Cyclic polypeptide, preparation method therefor and use thereof

Abstract

Provided in the present invention are a cyclic polypeptide, a preparation method therefor and the use thereof. Specifically provided is a compound represented by formula I or a pharmaceutically acceptable salt thereof. The compound provided in the present invention has a relatively good affinity for a fibroblast activation protein (FAP) and cell viability, and is suitable for clinical promotion and application.

Description

A cyclic polypeptide, its preparation method and application

[0001] This application claims priority to Chinese patent application 2024109777762 with a filing date of 2024 / 7 / 19. This application incorporates the entirety of the aforementioned Chinese patent application. TECHNICAL FIELD

[0002] The present application relates to a cyclic polypeptide, its preparation method and application. BACKGROUND

[0003] Chemotherapy is still widely used in the treatment of cancer patients and other diseases. Traditional anticancer chemotherapy drugs act on the basic mechanism of cell survival and cannot effectively distinguish between healthy cells and malignant cells. In addition, these drugs do not effectively reach and accumulate at the disease site after systemic administration. The non-specific mechanism of action and low efficiency of tumor site localization are the causes of side effects and poor treatment effect.

[0004] In order to be able to more effectively treat diseases, the development of targeted drugs is one of the hotspots in the research and development of new drugs in recent years, and such drugs can selectively localize at the disease site and exert effects after systemic administration. Such drugs are substances formed by combining representative chemicals with therapeutic effects (such as cytotoxic drugs or radionuclides) with ligands with cell-specific targeting, forming conjugated drugs. Disease-specific monoclonal antibodies, peptides and small molecule ligands are the preferred ligands for the development of targeted drug products. For targeted applications, the use of small molecule or polypeptide ligands has faster and more effective tumor penetration, lower immunogenicity and lower manufacturing costs than larger molecules (such as antibodies).

[0005] Tumor is a complex composed of tumor cells and their surrounding stromal cells and non-cellular components, and the occurrence and development of tumor is a dynamic process of mutual promotion and co-evolution between tumor cells and their microenvironment (TME). The tumor microenvironment is composed of a variety of heterogeneous cell types such as immune cells, including endothelial cells, fibroblasts (cancer associated fibroblasts, CAFs) and their extracellular products. Among them, cancer associated fibroblasts (CAFs) are the most important stromal cells in the tumor microenvironment, accounting for about 50% of the total number of tumor tissue cells. CAFs play an important role in tumor growth, metastasis, drug resistance and treatment resistance, and are one of the hotspots in the research of tumor diagnosis and treatment in recent years.

[0006] A prominent feature of CAFs is the high expression of seprase or fibroblast activation protein (FAP). Both are the same kind of cell surface membrane serine protease, with dipeptidyl peptidase (DPP) and collagenase activities, which can degrade dipeptides and type I collagen. FAP has similar domains and dipeptidyl peptidase activity as Dipeptidyl peptidase IV (PPIV), and belongs to the same serine protease family. However, FAP has a unique endopeptidase activity that can cleave gelatin, denatured type I collagen and alpha 2-anti fibrin, while DPPIV does not have this function, so the two can be distinguished. FAP is selectively expressed on the surface of stromal fibroblasts in more than 90% of epithelial malignant tumors, including breast cancer, ovarian cancer, lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, skin melanoma, etc.

[0007] It has important medical value to develop radiotherapy drugs with better target affinity, higher enrichment in tumor tissue or longer residence time. SUMMARY

[0008] The technical problem to be solved by the present application is to overcome the defect of single structure of existing cyclic polypeptide compounds, and therefore the present application provides a cyclic polypeptide, a preparation method and application thereof. The cyclic polypeptide compound has good affinity and cell activity, and is suitable for clinical promotion and application.

[0009] The present application provides a compound represented by formula I or a pharmaceutically acceptable salt thereof;

[0010] -X1- is

[0011] The ring A is a 3-6 membered heterocycloalkylene, the heteroatom of the 3-6 membered heterocycloalkylene is selected from one or more of N, O and S, the number of heteroatoms is 1, 2 or 3, and at least one N is contained;

[0012] -X2- is

[0013] The ring B is a 3-6 membered heterocycloalkylene, the heteroatom of the 3-6 membered heterocycloalkylene is selected from one or more of N, O and S, the number of heteroatoms is 1, 2 or 3, and at least one N is contained;

[0014] -W- is -NH-CO- or -NH-CO-NH-;

[0015] R 1 is C 1-10 alkyl;

[0016] R 2 is C1-C6 alkyl or C1-C6 alkyl substituted with 1, 2, or 3 R 2-1 ; each R

[0017] R 2-1 is independently C1-C6 alkyl, halogen, hydroxyl (-OH), guanidyl (-NHCNHNH2), carboxyl (-COOH), or amido (-CONH2);

[0018] R 3 is H, C1-C6 alkyl, or C1-C6 alkyl substituted with 1, 2, or 3 R 3-1 ; each R

[0019] R 3-1 is independently carboxyl or amido;

[0020] R 4 is C1-C6 alkylene-R 4-1 ; each R

[0021] R 4-1 is C6-C 10 aryl, 3-8 membered cycloalkyl, C6-C 4-1-1 aryl, or 3-8 membered cycloalkyl substituted with 1, 2, or 3 R 10 ; each R 4-1-2 is independently C1-C6 alkyl, halogen, hydroxyl, or C1-C6 alkyl substituted with 1, 2, or 3 R

[0022] R 4-1-1 and R 4-1-2 are each independently halogen, hydroxyl, or C1-C6 alkyl;

[0023] R 5 is hydroxyl or

[0024] R 5-1 and R 5-2 are each independently H, C1-C6 alkyl, or C1-C6 alkyl substituted with 1, 2, or 3 R 5-1-1 ; each R

[0025] R 5-1-1 are each independently amino (-NH2), hydroxyl, carboxyl, or amido;

[0026] -L1- and -L2- are independently -(CH2) n -L 1-1 -(CH2) m -; L 1-1 is independently S, O, or NH; n and m are independently 1, 2, or 3;

[0027] the ring C is C6-C 10arylene or 5-12 membered heteroarylene, the heteroatoms of the 5-12 membered heteroarylene being selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3;

[0028] -R 6 is -H or -(CH2) e -R 6-1 -(CH2) t -NH2; R 6-1 is S, O or NH; e and t are independently 1, 2 or 3;

[0029] The compounds of formula I satisfy one or two of the following conditions:

[0030] (1) the ring A is a 4 membered heterocycloalkylene, the heteroatoms of the 4 membered heterocycloalkylene being selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N being present;

[0031] (2) R 4-1 is a 3-8 membered cycloalkyl or a 3-8 membered cycloalkyl substituted by 1, 2 or 3 R 4-1-2 groups.

