Cracking branched chain connector compound for prodrug delivery system as well as preparation and application of cleavable branched chain connector compound

Abstract

The invention discloses a novel cleavable linker compound shown as a formula (1) and pharmaceutically acceptable salts, solvates, polymorphs or isomers of the novel cleavable linker compound. The novel cleavable linker compound can be used for a prodrug delivery system. The invention also provides an albumin or antibody covalent binding camptothecin derivative prodrug compound formula (J) and a camptothecin derivative prodrug compound formula (L) as well as pharmaceutically acceptable salts, solvates, polymorphs or isomers of the prodrug compound formula (J) and the pharmaceutically acceptable salts, solvates, polymorphs or isomers of the prodrug compound formula (L). The invention also provides a synthesis method of the compound and a preparation method of the compound in an enzyme release prodrug system. The invention also provides an application of the compound in preparation of antitumor drugs, and an application in preparation of albumin combined antitumor drugs or antibody-drug conjugates. The invention innovatively provides that a trigger fragment in the compound is connected to a novel linker through p-hydroxyl or p-amino, an active drug is connected to the novel linker through a hydroxyl part of the active drug, and a modified fragment is connected to the novel linker through amino. The method has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical technology and pharmaceutical preparation prodrug design, and relates to the design, synthesis and synthetic products of a new branched linker of a cleavable prodrug drug delivery system, and its application in the prodrug drug delivery system. Background Art

[0002] As people's understanding of tumors deepens, different treatment methods such as small molecule cytotoxic drugs, nucleic acids, proteins or peptides, and immunomodulators are also developing. Among them, chemotherapy is still one of the important means of treating cancer, but while chemotherapy uses cytotoxic drugs to kill tumor cells, it will inevitably affect normal tissues and cause various side effects.

[0003] The characteristics of tumor cells are abnormal growth and rapid proliferation, so most chemotherapy drugs target this characteristic and select compounds that are highly toxic to cells. However, due to the lack of selectivity, the drugs destroy normal tissues while killing tumor cells, adding an extra burden to the already weak cancer patients. Although some drugs, such as camptothecin derivatives, have a place in anti-cancer drugs with good effects, they are difficult to administer and have poor patient adaptability due to their own physical properties, such as poor water solubility.

[0004] Therefore, how to modify these drugs to increase their targeting, solubility, stability, and improve the clinical adaptability of the drugs has become a major challenge in the development of chemotherapeutic drugs. The novel linker of the present invention, which can simultaneously provide a trigger, modify the connection site of the side chain, and can achieve self-cleavage under specific conditions to release the active drug, has become one of the methods to solve this problem.

[0005] Glucuronide prodrugs are selectively activated by β-glucuronidase, which is highly expressed in the microenvironment of many solid tumors such as lung cancer, breast cancer, and gastrointestinal cancer. In the past two decades, it has been used to deliver drugs around tumors. The prodrug form can reduce the toxicity of active drugs, but because glucuronide prodrugs are cleared by the kidneys and metabolized quickly, the development of this type of prodrug is limited.

[0006] Human serum albumin (HSA) is an endogenous protein that is abundant in plasma. As a nutrient, it is preferentially taken up by tumors. After being linked to albumin, its macromolecular properties can bring EPR effect to prodrugs. Albumin's stable structure and half-life of up to 19 days can stabilize prodrugs and enhance their half-life. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the purpose of the present invention is to propose a new general formula compound of a cleavable linker / branched linker for use in a prodrug drug delivery system, and its further synthetic products, and its preparation method and application, including application in a prodrug drug delivery system. The present invention innovatively proposes for the first time a new idea of ​​triggering drug release by hydrolyzing peptide bonds or glycosidic bonds by cathepsin or β-glucuronidase. Specifically, the branched linker compound that can be used in a prodrug drug delivery system of the present invention hydrolyzes peptide bonds into amino groups by cathepsin, and glycosidic bonds into hydroxyl groups by β-glucuronidase or galactosidase; and then 1.6 self-cleavage occurs and the corresponding active drug is released through a self-closed loop process.

[0008] The present invention proposes a new cleavable branched linker compound for use in a prodrug delivery system, which has one or more sites that can be independently modified, and can combine different triggers, modified side chains, and / or active drugs together to form a new compound. The structure of the cleavable linker is shown in the following formula (1):

[0009]

[0010] Wherein, T represents the attachment site for connecting R-TR;

[0011] In the R-TR, TR is selected from one or more of a cathepsin substrate, a cathepsin substrate amino acid or short peptide chain, a β-glucuronidase substrate, a β-galactosidase substrate, a metalloprotease substrate, an aromatic boronic acid or boric acid ester that can be oxidized to a hydroxyl group, a nitro group, an azide group, an azo group that can be reduced to an amino group, a phosphate ester of a hydroxyl group, and a sulfate ester of a hydroxyl group; R is a substituent group selected from one or more of -H, PEG, maleimide-modified PEG, sugar, folic acid, polypeptides, antibodies, and protective groups;

[0012] Wherein, A represents the attachment site for ligating LR;

[0013] The LR is selected from H, CH3(CH2) n , nitro, methoxy, PEG chain, maleimide-modified PEG, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, fatty chain, polyamino acid chain, sugar chain, fatty acid, sugar, folic acid, polypeptide or antibody;

[0014] Wherein, D represents the connection site for connecting DR;

[0015] The DR contains naked -OH, -NH2, -NHR or -SH; the DR includes anti-tumor drugs camptothecin compounds and their derivatives SN-38, DXd, isitecan, belotecan, anti-tumor drugs paclitaxel, docetaxel, podophyllotoxin, CA4;

[0016] Wherein, X is O, N or S;

[0017] Wherein, R2 is H or CH3(CH2) n ; n = 0-20;

[0018] Among them, R1 is an electron-withdrawing group, including fluorine, chlorine, bromine, cyano, nitro, carboxylic acid, sulfonic acid, carboxylate, sulfonate, amide, and a group connected by an amide bond.

[0019] The specific structures of the branched linker compounds include those shown in the following formulas (1-1) and (1-2):

[0020] The linking site T of formula (1-1) is linked by an amide bond:

[0021]

[0022] Wherein, TR is selected from single amino acids, dipeptides, and tetrapeptides in tissue protease substrates and metalloprotease substrates; wherein single amino acids are selected from single amino acids without protection or with protection groups, PEG chains, polyamino acid chains, and maleimide-modified single amino acids, including -Lys-, -Cit-, -Arg-, -Leu-, -His-, -Asp-, -Glu-, -Ala-, -Val-, -Ile-, -Pro-, -Phe-, -Trp-, -Met-, -Ser-, -Cys- or -Asn-, etc.; dipeptides are selected from single amino acids without protection or with protection groups, PEG chains, polyamino acid chains, and single amino acids modified with maleimide, including -Lys-, -Cit-, -Arg-, -Leu-, -His-, -Asp-, -Glu-, -Ala-, -Val-, -Ile-, -Pro-, -Phe-, -Trp-, -Met-, -Ser-, -Cys- or -Asn-, etc. A dipeptide modified with a protecting group, a PEG chain, a polyamino acid chain, and maleimide includes -Phe-Lys-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Ile-Cit, -Trp-Cit-, -Phe-Gly-, -Ala-Ala- or -Phe-Arg-, etc.; a tetrapeptide selected from a tetrapeptide without protection or with a protecting group, a PEG chain, a polyamino acid chain, and maleimide modification includes -Gly-Gly-Phe-Gly-.

[0023] The connection point T of formula (1-2) is connected by an ether bond or an ester bond:

[0024]

[0025] Among them, TR includes β-glucoside, β-galactoside, phosphate, sulfate, and pyrophosphate.

[0026] Wherein, A represents the attachment site for ligating LR;

[0027] The LR is selected from H, CH3(CH2) n, nitro, methoxy, PEG chain, maleimide-modified PEG, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, fatty chain, polyamino acid chain, sugar chain, fatty acid, sugar, folic acid, polypeptide or antibody;

[0028] When the connection point A is preferably an amide bond, the structure of the branched linker compound is shown in the following formula (1-5):

[0029]

[0030] Among them, LLR is a linker modification fragment, including one or more of PEG, sugar, alkyl chain, maleimide-modified PEG, modified alkyl chain, and fatty acid.

[0031] The group connected to the connection point T is preferably β-glucoside, β-galactoside, phosphate, sulfate, pyrophosphate;

[0032] When the group connected to the connection point A is preferably H, the structure of the branched linker compound is shown in the following formula (1-6):

[0033]

[0034] T is selected from a single amino acid, a dipeptide, or a tetrapeptide selected from a cathepsin substrate or a metalloprotease substrate;

[0035] The single amino acid is selected from single amino acids without protection or with protection groups, PEG chains, polyamino acid chains and maleimide-modified single amino acids, including -Lys-, -Cit-, -Arg-, -Leu-, -His-, -Asp-, -Glu-, -Ala-, -Val-, -Ile-, -Pro-, -Phe-, -Trp-, -Met-, -Ser-, -Cys- or -Asn-; the dipeptide is selected from single amino acids without protection or with protection groups, PEG chains, polyamino acid chains and maleimide-modified Imidyl-modified dipeptides include -Phe-Lys-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Ile-Cit, -Trp-Cit-, -Phe-Gly-, -Ala-Ala- or -Phe-Arg-, etc.; tetrapeptides are selected from tetrapeptides without protection or with protecting groups, PEG chains, polyamino acid chains and maleimide-modified tetrapeptides, including -Gly-Gly-Phe-Gly-.

