Bicentric platinum complexes targeting drug-resistant ovarian cancer cells, synthetic methods and uses thereof

Abstract

The application discloses a binuclear platinum complex targeting ovarian cancer drug-resistant cells and a synthesis method and application thereof. A binuclear platinum complex is synthesized by taking 4'-(3,5-dibromophenyl)-2,2':6',2"-terpyridine as an active ligand. The binuclear platinum complex targeting ovarian cancer drug-resistant cells has good inhibiting effects on ovarian cancer drug-resistant strain cells SK-OV-3CR, and is higher than that of cisplatin drugs, overcomes the drug resistance of clinical drugs, has potential medicinal value, and is expected to be used for preparation of various anti-tumor drugs. The binuclear platinum complex targeting ovarian cancer drug-resistant cells can target and inhibit the growth of SKO3cisR, has good anti-cancer activity and tumor targeting property, shows superior in-vivo and in-vitro anti-tumor activity, has potential medicinal value, and is expected to be used for preparation of various anti-tumor drug.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, specifically to binuclear platinum complexes targeting drug-resistant ovarian cancer cells, their synthesis methods, and applications. Background Technology

[0002] Cancer is generally treated with a variety of methods, including radiotherapy, surgery, and chemotherapy. However, surgery and radiotherapy are important means of local treatment. While platinum-based drugs inhibit tumor cell growth during chemotherapy, they also have varying degrees of toxicity to different types of normally proliferating cells in the body. Therefore, the development and treatment of targeted non-platinum drugs in recent years have shown promising prospects (Guo, Z.; et al. Chem. Soc. Rev., 2013, 42::202-224.). However, they are currently still in the clinical trial stage, and further in-depth observation and accumulation are needed for clinical use. Therefore, there is still a significant gap before large-scale clinical promotion and use.

[0003] Currently, cisplatin and its derivatives cause serious adverse reactions in clinical practice, including nephrotoxicity and drug resistance. Therefore, there is an urgent need for researchers to develop a targeted, highly effective, and low-toxicity platinum-based anticancer complex.

[0004] In recent years, a large number of terpyridine derivative metal complexes have been reported, and these complexes have good anticancer activity. However, there is still a lack of such complexes with targeting properties. Summary of the Invention

[0005] One of the objectives of this invention is to provide binuclear platinum complexes that target drug-resistant ovarian cancer cells.

[0006] This invention provides a binuclear platinum complex targeting drug-resistant ovarian cancer cells, with the chemical formula [Pt(tpy3)Cl][Pt(DMSO)Cl3](tpy3Pt), and its chemical structural formula is shown below:

[0007]

[0008] Another object of the present invention is to provide a method for synthesizing the above-mentioned binuclear platinum complex targeting ovarian cancer drug-resistant cells.

[0009] Specifically, the method for synthesizing the binuclear platinum complex tpy3Pt is as follows: ligand 4'-(3,5-dibromophenyl)-2,2':6',2”-terpyridine (tpy3), metal salt cis-Pt(DMSO)2Cl2, anhydrous CH3OH, and acetone are subjected to a coordination reaction at 45-80℃ for 3 days. After filtration, the mixture is dried in a vacuum drying oven at 45℃ to obtain the binuclear platinum complex tpy3Pt.

[0010] The synthesis temperature of the binuclear platinum complex of the present invention must be between 45-80°C. If the temperature exceeds 80°C, the tubes will burn completely and the yield will be low. If the temperature is below 45°C, almost no product will be generated and the yield will be extremely low, making separation difficult. After this optimization, the reaction system reacts at 80°C, and the yield of the target product obtained by the system is the highest.

[0011] The reaction of this invention requires a mixed solution of acetone and methanol, with a total volume between 1.5 and 10.0 mL. Too low a volume results in many impurities, while too high a volume leads to extremely low yields. The reaction condition with the highest yield is achieved when the mixed solution contains 3.5 mL of anhydrous CH3OH and 0.5 mL of acetone. Without acetone, almost no product is formed; without methanol, there are many byproducts that are difficult to separate and process.

