'-terminus; G'' and H'' comprise a sequence which codes for A', and j is 0 or 1 (when j is 0, A' and B are directly bonded, and when j is 1, A' and B are connected by a linker L).

117. A composition comprising a compound according to claim 113, 114 or 116.

118. A method for linking an initiator oligonucleotide and a double-stranded oligonucleotide having an overhang by ligation, wherein a first strand of the double-stranded oligonucleotide has an overhang and a second strand of the double-stranded oligonucleotide has an overhang complementary to the initiator oligonucleotide, the method comprising ligating in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang of the first strand of the double-stranded oligonucleotide.

119. The method of claim 118, wherein the ligation is chemical ligation.

120. The method of claim 118, wherein the bond is a phosphodiester bond.

121. The method of claim 120, wherein the initiator oligonucleotide comprises a phosphate group at its 3'-terminus, and the first strand of the double-stranded oligonucleotide comprises a hydroxy group at its 5'-terminus and a phosphate group at its 3'-terminus, and the hydroxy group at the 5'-terminus of the first strand of the double-stranded oligonucleotide is bonded to the phosphate group at the 3'-terminus of the initiator oligonucleotide via a phosphodiester bond by chemical ligation.

122. The method of any one of claims 118 to 121, wherein the overhang of the double-stranded oligonucleotide is 4 to 6 bases in length.

123. A method for ligating a double-stranded oligonucleotide tag to a headpiece comprising an oligonucleotide having an overhang, wherein a first strand of the double-stranded oligonucleotide tag has an overhang and a second strand of the double-stranded oligonucleotide tag has an overhang complementary to the overhang of an oligonucleotide comprised in the headpiece, the method comprising ligating in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang of the first strand of the double-stranded oligonucleotide tag.

124. The method of claim 123, wherein the ligation is chemical ligation.

125. The method of claim 123, wherein the linkage is a phosphodiester linkage.

126. The method of claim 125, wherein the oligonucleotide of the headpiece has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, the first strand of the double-stranded oligonucleotide tag has a hydroxy group at its 5'-end and a phosphate group at its 3'-end, the second strand has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the second strand of the double-stranded oligonucleotide tag has an overhang complementary to the overhang of the headpiece, and the method comprises chemically ligating the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the headpiece, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the headpiece, respectively, via phosphodiester linkage.

127. The method of any one of claims 123 to 126, wherein the overhang of the double-stranded oligonucleotide tag is 4 to 6 bases in length.

128. A method for selecting an oligonucleotide-encoded compound, comprising: (a) contacting an oligonucleotide-encoded compound, or a library containing a plurality of oligonucleotide-encoded compounds, obtained by the method of claim 1, 12, 23, 34, 45, 57, 68, 79, 90 or 101, with a biological target under conditions suitable for binding of the oligonucleotide-encoded compound or at least one oligonucleotide-encoded compound contained in the library to the biological target; and (b) identifying the oligonucleotide-encoded compound bound to the biological target in step (a).

129. The method according to claim 128, further comprising the steps (1) and (2) of: (1) determining the structure of a building block encoded by an oligonucleotide contained in a compound encoded by an oligonucleotide selected by the method according to claim 128; and (2) preparing the building block whose structure has been determined in step (1).

130. A method for producing an oligonucleotide-encoded compound, comprising: (a) providing a headpiece, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemically reactive site at its 3'-end via a spacer and a hydroxyl group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece by chemical ligation in the presence of a splint oligonucleotide, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, and phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxyl group at the 5'-end of the single-stranded oligonucleotide of the headpiece; and (c) directly or indirectly linking at least one building block to the chemically reactive site of the headpiece; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag encodes the building block.