[0036] When the R1 is a nitro group, the structure of the branched linker compound is as shown in the following formula (J):

[0037]

[0038] When the R1 is an amide bond-connected group, the branched linker compound further includes a connection site L1, and the structure of the branched linker compound is shown in the following formula (L):

[0039]

[0040] The group connected to the connection point T is selected from: cathepsin substrate amino acid or short peptide chain; β-glucuronidase substrate; galactosidase substrate; metalloprotease substrate; aromatic boronic acid or boric acid ester that can be oxidized to hydroxyl; nitro, azide, azo and other groups that can be reduced to amino groups; hydroxyl phosphate; hydroxyl sulfate, etc.

[0041] The group connected to the linking site A is a linking group LR used to adjust the physical and chemical properties of the compound or to connect antibodies, peptides, albumin, etc.; LR is selected from: H, a fat chain, a PEG chain, a polyamino acid chain, a sugar chain, and a maleimide-modified PEG chain, a maleimide-modified fat chain, a maleimide-modified polyamino acid chain, a maleimide-modified sugar chain, etc.;

[0042] D is a pharmaceutically active drug, wherein the active drug D has exposed -OH, -NH2, -NHR, -SH, including but not limited to anti-tumor drugs, anti-inflammatory drugs, anti-aging drugs and drugs for treating fibrosis, etc.;

[0043] X represents the connection site in the active drug D; it is O, N or S;

[0044] Wherein, R2 is H or CH3(CH2) n ; n = 0-20;

[0045] R3 is selected from H, C1-C6 alkyl or cycloalkyl;

[0046] L1 is selected from H, an amino protecting group, a C1-C6 alkyl or cycloalkyl group, a fatty chain, a linear or branched PEG chain, a sugar chain, a polyamino acid chain, a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, a maleimide-modified sugar chain;

[0047] R3 and L1 can be optionally linked together to form 3 to 6 rings, and the rings formed by R3 and L1 can be selected from

[0048] R4 is selected from one or more of H, C1-C6 alkyl or cycloalkyl;

[0049] L2 is selected from H, an amino protecting group, a C1-C6 alkyl or cycloalkyl group, a fatty chain, a linear or branched PEG chain, a sugar chain, a polyamino acid chain, a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, a maleimide-modified sugar chain;

[0050] The branched linker compound (L) includes (L-5) and (L-6), which are respectively shown in the following formulas:

[0051]

[0052] in,

[0053] In formula (L-5), AA represents an amino acid, m represents the number of amino acids, and m is selected from 1-6; L3 is selected from H, an amino protecting group, a fatty chain, a PEG chain, a polyamino acid chain, a sugar chain, and one or more of a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; R6 and R7 are selected from H or a C1-C6 alkyl or cycloalkyl group or independently, L1 is selected from a C1-C6 alkyl or cycloalkyl group, or R6 and L1 can form a cycloalkyl group; L2 is selected from H, an amino protecting group, a fatty chain, a PEG chain, One or more of a polyamino acid chain, a sugar chain, a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; L2 and L3 are selected together or independently from H, an amino protecting group, a fatty chain, a PEG chain, a polyamino acid chain, a sugar chain, and one or more of a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; L2 and L3 are not simultaneously selected from a maleimide-modified PEG chain, a fatty chain, a polyamino acid chain, and a sugar chain;

[0054] In formula (L-6), T is selected from one or more of β-glucoside, β-galactoside, phosphate, pyrophosphate or sulfate; L4 is selected from hydrogen, C1-C6 alkyl or cycloalkyl, nitro, amino, methoxy, carboxyl, ester, fatty chain, linear or branched PEG chain, sugar chain, polyamino acid chain R 10Selected from hydrogen, C1-C3 alkyl or cycloalkyl; L5 is selected from hydrogen, amino protecting group, C1-C6 alkyl or cycloalkyl, fatty chain, linear or branched PEG chain, sugar chain, polyamino acid chain, maleimide-modified PEG chain, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, maleimide-modified sugar chain; R6 and R7 are selected from H or C1-C6 alkyl or cycloalkyl together or independently, L1 is selected from C1-C6 alkyl or cycloalkyl, or R6 and L1 can form a cycloalkyl; L2 is selected from H, amino protecting group, fatty chain, PEG chain, polyamino acid chain, sugar chain, and one or more of maleimide-modified PEG chain, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, and maleimide-modified sugar chain.

[0055] The present invention also provides an albumin or antibody covalently bound prodrug and a pharmaceutically acceptable salt, solvate, polymorph or isomer thereof, the structure of which is as shown in the compound formula (L) and formula (J);

[0056] The compounds of formula (L) and formula (J) include the following formulas (L1) to (L6), formula (J1) and formula (J4):

[0057]

[0058] Wherein, in the above formula (L1) to formula (L6), formula (J1) and formula (J4), n, o, and m represent the number of repeating units, n is selected from 1-24; o is selected from 2-6; and m is selected from 0-12;

[0059] In formula (L1) to formula (L4), L' is selected from: One or more of;

[0060] In formula (L2), R' is selected from hydrogen, acetyl, amino protecting groups including Boc, Cbz, Fmoc, Alloc, and PEG chains, polyamino acid chains, sugar chains, and fatty chains; in formula (L4), R" is selected from hydrogen, nitro, and methoxy;

[0061] D1 represents camptothecin or other hydroxyl-containing drugs, including:

[0062]

[0063] The present invention also provides albumin or antibody covalently bound prodrugs of Formula L and Formula J and pharmaceutically acceptable salts, solvates, polymorphs or isomers thereof. Formula (L1) to Formula (L6) and Formula (J1) and Formula (J4) include the following formulas (J1-1), (J4-1), (L4-1), (L7-1), (L1-1), (L7-2), (L7-3), (L7-4):

[0064]

[0065]

[0066]

[0067] The present invention also provides a method for preparing a branched linker of formula (L), wherein the preparation reaction process of the method is shown in the following formula:

[0068]

[0069] The reaction steps include:

[0070] a) Substitution reaction: Under alkaline conditions, compound 1 and a conventional hydroxyl protecting group (P) such as benzyl bromide, p-methoxybenzyl bromide MOMCl, etc. undergo a nucleophilic substitution reaction, the base is potassium carbonate, cesium carbonate, sodium carbonate, etc., and the solvent is acetone, acetonitrile or NN-dimethylformamide, etc.

[0071] b) Reduction reaction: Compound 2 is reduced by zinc powder / acid or iron powder / acid system to obtain compound 3, and the solvent is a conventional organic solvent / acid.

[0072] c) Condensation reaction: under nitrogen conditions, compound 3 reacts with formic acid and acetic anhydride to generate compound 4; d) Reduction reaction: under nitrogen conditions, compound 4 is dissolved in a solvent with borane dimethyl sulfide and undergoes a reduction reaction to generate compound 5;

[0073] e) Substitution reaction: Under alkaline conditions, compound 5 and BOC anhydride undergo substitution reaction to obtain compound 6, and the base is DIPEA, DMAP, etc.

[0074] f) Hydrolysis reaction: Under alkaline conditions, compound 6 undergoes hydrolysis reaction to obtain compound 7, and the base is LiOH, NaOH and KOH.

[0075] g) Condensation reaction: Compound 7 undergoes a condensation reaction with an amine condensation agent to generate compound 8. The condensation agent may be a commonly used condensation agent such as DCC, EEDQ, HATU, EDC / HOBt, PyBOP, etc.

[0076] h) Decomposition reaction: Compound 8 is subjected to a deprotection reaction such as Pd / C to generate compound 9, and the solvent is methanol or a mixed solvent of methanol, tetrahydrofuran and ethyl acetate.

[0077] i) Etherification reaction: Under nitrogen protection, benzyl bromide substrates with different triggers react with silver oxide or base to generate compound 10, and the solvent is anhydrous tetrahydrofuran, anhydrous dichloromethane or anhydrous acetonitrile.

[0078] j) Deprotection reaction: Compound 10 is deprotected from N-Boc under acidic conditions to obtain compound 11, the acid is hydrochloric acid, trifluoroacetic acid, etc., and the solvent is tetrahydrofuran or dichloromethane, etc.

[0079] k) Condensation reaction: Under nitrogen protection, compound 11 is dissolved in an organic solvent, and di(trichloromethyl) carbonate and anhydrous organic base such as triethylamine, DIPEA, pyridine, etc. are added. After reacting for 1 hour, drug (D) and DMAP are added, and the reaction is carried out at 20-60°C overnight to obtain compound 12. The drug (D) must have exposed -OH, -NH2, -NHR, -SH, and the solvent is anhydrous tetrahydrofuran or dichloromethane, etc.

[0080] In a specific implementation, the steps include:

[0081] a) Substitution reaction: Under alkaline conditions, compound 1 and a conventional hydroxyl protecting group (P) such as benzyl bromide, p-methoxybenzyl bromide MOMCl, etc. undergo a nucleophilic substitution reaction to generate compound 2, the base is potassium carbonate, cesium carbonate, sodium carbonate, etc., the solvent is acetone, acetonitrile or NN-dimethylformamide, etc., the reaction temperature is 20-80°C, wherein the molar ratio of compound 1 to the base is 1:1.5-2; the molar ratio of compound 1 to the protecting group is 1:1.5-2.

[0082] b) Reduction reaction: Compound 2 is reduced by zinc powder / acid or iron powder / acid system to obtain compound 3, the solvent is a conventional organic solvent / acid, the reaction temperature is 20-80°C, and the molar ratio of compound 2 to iron powder or zinc powder is 1:5.