[0032] In one aspect, certain groups in the compounds of formula I or pharmaceutically acceptable salts thereof are defined as follows, and the groups not mentioned are as defined in any aspect of the application (simply "in one aspect").

[0033] In one aspect, the 3-6 membered heterocycloalkylene in ring A is a 4-6 membered heterocycloalkylene (e.g. a 4 membered heterocycloalkylene), the heteroatoms of the heterocycloalkylene being preferably N, O or S, the number of heteroatoms being preferably 1 or 2, and at least one N being present, e.g. the 3-6 membered heterocycloalkylene is

[0034] In one aspect, the 3-6 membered heterocycloalkylene in ring B is a 4-6 membered heterocycloalkylene (e.g. a 5 membered heterocycloalkylene), the heteroatoms of the heterocycloalkylene being preferably N, O or S, the number of heteroatoms being preferably 1 or 2, and at least one N being present, e.g. the 3-6 membered heterocycloalkylene is

[0035] In one aspect, R 1 , the C 1-10 alkyl is a linear C 1-10 alkyl, e.g. a linear C 3-10 alkyl, preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl or n-nonyl, further preferably n-butyl or n-pentyl.

[0036] In one aspect, R 2In one aspect, the C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl. 2-1 In one aspect, the C1-C6alkyl of the substituted C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl.

[0037] In one aspect, R 2-1 In one aspect, the C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl.

[0038] In one aspect, R 2-1 In one aspect, the halo is independently fluorine, chlorine, bromine, or iodine.

[0039] In one aspect, R 3 In one aspect, the C1-C6alkyl of the substituted C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl. 3-1 In one aspect, the C1-C6alkyl of the substituted C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl.

[0040] In one aspect, R 4 In one aspect, the C1-C6alkyl of the substituted C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl.

[0041] In one aspect, R 4-1 In one aspect, the C6-C10aryl of the substituted C6-C10aryl is independently phenyl or naphthyl, for example phenyl. 10 In one aspect, the C6-C10aryl of the substituted C6-C10aryl is independently phenyl or naphthyl, for example phenyl. 4-1-1 In one aspect, the C6-C10aryl of the substituted C6-C10aryl is independently phenyl or naphthyl, for example phenyl. 10 In one aspect, the C6-C10aryl of the substituted C6-C10aryl is independently phenyl or naphthyl, for example phenyl. 10 In one aspect, the C6-C10aryl of the substituted C6-C10aryl is independently phenyl or naphthyl, for example phenyl.

[0042] In one aspect, R 4-1 In one aspect, the 3-8 membered cycloalkyl of the substituted 3-8 membered cycloalkyl is independently cycloheptyl, cyclohexyl, cyclopentyl, cyclobutyl, or cyclopropyl, for example cyclohexyl. 4-1-2 In one aspect, the 3-8 membered cycloalkyl of the substituted 3-8 membered cycloalkyl is independently cycloheptyl, cyclohexyl, cyclopentyl, cyclobutyl, or cyclopropyl, for example cyclohexyl.

[0043] In one aspect, R 4-1-1 and R 4-1-2 In one aspect, the C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl.

[0044] In one aspect, R 4-1-1 and R 4-1-2 In one aspect, the halo is independently fluorine, chlorine, bromine, or iodine.

[0045] In one aspect, R 5-1 and R 5-2In the case of C1-C6 alkyl groups and alkyl groups with one, two, or three R atoms, the C1-C6 alkyl groups are used to form the C1-C6 alkyl groups. 5-1-1 The substituted C1-C6 alkyl groups are independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl, for example, ethyl, isopropyl, or n-propyl.

[0046] In one scheme, in ring C, C6 to C 10 The arylene group is phenylene or naphthylene, for example, phenylene (e.g. ).

[0047] In one embodiment, the 5-12-membered heteroaryl group in ring C is a 5-6-membered heteroaryl group, and the heteroatom is preferably N, O or S, and the number of heteroatoms is preferably 1, 2 or 3.

[0048] In one scheme, -X1- is The ring A is a 4-membered heterocyclic alkyl group, wherein the heteroatom of the 4-membered heterocyclic alkyl group is selected from one or more of N, O, and S, and the number of heteroatoms is 1, 2, or 3, and it contains at least one N; and the N is located at the β-position of the carboxyl group, for example, -X1-.

[0049] In one scheme, -X2- is The ring B is a 5-membered heterocyclic alkyl group, wherein the heteroatom of the 5-membered heterocyclic alkyl group is selected from one or more of N, O and S, and the number of heteroatoms is 1, 2 or 3, and it contains at least one N.

[0050] In one of the schemes, R 2 For 1, 2 or 3 R 2-1 Substituted C1 to C6 alkyl groups.

[0051] In one of the schemes, R 2-1 Each is independently a C1 to C6 alkyl or hydroxyl group.

[0052] In one of the schemes, R 3 For 1, 2 or 3 R 3-1 Substituted C1 to C6 alkyl groups.

[0053] In one of the schemes, R 3-1 It is an amide group.

[0054] In one of the schemes, R 4-1 C6~C 10 Aryl or 3-8 membered cycloalkyl, preferably, R 4-1 It is a 3-8 membered cycloalkyl group, such as cyclohexyl.

[0055] In one of the schemes, R 5-1 and R 5-2each independently H or substituted C1-C6 alkyl. 5-1-1 substituted C1-C6 alkyl.

[0056] In one aspect, R 5-1-1 each independently amino or carboxyl.

[0057] In one aspect, L 1-1 is S.

[0058] In one aspect, the ring C is C6-C 10 arylene.

[0059] In one aspect, R 6-1 is S.

[0060] In one aspect, the compound of Formula I satisfies one or two of the following conditions:

[0061] (1) the ring A is 4-membered heterocycloalkylene, the heteroatoms of the 4-membered heterocycloalkylene being selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N being present;

[0062] (2) R 4-1 is 3-8 membered cycloalkyl.

[0063] In one aspect, -X1- is wherein is connected to X2.