[0012] The reaction time of this invention is 3 days to achieve a relatively pure product that is easy to separate. Beyond 3 days, the product quality no longer improves.

[0013] A third objective of this invention is to provide applications of the aforementioned binuclear platinum complex tpy3Pt.

[0014] Specifically, the application of the binuclear platinum complex tpy3Pt in the preparation of targeted therapies for ovarian cancer. Further, the application of the binuclear platinum complex tpy3Pt in the preparation of targeted therapies for drug-resistant ovarian cancer strains is discussed.

[0015] Compared with existing technologies, this invention uses the terpyridine derivatives tpy3-tpy4 as active ligands to synthesize three binuclear platinum complexes targeting drug-resistant ovarian cancer cells: [Pt(tpy3)Cl][Pt(DMSO)Cl3](tpy3Pt) and [Pt(tpy4)Cl]Cl·CH3OH(tpy4Pt). Their activity and toxicity against human ovarian cancer SK-OV-3 (SKO3), cisplatin-resistant strain SK-OV-3 / DDP (SKO3cisR), and normal HL-7702 cells were investigated. The results showed that tpy3Pt-tpy4Pt effectively inhibited the proliferation of human ovarian cancer SKO3cisR, with an IC50 value of [Pt(tpy3)Cl][Pt(DMSO)Cl3](tpy3Pt) and [Pt(tpy4)Cl]Cl·CH3OH(tpy4Pt). 50 The effective values ​​ranged from 1.04 to 3.27 μM. In particular, tpy3Pt exhibited anticancer activity as low as 1.04 ± 0.19 μM, significantly higher than its ligands tpy4, cis-Pt(DMSO)2Cl2, tpy4Pt, and the clinical drug cisplatin. Furthermore, these ligands showed minimal inhibitory effects on normal HL-7702 cells (>45.0 μM), indicating that the binuclear platinum complex tpy3Pt can target and inhibit the growth of SKO3cisR, demonstrating excellent anticancer activity and tumor targeting. In conclusion, the binuclear platinum complex tpy3Pt exhibits superior in vitro and in vivo antitumor activity, possesses the ability to overcome cisplatin resistance, and has potential pharmaceutical value, holding promise for the preparation of various antitumor drugs. Attached Figure Description

[0016] Figure 1 This is an X-ray single-crystal structure diagram of the binuclear platinum complex tpy3Pt obtained in Example 1 of the present invention;

[0017] Figure 2 This is an X-ray single-crystal structure diagram of the complex tpy4Pt obtained in Example 1 of the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0019] The metal salt cis-Pt(DMSO)2Cl2 involved in the synthesis method described in this invention can be prepared with reference to existing literature (Al-Allaf, TAK; et al. Transit. Met. Chem., 1998, 23: 403-406.); the ligands tpy3-tpy4 were synthesized according to the synthesis method in the literature (K. Czerwińska, B. Machura, S. Kula, S. Krompiec, K. Erfurt, C. Roma-Rodrigues, ARFernandes, L.Shul'pina, N.S. Ikonnikov and GB.Shul'pin, Dalton Trans., 2017, 46, 9591-9604.).

[0020] Example 1

[0021] In a 15.0 mL high-temperature pressure-resistant tube, 0.1 mmol of ligands tpy3-tpy4, the metal salt cis-Pt(DMSO)2Cl2, 3.5 mL of anhydrous CH3OH, and 0.5 mL of acetone were added. The coordination reaction was carried out at 80 °C for 3.0 days. After filtration, the mixture was dried in a vacuum drying oven at 45 °C to obtain bulk crystals tpy3Pt-tpy4Pt. The yield of tpy3Pt was 81.1%, and the yield of tpy4Pt was 90.4%.