[0083] c) Condensation reaction: under nitrogen, compound 3 reacts with formic acid and acetic anhydride to generate compound 4, the molar ratio of compound 3 to formic acid is 1:5-10, the molar ratio of compound 3 to acetic anhydride is 1:5-10, the reaction temperature is 0-80°C, the reaction time is 2-3 hours; the solvent is anhydrous tetrahydrofuran;

[0084] d) Reduction reaction: under nitrogen, compound 4 and borane dimethyl sulfide are dissolved in a solvent, and a reduction reaction occurs to generate compound 5, the molar ratio of compound 4 to borane dimethyl sulfide is 1:3, the reaction temperature is 0-5°C, and the reaction time is 2-3 hours; the solvent is anhydrous tetrahydrofuran;

[0085] e) Substitution reaction: Under alkaline conditions, compound 5 and BOC anhydride undergo substitution reaction to obtain compound 6, the base is DIPEA, DMAP, etc., the reaction temperature is 20-80°C, and the solvent is BOC anhydride.

[0086] f) Hydrolysis reaction: Under alkaline conditions, compound 6 undergoes hydrolysis reaction to obtain compound 7, the base is LiOH, NaOH and KOH, the molar ratio of compound 4 to borane dimethyl sulfide is 1:2-5, the reaction temperature is 0-30°C, and the solvent is tetrahydrofuran / methanol / acetonitrile / dioxane and water.

[0087] g) Condensation reaction: Compound 7 reacts with amine under the action of a condensing agent to generate compound 8. The condensing agent can be a commonly used condensing agent such as DCC, EEDQ, HATU, EDC / HOBt, PyBOP, etc. The molar ratio of compound 7 to amine is 1:1-2, and the molar ratio of compound 7 to condensing agent is 1:2-5. The reaction temperature is 0-30°C, and the solvent is a conventional organic solvent such as dichloromethane, NN-dimethylformamide, acetonitrile, etc.

[0088] h) Decomposition reaction: Compound 8 undergoes a deprotection reaction such as Pd / C to generate compound 9, the molar ratio of compound 7 to Pd / C is 1:0.1-0.2, the reaction temperature is 0-60°C, and the solvent is methanol or a mixed solvent of methanol and other organic solvents including tetrahydrofuran and / or ethyl acetate.

[0089] i) Etherification reaction: Under nitrogen protection, the benzyl bromide substrate of the same trigger is reacted with silver oxide or base to generate compound 10. Compound 9 can also react with the benzyl alcohol substrate of the trigger to generate compound 10 under the action of phosphorus reagent and azo. The molar ratio of compound 9 to different benzyl bromides or benzyl alcohols is 1:1-1.2, and the molar ratio of compound 9 to silver oxide / phosphorus reagent / azo is 1:1.2-2. The reaction temperature is 0-60°C, and the solvent is anhydrous tetrahydrofuran, anhydrous dichloromethane or anhydrous acetonitrile.

[0090] j) Deprotection reaction: Compound 10 is deprotected from N-Boc under acidic conditions to obtain compound 11, the acid is hydrochloric acid, trifluoroacetic acid, etc., the reaction temperature is 0-60°C, and the solvent is tetrahydrofuran / water or dichloromethane, etc.

[0091] l) Condensation reaction: under nitrogen protection, compound 11 is dissolved in an organic solvent, di(trichloromethyl) carbonate and anhydrous organic base are added, the molar ratio of compound 11 to di(trichloromethyl) carbonate is 1:0.5, the molar ratio of compound 11 to anhydrous organic base is 1:3-5, after reacting for 1 hour, drug (D) and DMAP are added, and the reaction is carried out at 20-60°C overnight to obtain compound 12, the molar ratio of compound 11 to drug (D) derivative is 1:1-1.2; the drug (D) must satisfy the requirements of having exposed -OH, -NH2, -NHR, -SH, and the solvent is anhydrous tetrahydrofuran or dichloromethane.

[0092] The present invention also provides a method for preparing a prodrug compound (J1) in which albumin or an antibody is covalently bound to a camptothecin derivative. The reaction process of the preparation method is shown in the following formula:

[0093]

[0094] The reaction steps include:

[0095] 1) Bromination reaction: Compound 1 is subjected to bromination reaction to obtain compound 2; the bromination reagent is phosphorus tribromide, triphenylphosphine and carbon tetrabromide, etc., and the solvent is anhydrous dichloromethane;

[0096] 2) Etherification reaction: Compound 2 is subjected to an etherification reaction to generate compound 3, wherein the organic solvent is anhydrous acetonitrile;

[0097] 3) Reduction reaction: Under nitrogen conditions, compound 3 and borane dimethyl sulfide are dissolved in a solvent to undergo a reduction reaction to generate compound 4, and the solvent is anhydrous tetrahydrofuran;

[0098] 4) Condensation reaction: under nitrogen protection, compound 4 is dissolved in an organic solvent, di(trichloromethyl) carbonate and triethylamine are added, reacted for 1 hour, hydroxyl-containing drugs are added, and reacted at room temperature overnight to obtain compound 5;

[0099] 5) Deprotection: Under nitrogen protection, compound 5 is dissolved in an organic solvent, and a 0.2M aqueous base solution is added under ice bath condition to deprotect to obtain compound 6, wherein the base is one or a mixture of lithium hydroxide, sodium hydroxide, and potassium hydroxide; the organic solvent is one or a mixture of methanol, acetonitrile, tetrahydrofuran and water;

[0100] 6) Condensation reaction: Compound 6 and compound 9 are dissolved in an organic solvent and stirred at room temperature for 6-8 hours to react to generate the prodrug having the general structure of formula (J1). The organic solvent is one or a mixture of methanol, acetonitrile, tetrahydrofuran, N,N-dimethylformamide and water.

[0101] In a specific implementation, the steps include:

[0102] 1) Bromination reaction: Compound 1, triphenylphosphine and carbon tetrabromide are dissolved in a solvent and reacted at room temperature overnight to obtain compound 2, wherein the molar ratio of compound 1 to triphenylphosphine is 1:3, and the molar ratio of compound 1 to carbon tetrabromide is 1:3; the solvent is anhydrous dichloromethane;

[0103] 2) Substitution reaction: Compound 2, N-(2-hydroxy-5-nitrophenyl)formamide and silver oxide react in an organic solvent to generate compound 3, the molar ratio of compound 2 to N-(2-hydroxy-5-nitrophenyl)formamide is 1:1, the molar ratio of compound 2 to silver oxide is 1:1.4, and the reaction time is 12-14 hours; the organic solvent is anhydrous acetonitrile;

[0104] 3) Reduction reaction: under nitrogen, compound 3 and borane dimethyl sulfide are dissolved in a solvent, and a reduction reaction occurs to generate compound 4, the molar ratio of compound 3 to borane dimethyl sulfide is 1:3, the reaction temperature is 0-5°C, and the reaction time is 2-3 hours; the solvent is anhydrous tetrahydrofuran;

[0105] 4) Condensation reaction: under nitrogen protection, compound 4 is dissolved in an organic solvent, di(trichloromethyl) carbonate and triethylamine are added, the molar ratio of compound 4 to di(trichloromethyl) carbonate is 1:0.5, the molar ratio of compound 4 to triethylamine is 1:4, after reacting for 1 hour, a camptothecin derivative is added, and the reaction is carried out at room temperature overnight to obtain compound 5, the molar ratio of compound 4 to the camptothecin derivative is 1:1; the camptothecin derivative is SN38;

[0106] 5) Deprotection: Under nitrogen protection, compound 5 is dissolved in an organic solvent, and a 0.2M aqueous alkali solution is added under ice bath conditions to deprotect to obtain compound 6. The reaction time is 0.2-1 hour, and the molar ratio of compound 5 to the alkali is 1:8; the alkali is one or a mixture of lithium hydroxide, sodium hydroxide, and potassium hydroxide; the organic solvent is one or a mixture of methanol, acetonitrile, tetrahydrofuran and water;

[0107] 6) Condensation reaction: Compound 6 and Compound 9 are dissolved in an organic solvent and stirred at room temperature for 6-8 hours to react to generate the prodrug having the general formula (J-1), wherein the molar ratio of Compound 6 to Compound 9 is 1:1; the organic solvent is one or a mixture of methanol, acetonitrile, tetrahydrofuran, N,N-dimethylformamide and water.

[0108] Another object of the present invention is to provide a possible drug release mechanism under different conditions by connecting a ligand, an initiator and a drug to a branched linker to form a targeted drug linker.

[0109]

[0110] The linker hydrolyzes the peptide bond into amino groups by tissue proteases, or hydrolyzes the glycosidic bond into hydroxy groups by β-glucuronidase or galactosidase; then 1.6 self-cleavage occurs and the corresponding active drug is released through a self-closing process.

[0111] The present invention also provides a medicine and a pharmaceutical composition, which include the branched linker compound and / or the albumin covalently bound camptothecin derivative prodrug and pharmaceutically acceptable salts, solvates, polymorphs or isomers thereof and pharmaceutically acceptable carriers.

[0112] The present invention also proposes an application, wherein the branched linker compound (1) includes but is not limited to compounds of formula (J1-1), formula (J4-1), formula (L4-1), formula (L7-1), formula (L1-1), formula (L7-2), formula (L7-3), (formula L7-4), etc., and / or the albumin covalently bound camptothecin derivative prodrug and its pharmaceutically acceptable salt, solvate, polymorph or isomer, and the drug and / or pharmaceutical composition containing the aforementioned compound, in the preparation of anti-tumor drugs, in the preparation of albumin-bound anti-tumor drugs; and also includes the application in the preparation of albumin-bound β-glucuronidase prodrug for tumor treatment, antibody-drug conjugated tumor treatment.

[0113] The advantages and beneficial effects of the present invention include but are not limited to: the novel cleavable branched linker formula (I) proposed by the present invention can be used for prodrugs, the linker has multiple sites that can be independently modified, and different triggers, modified side chains, and / or active drugs are combined together to form a new compound. The active drug is made more stable, less toxic, and has increased targeting while still maintaining activity. The present invention provides albumin-bound camptothecin derivative prodrugs that can be cleaved by β-glucuronidase to trigger the self-cleavage of the branched linker, and the preparation method and application thereof.