[0064] In one aspect, -X2- is wherein is connected to -NH-.

[0065] In one aspect, -W- is -NH-CO-* or -NH-CO-NH-*, wherein the * is connected to R 1 .

[0066] In one aspect, R 4 is *-C1-C6 alkylene-R 4-1 , wherein the * is connected to methylene (methylene).

[0067] In one aspect, -L1- and -L2- are independently -(CH2) n -L 1-1 -(CH2) m -*, wherein the * is connected to ring C.

[0068] In one aspect, -W- is -NH-CO-, R 6 is H, R 4-1 is C6-C 10aryl or C6-C10aryl substituted by 1, 2 or 3 R 4-1-1 substituted C6-C10aryl; 10 aryl.

[0069] In one aspect, -W- is -NH-CO-NH-.

[0070] In one aspect, -X1- is

[0071] said ring A is a 3-6 membered heterocycloalkylene, the heteroatoms of said 3-6 membered heterocycloalkylene being selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N being contained;

[0072] said -X2- is

[0073] said ring B is a 3-6 membered heterocycloalkylene, the heteroatoms of said 3-6 membered heterocycloalkylene being selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N being contained;

[0074] said -W- is -NH-CO- or -NH-CO-NH-;

[0075] R 1 is C1-C6alkyl; 1-10 alkyl;

[0076] R 2 is C1-C6alkyl substituted by 1, 2 or 3 R 2-1 substituted C1-C6alkyl;

[0077] R 2-1 each independently is C1-C6alkyl or hydroxy;

[0078] R 3 is C1-C6alkyl substituted by 1, 2 or 3 R 3-1 substituted C1-C6alkyl;

[0079] R 3-1 is amido;

[0080] R 4 is C1-C6alkylene-R 4-1 ;

[0081] R 4-1 is C6-C10aryl or 3-8 membered cycloalkyl; 10 aryl or 3-8 membered cycloalkyl;

[0082] R 5 is hydroxy or

[0083] R 5-1 and R 5-2each independently H or substituted C1-C6 alkyl; 5-1-1 substituted C1-C6 alkyl;

[0084] R 5-1-1 each independently amino or carboxyl;

[0085] -L1- and -L2- are independently -(CH2) n -L 1-1 -(CH2) m -; L 1-1 is S; n and m are independently 1, 2 or 3;

[0086] said ring C is C6-C 10 arylene;

[0087] -R 6 is -H or -(CH2) e -R 6-1 -(CH2) t -NH2; R 6-1 is S; e and t are independently 1, 2 or 3;

[0088] said compound of formula I satisfies one or two of the following conditions:

[0089] (1) said ring A is 4-membered heterocycloalkylene, the heteroatoms of said 4- membered heterocycloalkylene are selected from one or more of N, O and S, the number of heteroatoms is 1, 2 or 3, and at least one N is contained;

[0090] (2) R 4-1 is 3-8 membered cycloalkyl.

[0091] In one aspect, -X1- is

[0092] In one aspect, -X2- is

[0093] In one aspect, -W-R is

[0094] In one aspect, -R 2 is

[0095] In one aspect, -R 3 is

[0096] In one aspect, -R 4 is

[0097] In one aspect, -R 5 is -OH,

[0098] In one aspect, -L1- and -L2- are -CH2-S-CH2-.

[0099] In one aspect, In one aspect,

[0100] In one aspect, -R 6 is -H or

[0101] In one aspect, the compound of Formula I is a compound of Formula I-1, a compound of Formula I-2, or a compound of Formula I-3:

[0102] wherein -X1-, -X2-, -W-, R 1 , R 2 , R 3 , R 4 , R 5 , -L1-, -L2-, ring C, and R 6 are each independently as described in any aspect of the application.

[0103] In one aspect, the compound of Formula I is any one of the following compounds:

[0104] The present application provides a pharmaceutical composition comprising the compound of Formula I or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable excipient. Preferably, the pharmaceutical composition targets FAP.

[0105] The present application also provides the use of the compound of Formula I or a pharmaceutically acceptable salt thereof, the pharmaceutical composition in the manufacture of a medicament for the diagnosis or treatment of a tumor, which can be a solid tumor positive for FAP expression, such as breast cancer, ovarian cancer, lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, prostate cancer, liver cancer, or skin melanoma.

[0106] Preferably, the medicament comprises a polypeptide conjugate, a radionuclide conjugate, preferably the conjugate is a FAP-targeting conjugate or a conjugate containing a FAP-targeting component (e.g., a dual-targeting conjugate comprising FAP).

[0107] The present application also provides a conjugate comprising the compound of Formula I or a pharmaceutically acceptable salt thereof and one or more molecules selected from the group consisting of (1) a cytotoxin, a radionuclide, and / or a small molecule drug, and (2) a linker group. The above-mentioned groups are preferably linked by a peptide-forming reaction.

[0108] The conjugated drug is, for example, a single-target (FAP-targeted) drug and a multi-target drug (containing a FAP target). Preferably, the conjugated drug is a FAP polypeptide-targeted conjugated drug or a FAP isotope-targeted conjugated drug.

[0109] The conjugated drug can be a drug for diagnosing or treating a tumor, which can be a solid tumor positive for FAP expression, such as breast cancer, ovarian cancer, lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, prostate cancer, liver cancer, or skin melanoma.

[0110] The present application also provides a method for preparing the compound of formula I or a pharmaceutically acceptable salt thereof, comprising the following steps: in the presence of a base (such as (NH4)2CO3), a ring-forming reaction is performed between a compound of formula II and a compound of formula III in a solution (such as a mixture of water and acetonitrile), to obtain the compound of formula I.

[0111] wherein n1, n2, m1 and m2 are independently 1, 2 or 3 (such as 1);

[0112] L 1-1a and L 1-1b are independently OH, SH or NH2 (such as SH);

[0113] Hal is independently halogen (such as Br);

[0114] -X1-, -X2-, -W-, R 1 , R 2 , R 3 , R 4 , R 5 , -L1-, -L2-, ring C and R 6 are each independently as described in any of the aspects of the present application.

[0115] The present application also provides a compound of formula II or a pharmaceutically acceptable salt thereof;

[0116] wherein n1, n2, L 1-1a , L 1-1b , -X1-, -X2-, -W-, R 1 , R 2 , R 3 , R 4 , R 5 , -L1-, -L2-, ring C and R 6 are each independently as described in any of the aspects of the present application.

