Polypeptide conjugate of camptothecin medicine and application of polypeptide conjugate
By developing polypeptide conjugates of camptothecin drugs, the specific activation mechanism of Legumain enzyme was used to solve the problem of lack of targeting and high toxic side effects of existing camptothecin drugs, and achieved efficient killing effect and low toxicity in the tumor microenvironment.
Patent Information
- Application Number
- CN202510252965.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-06-27
Smart Images
Figure CN120209071A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of polypeptide conjugates, and particularly relates to a polypeptide conjugate of a camptothecin drug and its application. Background Art
[0002] Due to their good anti-tumor activity, camptothecin drugs have been increasingly used in the anti-tumor field in recent years. However, due to their high toxicity, only three camptothecin drugs, irinotecan, topotecan, and belotecan, have been approved for marketing. And more of them have been used in the field of ADC drugs. Trodelvy and DS-8201 have been launched on the market. Although ADC has solved the efficacy problem, its use has been greatly limited due to its high toxicity. Therefore, developing a low-toxic camptothecin drug while maintaining its original anti-tumor activity can meet more clinical needs. Summary of the Invention
[0003] The present application provides a polypeptide conjugate of a camptothecin drug and its application, aiming to solve the problem that the existing camptothecin drugs lack targeting and have high toxic and side effects, resulting in limited clinical applications.
[0004] The first aspect of the present application provides a polypeptide conjugate of a camptothecin drug, and the structural formula of the polypeptide conjugate is shown as the following formula: E-P-L1-L2-L3-L4-L5-D;
[0005] Wherein, E is selected from the following groups:
[0006]
[0007] It is connected to P or L1 at the "1" position, 1 ≤ n ≤ 18, and X includes halogens;
[0008] P may or may not exist. When P exists, P includes polyethylene glycol;
[0009] L1 and L2 each independently include one or more of glycine, alanine, and serine;
[0010] L3 includes asparagine;
[0011] L4 may or may not exist. When L4 exists, L4 includes glycine and / or leucine;
[0012] L5 may or may not exist. When L5 exists, L5 includes the following structure:
[0013]
[0014] The "4" position is connected to the carboxyl terminus of L3 or L4, and the "5" position is connected to D; 0 ≤ n2 ≤ 40 and n2 is an integer. For example, n2 can be 0, 5, 8, 10, 12, 14, 16, 18, 20, 25, 28, 30, 34, 37, 39, 40, etc.; 0 ≤ n3 ≤ 40 and n3 is an integer. For example, n3 can be 0, 5, 8, 10, 12, 14, 16, 18, 20, 25, 28, 30, 34, 37, 39, 40, etc.
[0015] R1, R2, and R3 each independently include hydrogen and / or methyl.
[0016] D is a camptothecin compound.
[0017] According to some embodiments of the polypeptide conjugate of the camptothecin drug described in the present application, the structural formula of the polyethylene glycol is as shown in the following formula:
[0018]
[0019] Among them, the "2" position is connected to E, the "3" position is connected to the amino group of L1, 1 ≤ n1 ≤ 40 and n1 is an integer. For example, n1 can be 1, 2, 3, 5, 8, 10, 15, 18, 20, 26, 28, 30, 32, 36, 40, etc.
[0020] According to some embodiments of the polypeptide conjugate of the camptothecin drug described in the present application, the structural formula of D is selected from the following structures:
[0021]
[0022] Among them, the "6" position is connected to the carboxyl terminus of L5, L4 or L3, 0 ≤ n4 ≤ 20 and n4 is an integer. For example, n4 can be 0, 2, 3, 8, 10, 13, 16, 18, 20, etc.
[0023] According to some embodiments of the polypeptide conjugate of the camptothecin drug described in the present application, the structural formula of the polypeptide conjugate is selected from the following structures:
[0024]
[0025]
[0026]
[0027]
[0028] The second aspect of the present application provides a pharmaceutical composition, including the polypeptide conjugate of the camptothecin drug described in the first aspect of the present application and a pharmaceutically acceptable carrier thereof.
[0029] The third aspect of the present application provides an application of the polypeptide conjugate of the camptothecin drug described in the first aspect of the present application or the pharmaceutical composition described in the second aspect of the present application in the preparation of an anti-tumor drug for treatment or prevention.
[0030] According to some embodiments of the application described in the present application, the tumors include one or more of gastrointestinal cancer, colorectal cancer, colon cancer, liver cancer, hepatocellular carcinoma, pancreatic cancer, biliary tract cancer, gastric cancer, urogenital system cancer, bladder cancer, testicular cancer, cervical cancer, malignant mesothelioma, osteogenic sarcoma, esophageal cancer, laryngeal cancer, prostate cancer, hormone-resistant prostate cancer, lung cancer, small cell lung cancer, non-small cell lung cancer, breast cancer, triple-negative breast cancer, blood cancer, leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, lymphoma, Hodgkin lymphoma, non-Hodgkin lymphoma, follicular lymphoma, diffuse large B-cell lymphoma, ovarian cancer, brain cancer, neuroblastoma, Ewing sarcoma, kidney cancer, epidermoid carcinoma, skin cancer, melanoma, and oral cancer.
