Platinum (IV) prodrug taking EF-24 analogue as ligand as well as preparation method and application of platinum (IV) prodrug

Abstract

The invention belongs to the technical field of medicinal chemistry, and designs and synthesizes a preparation method and application of a platinum (IV) prodrug taking an EF-24 analogue as a ligand. Researches show that the synthesized compound shows good anti-proliferative activity to tested cancer cells, the compound 8 has optimal anti-tumor activity, the IC50 value range of the compound 8 is 0.22-0.52 mu M, and the tumor inhibition rate of the compound 8 to cis-platinum drug-resistant human lung cancer transplantation tumor is 67.2% (12.67 mg / kg). Besides, the anti-proliferative activity of the compound 8 to a cis-platinum drug-resistant cell A549 / CDDP is 146.92 times that of the cis-platinum, the anti-proliferative activity of the compound 8 to a cis-platinum drug-resistant cell A2780 / CDDP is 83.40 times that of the cis-platinum, and the toxicity of the compound 8 to a human normal lung cell BEAS-2B is lower than that of the positive drug cis-platinum. The anti-tumor effect of the compound 8 in a cis-platinum drug-resistant lung cancer transplantation model is better than that of cis-platinum, and no obvious toxic or side effect is observed. In-vivo and in-vitro anti-tumor research results show that the compound has potential application prospects in targeted treatment of lung cancer.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical chemistry and relates to the design and synthesis of a platinum (IV) prodrug, in particular to a platinum (IV) prodrug with an EF-24 analog as a ligand and a synthesis method thereof and application in the field of anti-tumor. Background Art

[0002] Today, lung cancer has become one of the most common and deadly malignant tumors in the world, and has seriously affected people's quality of life and health. Although current tumor diagnostic methods and treatment strategies are developing rapidly, and targeted drugs for the treatment of non-small cell lung cancer have made undeniable progress, the chemotherapy response rate and prognosis of patients still need to be improved. At present, chemotherapy is still one of the main means of treating malignant tumors. Cisplatin has a clear effect on non-small cell lung cancer and can be used alone or in combination with other anticancer drugs to treat non-small cell lung cancer in clinical practice. However, drug resistance and toxic side effects are prone to occur during chemotherapy, which in turn affects the treatment effect. Therefore, it is urgent to develop a multi-target platinum (IV) anticancer drug with strong targeting, high efficacy and low toxicity.

[0003] In order to overcome or alleviate the challenges of reduced accumulation of platinum in tumor cells, enhanced DNA repair ability and off-target effects, researchers have increasingly paid attention to the development of platinum (IV) complexes. On the one hand, these platinum (IV) complexes are more chemically inert than platinum (II) drugs in terms of kinetics, can effectively reduce off-target reactions with biological substances, and can serve as prodrugs of platinum (II) drugs. On the other hand, new compounds with ideal pharmacological characteristics can be obtained by modifying axial molecules with platinum (IV) prodrugs, with advantages such as enhanced cellular uptake, enhanced biological activity and reduced toxicity. Therefore, the development of multifunctional platinum (IV) prodrugs has become a promising strategy for exploring new platinum (IV) complexes with potential against lung cancer. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a platinum (IV) prodrug with an EF-24 (3a) analog as a ligand. This type of compound can overcome the shortcomings of existing anti-tumor drugs such as large toxic side effects and poor oral availability while treating lung cancer. Another purpose of the present invention is to provide a method for synthesizing this type of platinum (IV) complex with an EF-24 analog as a ligand.

[0005] The present invention is achieved through the following technical solutions:

[0006] A platinum (IV) prodrug with an EF-24 analog as a ligand, the general structural formula of which is shown in Formula 7 to Formula 10:

[0007]

[0008]

[0009] A further improvement of the present invention is:

[0010] A method for preparing a platinum (IV) prodrug using an EF-24 analog as a ligand comprises the following steps:

[0011] (1) reacting compound 1 with compound 2 in the presence of concentrated hydrochloric acid and glacial acetic acid to synthesize compound 3a or 3b;

[0012] (2) reacting compound 3a or 3b with succinic anhydride or glutaric anhydride under organic base conditions to synthesize compounds 4a-5a and 4b-5b;

[0013] (3) reacting compounds 4a-5a and 4b-5b with platinum (IV) complex 6 in the presence of a condensing agent and an organic base to synthesize compounds 7-10;

[0014] The synthetic route is as follows:

[0015]

[0016] Furthermore, the organic base in step (2) is triethylamine;

[0017] And / or, the condensing agent in step (3) is O-benzotriazole-N,N,N,N-tetramethyluronium tetrafluoroborate, and the organic base is triethylamine.