[0114] In a specific embodiment, it has been experimentally proved that the compound formula (J) composed of the present linker, including but not limited to formula (J1-1) and formula (J4-1), has excellent in vitro and in vivo stability and can quickly release active drugs under conditions simulating tumor microenvironment. After binding to albumin, the in vivo metabolism time is effectively improved. Among them, compound (J1-1) significantly prolonged the survival period of mice and inhibited tumor growth in the anti-tumor experiment of HCT116 xenograft tumor mouse model. It shows that the new branched linker and the compound constructed based on it can achieve the purpose of rapid drug release at the tumor site, improve the drugability of the drug, and increase the anti-cancer effect of the drug.

[0115] The present invention innovatively proposes a new cleavable linker compound that can be used in a prodrug drug delivery system, wherein the trigger fragment is connected to the new linker through a para-hydroxyl group or a para-amino group, the active drug is connected to the new linker through its own hydroxyl group, and the modified fragment is connected to the new linker through an amino group. According to its abundant modification sites, different modification methods are selected to adapt to different drug delivery needs, so as to achieve the purpose of improving targeting, reducing the toxicity of active drugs, and improving drugability. After administration of the present invention, the trigger fragment is released at a specific target point in the body, the modified fragment is stably circulated for a long time in the body, and the active drug part provides a therapeutic effect, ultimately achieving accumulation and directional drug release at the target site, reducing the toxic and side effects of the active drug, and improving the drugability of the drug. BRIEF DESCRIPTION OF THE DRAWINGS

[0116] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0117] Figure 1 : is the hydrogen spectrum of the prodrug compound (J1-1) of the example of the present invention.

[0118] Figure 2 This is a time-mouse tumor volume change curve in an in vivo tumor inhibition experiment of the prodrug compound (J1-1) of an example of the present invention.

[0119] Figure 3 It is a prodrug compound (J1-1) of the present invention, and inhibits cell growth in the presence of β-glucuronidase.

[0120] Figure 4 It is the drug release rate of the prodrug compound (J1-1) of the present invention under the action of β-glucuronidase.

[0121] Figure 5 The stability of the prodrug compound (J1-1) of the present invention in PBS and mouse plasma.

[0122] Figure 6 This is a graph showing the results of coupling L4-1 of Example 1 of the present invention with the OMTX monoclonal antibody targeting the FAP target.

[0123] Figure 7 This is a graph showing the results of Example L4-1 of the present invention coupled with 7B7 monoclonal antibody targeting B7-H3. DETAILED DESCRIPTION

[0124] The invention is further described in detail with reference to the following specific embodiments and drawings. The process, conditions, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art and are not particularly limited by the present invention.

[0125] Example 1 Synthesis of Compound (J1-1)

[0126] Synthesis of compound 2

[0127] Carbon tetrabromide (1.77 g, 5.36 mmol) was weighed in a three-necked flask, nitrogen was replaced, 20 mL of anhydrous dichloromethane was injected, and a solution of triphenylphosphine (1.4 g, 5.36 mmol) in anhydrous dichloromethane was added dropwise under ice bath. After stirring for 30 min, a solution of compound 1 (1 g, 1.34 mmol) in anhydrous dichloromethane was added dropwise, and the reaction was allowed to proceed overnight at room temperature. TLC detected that the reaction was complete, and the product was concentrated under reduced pressure to obtain a yellow oily liquid. Column chromatography purification (dichloromethane: methanol = 100: 1) was performed to obtain 750 mg of a light yellow fluffy solid with a yield of 83.9%. 1H NMR (400MHz, CDCl3) δ8.45(d,J=20.7Hz,1H),8.03(d,J=21.8Hz,1H),7.73(dd,J=21.2,7.0Hz,2H) ,7.57(d,J=13.9Hz,2H),7.41–7.28(m,3H),7.21(s,2H),7.06(dd,J=21.1,8.2Hz,1H),6.89(dd,J= 21.4,8.3Hz,1H),5.60(s,1H),5.41–5.21(m,3H),5.03(dd,J=21.1,6.9Hz,1H),4.44(d,J=21.7Hz ,2H),4.39–4.16(m,3H),3.71(d,J=21.5Hz,3H),3.55(s,2H),2.68(s,2H),2.02(d,J=18.8Hz,9H).

[0128] Synthesis of compound 3

[0129] Silver oxide (300 mg, 1.29 mmol), 2-hydroxy-5-nitroformamide benzene (186 mg, 1.02 mmol), and compound 2 (750 mg, 0.92 mmol) were weighed in a three-necked flask, nitrogen was replaced, 10 mL of anhydrous dichloromethane was injected, and the reaction was allowed to proceed overnight at room temperature. TLC detected that the reaction was complete, diatomaceous earth was filtered, the filtrate was collected, and the crude product was concentrated under reduced pressure. Column chromatography was performed for purification (dichloromethane: methanol = 100: 1 to 50: 1) to obtain 500 mg of a white fluffy solid with a yield of 52.2%. 1H NMR (400MHz, CDCl3) δ9.27(d,J=17.6Hz,1H),8.47(t,J=21.4Hz,2H),8.12(d,J=19.8Hz,1 H),8.02–7.91(m,2H),7.52(s,3H),7.45(s,3H),7.34(d,J=11.2Hz,1H),7.22(s,2H),7.06 –6.88(m,3H),5.43–5.35(m,1H),5.29(d,J=7.9Hz,2H),5.12(d,J=20.3Hz,3H),4.34(s,2 H), 4.17 (s, 2H), 3.71 (d, J = 14.6Hz, 3H), 3.56 (s, 2H), 2.70 (s, 2H), 2.03 (d, J = 17.1Hz, 9H).

[0130] Synthesis of compound 4

[0131] Under strict nitrogen protection, compound 3 (500 mg, 0.55 mmol) was weighed in a three-necked flask, nitrogen was replaced, 10 mL of anhydrous tetrahydrofuran was injected, and borane dimethyl sulfide (0.875 mL, 1.64 mmol) was slowly added dropwise under ice-salt bath, and reacted at room temperature for three hours. TLC detected that the reaction was complete, and the mixture was concentrated under reduced pressure to obtain 420 mg of a yellow solid with a yield of 85.4%.

[0132] Synthesis of compound 5

[0133] Compound 4 (100 mg, 0.11 mmol) and triphosgene (12.56 mg, 0.04 mmol) were weighed in a three-necked flask, nitrogen was replaced, 10 mL of anhydrous tetrahydrofuran was injected, DIEA (51.7 mg, 0.42 mmol) was slowly added dropwise under an ice bath, and the mixture was reacted at room temperature for one hour. SN38 (48 mg, 0.12 mmol) was added to the reaction system and stirred at 40°C overnight. The reaction was monitored by TLC. 10 mL of dichloromethane was added, the mixture was washed twice with 1M dilute hydrochloric acid and once with saturated sodium chloride solution, the organic phase was dried over anhydrous sodium sulfate, and the crude product was concentrated under reduced pressure. Column chromatography purification (dichloromethane: methanol = 100: 1 to 50: 1) gave 118 mg of a yellow solid, with a two-step yield of 81.0%.1HNMR(400MHz, CDCl3)δ8.56(s,1H),8.33(s,1H),8.28–8.22(m,1H),8.19–8.06(m,2H),7.84(s,1H),7.64(t,J=22.0Hz,5H),7.4 7(d,J=6.8Hz,2H),7.30(d,J=8.0Hz,2H),7.21–7.06(m,4H),7.01(s,1H),5.97(s,1H),5.73(d,J=16.2Hz,1H),5.50–5.36(m,1H), 5.35–5.26(m,4H),5.22(d,J=14.3Hz,3H),5.14(d,J=7.0Hz,3H),4.33–4.18(m,3H),3.61(s,2H),3.40(s,3H),3.15(dd,J=15.2,7 .5Hz,1H),2.97(s,2H),2.75(s,2H),2.06(s,9H),1.86(dd,J=14.0,7.0Hz,2H),1.40(t,J=7.7Hz,3H),1.01(dd,J=15.6,7.5Hz,3H ).13CNMR(101MHz, CDCl3)δ173.89,173.80,170.47,170.44,169.82,169.45,166.70,159.20,157.63,157.51,156.50,150.19,1 46.93,146.84,146.56,143.88,141.45,141.11,131.86,131.61,129.51,127.53,127.37,127.30,127.19,126.94,125.06,124.9 8,119.74,118.62,114.36,114.16,112.63,112.61,98.16,98.14,72.87,72.44,71.25,71.01,70.84,69.17,66.64,66.30,66.25,53.48,53.25,49.43,49.33,47.06,37.90,37.08,36.96,31.59,31.50,23.18,23.03,20.85,20.58,20.49,14.00,13.93,7.86.

[0134] Synthesis of compound 6

[0135] Under ice bath, compound 5 (118 mg, 0.09 mmol) was weighed in a bottle, 1 mL of water and 1 mL of acetonitrile were added, and 0.5 mL of 1M lithium hydroxide aqueous solution was slowly added dropwise. The reaction was allowed to react at room temperature for one hour, and the reaction was completed after LC-MS monitoring. The mixture was concentrated under reduced pressure to obtain 66 mg of a yellow solid, with a yield of 92.1%.