[0031] The beneficial effects of the present application include: The polypeptide conjugate of the camptothecin drug described in the present application can block the activity of the camptothecin drug, and it can be activated by Legumain highly expressed in tumor cells and tumor-associated macrophages in the slightly acidic microenvironment of the tumor, so that the drug is selectively released in the tumor microenvironment, causing tumor cell death, and it is rarely activated in normal tissues and blood, so the toxicity is low. Therefore, it has good targeting and can achieve multiple effects of inhibiting tumor growth and reducing the toxic and side effects of the drug. Description of the Drawings
[0032] Figure 1 It is a curve graph showing the treatment effects of the polypeptide conjugate shown in X1-X3 of the present application, the toxin molecule CX-P01, and cisplatin on A2780 tumors;
[0033] Figure 2 It is a curve graph showing the treatment effects of the polypeptide conjugate shown in X6-X11 of the present application, the toxin molecule SN38, and cisplatin on A2780 tumors;
[0034] Figure 3 It is a curve graph showing the treatment effects of the polypeptide conjugate shown in X1-X3 of the present application, the toxin molecule CX-P01, and cisplatin on SJSA-1 tumors;
[0035] Figure 4 It is a curve graph showing the treatment effects of the polypeptide conjugate shown in X6-X11 of the present application, the toxin molecule SN38, and cisplatin on SJSA-1 tumors. Detailed Embodiments
[0036] Embodiments of the present invention will be described in detail below. The examples of the embodiments are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.
[0037] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0038] Wherein: G represents glycine, A represents alanine, N represents asparagine, PAB represents aminobenzyl alcohol, S represents serine, MC represents maleimide group, L represents leucine, DMEA represents dimethylethylenediamine structure, MSPP represents 2-methylsulfonylpyrimidine structure, BA represents bromoacetic acid.
[0039] Example 1
[0040] Synthesis of MC-6PEG-AANG-AM-CX-P01 (X1)
[0041]
[0042] The synthesis route of the compound shown in X1 includes:
[0043]
[0044] The specific synthesis method includes the following steps:
[0045] (1) Synthesis of Compound 1-I
[0046] Boron trichloride (16 g, 136.6 mmol) was dissolved in 1,2-dichloroethane (50 mL). The temperature was lowered to 0 °C in an ice-water bath, and a solution of aniline (10 g, 107.4 mmol) in 100 mL of 1,2-dichloroethane was slowly added dropwise while maintaining the temperature below 5 °C. Then, 4-chlorobutyronitrile (11.2 g, 108.2 mmol) and aluminum trichloride (14.5 g, 108.7 mmol) were added to form a reaction solution. The ice bath was removed, and the reaction solution was slowly warmed to room temperature (25 °C) and reacted for 30 minutes. Then, the temperature was raised to reflux and reacted for 24 hours. After the reaction was completed, the reaction solution was cooled to room temperature (25 °C), 100 mL of 2N hydrochloric acid was slowly added, and then the temperature was raised to reflux and reacted for 0.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature (25 °C), extracted with chloroform (200 mL * 4), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with petroleum ether (PE): ethyl acetate (EA) with a volume ratio of 50:1 to 8:1) to obtain compound 1-I as a brown solid (3.1 g, yield 14.6%);
[0047] (2) Synthesis of compound 1-III
[0048] Compound 1-I (3.1 g, 15.7 mmol) and compound 1-II (4.1 g, 15.6 mmol) were added to toluene (200 mL), and then o-cresol (15 g, 138.7 mmol) and p-toluenesulfonic acid monohydrate (2 g, 10.5 mmol) were added to the toluene to form a reaction solution. The reaction solution was heated to reflux for water separation for 5 hours. HPLC detection showed that the reaction was complete. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with dichloromethane (DCM): methanol (MeOH) with a volume ratio of 100:1 to 20:1) to obtain compound 1-III as a yellow solid (5.6 g, yield 84.5%).
[0049] (3) Synthesis of compound 1-IV
[0050] Compound 1-III (5.6 g, 13.2 mmol) was dissolved in hexamethylphosphoramide (50 mL), purified water (100 mL) was added to form a reaction solution, and the reaction solution was heated to 100 °C and reacted for 48 hours. After the reaction was completed, the reaction solution was cooled to room temperature (25 °C), and purified by high-pressure reverse-phase preparation to obtain compound 1-IV as an off-white solid (1.6 g, yield 29.8%).
[0051] (4) Synthesis of compound 1-VI
[0052] Compound 1-IV (300 mg, 0.74 mmol) and 1-V (300 mg, 0.81 mmol) were dissolved in dichloromethane (50 mL). Pyridinium p-toluenesulfonate (80 mg, 0.32 mmol) was added to the dichloromethane to form a reaction solution. The reaction solution was heated to reflux for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature (25 °C) and evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with dichloromethane (DCM): methanol (MeOH) in a volume ratio of 100:1 to 30:1) to obtain Compound 1-VI as a yellow solid (260 mg, yield 49.2%).
[0053] (5) Synthesis of Compound 1-VII
[0054] Compound 1-VI (260 mg, 0.36 mmol) was dissolved in N,N-dimethylformamide (20 mL). Piperidine (100 mg, 1.17 mmol) was added to the N,N-dimethylformamide to form a reaction solution. The reaction solution was reacted at room temperature (25 °C) for 2 hours. HPLC detection showed that the raw materials had completely reacted. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by reverse-phase preparative chromatography to obtain Compound 1-VII as an off-white solid (110 mg, yield 61.4%).
[0055] (6) Synthesis of Compound MC-6PEG-AANG-AM-CX-P01
[0056] Compound 1-VII (110 mg, 0.22 mmol) and Compound 1-VIII (180 mg, 0.24 mmol) were dissolved in N,N-dimethylformamide (25 mL). HATU (120 mg, 0.32 mmol) and DIEA (120 mg, 0.93 mmol) were added to the N,N-dimethylformamide to form a reaction solution. The reaction solution was reacted at room temperature (25 °C) for 5 hours. HPLC detection showed that the raw materials had completely reacted. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparative chromatography to obtain MC-6PEG-AANG-AM-CX-P01 as an off-white solid (49 mg, yield 17.8%).