[0022] tpy3Pt was prepared using 0.2 mmol of the metal salt cis-Pt(DMSO)2Cl2. tpy4Pt was prepared using 0.1 mmol of the metal salt cis-Pt(DMSO)2Cl2.

[0023] Synthesis of the binuclear platinum complex tpy3Pt: The ligand 4'-(3,5-dibromophenyl)-2,2':6',2”-terpyridine (tpy3), the metal salt cis-Pt(DMSO)2Cl2, anhydrous CH3OH and acetone were subjected to a coordination reaction at 45-80℃ for 3 days. After filtration, the mixture was dried in a vacuum drying oven at 45℃ to obtain the binuclear platinum complex tpy3Pt.

[0024] Synthesis of the binuclear platinum complex tpy4Pt: The ligand 4'-2,2':6',2”-terpyridine, the metal salt cis-Pt(DMSO)2Cl2, anhydrous CH3OH and acetone were taken and subjected to a coordination reaction at 45-80℃ for 3 days. After filtration, the mixture was dried in a vacuum drying oven at 45℃ to obtain the binuclear platinum complex tpy4Pt.

[0025] The synthesis route is as follows:

[0026]

[0027] The obtained product was identified as follows:

[0028] (1) X-ray single-crystal structure diagram of the complex tpy3Pt, and its spectrum are shown below. Figure 1 As shown.

[0029] (2) Results of the infrared spectrum of the complex tpy3Pt.

[0030] IR(KBr):3919,3431,3102,3068,3025,2920,2002,1635,1607,1548,1477,1435,1417,1398,1352,1313,1295,1240,11 57,1127,1113,1053,1033,1010,974,929,902,862,839,800,783,752,746,721,704,678,662,631,468,444,420,412cm -1 .

[0031] (3) Elemental analysis results are shown in Table 1.

[0032] (4) X-ray single-crystal structure diagram of the complex tpy4Pt, and its spectrum are shown below. Figure 2 As shown.

[0033] (5) Infrared spectrum of complex tpy4Pt.

[0034] IR(KBr):4114,3298,3104,3064,2692,2482,1992,1893,1620,1607,1565,1477,1463,1432,1396,1369,1301,127 7,1267,1229,1167,1117,1104,1094,1054,1043,1033,987,872,841,794,785,752,714,693,662,629,488,442cm -1 .

[0035] (6) Elemental analysis results are shown in Table 1.

[0036] Table 1 shows the elemental analysis results of the complexes tpy3Pt-tpy4Pt in the examples.

[0037]

[0038] Therefore, the structural formula of the obtained complexes tpy3Pt-tpy4Pt can be determined as follows:

[0039]

[0040] To fully illustrate the pharmaceutical applications of the three binuclear platinum complexes tpy3Pt-tpy4Pt that target drug-resistant ovarian cancer cells described in this invention, the inventors conducted in vitro and in vivo antitumor activity experiments on them.

[0041] I. Experimental Study on the Inhibitory Activity of the Binuclear Platinum Complexes tpy3Pt-tpy4Pt Targeting Drug-Resistant Ovarian Cancer Cells on the Proliferation of Three Human Cell Lines

[0042] 1. Cell lines and cell culture

[0043] This experiment used three human cell lines: human ovarian cancer SK-OV-3 (SKO3), cisplatin-resistant SK-OV-3 / DDP (SKO3cisR), and normal HL-7702 cells.

[0044] All human cell lines were cultured in RPMI-1640 medium containing 100 U / mL penicillin, 10 wt% fetal blood, and 100 U / mL streptomycin, and incubated at 37°C in an incubator containing 5% CO2 by volume.

[0045] 2. Preparation of the test compound

[0046] All compounds used must have a purity of ≥95.0%. Their DMSO stock solutions were diluted with physiological buffer to a final solution of 40 μmol / L (final DMSO concentration ≤1.0%), and the inhibitory effect of each compound on the growth of normal cells or selected tumor cells at this concentration was tested.