131. The method of claim 130, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

132. The method of claim 130 or 131, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

133. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 132, wherein the metal salt is 134. The method of claim 133, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

135. A method for producing an oligonucleotide-encoded compound, comprising: (a) preparing a headpiece, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxyl group at its 5'-end; (b) phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxyl group at the 5'-end of the single-stranded oligonucleotide of the headpiece; and (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to the single-stranded oligonucleotide included in the encoded compound (m-1) in the presence of a splint oligonucleotide, the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and (c') a step of directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), the building block (m) being an independent building block; wherein after performing steps (b) and (c) once, one set of steps (b') and (c') is performed n times (n is a natural number from 1 to 10, m is a natural number up to n, and the mth time represents the number of times steps (b') and (c') are performed).), steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the m-th step, respectively; the single-stranded oligonucleotide tag in step (b) codes for the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, a sequence of the single-stranded oligonucleotide tag (m-1), and a structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively); the single-stranded oligonucleotide tag (m) codes for the building block (m) and is bound to the single-stranded oligonucleotide contained in the encoded compound (m-1) in the m-th step; The building block (m) is directly or indirectly attached to a chemically reactive site of the encoded compound (m-1) at the mth time.

136. The method according to claim 135, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

137. The method according to claim 135 or 136, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

138. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 137, wherein the metal salt is 139. The method of claim 135, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

140. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxyl group at its 5'-end; (b) in each reaction vessel, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, the sequence of the single-stranded oligonucleotide tag may differ from reaction vessel to reaction vessel, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxyl group at the 5'-end of the single-stranded oligonucleotide of the headpiece; (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each reaction vessel, the building block may differ from reaction vessel to reaction vessel; and (d) pooling together the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

141. The method of claim 140, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

142. The method of claim 140 or claim 141, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

143. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 142, wherein the metal salt is 144. The method of claim 140, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

145. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxy group at its 5'-end; (b) in each reaction vessel, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, the sequence of the single-stranded oligonucleotide tag may be different for each reaction vessel, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the single-stranded oligonucleotide of the headpiece; (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each reaction vessel, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in encoded compound (m-1);(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the dispensed reaction vessels, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; and (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture; wherein steps (b) and (c) are performed once, followed by performing step (d), and then performing steps (a') to (d') as one set n times (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are performed), and steps (b) and (c) can be performed in any order, and steps (b') and (c') can be performed in any order in the mth time, The single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of the single-stranded oligonucleotide tag (m-1), and a structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and binds to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) binds directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

146. The method according to claim 145, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

147. The method according to claim 145 or 146, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

148. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 147, wherein the metal salt is 149. The method of claim 145, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

150. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a single-stranded oligonucleotide, the single-stranded oligonucleotide of the headpiece having a chemical reaction site at its 3'-end via a spacer and a hydroxyl group at its 5'-end; (b) in each reaction vessel, phosphodiester-linking a single-stranded oligonucleotide tag to the single-stranded oligonucleotide of the headpiece in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag being a single-stranded oligonucleotide having a phosphate group at its 3'-end, the sequence of the single-stranded oligonucleotide tag may differ from reaction vessel to reaction vessel, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxyl group at the 5'-end of the single-stranded oligonucleotide of the headpiece; (c) directly or indirectly linking at least one building block to the chemical reaction site of the headpiece in each reaction vessel, the building block may differ from reaction vessel to reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels; (b') in each of the reaction vessels into which the mixture has been dispensed, phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in encoded compound (m-1) in the mixture by chemical ligation, wherein the single-stranded oligonucleotide tag (m) is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in encoded compound (m-1);(c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the dispensed reaction vessels, wherein the building block (m) is an independent building block, and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compound encoded in steps (b') and (c') into one to obtain a mixture; and (e) phosphodiester-linking a closing primer to the oligonucleotide of the encoded compound in the mixture by ligation; comprising: performing step (d) after performing step (b) and step (c) once, and then performing step (a') to step (d') n times as one set (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are performed), and then performing step (e), Steps (b) and (c) may be performed in any order, and steps (b') and (c') may be performed in any order in the m-th step, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of the single-stranded oligonucleotide tag (m-1), and a structural unit of the building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in steps (b) and (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and in the m-th step, binds to an oligonucleotide contained in the encoded compound (m-1); The building block (m) is directly or indirectly attached to a chemically reactive site of the encoded compound (m-1) at the mth time.