[0136] Synthesis of compound (J1-1)

[0137] Compound 6 (66 mg, 0.07 mmol) and 6-(maleimido)hexanoic acid succinimidyl ester (53 mg, 0.17 mmol) were weighed in a bottle, 2 mL of acetonitrile and 1 mL of methanol were added, and the pH of the system was adjusted to 8 with DIEA. The reaction was allowed to react at room temperature for five hours. The reaction was monitored by LC-MS and concentrated under reduced pressure. The product was purified by reverse phase column chromatography (0.1% trifluoroacetic acid aqueous solution: acetonitrile = 15:1 to 30:1), concentrated under reduced pressure, and freeze-dried to obtain 45 mg of a yellow-white solid with a yield of 59.2%. 1H NMR (400MHz, DMSO) δ12.81(s,1H),9.12(s,1H),8.53(s,1H),8.34(s,1H),8.28(s,1H),8.12(d,J=8.6Hz,1H),7.87(s, 1H),7.80(s,1H),7.49(s,2H),7.32(s,1H),7.22(d,J=7.6Hz,1H),7.15(d,J=7.2Hz,1H),6.98(s,1H),6.53(s,1H),5.8 7(s,1H),5.44(s,2H),5.36(d,J=31.7Hz,4H),4.93(d,J=6.1Hz,1H),3.93(d,J=9.1Hz,1H),3.42(d,J=7.3Hz,10H),3. 30(s,3H),3.06(s,2H),2.00(d,J=5.0Hz,2H),1.93–1.80(m,2H),1.44(d,J=6.6Hz,4H),1.22(d,J=9.0Hz,3H),1.15(d, J=7.3Hz,2H),0.88(s,3H).13CNMR(101MHz,DMSO)δ172.96,172.59,171.53,170.50,170.14,159.64,157.28,153.73, 152.28,150.50,150.13,146.79,146.54,146.39,145.76,145.68,141.14,134.89,131.86,131.61,130.40,129.35,12 8.99,127.42,127.36,125.18,123.41,120.90,119.41,116.70,115.35,114.37,102.04,97.09,75.93,75.44,73.33,72.86,71.81,71.11,65.74,50.03,37.88,37.40,36.98,35.56,35.46,30.74,28.22,26.25,25.19,22.57,14.24,8.25.

[0138] The relevant spectrum of compound J1-1 is attached Figure 1 .

[0139] Example 2 Stability Test

[0140] A PBS solution (1 mM, pH 7.4) of compound (J1-1) was incubated at 37° C. Corresponding samples (n=3) were taken on day 1, day 2, day 3, day 5, and day 7, and the contents of (J1-1) and SN38 were detected by HPLC.

[0141] Mouse plasma stability: 40 μL (J1-1) of PBS solution (1 mM, pH 7.4) and 360 μL of mouse plasma were incubated in a shaker at 37°C. Corresponding samples (n=3) were taken on days 1, 2, 3, 5, and 7, precipitated with cold acetonitrile, centrifuged at 4°C for 30 minutes, and the supernatant was taken to detect the content of SN38 by HPLC.

[0142] The experimental results are shown in Figure 5 The results showed that within seven days, the compound (J1-1) released less than 2% of SN38 in mouse plasma containing PBS at pH 7.4, indicating that the compound (J1-1) had excellent stability.

[0143] Example 3 Enzyme release experiment

[0144] The compound (J1-1) solution (100 μM, pH 7.4 or pH 5.5) was mixed with β-glucuronidase (300 U) and incubated in a shaker at 37° C. Corresponding samples (n=3) were taken at 1 min, 2 min, 5 min, 10 min, 20 min, 45 min, 60 min, and 90 min, precipitated with cold acetonitrile, centrifuged at 4° C. for 15 min, and the supernatant was taken to detect the content of SN38 by HPLC.

[0145] The experimental results are shown in Figure 4 The results showed that within 45 minutes, SN38 could be 100% released under the triggering of β-glucuronidase at pH 7.4 or pH 5.5, indicating that compound (J1-1) can release the drug rapidly and convert the prodrug into SN38 with antitumor activity.

[0146] Example 4 In vitro drug cytotoxicity experiment

[0147] The MTT method was used to determine the in vitro cytotoxicity of compound (J1-1) on HCT116, A549, MCF-7, HepG2, 4T1 cells, and in the presence of β-glucuronidase. 200 μL of culture medium containing 4000 cells was spread in the wells of a 96-well plate. After 24 hours of adherence in an incubator (37°C, 5% CO2), the culture medium was aspirated, and 200 μL of drug solution containing different concentrations or added with β-glucuronidase was added, and cultured in an incubator for 72 hours. The culture medium in the plate was aspirated, 100 μL of MTT solution (0.5 mg / mL) was added, and after being placed in the incubator for 3 hours, 100 μL of the triple solution was added to each well and placed in the incubator for 12 hours. The absorbance (OD) at 570 nm was measured using an enzyme reader. The cell viability was calculated according to the following formula:

[0148]

[0149] OD sample is the absorbance value of the drug-treated group, OD blank OD is the absorbance value of complete culture medium only. control is the absorbance value of the inoculated cells without drug.

[0150] The experimental results are shown in Figure 3 The results showed that at the cellular level, compound (J1-1) has low toxicity and can release active drugs under the triggering of β-glucuronidase to kill tumor cells.

[0151] Example 5 Antitumor Effect on HCT116 Xenograft Tumor Nude Mice

[0152] Female BALB / c nude mice (4 weeks old) were selected and, after three days of adaptation to the barrier center, HCT116 cells (5×10 6 ) was subcutaneously inoculated into the right flank of nude mice. When the tumor grew to 80-100 mm 3 Afterwards, the tumor-bearing nude mice were randomly divided into four groups, with six mice in each group. Physiological saline (blank group), 30 mg / kg of (J1-1), and 60 mg / kg of compound (J1-1) (supplementary treatment group) were injected into the tail vein twice a week for a total of five times, and the body weight and tumor volume of the nude mice were observed and recorded.

[0153] The experimental results are shown in Figure 2 The results showed that compound (J1-1) exhibited excellent therapeutic effects in the HCT116 cell xenograft tumor model. After five doses, the tumor volume was significantly reduced or even disappeared, indicating that compound (J1-1) has the ability to promote the growth of transplanted tumors.

[0154] Example 6 Synthesis of Compound (L1-1)

[0155] Intermediate A1 was synthesized by route 1

[0156]

[0157] To a solution of methyl 3-nitro-4-hydroxybenzoate (20 g, 100 mmol) in N,N-dimethylformamide (100 ml) were added potassium carbonate (27.6 g, 200 mmol) and benzyl bromide (17.8 ml, 150 mmol) in sequence. After stirring at 60 degrees Celsius for 6 hours, the mixture was poured into a mixed solvent of 400 ml of water and 150 ml of ethyl acetate. The organic phase was washed with water (50 ml x 2) and saturated brine (50 ml), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was washed with petroleum ether and purified to obtain the target product A1-1 (27.5 g, yield 96%). MS: 288 (M+H) + . 1HNMR (400MHz, CDCl3) δ8.52(d,J=2.0Hz,1H),8.18(dd,J=8.8,2.0Hz,1H),7.58–7.30(m,5H),7.18(d,J=8.8Hz,1H),5.31(s,2H),3.94(s,3H).

[0158] Add active zinc powder (31.2 g, 480 mol) to a solution of A1-1 (27.5 g, 96 mmol) in a mixed solvent of acetic acid and tetrahydrofuran (80 / 80 ml), stir at 70 degrees Celsius for 2 hours, filter, slowly pour the filtrate into a saturated sodium bicarbonate aqueous solution to precipitate solids, filter, and dry the filter cake to obtain the target product A1-2 (21.9 g, yield 89%). MS: 258 (M+H) + . 1H NMR (400MHz, CDCl3) δ7.49–7.33 (m, 7H), 6.87 (d, J = 8.3Hz, 1H), 5.14 (s, 2H), 3.86 (s, 3H).

[0159] 40 ml of formic acid and 100 ml of acetic anhydride were stirred at 70 degrees Celsius for 2 hours and then cooled to room temperature. A1-2 (21.9 g, 85 mmol) in tetrahydrofuran solution (150 ml) was slowly added to the above reaction system. After stirring at room temperature for 2 hours, most of the solvent was distilled off under reduced pressure. The remaining solution was slowly poured into a saturated sodium bicarbonate aqueous solution to precipitate a white solid, which was filtered and dried to obtain the target product A1-3 (21 g, yield 87%). MS: 286 (M+H) +. 1HNMR (400MHz, CDCl3) δ9.89 (S, J=7.8Hz, 2H), δ7.54 (d, J=7.8Hz, 2H), 7.42 (d, J= 8.3Hz,1H), δ7.44-7.24(m,5H),7.08(d,J=8.4Hz,1H),5.08(s,2H),3.88(s,3H).

[0160] Under nitrogen protection at 0 degrees Celsius, 2M borane dimethyl sulfide was slowly added dropwise to a solution of A1-3 (21 g, 74 mmol) in anhydrous tetrahydrofuran (150 ml) to obtain a tetrahydrofuran solution (74 ml, 148 mmol). After stirring at 0 degrees Celsius for 4 hours, the reaction was quenched with cold methanol. Most of the solvent was removed by distillation under reduced pressure. The remaining solution was slowly poured into a saturated sodium bicarbonate aqueous solution to precipitate a white solid, which was filtered and dried to obtain the target product A1-4 (16.4 g, yield 82%). MS: 272 (M+H) + . 1H NMR (400MHz, CDCl3) δ7.49–7.33(m,7H),6.87(d,J=8.3Hz,1H),5.14(s,2H),3.86(s,3H),2.91(s,3H).