[0047] 3. Cell growth inhibition assay (CCK-8 assay)

[0048] (1) Cells were digested, counted, and prepared to a concentration of 5×10⁻⁶. 4 Add 100 μL of cell suspension per well to a 96-well cell culture plate;

[0049] (2) Place the 96-well cell culture plate in a 37°C, 5% CO2 incubator for 24 h;

[0050] (3) Dilute the drug to the required concentration with complete culture medium, add 100 μL of the corresponding drug-containing culture medium to each well, and set up a negative control group at the same time;

[0051] (4) Place the 96-well cell culture plate in a 37°C, 5% CO2 incubator for 48 hours;

[0052] (5) Perform CCK-8 staining at λ = 450 nm and measure the OD value;

[0053] a) Add 10 μL of CCK-8 to each well and continue incubation in an incubator for 2 hours;

[0054] b) Shake gently for 10 minutes to mix thoroughly;

[0055] c) Test at λ = 450 nm. Read the OD value of each well using a microplate reader. Determine the number of viable cells based on the measured optical density (OD value). The higher the OD value, the stronger the cell activity. Use the formula:

[0056]

[0057] The inhibition rate of each compound on the growth of the selected cells was calculated, and then the IC50 of each tested compound on each selected cell line was calculated using the Bliss method. 50 The values ​​are shown in Table 2 below.

[0058] Table 2. IC50 of compounds for various cell lines 50 Value (μM)

[0059]

[0060] From Table 2 IC 50 Activity screening results showed that tpy3Pt-tpy4Pt effectively inhibited the proliferation of SKO3cisR in human ovarian cancer, with an IC50 value of [missing information].50 The effective values ​​ranged from 1.04 to 3.27 μM. In particular, tpy3Pt exhibited anticancer activity as low as 1.04 ± 0.19 μM, significantly higher than its ligands tpy4, cis-Pt(DMSO)2Cl2, tpy4Pt, and the clinical drug cisplatin. Furthermore, these ligands showed minimal inhibitory activity against normal HL-7702 cells (>45.0 μM), indicating that the binuclear platinum complex tpy3Pt can target and inhibit the growth of SKO3cisR, demonstrating excellent anticancer activity and tumor targeting. In conclusion, the binuclear platinum complex tpy3Pt exhibits superior in vivo antitumor activity, possesses the ability to overcome cisplatin resistance, and has potential pharmaceutical value, making it a promising candidate for the preparation of various antitumor drugs.

Claims

1. A binuclear platinum complex targeting drug-resistant ovarian cancer cells, characterized in that, Its chemical structural formula is shown below:

2. The method for synthesizing the binuclear platinum complex targeting drug-resistant ovarian cancer cells as described in claim 1, characterized in that, Take ligand 4'-(3,5-dibromophenyl)-2,2':6',2”-terpyridine, metal salt cis-Pt(DMSO)2Cl2, anhydrous CH3OH and acetone, and carry out a coordination reaction at 45-80℃ for 3 days. After filtration, dry in a vacuum drying oven at 45℃ to obtain the final product.

3. The method for synthesizing the binuclear platinum complex targeting drug-resistant ovarian cancer cells according to claim 2, characterized in that, The total volume of the anhydrous CH3OH and acetone mixture is between 1.5 and 10.0 mL.

4. The method for synthesizing the binuclear platinum complex targeting drug-resistant ovarian cancer cells according to claim 3, characterized in that, The amount of anhydrous CH3OH is 3.5 mL, and the amount of acetone is 0.5 mL.

5. The use of the binuclear platinum complex targeting drug-resistant ovarian cancer cells as described in claim 1 in the preparation of targeted drugs for the treatment of ovarian cancer.

6. The use of the binuclear platinum complex targeting drug-resistant ovarian cancer cells as described in claim 1 in the preparation of a drug for targeted treatment of drug-resistant ovarian cancer strains.

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