[0018] Further, in step (1), compound 1: compound 2 = 1: 2-3 on a molar basis;

[0019] And / or, in step (2), compound 3a or 3b: succinic anhydride or glutaric anhydride: organic base = 1:2-5: (1-3);

[0020] And / or, in step (3), compound 4a-5a or 4b-5b: platinum (IV) intermediate 6: organic base = 1: 0.8-1.2: (1-3).

[0021] Further, in step (1), the ratio of compound 1:compound 2 is 1:2.3 on a molar basis;

[0022] And / or, in step (2), compound 3a or 3b: succinic anhydride or glutaric anhydride: organic base = 1:3:1.5;

[0023] And / or, in step (3), the ratio of compounds 4a-5a and 4b-5b: platinum (IV) intermediate 6: organic base = 1:1:1.5.

[0024] Furthermore, the reaction temperature of step (1) is room temperature and the reaction time is 40-60h;

[0025] And / or, the reaction temperature of step (2) is 40-60°C and the reaction time is 8-10h;

[0026] And / or, the reaction temperature of step (3) is 20-40°C and the reaction time is 8-10 hours.

[0027] Furthermore, the steps (1) to (3) also include a separation and purification process.

[0028] A further improvement of the present invention is:

[0029] The use of the above-mentioned platinum (IV) prodrug with EF-24 analog as ligand in the preparation of anticancer drugs.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention introduces an EF-24 analog into the axial ligand of a platinum (IV) prodrug to obtain a platinum (IV) prodrug with an EF-24 analog as a ligand as a compound with a targeting function. Studies have shown that this type of platinum (IV) complex has good anti-lung cancer activity, represented by compound 8, which has a stronger anti-proliferation ability against A549 cells than CDDP, and has lower toxicity against normal human lung cells BEAS-2B. In addition, compound 8 showed a good inhibitory effect on cisplatin-resistant cells A549 / CDDP and cisplatin-resistant cells A2780 / CDDP. The anti-tumor effect of compound 8 in a cisplatin-resistant lung cancer transplantation model is better than that of cisplatin, and no obvious toxic side effects are observed. The results of in vivo and in vitro anti-tumor studies show that the compound has potential application prospects in the targeted treatment of lung cancer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the in vivo anti-tumor effect of compound 8 in the present invention; (A) images of excised tumors in each group, (B) tumor volume in each drug-treated group, (C) tumor mass in each drug-treated group, and (D) weight changes of mice in each group over 28 days. **p<0.01, *p<0.05

[0033] Figure 2 (A and B) are H&E staining and Ki67 staining of the main organs such as heart, liver, spleen, and kidney of mice after treatment with compound 8 in the example of the present invention for 28 days. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments.

[0035] Example 1: Preparation of Compounds 3a-3b

[0036] Compound 1 (16 mmol) was dissolved in glacial acetic acid (40 mL), and compound 2: 2-fluorobenzaldehyde (36.8 mmol) or 2-chlorobenzaldehyde (36.8 mmol) and concentrated hydrochloric acid (4 mL) were added, and stirred at room temperature for 48 h. The reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, 50% NaOH solution was added to adjust the pH to 8-10, and DCM (200 mL) was added, and washed with saturated sodium chloride (NaCl) aqueous solution. The organic phase was added in anhydrous Na 2 SO 4 The residue was dried on ice and concentrated in vacuo. The crude product was purified by silica gel column chromatography using petroleum ether and ethyl acetate as eluents to obtain compound 3a or 3b.

[0037]

[0038] 3,5-Bis((E)-2-fluorobenzylidene)piperidin-4-one (3a). Yellow solid, 3.6 g, yield 72.4%. 1 H NMR (500 MHz, DMSO-d 6 )δ7.82(s,2H),7.56–7.52(m 2H),7.50–7.47(m,2H),7.38–7.33(m,4H),4.24(s,4H),1.90(s,1H). 13 C NMR (125 MHz, DMSO-d 6 )δ183.79,172.53,161.79,159.81,132.71(d,J=8.6Hz),132.36,131.49,130.65,125.31( d,J=3.0Hz),122.20(d,J=12.9Hz),116.44(d,J=21.6Hz),45.20.HR-MS(m / z)(ESI):calcd for C 19 H 15 F 2 NO[M+H] + :312.1200; found:312.1210.Purity:98.55%(by HPLC).