151. The method of claim 150, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

152. The method of claim 150 or 151, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

153. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 152, wherein the metal salt is 154. The method of claim 150, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

155. A method for producing an oligonucleotide-encoded compound, comprising the steps of: (a) preparing a complex comprising a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p), wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to a single-stranded oligonucleotide contained in the complex in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag is a single-stranded oligonucleotide having a phosphate group at its 3'-end, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag is phosphodiester-linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; and (c) directly or indirectly attaching at least one building block to a chemically reactive site contained in the complex; and wherein steps (b) and (c) can be performed in any order, and wherein the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c).

156. The method of claim 155, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

157. The method of claim 155 or claim 156, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

158. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 157, wherein the metal salt is 159. The method of claim 155, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

160. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the hydroxy group at the 5'-end of the oligonucleotide contained in the complex and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag are phosphodiester-linked, respectively; (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex; (b') phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in the encoded compound (m-1) in the presence of a splint oligonucleotide by chemical ligation, the single-stranded oligonucleotide tag (m) having a phosphate group at the 3'-end and a hydroxy group at the 5'-end, and phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxy group at the 5'-end of the single-stranded oligonucleotide contained in the encoded compound (m-1); and (c') directly or indirectly binding at least one building block (m) to a chemical reaction site of the encoded compound (m-1), the building block (m) being an independent building block;carrying out step (b) and step (c) once, and then carrying out step (b') and step (c') as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the mth time represents the number of times steps (b') and (c') are carried out); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c); the encoded compound (m-1) comprises a chemical reaction site, a sequence of a single-stranded oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the single-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) codes for the building block (m) and is bound to an oligonucleotide contained in the encoded compound (m-1) at the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) at the mth time.

161. The method according to claim 160, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

162. The method according to claim 160 or claim 161, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

163. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 162, wherein the metal salt is 164. The method of claim 160, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer solution, the pH of the buffer solution being between 4 and 7.

165. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may be different for each reaction vessel, (c) directly or indirectly attaching at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; and (d) pooling together the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; wherein steps (b) and (c) can be performed in any order, and the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel.

166. The method of claim 165, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

167. The method of claim 165 or claim 166, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

168. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 167, wherein the metal salt is 169. The method of claim 165, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

170. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may be different for each reaction vessel, (c) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a step of phosphodiester-linking a single-stranded oligonucleotide tag (m) to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and a step of phosphodiester-linking the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) to the hydroxyl group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the dispensed reaction vessels, a step of directly or indirectly linking at least one building block (m) to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may differ from reaction vessel to reaction vessel; and (d') pooling the contents of each reaction vessel containing the compound encoded in step (b') and step (c') together to obtain a mixture thereof;carrying out step (b) and step (c) once, followed by carrying out step (d), and then carrying out step (a') to step (d') as one set n times (n represents a natural number from 1 to 10, m represents a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out); step (b) and step (c) can be carried out in any order, and step (b') and step (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel; the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a single-stranded oligonucleotide tag (m) and a building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mth time.

171. The method of claim 170, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

172. The method of claim 170 or claim 171, wherein step (b) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

173. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 172, wherein the metal salt is 174. The method of claim 170, wherein step (b) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

175. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex containing a building block (p), a headpiece, and a single-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a single-stranded oligonucleotide tag (p) is bound to the headpiece, the single-stranded oligonucleotide tag (p) is bound to the headpiece at its 3'-end and has a hydroxy group at its 5'-end, and the single-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the single-stranded oligonucleotide tag to an oligonucleotide contained in the complex in the presence of a splint oligonucleotide by chemical ligation, wherein the single-stranded oligonucleotide tag has a phosphate group at its 3'-end and a hydroxy group at its 5'-end, and the sequence of the single-stranded oligonucleotide tag may be different for each reaction vessel, (c) linking, via a phosphodiester bond, the phosphate group at the 3'-end of the single-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly binding at least one building block to a chemical reaction site contained in the complex in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling together the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a single-stranded oligonucleotide tag (m) is phosphodiester-linked to an oligonucleotide contained in an encoded compound (m-1) in the mixture in the presence of a splint oligonucleotide, wherein the single-stranded oligonucleotide tag (m) has a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, and the sequence of the single-stranded oligonucleotide tag (m) may differ from reaction vessel to reaction vessel, and the phosphate group at the 3'-end of the single-stranded oligonucleotide tag (m) is phosphodiester-linked to the hydroxyl group at the 5'-end of the oligonucleotide contained in the encoded compound (m-1); (c') in each of the dispensed reaction vessels, at least one building block (m) is directly or indirectly linked to a chemical reaction site of the encoded compound (m-1) in the mixture, wherein the building block (m) is an independent building block, and the building block (m) may differ from reaction vessel to reaction vessel; (d') pooling the contents of each reaction vessel containing the compound encoded in step (b') and step (c') into one to obtain a mixture thereof; and (e) ligating a closing primer to the oligonucleotide of the encoded compound in the mixture via a phosphodiester bond;carrying out step (d) after carrying out step (b) and step (c) once, and then carrying out step (d) as one set of steps (a') to (d') n times (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, respectively; the single-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to a single-stranded oligonucleotide tag (m) and a building block (m) (when m is 1, the single-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the single-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the single-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mth time.