[0057] Example 2
[0058] Synthesis of MC-6PEG-AANL-AM-CX-P01 (X2)
[0059]
[0060] The synthesis route of the compound shown in X2 includes:
[0061]
[0062] The specific synthesis method includes the following steps:
[0063] (1) Synthesis of Compound 2-II
[0064] Dissolve Compound 2-I (10 g, 24.3 mmol) in dry tetrahydrofuran (150 mL), then add toluene (50 mL), pyridine (2.31 mL) and lead tetraacetate (13.62 g, 29.3 mmol) to the tetrahydrofuran to form a reaction solution. Conduct nitrogen displacement treatment on the reaction solution, and then heat it to 80 °C for reaction for 5 hours. Filter out the insoluble substances, spin-dry the filtrate, dissolve the residue in ethyl acetate, and wash it 3 times with water. Dry the organic phase with anhydrous sodium sulfate, filter, evaporate to dryness under reduced pressure, and purify the product obtained by evaporation to dryness under reduced pressure through a silica gel column (elute with petroleum ether (PE):ethyl acetate (EA) with a volume ratio of 3:1 to 1:4) to obtain white solid of Compound 2-II (7.2 g, yield 73%).
[0065] (2) Synthesis of Compound 2-III
[0066] Dissolve Compound 1-IV (300 mg, 0.74 mmol) and 2-II (350 mg, 0.82 mmol) in dichloromethane (50 mL), then add pyridinium p-toluenesulfonate (80 mg, 0.32 mmol) to the dichloromethane to form a reaction solution. Heat the reaction solution to reflux for reaction for 8 hours. After the reaction is completed, cool the reaction solution to room temperature of 25 °C, evaporate to dryness under reduced pressure, and purify the product obtained by evaporation to dryness under reduced pressure through a silica gel column (elute with dichloromethane (DCM):methanol (MeOH) with a volume ratio of 100:1 to 30:1) to obtain yellow solid of Compound 2-III (245 mg, yield 42.9%).
[0067] (3) Synthesis of Compound 2-IV
[0068] Dissolve Compound 2-III (245 mg, 0.32 mmol) in N,N-dimethylformamide (20 mL), then add piperidine (100 mg, 1.17 mmol) to the N,N-dimethylformamide to form a reaction solution. React the reaction solution at room temperature of 25 °C for 2 hours. Detect by HPLC that the raw materials have completely reacted. Evaporate the reaction solution to dryness under reduced pressure, and purify the product obtained by evaporation to dryness under reduced pressure by reverse-phase preparation to obtain off-white solid of Compound 2-IV (89 mg, yield 51.0%).
[0069] (4) Synthesis of Compound MC-6PEG-AANL-AM-CX-P01
[0070] Compound 2-IV (89 mg, 0.16 mmol) and Compound 1-VIII (150 mg, 0.20 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then, HATU (100 mg, 0.26 mmol) and DIEA (100 mg, 0.78 mmol) were added to the N,N-dimethylformamide to form a reaction solution. The reaction solution was reacted at room temperature (25 °C) for 5 hours, and HPLC was used to detect that the raw materials had completely reacted. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain a white solid of MC-6PEG-AANL-AM-CX-P01 (28 mg, yield 14.0%).
[0071] Example 3
[0072] Synthesis of MC-6PEG-AAN-AM-CX-P01 (X3)
[0073]
[0074] The synthesis route of the compound shown in X3 includes:
[0075]
[0076] The specific synthesis method includes the following steps:
[0077] (1) Synthesis of Compound 3-II
[0078] Compound 3-I (2 g, 4.03 mmol) and tert-butyl glycinate (530 mg, 4.04 mmol) were dissolved in N,N-dimethylformamide (50 mL). Then, HATU (3.2 g, 8.42 mmol) and DIEA (2.5 g, 19.4 mmol) were added to the N,N-dimethylformamide to form a reaction solution. The reaction solution was reacted at room temperature (25 °C) for 5 hours, and HPLC was used to detect that the raw materials had completely reacted. The reaction solution was evaporated to dryness under reduced pressure. Dichloromethane (50 mL) and trifluoroacetic acid (15 mL) were added to the product obtained by evaporation to dryness under reduced pressure, and the mixture was reacted at room temperature (25 °C) for 2 hours. HPLC was used to detect that the raw materials had completely reacted, and then it was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with dichloromethane (DCM): methanol (MeOH) with a volume ratio of 100:1 to 12:1) to obtain a yellow solid of 3-II (850 mg, yield 38.1%).
[0079] (2) Synthesis of Compound 3-III
[0080] Compound 3-II (850 mg, 1.54 mmol) was dissolved in dry tetrahydrofuran (20 mL). Then, toluene (6 mL), pyridine (0.3 mL) and lead tetraacetate (1 g, 2.26 mmol) were added to the tetrahydrofuran to form a reaction solution. The reaction solution was purged with nitrogen, and then heated to 80 °C and reacted for 5 hours. After the reaction was completed, the insoluble substances were filtered off, the filtrate was evaporated to dryness, and the residue was purified by silica gel column chromatography (eluted with dichloromethane (DCM): methanol (MeOH) with a volume ratio of 100:1 to 15:1) to obtain compound 3-III as a yellow solid (460 mg, yield 52.6%).
[0081] (3) Synthesis of compound 3-IV
[0082] Compound 1-IV (300 mg, 0.74 mmol) and 3-III (460 mg, 0.81 mmol) were dissolved in dichloromethane (50 mL). Then, pyridinium p-toluenesulfonate (80 mg, 0.32 mmol) was added to the dichloromethane to form a reaction solution. The reaction solution was heated to reflux and reacted for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature (25 °C) and evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with dichloromethane (DCM): methanol (MeOH) with a volume ratio of 100:1 to 15:1) to obtain compound 3-IV as a light brown solid (385 mg, yield 56.9%).