[0117] The compound of formula II is preferably any of the following compounds:

[0118] wherein n1, n2, L 1-1a , L 1-1b , -X1-, -X2-, -W-, R 1 , R 2 , R 3 and R 5 are each independently as described in any of the aspects of the application.

[0119] Preferably, the compound of formula II is:

[0120] As used herein, the terms have the following meanings:

[0121] The term "pharmaceutically acceptable salt" refers to a salt of a compound with a pharmaceutically acceptable (relatively non-toxic, biologically compatible, suitable for patient use) acid or base. When a compound contains relatively acidic functionalities, base addition salts can be obtained by contacting the free form of the compound with a sufficient amount of the pharmaceutically acceptable base in a suitable inert solvent. Where the compound contains relatively basic functionalities, acid addition salts can be obtained by contacting the free form of the compound with a sufficient amount of the pharmaceutically acceptable acid in a suitable inert solvent. See, e.g., Handbook of Pharmaceutical Salts: Properties, Selection, and Use (P. Heinrich Stahl, 2002).

[0122] The term "halogen" refers to fluorine, chlorine, bromine or iodine.

[0123] Unless otherwise specified, the above cyclic polypeptides (compounds of formula I) are composed of natural amino acid residues / non-natural amino acid residues or derivatives thereof.

[0124] Unless otherwise specified, when ring A is a four-membered heterocycloalkyl, with N located beta to the carboxyl group.

[0125] The term "alkyl" refers to a straight or branched chain alkyl group having the indicated number of carbon atoms (e.g., C1-C6alkyl). Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, s-butyl, and the like. 10

[0126] The term "alkylene" refers to a divalent radical, which is attached to the rest of the molecule by two single bonds, the remainder of the definition being the same as for the term "alkyl."

[0127] ​The term "cycloalkyl" refers to a saturated cyclic group consisting solely of carbon atoms, having the number of ring carbon atoms designated (e.g., C3-C8or C3-C6), which is mono-, bi-, or tri-cyclic, and which is saturated. Cycloalkyl includes but is not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0128] The term "heterocycloalkyl" refers to a cyclic group having the number of ring atoms designated (e.g., 4-6 membered or 3-6 membered), the number of heteroatoms designated (e.g., 1, 2, or 3), and the kind of heteroatoms designated (one or more of N, O, and S), which is mono-, bi-, or tri-cyclic, and each ring of which is saturated, and which is connected to the rest of the molecule via a single bond. Heterocycloalkyl includes but is not limited to azetidinyl, tetrahydropyrrolyl, tetrahydrofuranyl, morpholinyl, piperidinyl, azacyclopentan-2-yl, azacyclohexan-2-yl, and the like.

[0129] The term "heterocycloalkyl" refers to a cyclic group having the number of ring atoms designated (e.g., 4-6 membered or 3-6 membered), the number of heteroatoms designated (e.g., 1, 2, or 3), and the kind of heteroatoms designated (one or more of N, O, and S), which is mono-, bi-, or tri-cyclic, and each ring of which is saturated, and which is connected to the rest of the molecule via a single bond. Heterocycloalkyl includes but is not limited to azetidinyl, tetrahydropyrrolyl, tetrahydrofuranyl, morpholinyl, piperidinyl, azacyclopentan-2-yl, azacyclohexan-2-yl, and the like.

[0130] The term "aryl" refers to a cyclic group consisting solely of carbon atoms, having the number of ring carbon atoms designated (e.g., C6-C 10 ) which is mono- or fused-rings, and at least one of which is aromatic (complies with Hückel's rule). The aryl group is connected to the rest of the molecule via a ring that is aromatic or a ring that is not aromatic. Aryl includes but is not limited to phenyl, naphthyl, and the like.

[0131] The term "arylene" is a divalent group connected to the rest of the molecule via two single bonds or three, the rest of which is defined as the term "aryl."

[0132] The term "heteroaryl" refers to a cyclic group having the number of ring atoms designated (e.g., 5-12 membered or 5-6 membered), the number of heteroatoms designated (e.g., 1, 2, or 3), and the kind of heteroatoms designated (one or more of N, O, and S), which is mono- or fused-rings, and at least one of which is aromatic (complies with Hückel's rule). The heteroaryl group is connected to the rest of the molecule via a ring that is aromatic or a ring that is not aromatic in a fused ring. Heteroaryl includes but is not limited to pyridinyl, pyrimidinyl, and the like.

[0133] The term "heteroaryl" refers to a cyclic group having the number of ring atoms designated (e.g., 5-12 membered or 5-6 membered), the number of heteroatoms designated (e.g., 1, 2, or 3), and the kind of heteroatoms designated (one or more of N, O, and S), which is mono- or fused-rings, and at least one of which is aromatic (complies with Hückel's rule). The heteroaryl group is connected to the rest of the molecule via a ring that is aromatic or a ring that is not aromatic in a fused ring. Heteroaryl includes but is not limited to pyridinyl, pyrimidinyl,

[0134] "-" in a structural fragment means that the structural fragment is connected to the rest of the molecule at that site. is a divalent group connected to the rest of the molecule via two single bonds or three, the rest of which is defined as the term "aryl."

[0135] The term "pharmaceutically acceptable excipient" refers to excipients and additives used in the production of pharmaceuticals and dispensing of prescriptions, and is all substances contained in pharmaceutical preparations other than active ingredients. See the People's Republic of China Pharmacopoeia (2020 edition) or Handbook of Pharmaceutical Excipients (Raymond C Rowe, 2009) for details.

[0136] The term "therapeutically effective amount" refers to the amount of a compound administered to a patient that is sufficient to effectively treat a disease, a radiation dose. The therapeutically effective amount will vary depending on the compound, the type of disease, the severity of the disease, the age of the patient, etc., but can be adjusted by those skilled in the art as appropriate.

[0137] The term "patient" refers to any animal, preferably a mammal, most preferably a human, who has been or will be treated. Mammals include, but are not limited to, cows, horses, sheep, pigs, cats, dogs, mice, rats, rabbits, guinea pigs, monkeys, humans, etc.

[0138] The term "treatment" refers to any of the following: (1) alleviating one or more biological manifestations of a disease; (2) interfering with one or more points in the biological cascade that leads to the disease; (3) slowing the development of one or more biological manifestations of the disease.