176. The method according to claim 175, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

177. The method according to claim 175 or 176, wherein step (b) and / or step (b') further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

178. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 177, wherein the metal salt is 179. The method of claim 175, wherein step (b) and / or step (b') is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

180. A compound of formula XII: A is a chemically reactive site; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-end of H; H is an oligonucleotide moiety having a hydroxy group at the 5'-end; and j is 0 or 1 (when j is 0, it indicates that A and D are directly bonded, and when j is 1, it indicates that there is a linker L between A and D), the compound.

181. A compound of formula XIII: A' is one or more building blocks; L is a linker; D is a spacer; F is a functional group that forms a bond with the 3'-terminus of H'; H' is an oligonucleotide having a hydroxy group at the 5'-terminus; H' comprises a sequence that codes for A'; and j is 0 or 1 (when j is 0, it indicates that A and D are directly bonded, and when j is 1, it indicates that there is a linker L between A' and D), a compound.

182. A composition comprising a compound according to claim 180 or 181.

183. A method for selecting an oligonucleotide-encoded compound, comprising: (a) contacting an oligonucleotide-encoded compound, or a library containing a plurality of oligonucleotide-encoded compounds, obtained by the method of claim 130, 135, 140, 145, 150, 155, 160, 165, 170 or 175, with a biological target under conditions suitable for binding of the oligonucleotide-encoded compound or at least one oligonucleotide-encoded compound contained in the library to the biological target; and (b) identifying the oligonucleotide-encoded compound bound to the biological target in step (a).

184. The method of claim 183, further comprising the following steps (1) and (2): (1) determining the structure of a building block encoded by an oligonucleotide contained in a compound encoded by an oligonucleotide selected by the method of claim 183; and (2) preparing the building block whose structure has been determined in step (1).

185. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a headpiece into two or more reaction vessels, the headpiece having a chemical reaction site and an oligonucleotide, the oligonucleotide of the headpiece comprising a phosphate group at the 3'-end and a hydroxyl group at the 5'-end; (b) in each reaction vessel, phosphodiester-linking a double-stranded oligonucleotide tag to the oligonucleotide of the headpiece by chemical ligation, the double-stranded oligonucleotide tag being composed of at least one double-stranded oligonucleotide, the first strand having a hydroxyl group at the 5'-end and a phosphate group at the 3'-end, and the second strand having a phosphate group at the 3'-end and a hydroxyl group at the 5'-end, the sequence of the double-stranded oligonucleotide tag being different for each reaction vessel, (c) linking at least one building block directly or indirectly to a chemical reaction site of the headpiece in each of the reaction vessels dispensed, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing a mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture by ligation, the Closing Primer having a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end of the second strand and a hydroxy group at the 5'-end, wherein the hydroxy group at the 5'-end of the first strand of the Closing Primer is linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the phosphate group at the 3'-end of the second strand of the Closing Primer is linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d') by phosphodiester linkage, respectively;carrying out step (d) after carrying out step (b) and step (c) once, and then carrying out step (d) as one set of steps (a') to (d') n times (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

186. The method of claim 185, further comprising the step of enzymatically blunting the overhanging end after phosphodiester-linking the Closing Primer by ligation, wherein the second strand of the Closing Primer contains modified nucleotides in step (e).