[0083] (4) Synthesis of compound 3-V
[0084] Compound 3-IV (385 mg, 0.42 mmol) was dissolved in N,N-dimethylformamide (20 mL). Then, piperidine (100 mg, 1.17 mmol) was added to the N,N-dimethylformamide to form a reaction solution, and the reaction was carried out at room temperature (25 °C) for 2 hours. HPLC detection showed that the raw materials reacted completely. The reaction solution was evaporated to dryness under reduced pressure, and the product obtained by evaporation to dryness under reduced pressure was purified by reverse-phase preparation to obtain compound 3-V as an off-white solid (185 mg, yield 63.7%).
[0085] (5) Synthesis of compound MC-6PEG-AAN-AM-CX-P01
[0086] Compound 3-V (185 mg, 0.27 mmol) and compound 3-VI (180 mg, 0.30 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then DIEA (100 mg, 0.78 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 5 hours. The raw materials were completely reacted as detected by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain a white solid of MC-6PEG-AAN-AM-CX-P01 (92 mg, yield 29.2%).
[0087] Example 4
[0088] Synthesis of MC-6PEG-GANG-AM-CX-P01 (X4)
[0089]
[0090] The synthesis route of the compound shown in X4 includes:
[0091]
[0092] The specific synthesis method includes the following steps:
[0093] Synthesis of compound MC-6PEG-GANG-AM-CX-P01
[0094] Compound 1-VII (110 mg, 0.22 mmol) and compound 4-I (180 mg, 0.24 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then HATU (120 mg, 0.32 mmol) and DIEA (120 mg, 0.93 mmol) were added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 5 hours. The raw materials were completely reacted as detected by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain a white solid of MC-6PEG-GANG-AM-CX-P01 (36 mg, yield 13.4%).
[0095] Example 5
[0096] Synthesis of MC-6PEG-SANG-AM-CX-P01 (X5)
[0097]
[0098] The synthesis route of the compound shown in X5 includes:
[0099]
[0100] The specific synthesis method includes the following steps:
[0101] Compound 1-VII (110 mg, 0.22 mmol) and Compound 5-I (180 mg, 0.23 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then, 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 120 mg, 0.32 mmol) and DIEA (120 mg, 0.93 mmol) were added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 5 hours. The reaction was monitored by HPLC and found to be complete. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparative chromatography to obtain a white solid of MC-6PEG-SANG-AM-CX-P01 (19 mg, yield 6.9%).
[0102] Example 6
[0103] Synthesis of MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38 (X6)
[0104]
[0105] The synthetic route of the compound shown in X6 includes:
[0106]
[0107] The specific synthesis method includes the following steps:
[0108] (1) Synthesis of Compound 6-I
[0109] SN38 (2 g, 5.10 mmol) was dissolved in dichloromethane (100 mL). Then, di-tert-butyl dicarbonate (3.2 g, 14.67 mmol) and pyridine (12 mL) were added to the dichloromethane to form a reaction solution, which was reacted at room temperature (25 °C) for 2 hours. The reaction was monitored by HPLC and found to have stopped. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with petroleum ether (PE):ethyl acetate (EA) with a volume ratio of 1:1 to 1:20) to obtain a pale yellow solid of Compound 6-I (1.6 g, yield 63.7%).
[0110] (2) Synthesis of Compound 6-II
[0111] Dissolve compound 6-I (500 mg, 1.02 mmol) in N,N-dimethylformamide (50 mL), then add p-nitrophenyl chloroformate (250 mg, 1.24 mmol), 4-dimethylaminopyridine (DMAP, 100 mg, 0.82 mmol) and DIEA (350 mg, 2.71 mmol) to the N,N-dimethylformamide to form a reaction solution. The reaction solution is reacted at room temperature (25 °C) for 4 hours. HPLC detects that the reaction is complete. The reaction solution is evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure is purified by silica gel column chromatography (eluted with petroleum ether (PE):ethyl acetate (EA) with a volume ratio of 1:1 to 1:20) to obtain compound 6-II as a pale yellow solid (420 mg, yield 62.6%).
[0112] (3) Synthesis of compound 6-IV
[0113] Dissolve compound 6-II (420 mg, 0.64 mmol) in N,N-dimethylformamide (30 mL), then add compound 6-III (300 mg, 0.86 mmol) and DIEA (250 mg, 1.94 mmol) to the N,N-dimethylformamide to form a reaction solution. The reaction solution is reacted at room temperature (25 °C) for 6 hours. HPLC detects that the raw materials have completely reacted. The reaction solution is evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure is purified by silica gel column chromatography (eluted with dichloromethane (DCM):methanol (MeOH) with a volume ratio of 50:1 to 15:1) to obtain compound 6-IV as a pale yellow solid (366 mg, yield 65.8%).
[0114] (4) Synthesis of compound 6-V
[0115] Add compound 6-IV (366 mg, 0.42 mmol) to dichloromethane (15 mL), then add trifluoroacetic acid (8 mL) to the dichloromethane to form a reaction solution. The reaction solution is reacted at room temperature (25 °C) for 2 hours. HPLC detects that the raw materials have completely reacted. The reaction solution is evaporated to dryness under reduced pressure, and the product obtained by evaporation to dryness under reduced pressure is purified by reverse-phase preparation to obtain compound 6-V as an off-white solid (205 mg, yield 62.4%).
[0116] (5) Synthesis of compound MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38
[0117] Compound 6-V (205 mg, 0.26 mmol) and compound 6-VI (350 mg, 0.32 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then, DIEA (200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 8 hours. The raw materials were completely reacted as detected by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain white solid MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38 (115 mg, yield 27.1%).
[0118] Example 7
[0119] Synthesis of MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38 (X7)
[0120]
[0121] The synthesis route of the compound shown in X7 includes:
[0122]
[0123] The specific synthesis method includes the following steps:
[0124] Compound 6-V (200 mg, 0.26 mmol) and compound 7-I (350 mg, 0.31 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then, DIEA (200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 8 hours. The raw materials were completely reacted as detected by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain white solid MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38 (89 mg, yield 20.8%).