[0139] Without deviating from the common sense in the art, the above-mentioned preferred conditions can be combined arbitrarily, i.e. to obtain each preferred example of the present application.

[0140] The reagents and raw materials used in the present application are commercially available.

[0141] The positive progress effect of the present application is that the cyclic peptide compound provided by the present application has one or more of the following advantages:

[0142] (1) It has high affinity to FAP target, good cell activity and good combination;

[0143] (2) It is simple to prepare and easy to apply in industrial production;

[0144] (3) As a targeted FAP cyclic peptide, it can form various conjugate combinations, including but not limited to polypeptide conjugate drugs, radionuclide conjugate drugs, etc. The conjugate drugs can be used for the diagnosis and treatment of tumors, have high tumor uptake and long retention time, and have good drug prospects. DETAILED DESCRIPTION

[0145] The present application will be further illustrated by the following examples, but the present application is not limited to the scope of the examples. The experimental methods in the following examples are not specified, and the methods and conditions are selected according to the conventional methods and conditions, or according to the instructions of the goods.

[0146] The method for preparing liquid phase purification of cyclic peptides used in the present application is shown in Table 1.

[0147] Table 1

[0148] The liquid phase analysis method used in the present application is as follows in Tables 2-4.

[0149] Equipment HPLC-MS Waters 2696-Micromass system

[0150] Table 2

[0151] Table 3

[0152] Table 4

[0153] The abbreviations of the compounds used in the present application and the corresponding structures are as follows in Table 5:

[0154] Table 5

[0155] The HT1080 hFAP 2# used in the present application can be constructed by the following method:

[0156] 1. Synthesize human FAP gene, add GCCACC at the N-terminal, clone into lentiviral vector pGWLV11-new (JUNZHI), construct human FAP in pGWLV11-new, and package lentivirus;

[0157] 2. Culture HT1080 WT (Chinese Academy of Sciences Cell Bank) cells, perform mycoplasma detection and STR identification;

[0158] 3. Plate HT1080 WT in a six-well plate, adhere overnight, add polybrene (Biyun Tian) at a final concentration of 10 μg / mL, infect HT1080 cells with packaged lentivirus, and set up MOI gradients of 10, 30, and 50;

[0159] 4. Set up a resistance concentration screening pre-experiment to determine the puromycin concentration that can kill all HT1080 WT cells after 3 days of culture;

[0160] 5. After 72 h of virus infection, add 5 μg / mL puromycin (Bi Yun Tian, pre-experiment result) for resistance screening, and obtain positive cell pool after 3 days of screening;

[0161] 6. Flow cytometry (ACEA Biocsience, Novocyte 3130) analysis to detect positive pool and flow cytometry sorting high positive area of positive cell pool, monoclonal cell line sorting and expansion culture of collected cells after sorting, FACS to identify monoclonal cell surface human FAP expression, and obtain HT1080 cell line overexpressing hFAP.

[0162] Synthesis step of compound 11 of example 1

[0163] Step 1: synthesis of 11-Pre-A1

[0164] Using Fmoc solid phase synthesis strategy, 0.3 mmol CTC resin (0.5 g, i.e. ) was used, and 3 eq. amino acids (Fmoc-Dab(Alloc)-OH, Fmoc-Cys(Trt)-OH, Fmoc-Cha-OH, Fmoc-Gln(Trt)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Pro-OH, Fmoc-hhy39-OH, Fmoc-Cys(Trt)-OH and Butyl Isothiocyanate) were sequentially added according to the polypeptide sequence, using PyBOP / DIEA (3 eq.) system for condensation, and 20% Pip / DMF for Fmoc protection group removal. After condensation was completed, MeOH was used for washing until clean, and 1.1 g of resin was obtained after drying; 10 mL of cleavage solution (87.5% TFA / 7.5% DTT / 2.5% TIS / 2.5% H2O) was used for cleavage for 2 h, and isopropyl ether was added to the filtered cleavage solution to precipitate the solid 120 mg.

[0165] Step 2: synthesis of 11

[0166] 11-Pre-A1 (120 mg; 123 umol) and 1,3-di(bromomethyl)benzene (40 mg; 147 umol) were dissolved in a mixed solution of H2O and CAN (100 mL) at room temperature, then saturated NH4HCO3 (1 mL) was added, and the reaction was allowed to proceed for 1 h, LCMS detection showed that the starting material was completely consumed, and the product was generated, flash purification. Lyophilization of the product gave 50 mg. Preparation purification gave 19.1 mg of the final product; purity 97.75%, MS: [M+H] + = 1075.2.

[0167] Compounds 12, 15, 16, 17, 18, 19, 20, 21, 22, 27 and 28 were synthesized using the solid phase synthesis Fmoc strategy according to the above method and the corresponding amino acid raw materials, see Table 6 below.

[0168] Table 6

[0169] Synthesis step of example 2 compound 13

[0170] Step 1: synthesis of 13-Pre-A1

[0171] Using Fmoc solid phase synthesis strategy, 0.3 mmol CTC resin (0.5 g, i.e. ) was charged with 3 eq. amino acids (Fmoc-Cys(Trt)-OH, Fmoc-Cha-OH, Fmoc-Gln(Trt)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Pro-OH, Fmoc-hhy39-OH, Fmoc-Cys(Trt)-OH and n-hexanoic acid) using PyBOP / DIEA (3 eq.) system for condensation and 20% Pip / DMF for Fmoc deprotection. After completion of condensation, MeOH was used to wash clean and the resin was dried by suction to get 0.7 g of resin; then 10 mL of cleavage solution (87.5% TFA / 7.5% DTT / 2.5% TIS / 2.5% H2O) was used for cleavage for 2 h, and isopropyl ether was added to the filtrate to precipitate the solid 110 mg.

[0172] Step 2: synthesis of 13

[0173] 13-Pre-A1 (110 mg; 124 umol) and 1,3,5-tris(bromomethyl)benzene (40 mg; 149 umol) were dissolved in a mixture of H2O and CAN (100 mL) at room temperature, intermediate SM2 (HSC2H4NH2) was added, followed by saturated NH4HCO3 (1 mL), and the reaction was allowed to proceed for 1 h, LCMS detection showed that the starting material was completely consumed and the product was generated, flash purification. Lyophilization of the product 50 mg. 20 mg was prepared and purified to obtain the final product 5.03 mg; purity 98.96%, MS: [M+H] + = 1076.88.