[0039] 3,5-Bis((E)-2-chlorobenzylidene)piperidin-4-one (3b). Yellow solid, 2.95 g, yield 53.7%. 1 HNMR (600 MHz, DMSO-d 6)δ8.00(s,2H),7.66–7.64(m,2H),7.54–7.49(m,4H),7.48–7.46(m,2H),4.40(s,4H). 13 C NMR (150 MHz, DMSO-d 6 )δ182.72,136.34,134.59,132.14,131.29,130.48,130.23,128.03,44.44.C 19 H 15 F 2 NO[M+H] + :344.0609; found:344.0608.Purity:96.15%(by HPLC).

[0040] Example 2: Preparation of Compounds 4a-5a and 4b-5b

[0041] Compound 3a (2 mmol) or 3b (2 mmol) was dissolved in dry DMF (5 ml), and succinic anhydride (6 mmol) or glutaric anhydride (6 mmol) and triethylamine (3 mmol) were added, and stirred at 50 ° C overnight. The reaction was monitored by TLC. After the reaction was completed, the solvent was removed by vortexing, DCM (100 ml) was added, and the mixture was washed with a saturated sodium chloride (NaCl) aqueous solution. The organic phase was washed with anhydrous Na 2 SO 4 After drying and concentration in vacuo, the crude product was purified by silica gel column chromatography using dichloromethane and methanol as eluents to obtain compounds 4a-5a and 4b-5b.

[0042]

[0043] 4-(3,5-Bis(E)-2-fluorobenzylidene)-4-oxopiperidin-1-yl)-4-oxobutanoic acid (4a). Yellow solid, 670 mg, 81.5%. 1 H NMR (400 MHz, DMSO-d 6 )δ11.98(s,1H),7.75(s,2H),7.60–7.52(m,4H),7.39–7.34(m,4H),4.76(d,J =11.1Hz,4H),2.42–2.37(m,2H),2.31–2.28(m,2H).HR-MS(m / z)(ESI):calcd for C 23 H 19 F 2 NO 4 [M+H] +:412.1360; found:412.1345.Purity:98.05%(byHPLC).

[0044] 4-(3,5-Bis((E)-2-chlorobenzylidene)-4-oxopiperidin-1-yl)-4-oxobutanoic acid (4b). Yellow solid, 730 mg, 82.4%. 1 H NMR (400 MHz, DMSO-d 6 )δ11.99(s,1H),7.83(d,J=7.3Hz,2H),7.62–7.55(m,4H),7.50–7.48(m,4H),4.72(s,4H),2.34–2.30(m,4H).HR-MS(m / z)(ESI):calcd forC 23 H 19 Cl 2 NO 4 [M+H] + :444.0769; found:444.0771.Purity:98.72%(by HPLC).

[0045] 5-(3,5-Bis((E)-2-fluorobenzylidene)-4-oxopiperidin-1-yl)-5-oxopentanoic acid (5a). Yellow solid, 720 mg, 84.7%. 1 H NMR (500 MHz, DMSO-d 6 )δ12.00(s,1H),7.73(d,J=12.3Hz,2H),7.62–7.54(d,J=6.7Hz,4H),7.38–7.35(m,4H),4.73(d,J=1 1.0Hz,4H),2.18(t,J=6.9Hz,2H),2.05(t,J=7.5Hz,2H),1.56–1.53(m,2H).HR-MS(m / z)(ESI):calcd for C 24 H 21 F 2 NO 4 [M+H] + :426.1517; found:426.1512.Purity:98.65% (by HPLC).