[0125] Example 8
[0126] Synthesis of MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38 (X8)
[0127]
[0128] The synthesis route of the compound shown in X8 includes:
[0129]
[0130] The specific synthesis method includes the following steps:
[0131] Compound 6-V (200 mg, 0.26 mmol) and compound 8-I (350 mg, 0.34 mmol) were dissolved in N,N-dimethylformamide (25 mL). Then DIEA (200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 8 hours. The raw materials were detected to have completely reacted by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38 as a white solid (131 mg, yield 32.9%).
[0132] Example 9
[0133] Synthesis of MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38-1 (X9)
[0134]
[0135] The synthetic route of the compound shown in X9 includes:
[0136]
[0137] The specific synthesis method includes the following steps:
[0138] (1) Synthesis of compound 9-I
[0139] Compound SN38 (2 g, 5.10 mmol) was dissolved in N,N-dimethylformamide (50 mL). Then p-nitrophenyl chloroformate (1.2 g, 5.95 mmol) and DIEA (1 g, 7.75 mmol) were added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 4 hours. The reaction was detected to be complete by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by silica gel column chromatography (eluted with petroleum ether (PE): ethyl acetate (EA) with a volume ratio of 1:1 to 1:20) to obtain compound 9-I as a light yellow solid (1.6 g, yield 56.3%).
[0140] (2) Synthesis of compound 9-II
[0141] Dissolve compound 9-I (1.6 g, 2.87 mmol) in N,N-dimethylformamide (100 mL), then add compound 6-III (1.0 g, 2.85 mmol) and N,N-diisopropylethylamine (DIEA, 650 mg, 5.04 mmol) to the N,N-dimethylformamide to form a reaction solution, and react at room temperature (25 °C) for 6 hours. HPLC detection shows that the raw materials have completely reacted. Evaporate the reaction solution to dryness under reduced pressure. Purify the product obtained by evaporation to dryness under reduced pressure through a silica gel column (elute with dichloromethane (DCM): methanol (MeOH) with a volume ratio of 50:1 to 15:1) to obtain compound 9-II as a yellow solid (1.72 g, yield 77.9%).
[0142] (3) Synthesis of compound 9-III
[0143] Add compound 9-II (1.72 g, 2.24 mmol) to dichloromethane (80 mL), then add trifluoroacetic acid (25 mL) to the dichloromethane to form a reaction solution, and react at room temperature (25 °C) for 2 hours. HPLC detection shows that the raw materials have completely reacted. Evaporate the reaction solution to dryness under reduced pressure, and purify the product obtained by evaporation to dryness under reduced pressure by reverse-phase preparation to obtain compound 9-III as an off-white solid (910 mg, yield 51.9%).
[0144] (4) Synthesis of compound MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38-1
[0145] Dissolve compound 9-III (300 mg, 0.38 mmol) and compound 6-VI (450 mg, 0.41 mmol) in N,N-dimethylformamide (30 mL), then add N,N-diisopropylethylamine (DIEA, 200 mg, 1.55 mmol) to the N,N-dimethylformamide to form a reaction solution, and react at room temperature (25 °C) for 8 hours. HPLC detection shows that the raw materials have completely reacted. Evaporate the reaction solution to dryness under reduced pressure. Purify the product obtained by evaporation to dryness under reduced pressure by high-pressure reverse-phase preparation to obtain MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38-1 as a white solid (143 mg, yield 23.3%).
[0146] Example 10
[0147] Synthesis of MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38-1 (X10)
[0148]
[0149] The synthetic route of the compound shown in X10 includes:
[0150]
[0151] The specific synthesis method includes the following steps:
[0152] Compound 9-III (300 mg, 0.38 mmol) and compound 7-I (450 mg, 0.39 mmol) were dissolved in N,N-dimethylformamide (30 mL). Then, N,N-diisopropylethylamine (DIEA, 200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 8 hours. The reaction was monitored by HPLC until the raw materials were completely reacted. The reaction solution was evaporated to dryness under reduced pressure. The product obtained after evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38-1 as a white solid (106 mg, yield 16.7%).
[0153] Example 11
[0154] Synthesis of MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 (X11)
[0155]
[0156] The synthetic route of the compound shown in X11 includes:
[0157]
[0158] The specific synthesis method includes the following steps:
[0159] Compound 9-III (300 mg, 0.38 mmol) and compound 8-I (450 mg, 0.44 mmol) were dissolved in N,N-dimethylformamide (30 mL). Then, N,N-diisopropylethylamine (DIEA, 200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution, which was reacted at room temperature (25 °C) for 8 hours. The reaction was monitored by HPLC until the raw materials were completely reacted. The reaction solution was evaporated to dryness under reduced pressure. The product obtained after evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 as a white solid (72 mg, yield 12.1%).
[0160] Example 12
[0161] Synthesis of MSPP-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 (X12)
[0162]
[0163] The synthetic route of the compound shown in X12 includes:
[0164]
[0165] The specific synthesis method includes the following steps:
[0166] Compound 9-III (300 mg, 0.38 mmol) and compound 12-I (500 mg, 0.44 mmol) were dissolved in N,N-dimethylformamide (30 mL), and then N,N-diisopropylethylamine (DIEA, 200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution. The reaction was carried out at room temperature (25 °C) for 8 hours, and the reaction of the raw materials was detected to be complete by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain MSPP-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 as a white solid (55 mg, yield 8.7%).