[0174] Xiangshen compounds 01, 14, 01-FITC fluorescent compounds, 23, 24, 25 and 26 were synthesized using Fmoc solid phase synthesis strategy according to the above method and corresponding amino acid raw materials, see Table 7 below.

[0175] Table 7

[0176] Structure of Xiangshen compound 01 and 01-FITC:

[0177] Effect test example 1 cell competition binding (IC 50 ) experiment

[0178] 1. Experimental steps

[0179] 1.1 Accurately weigh a certain amount of compound, add DMSO to dissolve the compound to 1 mM stock solution for standby, and store the solution at -20°C after dissolution.

[0180] 1.2 Take HT1080 hFAP 2# (purchased from Suzhou Jw Biosciences Co., Ltd.) in the logarithmic growth phase, wash the cells once with PBS, and then digest with trypsin containing 0.25% EDTA. Centrifuge at 400g for 5 min, and discard the supernatant.

[0181] 1.3 Resuspend each cell line with FACS buffer (PBS buffer + 2% FBS), and count the cells.

[0182] 1.4 Adjust the cell density to 2x10 6 cells / mL, and inoculate 1x10 5 cells / well into a U-bottom 96-well plate according to 50μL / well.

[0183] 1.5 Prepare 3x test compound using FACS buffer, and set up a control well without adding sample. Add 50μL of the corresponding compound to each well. Mix well, and incubate on ice for 15 min.

[0184] 1.6 Prepare 3x competing fluorescent molecule 01-FITC using FACS buffer, and set up a blank well without adding fluorescent molecule. Add 50μL of the corresponding compound to each well. Mix well, and incubate on ice for 60 min.

[0185] 1.7 Wash away the unbound compound with ice-cold FACS buffer, centrifuge at 400g for 5 min, discard the supernatant, and repeat once.

[0186] 1.8 Resuspend the cells in each well with 50μL FACS buffer, mix well, add 100μL 4% PFA solution, and fix at room temperature for 30 min. Detect the fluorescence signal using a flow cytometer.

[0187] 1.9 Analyze the data using Flowjo software, and calculate the mean fluorescence intensity value (MFI). The inhibition rate of competition binding is: inhibition rate (%) = (control group MFI - treatment group MFI) / control group MFI * 100. Use GraphPad Prism9 software to make a curve, with sample concentration as the X axis and the inhibition rate (%) of the test compound as the Y axis. Use a four-parameter nonlinear model to fit and calculate the IC 50 value.

[0188] 2. Experimental data

[0189] The results are shown in Table 8 below, wherein IC 50 Values A: 1-10 nM, B: 11-20 nM, C: 21-50 nM, D: >50 nM, the compounds of the present application can bind well to FAP-expressing cells, and have better cell binding activity than the reference compounds.

[0190] Table 8

[0191] Effect test example 2 SPR experiment

[0192] 1. Experimental procedure

[0193] 1.1 SPR experiments were performed on a Biacore 8k+ system. First, the SA chip (GE Healthcare, BR100531) was pretreated: three consecutive injections of 1 mol / L NaCl in 50 mM NaOH were performed for 1 min each; then the system was equilibrated with PBS-P buffer (20 mM phosphate buffer, pH 7.4, 2.7 mM KCl, 137 mM NaCl, 0.05% P20, 1 mM TCEP).

[0194] 1.2 Injection of Biotin-labeled Recombinant Human FAP Protein (Sino Biological, Inc, Cat# 10464-H07H-B): protein concentration 20 pg / mL, flow rate 10 pL / min, binding 500 s. The coupling amount of each channel was about 2000 RU.

[0195] 1.3 The sample to be tested was diluted with PBS-P buffer to a maximum concentration of 500 nM, with a final DMSO concentration of 2%, and was diluted 1:1 in PBS-P buffer containing 2% DMSO.

[0196] 1.4 Multi-cycle dose response: flow rate 30 pL / min, binding time of analyte 120 s, dissociation time 500 s. All experiments were performed at 15°C (sample chamber 25°C).

[0197] 1.5 The sensorgrams have been solvent corrected and data fitting was performed using the Biacore Insight Evaluation software.

[0198] 2. Experimental data

[0199] The results are shown in Table 9 below, wherein A: 1-20 nM, B: 20-50 nM, C: 50-100 nM, D: >100 nM.

[0200] Table 9

[0201] As can be seen from the above table data, the cyclic peptide molecules described in the application have better FAP affinity than the reference compounds.

[0202] Effect Test Example 3 In Vitro Mouse Serum Stability Experiment

[0203] 1. Experimental process

[0204] 1.1 Experimental preparation

[0205] 1.1.1 Intermediate diluent: 100 mL methanol was added to 100 mL acetonitrile, 200 mL water was mixed and used, and was stored at 4°C;

[0206] 1.1.2 Internal standard precipitant: 5 ng / mL Verapamil, 50 ng / mL Glibenclamide, 500 ng / mL Tolbutamide in MeOH (all obtained from China Institute for Drug Control);

[0207] 1.1.3 Test compound: accurately weigh a certain mass of 13, 16, 17, 18, 23, dissolve in DMSO to obtain a 2 mM stock solution; use the intermediate diluent to dilute the stock solution to prepare a 200 μM working solution

[0208] 1.2 Experimental operation

[0209] 1.2.1 Prepare eight connected tubes needed for incubation and sampling, and label the species and time points;

[0210] 1.2.2 Add 200 μL of internal standard precipitant in the EP tube or 96-well plate, and store at 4°C for standby;

[0211] 1.2.3 Mix 4 μL of 200 μM test sample working solution with 396 μL of various species serum, respectively, to prepare various species test sample serum samples with a concentration of 2 μM;

[0212] 1.2.4 Take 20 μL of the test incubation tube at 0, 0.5, 1, 4, 8, 24 h, and the positive control group at 0, 30, 60 min, and add it to the internal standard-containing precipitation tube;

[0213] 1.2.5 3700 rpm centrifugation for 10 min, take the supernatant, dilute with water at a ratio of 1:1, and then inject the sample.

[0214] 1.3 Analysis method;

[0215] Method 1 is shown in Table 10 below.

[0216] Table 10

[0217] Method 2 is shown in Table 11 below:

[0218] Table 11

[0219] 2. Experimental data

[0220] The results are shown in Table 12 below:

[0221] Table 12

[0222] As can be seen from the above table, the compound of the present application has good stability, and the stability of the tested compound in mouse serum is t 1 / 2 for nearly 7 h and above.