[0046] 5-(3,5-Bis((E)-2-chlorobenzylidene)-4-oxopiperidin-1-yl)-5-oxopentanoic acid (5b). Yellow solid, 690 mg, 75.5%. 1 H NMR (400 MHz, DMSO-d 6)δ11.98(s,1H),7.81(d,J=20.6Hz,2H),7.63–7.56(m,3H),7.52–7.47(m,5H),4.69(d,J=22.2H z,4H),2.12(t,J=7.2Hz,2H),2.04(t,J=7.3Hz,2H),1.57–1.49(m,2H).HR-MS(m / z)(ESI):calcd for C 24 H 21 Cl 2 NO 4 [M+Na] + :480.0745; found:480.0742.Purity:97.35% (by HPLC).

[0047] Example 3: Preparation of Compound 7-10

[0048] Compound 4a-5a (0.3 mmol) or 4b-5b (0.3 mmol) was dissolved in dry DMF (3 mL), TBTU (0.45 mmol), triethylamine (0.45 mmol) and complex 6 (0.3 mmol) were added, and stirred at 30°C overnight. The reaction was monitored by TLC. After the reaction was completed, the reaction mixture was diluted with 100 mL DCM and then washed three times with a saturated sodium chloride (NaCl) aqueous solution. The organic phase was stirred in anhydrous Na 2 SO 4 The residue was dried on ice and concentrated in vacuo. The crude product was purified by silica gel column chromatography using dichloromethane and methanol as eluents to obtain the title compound 7-10.

[0049]

[0050] (OC-6-33)-Diaminetrichloro(4-(3,5-bis((E)-2-fluorobenzylidene)-4-oxopiperidin-1-yl)-4-oxobutanoic acid)-platinum (7). Yellow solid, 123 mg, yield 55.2%. 1 H NMR (400 MHz, DMSO-d 6 )δ7.74(s,2H),7.57–7.54(m,4H),7.38–7.34(m,4H),6.50–5.72(m,6H),4.76(d,J=7.5Hz,4H),2.40–2.36(m,4H). 13 C NMR (125 MHz, DMSO-d 6)δ186.06,180.04,170.99,161.92,159.94,134.55(d,J=31.1Hz),132.55,131.50,128.87,125.37(d,J=19.1Hz),122 .48(d,J=12.8Hz),122.25(d,J=12.7Hz),116.44(d,J=14.0Hz),46.52,42.94,31.45,28.38.HR-MS(m / z)(ESI):calcd for C 23 H 24 Cl 3 F 2 N 3 O 4 Pt[M+Na] + :767.0346; found:767.0348.Elemental analysis(%):calcd for C 23 H 24 Cl 3 F 2 N 3 O 4 Pt: C, 37.04; H, 3.24; N, 5.63; found: C, 37.31; H, 3.35; N, 5.51. Purity: 97.46% (by HPLC).

[0051] (OC-6-33)-Diaminetrichloro(5-(3,5-bis((E)-2-fluorobenzylidene)-4-oxopiperidin-1-yl)-5-oxopentanoic acid)-platinum (8). Yellow solid, 97 mg, 42.7%. 1 H NMR (600 MHz, DMSO-d 6 )δ7.72(d,J=14.7Hz,2H),7.59–7.55(m,4H),7.39–7.35(m,4H),6.33–5.98(m,6 H),4.74(s,4H),2.23(t,J=7.3Hz,2H),2.10(t,J=7.3Hz,2H),1.57–1.52(m,2H). 13 C NMR (125 MHz, DMSO-d 6)δ186.32,180.44,171.54,161.92,159.93,134.79,132.52,131.54,128.79,125.40(d,J=27.6Hz),122.49(d,J= 13.0Hz),122.27(d,J=12.8Hz),116.41(J=21.7Hz),46.58,42.69,35.74,31.50,21.31.HR-MS(m / z)(ESI):calcd for C 24 H 26 Cl 3 F 2 N 3 O 4 Pt[M+Na] + :781.0502; found:781.0489.Elemental analysis(%):calcd for C 24 H 26 Cl 3 F 2 N 3 O 4 Pt: C, 37.93; H, 3.45; N, 5.53; found: C, 37.58; H, 3.58; N, 5.42. Purity: 97.00% (by HPLC).