[0161] To a solution of A1-4 (16.4 g, 60.7 mmol) in tetrahydrofuran / methanol / water (30 / 30 / 10 ml) was added sodium hydroxide (4.8 g, 120 mmol) and stirred for 4 hours under hydrogen atmosphere at room temperature. 1M hydrochloric acid was used to adjust the pH to 3-4 to precipitate a white solid, which was filtered and the filter cake was dried to obtain the target product A1-7 (13.8 g, yield 89%). MS: 258 (M+H) + . .MS:372(M+H)+. 1HNMR (400MHz, CDCl3) δ7.51–7.33 (m, 7H), 6.88 (d, J = 8.3Hz, 1H), 5.13 (s, 2H), 2.90 (s, 3H).

[0162] To a solution of A1-5 (13.8 g, 53.4 mmol) in tert-butanol (50 ml) was added Boc anhydride (58 g, 270 mmol), DMAP (1.2 g, 10 mmol) and DIPEA (4.7 ml, 270 mmol) and stirred at 60°C for 48 hours, poured into a saturated aqueous ammonium chloride solution, extracted with EA, dried over anhydrous magnesium sulfate, filtered, and the filtrate was collected and dried by column chromatography to obtain the target product A1-6 (16.3 g, yield 74%). MS: 414 (M+H) +. MS:372(M+H)+. 1H NMR (400MHz, CDCl3) δ7.51–7.33 (m, 7H), 6.88 (d, J = 8.3Hz, 1H), 5.13 (s, 2H), 2.89 (s, 3H), 1.45 (s, 9H), 1.20 (s, 9H).

[0163] Palladium carbon (1.6 g) was added to a solution of A1-6 (16.3 g, 39 mmol) in methanol (100 ml) and stirred for 4 hours under hydrogen atmosphere at room temperature, filtered, and the filtrate was dried to obtain the target product A1-7 (12.6 g, yield 89%). MS: 324 (M+H) + .

[0164] A1-8 was synthesized according to the general method.

[0165] General method 1:

[0166] Add A1-7 (1 equivalent), benzylic bromide intermediates with different triggers (1 equivalent) and silver oxide (1.5 equivalents) to a dry two-necked flask, add anhydrous tetrahydrofuran or anhydrous acetonitrile solution under nitrogen and light-proof environment, stir at room temperature for 12-24 hours, filter, concentrate the filtrate, and purify the crude product by column chromatography.

[0167] A1-8 yield 78%, MS: 683 (M+H) + . 1H NMR(400MHz, CDCl3)δ8.99(s,1H),7.84–7.65(m,2H),7.62–7.41(m,3H),7.19(dd,J=25.8,11.3Hz ,2H),6.85(d,J=8.1Hz,1H),5.95–5.71(m,2H),5.25–5.15(m,2H),5.10(d,J=10.4Hz,1H),5.01(s ,2H),4.67(p,J=6.9Hz,1H),4.55–4.43(m,2H),4.13(t,J=7.3Hz,1H),3.05(s,3H),2.09–1.91(m, 1H), 1.47 (d, J = 22.7Hz, 9H), 1.36 (d, J = 6.9Hz, 4H), 1.20 (d, J = 13.9Hz, 9H), 0.86 (t, J = 5.7Hz, 6H).

[0168] Trifluoroacetic acid (2 ml) was added to a solution of A1-8 (1.3 g, 1.9 mmol) in dichloromethane (10 ml). After stirring at room temperature for 4 hours, dichloromethane and trifluoroacetic acid were removed by distillation under reduced pressure to obtain the target crude product A1-10 (0.92 g, yield 92%). MS: 527 (M+H) + .

[0169] To a solution of A1-9 (0.92 g, 1.75 mmol) in chloroform (10 ml) were added EDCI.HCl (668 mg, 3.5 mmol), Hobt (270 mg, 2 mmol) and N-Boc piperazine (651 mg, 3.5 mmol) and triethylamine (478 μl, 3.5 mmol). After stirring at room temperature for 6 hours, the mixture was poured into a saturated aqueous ammonium chloride solution and extracted with dichloromethane. The organic phase was collected, dried, filtered, concentrated, and column chromatographed to obtain the target product A1 (1.08 g, yield 89%). MS: 695 (M+H) + . 1H NMR (400MHz, CDCl3) δ8.69(s,1H),7.56(d,J=8.1Hz,2H),7.33(d,J=8.3Hz,2H),6.77(dd,J=13.0,7.8Hz ,2H),6.69–6.56(m,2H),5.99–5.82(m,1H),5.34(dd,J=18.5,7.7Hz,2H),5.22(d,J=10.2Hz,1H),5.01( s,2H),4.65(p,J=7.0Hz,1H),4.56(t,J=9.7Hz,2H),4.35(s,1H),4.04(t,J=6.6Hz,1H),3.76–3.31(m,9 H),2.83(s,3H),2.16(dq,J=13.3,6.7Hz,1H),1.71(s,6H),1.46(s,9H),0.94(dt,J=25.8,12.9Hz,6H).

[0170] Synthesis of intermediate A1-a1

[0171]

[0172] A1 (300 mg, 0.432 mmol) was added to a dry two-necked flask, dissolved in 10 ml of anhydrous dichloromethane, and anhydrous DIPEA (300 μL, 1.73 mmol) was added under nitrogen atmosphere. A dichloromethane solution (2 ml) of triphosgene (64 mg, 0.216 mmol) was added at 0°C. After stirring at room temperature for 1 hour, 2-(trimethylsilyl)ethyl 2-hydroxyacetate (176 mg, 1.29 mmol) and DMAP (157 mg, 1.29 mmol) were added. The mixture was stirred at 50°C for 16 hours, poured into a saturated aqueous ammonium chloride solution, extracted with dichloromethane, and the organic phase was collected, dried, filtered, concentrated, and column chromatography to obtain the target product A1 (279 mg, yield 72%). MS: 897 (M+H) +. 1H NMR(400MHz, CDCl3)δ8.92(s,1H),7.52(t,J=12.0Hz,2H),7.42–7.19(m,5H),6.96(d,J=8.4Hz ,1H),5.87(ddt,J=16.1,10.6,5.4Hz,1H),5.68(d,J=7.9Hz,1H),5.34–5.22(m,2H),5.17(d,J= 10.4Hz,1H),5.06(s,2H),4.73–4.48(m,4H),4.31–4.06(m,3H),3.70–3.35(m,7H),3.17(s,2H) ,2.28–2.04(m,2H),1.44(s,9H),1.38(d,J=6.8Hz,3H),0.95–0.83(m,6H),0.04–-0.02(m,9H).

[0173] Synthesis of intermediate A1-a2

[0174]

[0175] To a solution of A1-a1 (279 mg, 0.311 mmol) in tetrahydrofuran (15 ml) was added tetrabutylammonium fluoride (162 mg, 0.622 mmol). After stirring at room temperature for 8 hours, the mixture was poured into a saturated aqueous solution of ammonium chloride, extracted with EA, dried over anhydrous magnesium sulfate, filtered, and the filtrate was collected and dried to give the target product A1-a2 (220 mg, yield 89%). MS: 797 (M+H) + .

[0176] Synthesis of intermediate A1-a3

[0177]

[0178] A1-a2 (277 mg, 0.277 mmol), exitecan mesylate (153 mg, 0.277 mmol) and DIPEA (97 μL, 0.554 mmol) were dissolved in 15 ml of DMF, and a DMTMM (150 mg, 0.554 mmol) solution in DMF (2 ml) was added dropwise under ice bath. After stirring under ice bath for 4 hours, the mixture was poured into saturated aqueous ammonium chloride solution, extracted with EA, dried over anhydrous magnesium sulfate, filtered, and the filtrate was collected and dried by column chromatography to obtain the target product A1-a3 (238 mg, yield 71%). MS: 1213 (M+H) + .

[0179] Synthesis of intermediate A1-a4

[0180]

[0181] To a solution of A1-a3 (238 mg, 0.197 mmol) in DMF (10 ml) was added tetrakistriphenylphosphine palladium (23 mg) and piperidine (46 μl, 0.394 mmol) and stirred at room temperature under nitrogen for 12 hours, filtered, and the filtrate was collected and dried by column chromatography to obtain the target product A1-a4 (160 mg, yield 72%). MS: 1130 (M+H) + .

[0182] Synthesis of intermediate A1-a5

[0183]

[0184] To a solution of A1-a4 (160 mg, 0.142 mmol) in DMF (5 ml) were added 2-(2-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamide)ethoxy)ethoxy)acetic acid (50 mg, 0.142 mmol) and DIPEA (50 μl, 0.284 mmol), and a solution of DMTMM (78 mg, 0.284 mmol) in DMF (2 ml) was added dropwise at 0°C. After stirring for 12 hours, DMF was removed by distillation under reduced pressure. The crude product was separated and purified by C18 flash to obtain the target product A1-a5 (142 mg, yield 68%). MS: 1468 (M+H) + .

[0185] Synthesis of intermediate A1-a6

[0186]

[0187] Trifluoroacetic acid (2 ml) was added to a solution of A1-a5 (142 mg, 0.096 mmol) in dichloromethane (10 ml). After stirring at room temperature for 4 hours, dichloromethane and trifluoroacetic acid were removed by distillation under reduced pressure to obtain the target crude product A1-a6 (121 mg, yield 92%). MS: 1368 (M+H) + .

[0188] Synthesis of L1-1

[0189]

[0190] To a solution of A1-a6 (121 mg, 0.088 mmol) in DMF (5 ml) were added 2,5,8,11,14,17,20,23-octaoxadocosa-25-oic acid (35 mg, 0.088 mmol) and DIPEA (30 μl, 0.176 mmol), and a solution of DMTMM (49 mg, 0.176 mmol) in DMF (2 ml) was added dropwise at 0°C. After stirring for 12 hours, DMF was removed by distillation under reduced pressure. The crude product was separated and purified by HPLC to obtain the target product A1-a (62 mg, yield 68%). MS: 1748 (M+H) + .