187. The method according to claim 185 or claim 186, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a cyano derivative or an imidazole derivative.

188. The method according to claim 185 or 186, wherein step (b) and / or step (b') and / or step (e) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

189. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 188, wherein the metal salt is 190. The method of claim 185, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

191. The method of claim 185, wherein the headpiece oligonucleotide has an overhang, the overhang being 4 to 6 bases in length.

192. The method of claim 191, wherein the overhang is 5 bases in length.

193. The method of claim 191 or claim 192, wherein the headpiece oligonucleotide has an overhang at the 3'-end.

194. The method according to claim 193, wherein in step (b) and / or step (b'), the double-stranded oligonucleotide tag (m-1) and / or the first strand of the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that in the nth time, the dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m) is not present.

195. The method of claim 185, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

196. The method of claim 195, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

197. A method for producing an oligonucleotide-encoded compound, comprising: (a) dispensing a complex comprising a building block (p), a headpiece and a double-stranded oligonucleotide tag (p) into two or more reaction vessels, wherein in the complex, at least one building block (p) is directly or indirectly bound to the headpiece, and a double-stranded oligonucleotide tag (p) is bound to the headpiece, the double-stranded oligonucleotide tag (p) being composed of at least one double-stranded oligonucleotide, bound to the headpiece at the 5'-end of the first strand and the 3'-end of the second strand, having a phosphate group at the 3'-end of the first strand and a hydroxyl group at the 5'-end of the second strand, and the double-stranded oligonucleotide tag (p) encodes the building block (p); (b) in each of the reaction vessels, phosphodiester-linking the double-stranded oligonucleotide tag to the oligonucleotide contained in the complex by chemical ligation, the double-stranded oligonucleotide tag is composed of at least one double-stranded oligonucleotide, the first strand having a hydroxy group at the 5'-end, a phosphate group at the 3'-end, the second strand having a phosphate group at the 3'-end, and a hydroxy group at the 5'-end, the sequence of the double-stranded oligonucleotide tag may be different for each reaction vessel; (c) linking, via phosphodiester linkage, the hydroxy group at the 5'-end of the first strand of the double-stranded oligonucleotide tag to the phosphate group at the 3'-end of the oligonucleotide contained in the complex, and the phosphate group at the 3'-end of the second strand of the double-stranded oligonucleotide tag to the hydroxy group at the 5'-end of the oligonucleotide contained in the complex; (d) directly or indirectly linking at least one building block to a chemical reaction site contained in the complex in each of the dispensed reaction vessels, the building block may be different for each reaction vessel; (d) pooling the contents of each reaction vessel containing the compounds encoded in steps (b) and (c) into one to obtain a mixture thereof; (a') dispensing the mixture of encoded compounds (m-1) into two or more reaction vessels;(b') in each of the dispensed reaction vessels, a double-stranded oligonucleotide tag (m) is bonded via a phosphodiester bond to an oligonucleotide contained in the encoded compound (m-1) in the mixture by chemical ligation, wherein the double-stranded oligonucleotide tag (m) is composed of an independent double-stranded oligonucleotide, and has a hydroxy group at the 5'-end and a phosphate group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a hydroxy group at the 5'-end of the second strand, or has a hydroxy group at the 5'-end and a hydroxy group at the 3'-end of the first strand, and a phosphate group at the 3'-end and a phosphate group at the 5'-end of the second strand, and the sequence of the double-stranded oligonucleotide tag (m) may be different for each reaction vessel, (c') linking at least one building block (m) directly or indirectly to a chemical reaction site of the encoded compound (m-1) in the mixture in each of the reaction vessels dispensed, the building block (m) being an independent building block and the building block (m) may be different for each reaction vessel; (d') pooling the contents of each reaction vessel containing the compounds encoded in steps (b') and (c') into one to obtain a mixture;and (e) a step of phosphodiester-linking a Closing Primer to an oligonucleotide of the encoded compound in the mixture by ligation, the Closing Primer having a hydroxy group at the 5'-end of the first strand, a hydroxy group at the 3'-end, and a phosphate group at the 3'-end of the second strand and a hydroxy group at the 5'-end, wherein the hydroxy group at the 5'-end of the first strand of the Closing Primer is linked to the phosphate group at the 3'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d'), and the phosphate group at the 3'-end of the second strand of the Closing Primer is linked to the hydroxy group at the 5'-end of the oligonucleotide contained in the encoded compound in the mixture obtained in step (d') by phosphodiester linkage, respectively;carrying out step (d) after carrying out step (b) and step (c) once, and then carrying out step (d) as one set of steps (a') to (d') n times (n is a natural number from 1 to 10, m is a natural number up to n, and the nth time and the mth time represent the number of times steps (a') to (d') are carried out), and then carrying out step (e); steps (b) and (c) can be carried out in any order, and steps (b') and (c') can be carried out in any order in the mth time, respectively; the double-stranded oligonucleotide tag in step (b) encodes the building block in step (c) for each reaction vessel, the encoded compound (m-1) comprises a chemical reaction site, a sequence of an oligonucleotide tag (m-1), and a structural unit of a building block (m-1), and is not bound to the double-stranded oligonucleotide tag (m) and the building block (m) (when m is 1, the double-stranded oligonucleotide tag (m-1) and the building block (m-1) refer to the double-stranded oligonucleotide tag and the building block used in step (b) and step (c), respectively); the double-stranded oligonucleotide tag (m) encodes the building block (m) for each reaction vessel, and is bound to an oligonucleotide contained in the encoded compound (m-1) in the mth time; and the building block (m) is bound directly or indirectly to the chemical reaction site of the encoded compound (m-1) in the mth time.