[0167] Example 13
[0168] Synthesis of BA-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 (X13)
[0169]
[0170] The synthesis route of the compound shown in X13 includes:
[0171]
[0172] The specific synthesis method includes the following steps:
[0173] Compound 9-III (300 mg, 0.38 mmol) and compound 13-I (450 mg, 0.45 mmol) were dissolved in N,N-dimethylformamide (30 mL), and then N,N-diisopropylethylamine (DIEA, 200 mg, 1.55 mmol) was added to the N,N-dimethylformamide to form a reaction solution. The reaction was carried out at room temperature (25 °C) for 8 hours, and the reaction of the raw materials was detected to be complete by HPLC. The reaction solution was evaporated to dryness under reduced pressure. The product obtained by evaporation to dryness under reduced pressure was purified by high-pressure reverse-phase preparation to obtain BA-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1 as a white solid (29 mg, yield 5.0%).
[0174] 1. Experimental study on the cleavage activation of legumain enzyme (asparagine endopeptidase) of the camptothecin-based drug polypeptide conjugate described in this application
[0175] Buffer preparation: distilled water, 50 mM 2-(N-morpholino)ethanesulfonic acid (MES), 250 mM sodium chloride, adjusted to pH 5.0 with 0.5 M sodium hydroxide. Legumain was selected at a concentration of 1 mg / mL. The compounds shown in Examples 1-13 were respectively formulated into solutions with a concentration of 0.5 μmol / mL using the buffer. Accurately pipette 50 μL of the above 0.5 μmol / mL solution and 50 μL of the buffer into a centrifuge tube, add 100 μL of Legumain, and react at 37 °C for 2 h. Each reaction solution was detected by LC MS, and the results are shown in Table 1.
[0176] Table 1
[0177] Digestion product MC-6PEG-AANG-AM-CX-P01(X1) G-AM-CX-P01 MC-6PEG-AANL-AM-CX-P01(X2) L-AM-CX-P01 MC-6PEG-AAN-AM-CX-P01(X3) CX-P01 MC-6PEG-GANG-AM-CX-P01(X4) G-AM-CX-P01 MC-6PEG-SANG-AM-CX-P01(X5) G-AM-CX-P01 MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38(X6) G-PAB-DMEA(4PEG)-SN38 MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38(X7) L-PAB-DMEA(4PEG)-SN38 MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38(X8) SN38 MC-6PEG-AANG-PAB-DMEA(4PEG)-SN38-1(X9) G-PAB-DMEA(4PEG)-SN38-1 MC-6PEG-AANL-PAB-DMEA(4PEG)-SN38-1(X10) L-PAB-DMEA(4PEG)-SN38-1 MC-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1(X11) SN38 MSPP-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1(X12) SN38 BA-6PEG-AAN-PAB-DMEA(4PEG)-SN38-1(X13) SN38
[0178] It can be seen from Table 1 that the polypeptide conjugate of the camptothecin drug described in this application can be activated by the legumain enzyme highly expressed in tumor cells and tumor-associated macrophages.
[0179] 2. Experimental study on the activation of the polypeptide conjugate of the camptothecin drug described in this application by tumor homogenate
[0180] The PBS buffer was purchased from Beijing LanJieKe Technology Co., Ltd., Cat. NO: BL302A, Lot. No: 24149299.
[0181] CT26 tumor tissue homogenate: CT26 tumor tissue taken from C57BL / 6 mice with CT26 tumorigenesis model, and homogenate prepared using Jingxin F6 / 10 handheld homogenizer.
[0182] The polypeptide conjugates described in Examples 1-13 of this application were respectively formulated into solutions with a concentration of 0.5 mg / ml using PBS buffer. Respectively take 0.5 mL of the above solution, and add 300 micrograms of CT26 tumor tissue homogenate. The above solution was placed at 37 °C for 2 h. The generated compounds were detected by liquid chromatography-mass spectrometry (LC-MS), and the results are shown in Table 2.
[0183] Table 2
[0184]
[0185]
[0186] It can be seen from Table 2 that the polypeptide conjugate of the camptothecin drug described in this application can be activated by tumor homogenate and release small toxin molecules.
[0187] 3. Stability study of the polypeptide conjugate of the camptothecin drug described in this application in mouse normal tissue homogenate
[0188] The PBS buffer was purchased from Beijing LanJieKe Technology Co., Ltd., Cat. NO: BL302A, Lot. No: 24149299.
[0189] Mouse normal tissue homogenate: Organs were taken from 8-week-old C57BL / 6 mice after sacrifice and made into tissue homogenate using a Jingxin F6 / 10 handheld homogenizer.
[0190] The polypeptide conjugates of the camptothecin drugs described in Examples 1-13 of this application were respectively prepared into 0.5 mg / ml solutions with PBS buffer. 0.5 mL of each of the above solutions was taken and 300 micrograms of normal tissue homogenate was added, and the solutions were placed at 37 °C for 2 h. The release percentage of the drug in normal tissues was compared by detecting the reduction of the compound and the increase of the toxic molecule by high performance liquid chromatography (HPLC):
[0191] Release percentage = molar amount calculated from the peak area of the toxic molecule (see Table 1) / molar amount before activation of the polypeptide conjugate. The results are shown in Table 3: in %.
[0192] Table 3
[0193]
[0194]
[0195] It can be seen from Table 3 that: the polypeptide conjugates of the camptothecin drugs described in this application are partially released in the liver, kidney and lung, and there is almost no release in the heart, spleen, muscle and blood, and X1, X3-X5, and there is a small amount of release of other compounds.