[0052] (OC-6-33)-Diaminetrichloro(4-(3,5-bis((E)-2-chlorobenzylidene)-4-oxopiperidin-1-yl)-4-oxobutanoic acid)-platinum (9). Yellow solid, 140 mg, 60.1%. 1 H NMR (400 MHz, DMSO-d 6 )δ7.83(s,2H),7.63–7.56(m,4H),7.52–7.50(m,4H),6.30–5.89(m,6H),4.73(s,4H),2.42–2.39(m,2H),2.34–2.31(m,2H). 13 C NMR (125 MHz, DMSO-d 6 )δ186.39,180.00,170.96,134.54,134.40,133.24(d,J=6.2Hz),132.62(d,J=18.0Hz),131.57(d d,J=38.2,4.9Hz),130.42,128.11,127.95,46.21,42.67,31.44,28.35.HR-MS(m / z)(ESI):calcd for C 23 H24 Cl 5 N 3 O 4 Pt[M+Na] + :800.9725; found:800.9733.Elemental analysis(%):calcd for C 23 H 24 Cl 5 N 3 O 4 Pt: C, 35.47; H, 3.11; N, 5.40; found: C, 35.76; H, 3.35; N, 5.28. Purity: 98.02% (by HPLC).

[0053] (OC-6-33)-Diaminetrichloro(5-(3,5-bis((E)-2-chlorobenzylidene)-4-oxopiperidin-1-yl)-5-oxopentanoic acid)-platinum (10). Yellow solid, 114 mg, 48.1%. 1 HNMR (400 MHz, DMSO-d 6 )δ7.80(d,J=19.5Hz,2H),7.62–7.50(m,8H),6.37–5.85(m,6H),4.69(d,J= 9.9Hz,4H),2.17(t,J=7.2Hz,2H),2.08(t,J=7.1Hz,2H),1.57–1.50(m,2H). 13 C NMR (125 MHz, DMSO-d 6 )δ186.63,180.43,171.54,134.72,134.56,134.39,133.21(d,J=8.8Hz),132.64(d,J=15.6Hz),13 1.73,131.47,130.36,128.14,127.92,46.24,42.56,35.75,31.50,21.26.HR-MS(m / z)(ESI):calcd forC 24 H 26 Cl 5 N 3 O 4 Pt[M+Na] + :814.9882; found:814.9888.Elemental analysis(%):calcd forC 23 H 24 Cl 5 N 3 O 4Pt: C, 36.36; H, 3.31; N, 5.30; found: C, 36.61; H, 3.39; N, 5.16. Purity: 98.87% (by HPLC).

[0054] Example 4: In vitro antiproliferative activity assay

[0055] 1. Experimental Methods

[0056] The CCK-8 detection kit was used to detect the cytotoxicity of compounds 7-10 obtained by coupling EF-24 analogs with platinum (IV) complexes and the corresponding ligands 4a, 4b, 5a, and 5b against four human cancer cell lines A549 (lung), NCI-H460 (lung), A2780 (ovary), and SGC-7901 (stomach). First, the antiproliferative activity of EF-24 analogs coupled with platinum (IV) complexes is shown in Table 1, and cisplatin, EF-24 (3a) and its analogs (3b) were used as positive controls. All cells were seeded in 96-well plates (2000 cells per well, 200 μL) and incubated in 5% CO 2 The cells were incubated overnight in a humidified environment at 37°C. The cells were then treated with different concentrations of the test compound under the same conditions for 72 hours. After 72 hours of incubation, fresh CCK-8 solution (10 μL) was added and incubated at 37°C for 2 hours. The samples were recorded at a wavelength of 450 nm using an ELISA reader, and the IC was calculated using SPSS software. 50 value.

[0057] Table 1 Antiproliferative activity of compounds 7-10 against different cancer cell lines

[0058]

[0059] IC 50 ,mean±SD(μM) a , half-inhibitory concentration, values ​​are expressed as the mean ± SD of three parallel experiments for each compound. b , cisplatin. CDDP / 5a c , cisplatin and 5a were used in equimolar combination.

[0060] Table 2 Antiproliferative activity of compound 8 against cisplatin-resistant cells and normal cells

[0061]

[0062] IC 50 ,mean±SD(μM) a , half inhibitory concentration, values ​​are expressed as the mean ± SD of three parallel experiments. b , cisplatin. CDDP / 5a c, cisplatin and 5a were used in combination with equal moles. RF d (Drug resistance factor) = IC 50 (A549 / CDDP) / IC 50 (A549).RF e (Drug resistance factor) = IC 50 (A2780 / CDDP) / IC 50 (A2780).RF f (Drug resistance factor) = IC 50 (BEAS-2B) / IC 50 (A549).