[0191] Example 7 Synthesis of Compound (L4-1)

[0192] Intermediates C1 and D1 were synthesized using route 3

[0193] Route 3

[0194]

[0195] C1-1 and D1-1 were synthesized according to general method 1.

[0196] C1-1 yield 81%, MS: 791 (M+H) + .

[0197] D1-1 yield 79%, MS: 746 (M+H) + .

[0198] C1-2 and D1-2 were synthesized according to the synthesis method of A1-9, C1-1 yield 91%, MS: 691 (M+H) + . D1-1 yield 93%, MS: 646 (M+H) + .

[0199] The synthesis of C1 and D1 was based on the synthesis method of A1. The yield of C1 was 84%, MS: 805 (M+H) + . D1-1 yield 82%, MS: 760 (M+H) + .

[0200] Synthesis of intermediate C1-a1

[0201]

[0202] The synthesis of C1-a1 was prepared by referring to the synthesis method of A1-a1. The yield of C1-a1 was 74%, and MS was 1223 (M+H). + .

[0203] Synthesis of intermediate C1-a2

[0204]

[0205] To a solution of C1-a1 (1 equivalent) in tetrahydrofuran / methanol / water (3:3:1) was added 1M lithium hydroxide aqueous solution (5 equivalents) and stirred at room temperature for 4 hours. The target product C1-a2 was purified by C18 flash (yield 73%). MS: 1083 (M+H) + .

[0206] Synthesis of intermediate C1-a3

[0207]

[0208] The synthesis of C1-a3 was prepared by referring to the synthesis method of A1-a6. The yield of C1-a3 was 86%, MS: 1123 (M+H) + .

[0209] Synthesis of L4-1

[0210]

[0211] Anhydrous DIPEA (2 equivalents) and 2,5-dioxopyrrolidin-1-yl 31-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-28-oxo-3,6,9,12,15,18,21,24-octaoxa-27-azatridecanoate (1.2 equivalents) were added to a solution of C1-a3 (1 equivalent) in anhydrous DMF. After stirring at room temperature for 12 hours, the target product C1-a2 was purified by HPLC (yield 62%). MS: 1557 (M+H) + .

[0212] Example 8 Coupling of Compound L4-1 and Antibody

[0213] Compound L4-1 was coupled with FAP target antibody OMTX, and the results are shown in Figure 6 Compound L4-1 and FAP target antibody OMTX can be successfully coupled with a DAR value of 4.22.

[0214] Example 9 Coupling of Compound L4-1 and Antibody

[0215] Compound L4-1 was coupled with B7H3 target antibody 7b7. Figure 7 Compound L4-1 and B7H3 target antibody 7B7 can be successfully coupled with a DAR value of 3.69.

[0216] The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention and are protected by the attached claims.

Claims

1. A branched linker compound that can be used in a prodrug delivery system and a pharmaceutically acceptable salt, solvate, polymorph or isomer thereof, characterized in that: The structure of the branched linker compound is shown in formula (1): Wherein, T represents the attachment site for connecting R-TR; In the R-TR, TR is selected from one or more of a cathepsin substrate, a cathepsin substrate amino acid or short peptide chain, a β-glucuronidase substrate, a β-galactosidase substrate, a metalloprotease substrate, an aromatic boronic acid or boric acid ester that can be oxidized to a hydroxyl group, a nitro group, an azide group, an azo group that can be reduced to an amino group, a phosphate ester of a hydroxyl group, and a sulfate ester of a hydroxyl group; R is a substituent group selected from one or more of -H, PEG, maleimide-modified PEG, sugar, folic acid, polypeptides, antibodies, and protective groups; Wherein, A represents the attachment site for ligating LR; The LR is selected from H, CH3(CH2) n , nitro, methoxy, PEG chain, maleimide-modified PEG, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, fatty chain, polyamino acid chain, sugar chain, fatty acid, sugar, folic acid, polypeptide or antibody; Wherein, D represents the connection site for connecting DR; The DR contains naked -OH, -NH2, -NHR or -SH; the DR includes anti-tumor drugs camptothecin compounds and their derivatives SN-38, DXd, isitecan, belotecan, anti-tumor drugs paclitaxel, docetaxel, podophyllotoxin, CA4; Wherein, X is O, N or S; Wherein, R2 is H or CH3(CH2) n ; n = 0-20; Among them, R1 is an electron-withdrawing group, including fluorine, chlorine, bromine, cyano, nitro, carboxylic acid, sulfonic acid, carboxylate, sulfonate, amide, and a group connected by an amide bond.

2. The branched linker compound according to claim 1, characterized in that: When the connection site T is connected by an amide bond, the structure of the branched linker compound is as shown in the following formula (1-1): wherein TR is selected from a single amino acid, a dipeptide, or a tetrapeptide selected from a tissue protease substrate or a metalloprotease substrate; The single amino acid is selected from the group consisting of unprotected or protected, PEG chains, polyamino acid chains, and maleimide-modified single amino acids, including -Lys-, -Cit-, -Arg-, -Leu-, -His-, -Asp-, -Glu-, -Ala-, -Val-, -Ile-, -Pro-, -Phe-, -Trp-, -Met-, -Ser-, -Cys- or -Asn-; the dipeptide is selected from the group consisting of unprotected or protected, PEG chains, polyamino acid chains, and maleimide-modified single amino acids. Imidyl-modified dipeptides include -Phe-Lys-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Ile-Cit, -Trp-Cit-, -Phe-Gly-, -Ala-Ala- or -Phe-Arg-; tetrapeptides selected from tetrapeptides without protection or with protecting groups, PEG chains, polyamino acid chains and maleimide-modified tetrapeptides include -Gly-Gly-Phe-Gly-.

3. The branched linker compound according to claim 1, characterized in that: When the connection point T is connected by an ether bond or an ester bond, the structure of the branched linker compound is as shown in the following formula (1-2): Among them, TR includes β-glucoside, β-galactoside, phosphate, sulfate, and pyrophosphate.

4. The branched linker compound according to claim 1, characterized in that: When the connection point A is connected by an amide bond, the structure of the branched linker compound is as shown in the following formula (1-5): Wherein, LLR is a linker modification fragment, including one or more of PEG, sugar, alkyl chain, maleimide-modified PEG, modified alkyl chain, and fatty acid; The groups connected to the connection point T include β-glucoside, β-galactoside, phosphate, sulfate, and pyrophosphate.

5. The branched linker compound according to claim 1, characterized in that: When the group connected to the connection point A is H, the structure of the branched linker compound is shown in the following formula (1-6): T is selected from a single amino acid, a dipeptide, or a tetrapeptide selected from a cathepsin substrate or a metalloprotease substrate; The single amino acid is selected from the group consisting of unprotected or protected, PEG chains, polyamino acid chains, and maleimide-modified single amino acids, including -Lys-, -Cit-, -Arg-, -Leu-, -His-, -Asp-, -Glu-, -Ala-, -Val-, -Ile-, -Pro-, -Phe-, -Trp-, -Met-, -Ser-, -Cys- or -Asn-; the dipeptide is selected from the group consisting of unprotected or protected, PEG chains, polyamino acid chains, and maleimide-modified single amino acids. Imidyl-modified dipeptides include -Phe-Lys-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Ile-Cit, -Trp-Cit-, -Phe-Gly-, -Ala-Ala- or -Phe-Arg-; tetrapeptides selected from tetrapeptides without protection or with protecting groups, PEG chains, polyamino acid chains and maleimide-modified tetrapeptides include -Gly-Gly-Phe-Gly-.

6. The branched linker compound according to claim 1, characterized in that: When the R1 is an amide bond-connected group, the branched linker compound further includes a connection site L1, and the structure of the branched linker compound is shown in the following formula (L): Wherein, R3 is selected from one or more of H, C1-C6 alkyl or cycloalkyl; L1 is selected from one or more of H, amino protecting group, aliphatic chain, PEG chain, polyamino acid chain, sugar chain, and maleimide-modified PEG chain, maleimide-modified aliphatic chain, maleimide-modified polyamino acid chain, maleimide-modified sugar chain; R3 and L1 can be connected to form 3 to 6 rings, including The L2 is selected from one or more of H, an amino protecting group, a C1-C6 alkyl or cycloalkyl group, a fat chain, a linear or branched PEG chain, a sugar chain, a polyamino acid chain, a maleimide-modified PEG chain, a maleimide-modified fat chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; R4 is selected from one or more selected from H, C1-C6 alkyl or cycloalkyl; When the R1 is a nitro group, the structure of the branched linker compound is as shown in the following formula (J):

7. The branched linker compound according to claim 6, characterized in that: The branched linker compound (L) includes (L-5) and (L-6), which are respectively shown in the following formulas: in, In formula (L-5), AA represents an amino acid, m represents the number of amino acids, and m is selected from 1-6; L3 is selected from H, an amino protecting group, a fatty chain, a PEG chain, a polyamino acid chain, a sugar chain, and one or more of a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; R6 and R7 are selected from H or a C1-C6 alkyl or cycloalkyl group or independently, L1 is selected from a C1-C6 alkyl or cycloalkyl group, or R6 and L1 can form a cycloalkyl group; L2 is selected from H, an amino protecting group, a fatty chain, a PEG chain, One or more of a polyamino acid chain, a sugar chain, a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; L2 and L3 are selected together or independently from H, an amino protecting group, a fatty chain, a PEG chain, a polyamino acid chain, a sugar chain, and one or more of a maleimide-modified PEG chain, a maleimide-modified fatty chain, a maleimide-modified polyamino acid chain, and a maleimide-modified sugar chain; L2 and L3 are not simultaneously selected from a maleimide-modified PEG chain, a fatty chain, a polyamino acid chain, and a sugar chain; In formula (L-6), T is selected from one or more of β-glucoside, β-galactoside, phosphate, pyrophosphate or sulfate; L4 is selected from hydrogen, C1-C6 alkyl or cycloalkyl, nitro, amino, methoxy, carboxyl, ester, fatty chain, linear or branched PEG chain, sugar chain, polyamino acid chain R 10 Selected from hydrogen, C1-C3 alkyl or cycloalkyl; L5 is selected from hydrogen, amino protecting group, C1-C6 alkyl or cycloalkyl, fatty chain, linear or branched PEG chain, sugar chain, polyamino acid chain, maleimide-modified PEG chain, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, maleimide-modified sugar chain; R6 and R7 are selected from H or C1-C6 alkyl or cycloalkyl together or independently, L1 is selected from C1-C6 alkyl or cycloalkyl, or R6 and L1 can form a cycloalkyl; L2 is selected from H, amino protecting group, fatty chain, PEG chain, polyamino acid chain, sugar chain, and one or more of maleimide-modified PEG chain, maleimide-modified fatty chain, maleimide-modified polyamino acid chain, and maleimide-modified sugar chain.