[0196] 4. Toxicity experiment comparison (CCK8) of the polypeptide conjugates of the camptothecin drugs described in this application in tumor cell lines
[0197] Cells of different types (A2780 (ovarian cancer), SJSA-1 (sarcoma), and SKBR3 (breast cancer)) were cultured separately in complete medium (RPMI1640 (DMEM high-glucose medium) + 10% fetal bovine serum + 1X P / S + 1 mM sodium pyruvate solution). The cells were cultured in an incubator at 37°C and 5% CO2 until there were enough cells. The cells were collected, centrifuged at 1000g for 5 minutes, resuspended in an appropriate volume of 10% RPMI1640 (DMEM high-glucose medium) medium, and the cells were counted. 100 μL of cell culture medium containing different concentrations of drugs (the highest concentration well was prepared into a 5000 nmol / L solution, and then diluted 3-fold for each concentration. A total of 10 concentrations were measured, that is, the drug concentrations in each well were: 5000 nmol / L, 1667 nmol / L, 556 nmol / L, 185 nmol / L, 61.7 nmol / L, 20.6 nmol / L, 6.9 nmol / L, 2.3 nmol / L, 0.76 nmol / L, 0.25 nmol / L) was added to a 96-well culture plate. Control wells (0.1% DMSO) without drugs but only with the corresponding drug solvent were set, as well as zero-adjustment wells (Blank) with only medium and no cells. Each group had 3 parallel wells. Then the cells after counting were inoculated onto a 96-well culture plate, 100 μL of cell suspension per well, and the inoculation concentration of the cells was 5000 cells (100 μL) / well. Then the plate was placed in an incubator at 37°C and 5% carbon dioxide for 48 hours. After 48 hours, 10 μL of cell proliferation staining reagent (CCK8) was added to each well and incubated in the cell incubator for about 2 hours, and the absorbance at 450 nm was measured.
[0198] Note: 1X means one-fold, and P / S is penicillin / streptomycin. 1X P / S is a one-fold concentration solution of penicillin / streptomycin.
[0199] Legumain activation operation: Buffer preparation: distilled water, 50 mM MES, 250 mM sodium chloride, and the pH was adjusted to 5.0 with 0.5 M sodium hydroxide. The concentration of Legumain was selected as 1 mg / mL. The polypeptide conjugate was prepared into a solution with a concentration of 0.5 μmol / mL with the buffer. Exactly 50 μL of 0.5 μmol / mL polypeptide conjugate and 50 μL of buffer were pipetted into a centrifuge tube, 100 μL of Legumain was added, and it was placed at 37°C for 2 hours.
[0200] Calculate the cell survival rate and the half-maximal inhibitory concentration (IC50) of the drug on the cells. The IC50 is the half-maximal inhibitory concentration calculated by software based on the cell survival rates at the above 10 drug concentrations.
[0201] The specific experimental results of the half-maximal inhibitory concentration (IC50) of the polypeptide conjugate drug prototype against cells are shown in Table 4, and the specific experimental results of the half-maximal inhibitory concentration (IC50) of the polypeptide conjugate drug against cells after activation by Legumain are shown in Table 5: (the unit is nmol / L):
[0202] Remark: The structural formula of CX-P01 is:
[0203]
[0204] Table 4
[0205]
[0206] It can be seen from Table 4 that: compared with the single toxin molecule, the cytotoxicity of the camptothecin-based drug polypeptide conjugate described in this application is generally reduced by 10 - 60 times, indicating that making a polypeptide conjugate by connecting the toxin molecule with a Linker can greatly reduce the toxicity of the toxin molecule.
[0207] Table 5
[0208]
[0209]
[0210] It can be seen from Table 5 that: after activation by Legumain, the toxicity of the camptothecin-based drug polypeptide conjugate described in this application is greatly increased compared with that before activation, indicating that in the environment with high expression of Legumain in the tumor microenvironment, the polypeptide drug conjugate can be activated and release toxin molecules, thereby killing tumor cells.
[0211] 5. Detection experiment of the maximum lethal concentration (MTD) of the camptothecin-based drug polypeptide conjugate described in this application in mice
[0212] Test animals: C57BL / 6 mice, 6 - 8 weeks old, all female. The mice were randomly grouped with six mice in each group. The mice were administered drugs at different concentration gradients (the initial dose of the toxin molecule (CX - P01 / SN38) was 10 mg. If it was completely non - toxic, the dose was increased by 10 mg / kg. If it was close to the MTD, the dose was increased or decreased by 5 mg / kg. If the dose was basically within the MTD range, the dose was further verified by increasing or decreasing by 2 mg / kg. The polypeptide conjugate described in this application was started at a dose of 150 mg / kg and then increased by 50 mg / kg. If the dose was basically within the MTD range, the dose was further verified by increasing or decreasing by 20 mg / kg), and monitored for 14 days. The mice were euthanized when they lost 20% of their initial body weight and were considered to have died from poisoning. The maximum tolerated dose (MTD) was defined as the highest dose level at which none of the six mice died due to the drug, and the weight loss of an individual mouse did not exceed 20%, or the average weight loss within the group did not exceed 15%. The experimental results are shown in Table 6.
[0213] Table 6
[0214]
[0215]
[0216] It can be seen from Table 6 that for the polypeptide conjugate of the camptothecin - type drug described in this application, the MTD in mice is 2 - 8 times higher than that of the individual toxin molecule, and the Linker of X1 shows the greatest increase.
[0217] 6. Pharmacodynamic study of the polypeptide conjugate of the camptothecin - type drug described in this application in the A2780 human ovarian cancer mouse model
[0218] Test drugs: The polypeptide conjugate of the camptothecin - type drug described in the examples of this application, the individual toxin molecule, cisplatin, and a normal saline control group.
[0219] Test animals: BALB / c mice, 6 - 8 weeks old, all female.
[0220] The dosages of the toxin molecules CX - P01 and SN38 were 5 mg / kg. The dosages of the polypeptide conjugates of the camptothecin - type drugs described in the examples of this application were X1 - X3 at 12.3 μmol / kg, X6 - X11 at 12.7 μmol / kg, and cisplatin at 3 mg / kg.