[0063] 2. Experimental results

[0064] The results of in vitro experiments showed that the antiproliferative activities of target compounds 7-10 were superior to those of their respective positive drugs.

[0065] Among them, compound 8 has the strongest antiproliferative activity against four types of human cancer cells, with IC 50 The values ​​were 0.22 to 0.45 μM. It is worth noting that compound 8 (IC 50 =0.22 μM) showed a stronger antiproliferative effect than complex 7 (IC 50 =0.32 μM), and 15.4, 25.68, and 9.91 times more potent than 5a alone, CDDP, and CDDP / 5a combined (molar ratio of 1:1), respectively. Interestingly, Pt(IV) complexes 9 and 10 also showed similar phenomena. In particular, the NCI-H460, A2780, and SGC-7901 cell assays obtained consistent trends for Pt(IV) complexes 7-10. In addition, the combination of cisplatin and 5a (IC 50 =1.91-2.62 μM, molar ratio of 1:1) had a better inhibitory effect on A549, NCI-H460, A2780 and SGC-7901 cells than cisplatin alone (IC 50 =4.97-7.07 μM) and 5a alone (IC 50 =3.39~4.58μM).

[0066] It is noteworthy that the IC values ​​of Pt(IV) complexes 7-8 and 9-10 are 50 The difference in values ​​can be attributed to the presence of axial ligands in the Pt(IV) complexes. The results suggest that the incorporation of longer carbon chains in the linker may contribute to the enhanced anticancer effects of Pt(IV) complexes. Overall, among these Pt(IV) complexes, compound 8 exhibited the highest cytotoxicity against four human cancer cells, so complex 8 was selected for further investigation in this study.

[0067] In addition, cell resistance is an important factor that hinders the progress of anti-tumor drugs. It often occurs in chemotherapy-induced cancer cell apoptosis and is a key challenge in drug development. Therefore, this study used two resistant cell lines, A549 / CDDP (cisplatin-resistant cells) and A2780 / CDDP (cisplatin-resistant cells), as research objects to investigate the optimal antitumor activity of compound 8 against resistant cancer cells. As shown in Table 2, A549 / CDDP and A2780 / CDDP cells showed the best antitumor activity against cisplatin (IC 50 The drug resistance of compound 8 to A549 / CDDP and A2780 / CDDP cells was consistent with the expected value, and the resistance factors were 6.50 and 6.13, respectively. However, in contrast, compound 8 had a sustained efficacy against A549 / CDDP and A2780 / CDDP cells, with IC 50 The values ​​are 0.25~0.52μM, and the resistance factors are only 1.14 and 1.16. In addition, as shown in Table 2, the selectivity index (SI) values ​​of cisplatin and the combination group (CDDP+5a) for cells are poor, 0.40 and 1.23, respectively, while the selectivity index of compound 8 is 13.82, which is higher than that of cisplatin and the combination group, indicating that compound 8 has the characteristics of high efficacy and high selectivity. The above experimental results show that the platinum (IV) complex 8 derived from cisplatin functionalized with EF-24 analogues can effectively overcome cisplatin resistance, improve efficacy and reduce toxicity. Therefore, compound 8 is a potential candidate drug for the treatment of lung cancer.

[0068] Example 5: In vivo anti-tumor activity experiment

[0069] 1. Model building

[0070] Twenty-five 4-week-old female nude mice were purchased from Hangzhou Ziyuan Experimental Animal Technology Co., Ltd. and raised under pathogen-free conditions. Logarithmically growing A549 / CDDP cells were subcutaneously inoculated into the right side of BALB / c nude mice to establish the A549 / CDDP xenograft model. When the tumor volume reached approximately 100 mm 3 At 14:00, mice were randomly divided into 5 experimental groups according to their weight and tumor size: Group 1 was the control group, Group 2 was treated with cisplatin (5 mg / kg), Group 3 was treated with 5a (20 mg / kg), Group 4 was treated with a combination of CDDP and 5a (5+20 mg / kg), and Group 5 was treated with compound 8 (12.67 mg / kg). Mice in Groups 1 and 3 were intravenously injected with saline and compound 5a through the tail vein once every 2 days for 4 consecutive weeks. Mice in Groups 2, 4, and 5 were intravenously injected with the test compound through the tail vein once every 7 days for 4 weeks, and the changes in body weight and tumor volume were monitored at the same time. The tumor inhibition rate was calculated based on the treatment results of each compound.