198. The method of claim 197, further comprising the step of enzymatically blunting the protruding end of the Closing Primer after phosphodiester linking the Closing Primer by ligation, wherein the second strand of the Closing Primer contains modified nucleotides.

199. The method of claim 197 or claim 198, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, the condensing agent being a cyano derivative or an imidazole derivative.

200. The method of claim 197 or 198, wherein step (b) and / or step (b') and / or step (e) further comprises forming a phosphodiester bond by chemical ligation in the presence of a divalent metal salt.

201. Divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ or Mn 2+ The method of claim 200, wherein the metal salt is 202. The method of claim 197, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 7.

203. The method of claim 197, wherein the oligonucleotide contained in the complex has an overhang, the overhang being 4 to 6 bases in length.

204. The method of claim 203, wherein the overhang is 5 bases in length.

205. The method of claim 203 or claim 204, wherein the oligonucleotide contained in the complex has an overhang at its 3' end.

206. The method according to claim 205, wherein in step (b) and / or step (b'), the double-stranded oligonucleotide tag (m-1) and / or the first strand of the double-stranded oligonucleotide tag (m) has an overhang on the 3'-end side, and the chemical ligation is performed in the presence of a dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m-1) and / or the double-stranded oligonucleotide tag (m), provided that in the nth time, the dummy oligonucleotide comprising a sequence complementary to the overhang on the 3'-end side of the first strand of the double-stranded oligonucleotide tag (m) is not present.

207. The method of claim 197, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a condensing agent, and the condensing agent is a carbodiimide derivative.

208. The method of claim 207, wherein step (b) and / or step (b') and / or step (e) is a step of forming a phosphodiester bond by chemical ligation in the presence of a buffer, the pH of the buffer being between 4 and 8.

209. A method for selecting an oligonucleotide-encoded compound, comprising: (a) contacting an oligonucleotide-encoded compound, or a library containing a plurality of oligonucleotide-encoded compounds, obtained by the method of claim 185 or 197, with a biological target under conditions suitable for binding of the oligonucleotide-encoded compound or at least one oligonucleotide-encoded compound contained in the library to the biological target; and (b) identifying the oligonucleotide-encoded compound that binds to the biological target in step (a).

210. The method of claim 209, further comprising the following steps (1) and (2): (1) determining the structure of a building block encoded by an oligonucleotide contained in a compound encoded by an oligonucleotide selected by the method of claim 209; and (2) preparing the building block whose structure has been determined in step (1).

Images