8. An albumin or antibody covalently bound prodrug and a pharmaceutically acceptable salt, solvate, polymorph or isomer thereof, characterized in that: Its structure is as shown in the compound formula (L) and formula (J) as claimed in claim 3; The compounds of formula (L) and formula (J) include the following formulas (L1) to (L6), formula (J1) and formula (J4): Wherein, in the above formula (L1) to formula (L6), formula (J1) and formula (J4), n, o, and m represent the number of repeating units, n is selected from 1-24; o is selected from 2-6; and m is selected from 0-12; In formula (L1) to formula (L4), L' is selected from: One or more of; In formula (L2), R' is selected from hydrogen, acetyl, amino protecting groups including Boc, Cbz, Fmoc, Alloc, and PEG chains, polyamino acid chains, sugar chains, and fatty chains; in formula (L4), R" is selected from hydrogen, nitro, and methoxy; D1 represents hydroxyl-containing drugs including camptothecins. D1 includes:

9. The albumin or antibody covalently bound prodrug and pharmaceutically acceptable salts, solvates, polymorphs or isomers thereof according to claim 8, characterized in that: Formula (L1) to Formula (L6) and Formula (J1) and Formula (J4) include the following formulas (J1-1), (J4-1), (L4-1), (L7-1), (L1-1), (L7-2), (L7-3), (L7-4):

10. A method for preparing the branched linker formula (L) as claimed in claim 6, characterized in that: The preparation reaction process of this method is shown in the following formula: The reaction steps include: a) Substitution reaction: Under alkaline conditions, compound 1 and the hydroxyl protecting group undergo a nucleophilic substitution reaction in a solvent to generate compound 2; b) Reduction reaction: Compound 2 is reduced by zinc powder / acid or iron powder / acid system to obtain compound 3, and the solvent is a conventional organic solvent / acid; c) Condensation reaction: Under nitrogen conditions, compound 3 reacts with formic acid and acetic anhydride to generate compound 4; d) Reduction reaction: Under nitrogen conditions, compound 4 and borane dimethyl sulfide are dissolved in a solvent and undergo a reduction reaction to generate compound 5; e) Substitution reaction: Under alkaline conditions, compound 5 and BOC anhydride undergo substitution reaction to obtain compound 6; f) Hydrolysis reaction: Under alkaline conditions, compound 6 undergoes hydrolysis reaction to obtain compound 7; g) condensation reaction: compound 7 reacts with amine under the action of a condensing agent to generate compound 8; h) Decomposition reaction: Compound 8 is subjected to a Pd / C deprotection reaction to generate compound 9, and the solvent is methanol or a mixed solvent of methanol, tetrahydrofuran and / or ethyl acetate; i) Etherification reaction: Under nitrogen protection, benzyl bromide substrates with different triggers react with silver oxide or base to generate compound 10, and the solvent is anhydrous tetrahydrofuran, anhydrous dichloromethane or anhydrous acetonitrile; j) Deprotection reaction: Compound 10 is deprotected from N-Boc under acidic conditions in a solvent to obtain compound 11; k) Condensation reaction: Under nitrogen protection, compound 11 was dissolved in an organic solvent, and di(trichloromethyl) carbonate and anhydrous organic base were added. After reacting for 1 hour, active drug and DMAP were added, and the reaction was carried out at 20-60°C overnight to obtain compound 12.

11. The preparation method according to claim 10, characterized in that: In step a), the hydroxyl protecting group includes benzyl bromide, p-methoxybenzyl bromide MOMCl; the base includes potassium carbonate, cesium carbonate, sodium carbonate; the solvent includes acetone, acetonitrile or NN-dimethylformamide; the molar ratio of compound 1 to the base is 1:(1.5-2); the molar ratio of compound 1 to the protecting group is 1:(1.5-2); In step b), the molar ratio of the compound 2 to the zinc powder or iron powder is 1:5; In step c), the molar ratio of compound 3 to formic acid is 1:(5-10), and the molar ratio of compound 3 to acetic anhydride is 1:(5-10); In step d), the molar ratio of compound 4 to borane dimethyl sulfide is 1:3; In step e), the base includes DIPEA and DMAP; In step f), the base comprises LiOH, NaOH or KOH; the molar ratio of compound 4 to borane dimethyl sulfide is 1:(2-5); In step g), the condensing agent includes DCC, EEDQ, HATU, EDC / HOBt, PyBOP; the molar ratio of compound 7 to amine is 1:(1-2), and the molar ratio of compound 7 to condensing agent is 1:(2-5); In step h), the molar ratio of compound 8 to Pd / C is 1:(0.1-0.2); In step i), the molar ratio of compound 9 to different benzyl bromides or benzyl alcohols is 1:(1-1.2), and the molar ratio of compound 9 to silver oxide / phosphorus reagent / azo is 1:(1.2-2); In step j), the acid includes hydrochloric acid or trifluoroacetic acid, and the solvent includes tetrahydrofuran or dichloromethane; In step k), the anhydrous organic base includes triethylamine, DIPEA, and pyridine; the drug contains exposed -OH, -NH2, -NHR, and -SH; the molar ratio of compound 11 to di(trichloromethyl)carbonate is 1:0.5, and the molar ratio of compound 11 to the anhydrous organic base is 1:(3-5); the molar ratio of compound 11 to the active drug is 1:(1-1.2).

12. A method for preparing a prodrug compound (J1) of a camptothecin derivative covalently bound to an albumin or an antibody, characterized in that: The reaction process of the preparation method is shown in the following formula: The reaction steps include: 1) Bromination reaction: Compound 1 is subjected to bromination reaction to obtain compound 2; the bromination reagent includes phosphorus tribromide, triphenylphosphine and carbon tetrabromide, and the solvent is anhydrous dichloromethane; 2) Etherification reaction: Compound 2 is subjected to an etherification reaction to generate compound 3, wherein the organic solvent is anhydrous acetonitrile; 3) Reduction reaction: Under nitrogen conditions, compound 3 and borane dimethyl sulfide are dissolved in a solvent to undergo a reduction reaction to generate compound 4, and the solvent is anhydrous tetrahydrofuran; 4) Condensation reaction: Under nitrogen protection, compound 4 is dissolved in an organic solvent, di(trichloromethyl) carbonate and triethylamine are added, and after reacting for 1 hour, a hydroxyl-containing drug is added, and the reaction is carried out at room temperature overnight to obtain compound 5; 5) Deprotection: Under nitrogen protection, compound 5 was dissolved in an organic solvent, and a 0.2 M aqueous base solution was added under ice bath condition to deprotect to obtain compound 6; 6) Condensation reaction: Compound 6 and compound 9 are dissolved in an organic solvent and stirred at room temperature for 6-8 hours to react to generate the prodrug having the general structure of (J1).

13. The preparation method according to claim 12, characterized in that: In step 1), the molar ratio of compound 1 to the bromination reagent is 1:3; In step 3), the molar ratio of compound 3 to borane dimethyl sulfide is 1:3; In step 4), the molar ratio of compound 4 to bis(trichloromethyl) carbonate is 1:0.5, the molar ratio of compound 4 to triethylamine is 1:4; the molar ratio of compound 4 to the hydroxyl-containing drug is 1:1; In step 5), the base includes one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide; the organic solvent includes one or more of methanol, acetonitrile, tetrahydrofuran, and water; the molar ratio of the compound 5 to the base is 1:8; In step 6), the molar ratio of compound 6 to compound 9 is 1:1; the organic solvent is one or a mixture of methanol, acetonitrile, tetrahydrofuran, N,N-dimethylformamide and water.

14. A drug and / or a pharmaceutical composition, characterized in that: It comprises the branched linker compound according to any one of claims 1 to 7, the albumin or antibody covalently bound prodrug according to claims 8 and 9, and pharmaceutically acceptable salts, solvates, polymorphs or isomers thereof, and pharmaceutically acceptable carriers.

15. Use of the branched linker compound according to any one of claims 1 to 7, the albumin or antibody covalently bound prodrug according to claims 8 and 9 and pharmaceutically acceptable salts, solvates, polymorphs or isomers thereof, and the drug and / or pharmaceutical composition according to claim 14 in the preparation of anti-tumor drugs, and in the preparation of albumin or antibody-bound anti-tumor drugs.

16. The use according to claim 15, characterized in that The application includes the application in the preparation of albumin-bound β-glucuronidase prodrug for tumor treatment and antibody-drug conjugated tumor treatment.

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