[0071] 2. Experimental results

[0072] like Figure 1As shown in AC, the tumor growth inhibition (TGI) rate of the cisplatin-treated group was 26.6% compared with the saline-treated group, indicating that cisplatin has resistance to A549 / CDDP cells, which is consistent with the results of in vitro antiproliferative activity. In addition, compared with the cisplatin-treated group, the 5a-treated group (TGI = 47.8%) can effectively inhibit tumor growth. In addition, when cisplatin and 5a were used in combination (dosage of 5 + 20 mg / kg), compared with cisplatin alone or 5a alone, their combined drug TGI was 58.1%, and the efficacy was stronger than that of the single-dose group. Compound 8 showed the best effect in inhibiting tumor growth, with a TGI rate of 67.2%, which was significantly higher than cisplatin, 5a or their combination, indicating that compound 8 effectively overcame cisplatin resistance in the A549 / CDDP xenograft model. More importantly, Figure 1 D The results of body weight changes showed that there was no significant weight loss in the compound 8 treatment group, while there was a late weight loss in the cisplatin treatment group or the cisplatin and 5a combination treatment group.

[0073] In addition, to further explore the antitumor effect and potential side effects of compound 8, we performed hematoxylin and eosin (H&E) staining on sections of major organs such as heart, liver, spleen, kidney, and tumor. Figure 2 As shown in A, compared with the control group, compound 8 did not cause obvious damage or pathological changes in the heart, liver, spleen and kidney. More importantly, the number of Ki67-positive tumor cells in the compound 8 treatment group was significantly less than that in the other treatment groups, which is consistent with the anti-tumor activity results observed in vivo ( Figure 2 B). In summary, compared with cisplatin, compound 8 has enhanced therapeutic efficacy and reduced adverse reactions, and also has the ability to reverse cisplatin resistance.

[0074] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A platinum (IV) prodrug with an EF-24 analog as a ligand, characterized in that: The general structural formula is shown in Formula 7-10:

2. The method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 1, characterized in that: The following steps are involved: (1) reacting compound 1 with compound 2 in the presence of concentrated hydrochloric acid and glacial acetic acid to synthesize compound 3a or 3b; (2) reacting compound 3a or 3b with succinic anhydride or glutaric anhydride under organic base conditions to synthesize compounds 4a-5a and 4b-5b; (3) reacting compounds 4a-5a and 4b-5b with platinum (IV) complex 6 in the presence of a condensing agent and an organic base to synthesize compounds 7-10; The synthetic route is as follows:

3. A method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 2, characterized in that: The organic base in step (2) is triethylamine; And / or, the condensing agent in step (3) is O-benzotriazole-N,N,N,N-tetramethyluronium tetrafluoroborate, and the organic base is triethylamine.

4. A method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 2, characterized in that: In terms of molar amount, in step (1), compound 1: compound 2 = 1: 2-3; And / or, in step (2), compound 3a or 3b: succinic anhydride or glutaric anhydride: organic base = 1:2-5: (1-3); And / or, in step (3), compound 4a-5a or 4b-5b: platinum (IV) intermediate 6: organic base = 1: 0.8-1.2: (1-3).

5. A method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 4, characterized in that: In terms of molar amount, in step (1), compound 1: compound 2 = 1: 2.3; And / or, in step (2), compound 3a or 3b: succinic anhydride or glutaric anhydride: organic base = 1:3:1.5; And / or, in step (3), the ratio of compounds 4a-5a and 4b-5b: platinum (IV) intermediate 6: organic base = 1:1:1.

5.

6. A method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 2, characterized in that: The reaction temperature of step (1) is room temperature and the reaction time is 40-60h; And / or, the reaction temperature of step (2) is 40-60°C and the reaction time is 8-10h; And / or, the reaction temperature of step (3) is 20-40°C and the reaction time is 8-10 hours.

7. A method for preparing a platinum (IV) prodrug with an EF-24 analog as a ligand according to claim 2, characterized in that: The steps (1) to (3) also include a separation and purification process.

8. Use of a platinum (IV) prodrug with an EF-24 analog as a ligand as claimed in claim 1 in the preparation of anticancer drugs.

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