[0221] The A2780 cells were purchased from ATCC. The cells were cultured in DMEM medium containing 10% fetal bovine serum at 37°C and 5% CO2. Sub - culture was performed every three days, and cells within 15 passages were used. 5×10 6 corresponding cells were subcutaneously injected into the right chest of nude mice. When the tumor reached approximately 100 mm 3After that, the mice were randomly divided into groups of 6 each. Then the treatment started, and the day when the treatment started was the first day. The control group was given normal saline. The drug was administered once a week for three consecutive weeks. The experimental results are shown in Table 7, and the tumor growth curve of A2780 is as Figure 1 and Figure 2 shown.
[0222] Table 7
[0223]
[0224]
[0225] As can be seen from Table 7, Figure 1 , Figure 2 the polypeptide conjugates X1, X6, and X9 of the camptothecin drugs described in this application have significantly better tumor inhibition rates than the camptothecin toxin molecule alone at equimolar doses, and the efficacy of all the polypeptide conjugates of the camptothecin drugs in this application is better than that of the traditional chemotherapeutic drug cisplatin.
[0226] 7. Efficacy study of the polypeptide conjugate of the camptothecin drug described in this application in the treatment of SJSA-1 sarcoma animal model
[0227] Test drugs: The polypeptide conjugate of the camptothecin drug described in this application, the individual toxin molecule, cisplatin, and the normal saline control group.
[0228] Test animals: 6-8-week-old BALB / c mice, all female.
[0229] Drug administration dose: The dosage of the toxin molecules CX-P01 and SN38 was 5 mg / kg, the dosage of the polypeptide conjugate of the camptothecin drug described in this application was X1-X3 at 12.3 μmol / kg, X6-X11 at 12.7 μmol / kg, and cisplatin at 3 mg / kg.
[0230] Preparation of tumor model:
[0231] Experimental operation: SJSA-1 cells were purchased from ATCC. The cells were cultured in DMEM medium containing 10% fetal bovine serum at 37 °C and 5% CO2. Passage was carried out every three days, and cells within 15 passages were used. 4×10 6 corresponding cells were subcutaneously injected into the right chest of nude mice. After the tumor reached at least 100 mm 3 , the mice were randomly divided into groups of 4 each. Then the treatment started, and the day when the treatment started was the first day. The control group was given normal saline. The drug was administered once a week for two consecutive weeks. The experimental results are shown in Table 8, and the tumor growth curve of SJSA-1 is as Figure 3 and Figure 4 shown.
[0232] Table 8
[0233]
[0234] As can be seen from Table 8, Figure 3 , Figure 4 it can be seen that the camptothecin drugs described in this application all have a certain tumor inhibitory effect. Among them, at equimolar doses, X1, X6, and X9 have significantly better tumor inhibition rates compared to the camptothecin toxin molecule alone, indicating that these polypeptide conjugates can not only reduce the toxicity of the toxin molecule but also improve the anti-tumor efficacy of the toxin molecule.
[0235] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions, and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.
Claims
1. A polypeptide conjugate of a camptothecin drug, characterized in that: The structural formula of the polypeptide conjugate is shown as follows: EP-L1-L2-L3-L4-L5-D; Wherein, E is selected from the following groups: The "1" position is connected to P or L1, 1≤n≤18, and X includes halogen; P is present or absent, and when P is present, P comprises polyethylene glycol; L1 and L2 each independently include one or more of glycine, alanine and serine; L3 includes asparagine; L4 is present or absent, and when L4 is present, L4 comprises glycine and / or leucine; L5 may or may not exist. When L5 exists, L5 includes the following structure: The "4" position is connected to the carboxyl end of L3 or L4, and the "5" position is connected to D; 0≤n2≤40, and n2 is an integer, 0≤n3≤40, and n3 is an integer; R1, R2 and R3 each independently include hydrogen and / or methyl; D is a camptothecin compound.
2. The polypeptide conjugate of camptothecin drugs according to claim 1, characterized in that: The structural formula of the polyethylene glycol is shown below: Among them, the "2" position is connected to E, the "3" position is connected to the amino group of L1, 1≤n1≤40, and n1 is an integer.
3. The polypeptide conjugate of camptothecin drugs according to claim 1, characterized in that: The structural formula of D is selected from the following structures: Wherein, the "6" position is connected to the carboxyl end of L5, L4 or the carboxyl end of L3, 0≤n4≤20, and n4 is an integer.
4. The polypeptide conjugate of camptothecin drugs according to claim 1, characterized in that: The structural formula of the polypeptide conjugate is selected from the following structures:
5. A pharmaceutical composition, characterized in that It comprises the polypeptide conjugate of the camptothecin drug according to any one of claims 1 to 4 and a pharmaceutically acceptable carrier thereof.
6. Use of the polypeptide conjugate of camptothecin drugs according to any one of claims 1 to 4 or the pharmaceutical composition according to claim 5 in the preparation of drugs for treating or preventing anti-tumor.
7. The use according to claim 6, characterized in that: The tumors include one or more of gastrointestinal cancer, colorectal cancer, colon cancer, liver cancer, hepatocellular carcinoma, pancreatic cancer, biliary tract cancer, gastric cancer, genitourinary system cancer, bladder cancer, testicular cancer, cervical cancer, malignant mesothelioma, osteogenic sarcoma, esophageal cancer, laryngeal cancer, prostate cancer, hormone-resistant prostate cancer, lung cancer, small cell lung cancer, non-small cell lung cancer, breast cancer, triple-negative breast cancer, blood cancer, leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, follicular lymphoma, diffuse large B-cell lymphoma, ovarian cancer, brain cancer, neuroblastoma, Ewing's sarcoma, kidney cancer, epidermoid carcinoma, skin cancer, melanoma and oral cancer.