Claims

1. A compound of Formula I: ###0001### or a pharmaceutically acceptable salt thereof. - X1is the ring A is a 3-6 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; - X2- is the ring B is a 3-6 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; -W- is -NH-CO- or -NH-CO-NH-; R 1 is C 1-10 alkyl; R 2 C1-C6-alkyl or C1-C6-alkyl substituted by 1, 2 or 3 R 2-1 substituents; R 2-1 each independently is C1-C6alkyl, halogen, hydroxyl, guanidinyl, carboxyl, or amido; R 3 H, C1-C6 alkyl or C1-C6 alkyl substituted by 1, 2 or 3 R 3-1 substituents; R 3-1 independently carboxyl or amido; R 4 C1-C6alkylene-R 4-1 ; R 4-1 C6-C10aryl, 3- to 8-membered cycloalkyl, C6-C10aryl or 3- to 8-membered cycloalkyl substituted by 1, 2 or 3 R 10 substituted C6-C10aryl or 3- to 8-membered cycloalkyl; R 4-1-1 substituted C6-C10aryl or 3- to 8-membered cycloalkyl; R 10 substituted C6-C10aryl or 3- to 8-membered cycloalkyl; R 4-1-2 substituted C6-C10aryl or 3- to 8-membered cycloalkyl; R R 4-1-1 and R 4-1-2 each independently halogen, hydroxy, or Ci-C6alkyl; R 5 is hydroxyl or R 5-1 and R 5-2 each independently is H, C1-C6alkyl or C1-C6alkyl substituted with 1, 2, or 3 R 5-1-1 substituents; R 5-1-1 each independently is amino, hydroxyl, carboxyl, or amido; - L1- and -L2- are independently -(CH2) n - L 1-1 - L m - L 1-1 are independently S, O or NH; n and m are independently 1, 2 or 3; said ring C is C6-C10aryl or 5-10 membered heteroaryl; 10 arylene or 5-12 membered heteroarylene, the heteroatoms of which are selected from one or more of N, O, and S, the number of heteroatoms being 1, 2, or 3; -R 6 is -H or -(CH2) e -R 6-1 -(CH2) t -NH2; R 6-1 is S, O or NH; e and t are independently 1, 2 or 3; the compound of formula I satisfies one or two of the following conditions: (1) the ring A is a 4 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; (2) R 4-1 is 3-8 membered cycloalkyl or 3-8 membered cycloalkyl substituted with 1, 2, or 3 R 4-1-2 substituted 3-8 membered cycloalkyl.

2. The compound of claim 1, or a pharmaceutically acceptable salt thereof, having the formula I, wherein which satisfies one or more of the following conditions: (1) In ring A, the 3-6 membered heterocycloalkylene group can be a 4-6 membered heterocycloalkylene group, the heteroatoms of the heterocycloalkyl group are preferably N, O or S, the number of heteroatoms is preferably 1 or 2, and at least one N is contained, for example the 3-6 membered heterocycloalkylene group is (2) in ring B, the 3-6 membered heterocycloalkylene group can be a 4-6 membered heterocycloalkylene group, the heteroatom(s) of the heterocycloalkyl group preferably being N, O or S, the number of heteroatoms preferably being 1 or 2, and at least one N being present, for example the 3-6 membered heterocycloalkylene group is (3) R 1 In particular, the C 1-10 alkyl is linear C 1-10 alkyl, for example linear C 3-10 alkyl, preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl or n-nonyl, further preferably n-butyl or n-pentyl; (4) R 2 C1-C6alkyl and C1-C6alkyl in C1-C6alkyl substituted by 1, 2, or 3 R 2-1 C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example methyl; (5) R 2-1 In particular, the C1-C6alkyl group is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-butyl, for example methyl. (6) R 2-1 In some embodiments, the halogen is independently fluorine, chlorine, bromine, or iodine. (7) R 3 C1-C6alkyl and C1-C6alkyl in C1-C6alkyl substituted by 1, 2, or 3 R 3-1 C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, for example, ethyl; (8) R 4 In particular, the C1-C6 alkylene group is independently methylene, ethylene, n- propylene, i-propylene, n-butylene, i-butylene or t-butylene, for example methylene. (9)R 4-1 In the middle, C6~C 10 aryl and one, two or three R 4-1-1 Replacement of C6~C 10 C6-C in aryl groups 10 The aryl group can be phenyl or naphthyl, for example, phenyl; (10) R 4-1 In particular, the 3-8 membered cycloalkyl or the 3-8 membered cycloalkyl substituted with 1, 2, or 3 R 4-1-2 In particular, the 3-8 membered cycloalkyl or the 3-8 membered cycloalkyl substituted with 1, 2, or 3 R In particular, the 3-8 membered cycloalkyl or the 3-8 membered cycloalkyl substituted with 1, 2, or 3 R (11) R 4-1-1 and R 4-1-2 wherein said C1-C6alkyl is independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-butyl; (12) R 4-1-1 and R 4-1-2 wherein said halogen is independently fluorine, chlorine, bromine or iodine; (13) R 5-1 and R 5-2 Among them, the C1-C6 alkyl and the C1-C6 alkyl substituted by 1, 2 or 3 R 5-1-1 The C1-C6 alkyl in the C1-C6 alkyl substituted by 1, 2 or 3 R (14) in ring C, said C6-Ci2-alkyl is optionally substituted by one or more halogen; 10 arylene is phenylene or naphthylene, for example phenylene; (15) in the ring C, the 5-12 membered heteroarylene is a 5-6 membered heteroarylene, the heteroatoms of which are preferably N, O or S, the number of heteroatoms being preferably 1, 2 or 3.

3. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein which satisfies one or more of the following conditions: (1) said -X1- is said ring A is 4-membered heterocycloalkylene, the heteroatom of said 4-membered heterocycloalkylene is selected from one or more of N, O and S, the number of heteroatoms is 1, 2 or 3, and at least one N; and said N is located in the beta position to the carboxyl group, for example -X1- is (2) -X2- is the ring B is a 5 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; (3) R 2 C1-C6alkyl substituted by 1, 2, or 3 R 2-1 C1-C6alkyl substituted by 1, 2, or 3 R (4) R 2-1 each independently is C1-C6alkyl or hydroxy; (5) R 3 C1-C6alkyl substituted by 1, 2, or 3 R 3-1 C1-C6alkyl substituted by 1, 2, or 3 R (6) R 3-1 is an amide group; (7) R 4-1 is C6-Ci8-aryl or 3-8 membered cycloalkyl, preferably R 10 is C6-Ci8-aryl or 3-8 membered cycloalkyl, preferably R 4-1 is 3-8 membered cycloalkyl, for example cyclohexyl; (8) R 5-1 and R 5-2 each independently is H or C1-C6 alkyl substituted with 1, 2, or 3 R 5-1-1 substituents; (9) R 5-1-1 each independently is amino or carboxyl; (10) L 1-1 is S; (11) said ring C is C6-Ci0aryl or C1-C6alkyl; 10 arylene; (12) R 6-1 is S; (13) -W- is -NH-CO-NH-, preferably, when -W- is -NH-CO-, R 6 is H, R 4-1 is H, R 10 C6-Cι0aryl or C6-Cι0aryl substituted by 1, 2 or 3 R 4-1-1 C6-Cι0aryl or C6-Cι0aryl substituted by 1, 2 or 3 R 10 C6-Cι0aryl or C6-Cι0aryl substituted by 1, 2 or 3 R (14) the compound of Formula I satisfies the following condition: the ring A is a 4-membered heterocycloalkylene, the heteroatom of the 4-membered heterocycloalkylene is selected from one or more of N, O and S, the number of heteroatoms is 1, 2 or 3, and at least contains one N, and / or, R 4-1 is 3-8 membered cycloalkyl.

4. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein which satisfies one or more of the following conditions: (1) -X1- is wherein is attached to X2; (2) -X2- is wherein is attached to -NH-; (3) -W- is -NH-CO-* or -NH-CO-NH-*, where the * end is to R 1 connected; (4) R 4 is *-C1-C6alkylene-R 4-1 wherein the *-end is attached to the methylene group; (5) -L1- and -L2- are independently -(CH2) n -L 1-1 -(CH2) m - *, wherein the * is attached to Ring C.

5. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein in the compound of formula I, - X1is the ring A is a 3-6 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; - X2- is the ring B is a 3-6 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; -W- is -NH-CO- or -NH-CO-NH-; R 1 is C 1-10 alkyl; R 2 C1-C6alkyl substituted by 1, 2, or 3 R 2-1 C1-C6alkyl substituted by 1, 2, or 3 R R 2-1 each independently is C1-C6alkyl or hydroxy; R 3 C1-C6alkyl substituted by 1, 2, or 3 R 3-1 substituted C1-C6alkyl; R 3-1 is an amido group; R 4 is C1-C6alkylene-R 4-1 ; R 4-1 C6-Ci8aryl or 3-8 membered cycloalkyl; and 10 C6-Ci8aryl or 3-8 membered cycloalkyl; and R 5 is hydroxyl or R 5-1 and R 5-2 each independently is H or C1-C6 alkyl substituted with 1, 2, or 3 R 5-1-1 substituents; R 5-1-1 each independently is amino or carboxyl; - L1- and -L2- are independently -(CH2) n - L 1-1 - (CH2) m - L 1-1 is S; n and m are independently 1, 2 or 3; said ring C is C6-C10aryl or heteroaryl; 10 arylene; -R 6 is -H or -(CH2) e -R 6-1 -(CH2) t -NH2; R 6-1 is S; e and t are independently 1, 2 or 3; the compound of formula I satisfies one or two of the following conditions: (1) the ring A is a 4 membered heterocycloalkylene, the heteroatoms of which are selected from one or more of N, O and S, the number of heteroatoms being 1, 2 or 3, and at least one N; (2) R 4-1 is 3-8 membered cycloalkyl.

6. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein which satisfies one or more of the following conditions: (1) -X1- is (2) -X2- is (3) -W-R is (4) -R 2 To (5) -R 3 To (6) -R 4 To (7) -R 5 is -OH, (8) -L1- and -L2- are -CH2-S-CH2-; (9) For (10) -R 6 -H or 7. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein The compound of formula I is a compound of formula I-1, I-2 or I-3; wherein -X1-, -X2-, -W-, R 1 , R 2 , R 3 , R 4 , R 5 , -L1-, -L2-, ring C and R 6 each independently are as described in claim 1.

8. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein The compound of formula I is any one of the following compounds:

9. A pharmaceutical composition comprising a compound of formula I according to any one of claims 1-8 or a pharmaceutically acceptable salt thereof and a pharmaceutical excipient, preferably, the pharmaceutical composition targets FAP.

10. Use of a compound of formula I according to any one of claims 1-8 or a pharmaceutically acceptable salt thereof or a pharmaceutical composition according to claim 9 for the manufacture of a medicament for the diagnosis or treatment of a tumor, which can be a solid tumor positive for FAP expression, such as breast cancer, ovarian cancer, lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, prostate cancer, liver cancer or skin melanoma, preferably, the medicament comprises a polypeptide conjugate, a radionuclide conjugate, further preferably, the conjugate is a FAP-targeting conjugate or a conjugate comprising a FAP-targeting component.

11. A conjugated drug, which is a compound of Formula I or a pharmaceutically acceptable salt thereof according to any one of claims 1-8 conjugated with one or more molecules selected from the group consisting of (1) cytotoxins, nuclides and / or small molecule drugs, (2) linker groups, preferably, the compound of Formula I or a pharmaceutically acceptable salt thereof is linked to the group(s) via a peptide-forming reaction; the conjugated drug is, for example, a single-target drug and a multi-target drug, further preferably, the conjugated drug is a FAP polypeptide-targeted conjugated drug or a FAP nuclide-targeted conjugated drug; the conjugated drug can be a drug for diagnosis or treatment of a tumor, which can be a solid tumor positive for FAP expression, such as breast cancer, ovarian cancer, lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, prostate cancer, liver cancer or skin melanoma.

12. A compound according to Formula II: ###0002### II or a pharmaceutically acceptable salt thereof. wherein n1, n2, L 1-1a , L 1-1b , -X1-, -X2-, -W-, R 1 , R 2 , R 3 , R 4 , R 5 , -L1-, -L2-, ring C and R 6 each independently as in any one of claims 1-8.

13. The compound of claim 12 of Formula II, or a pharmaceutically acceptable salt thereof, wherein, The compound of Formula II is any one of the following compounds:

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