18beta-glycyrrhetinic acid ester derivatives with antitumor activity, and preparation method and application thereof

Abstract

The application discloses a kind of 18 beta-glycyrrhetinic acid ester derivatives with PPAR gamma agonistic activity and its preparation method and application, belongs to chemical pharmaceutical technical field, specifically related to a kind of 18 beta-glycyrrhetinic acid ester derivatives molecules and its application as PPAR gamma agonist in antitumor aspect.The application uses Steglich esterification reaction, with dicyclohexyl carbodiimide and 4-dimethylaminopyridine as catalyst, 18 beta-glycyrrhetinic acid is reacted with different types of carboxylic acid, and a kind of novel 18 beta-glycyrrhetinic acid ester derivative molecules are obtained by semi-synthesis;Computer simulation molecular docking and in vitro enzyme activity experiment show that this kind of molecule can be used as PPAR gamma agonist and play significant antitumor activity.

Description

Technical Field

[0001] This invention belongs to the field of chemical pharmaceutical technology, specifically relating to a class of 18β-glycyrrhetinic acid derivatives with PPARγ agonist activity, their preparation methods, and their applications in antitumor therapy. Background Technology

[0002] Peroxisome proliferator-activated receptor-γ (PPARγ) is a nuclear receptor and one of the most widely studied ligand-induced transcription factors. PPARγ regulates cell proliferation in tissues and organs such as the colon, breast, and bladder; dysregulation of its signaling can increase the incidence of tumors in these organs. PPARγ can also regulate the expression of tumor cell differentiation-related genes, inhibiting tumor cell proliferation. Furthermore, PPARγ has significant effects on the maturation and function of various immune system-related cells, such as macrophages, dendritic cells, and lymphocytes. Activation of PPARγ can promote the transformation of macrophages from M1 to M2 types. Macrophages in this state are more inclined to participate in tissue repair and anti-inflammatory responses, reducing the release of inflammatory factors and thus enhancing their anti-tumor capabilities. Therefore, activating PPARγ is an effective anti-tumor strategy.

[0003] Glycyrrhetinic acid (GRA) is the main active ingredient of the traditional Chinese medicine licorice, and is an oleanane-type pentacyclic triterpenoid compound. Due to the different configurations of the 18th chiral carbon atom in the triterpenoid saponin nucleus, GRA has two epimers: α and β. 18β-GRA has a wide range of pharmacological activities, including anti-inflammatory, antiviral, antitumor, and hepatoprotective effects. Studies have shown that 18β-GRA can induce apoptosis in various tumor cells, including human liver cancer cells, gastric cancer cells, and epithelial ovarian cancer cells. However, its poor water solubility, low bioavailability, and unclear targeting limit its clinical application. Therefore, this study targeted PPARγ, esterifying the hydroxyl group at the C-3 position of 18β-GRA, and designed and synthesized 15 novel GRA ester derivatives as PPARγ agonists. The aim was to comprehensively improve the bioavailability and antitumor activity of 18β-GRA, and to explore and develop novel and highly effective antitumor drug molecules.

[0004] Summary of the Invention

[0005] The purpose of this invention is to provide a novel class of 18β-glycyrrhetinic acid ester derivatives, their synthesis methods, and their application as PPARγ agonists in antitumor therapy.

[0006] The technical solution adopted in this invention is as follows:

[0007] A class of 18β-glycyrrhetinic acid ester derivatives have the following general formula:

[0008]

[0009] The substituent R is selected from C1' to C15', and the structure is shown below:

[0010] R:

[0011]

[0012] Specifically, the molecular structure of the 18β-glycyrrhetinic acid ester derivative of the present invention is shown below:

[0013]

[0014]

[0015] This invention also provides a method for preparing the above-mentioned 18β-glycyrrhetinic acid ester derivatives, the specific steps of which are as follows:

[0016] Carboxylic acids with different substituents (compound B), dicyclohexylcarbodiimide (DCC), and 4-dimethylaminopyridine (DMAP) were dissolved in anhydrous dichloromethane (DCM) and stirred at room temperature for 30 minutes. Then, 18β-glycyrrhetinic acid (compound A) was added to the reaction mixture, and the mixture was stirred at room temperature for at least 12 hours. Finally, the solvent was removed by evaporation, and the residue was purified by silica gel column chromatography (eluent: ethyl acetate: petroleum ether = 1:2, volume ratio) to obtain 18β-glycyrrhetinic acid ester derivatives (compound C).

[0017]

[0018] The molar ratio of carboxylic acids with different substituents (compound B), dicyclohexylcarbodiimide (DCC), 4-dimethylaminopyridine (DMAP), and 18β-glycyrrhetinic acid (compound A) is 1:2:0.2:1.2.

[0019] The structural formula of compound B is as follows:

[0020] .

[0021] This invention demonstrates the in vitro cytotoxicity of 18β-glycyrrhetinic acid derivatives against two human colon cancer cell lines (HCT-116 and HCT-8) and one normal human cell line (L02) through in vitro tumor cell inhibition activity screening. The results show that all target compounds exhibited superior antiproliferative activity against both cancer cell lines compared to 18β-glycyrrhetinic acid, as shown in Table 1. Some derivatives, without harming normal cell lines, showed superior inhibitory activity against the HCT-116 cell line compared to the positive control gefitinib. Skeletal analysis of the 18β-glycyrrhetinic acid derivatives revealed that the introduction of phenylacetylphenylacetamide and aryl dihydrothiazole enhanced the antitumor activity of 18β-glycyrrhetinic acid better than lipoic acid and thiophene. Substituent analysis of the 18β-glycyrrhetinic acid derivatives showed that the introduction of methyl and methoxy groups enhanced the antitumor activity of the compounds compared to halogen atoms. Specifically, compound C1 (IC 50 (25 μmol / L) showed the strongest anti-proliferative activity against the HCT-116 cell line, significantly superior to gefitinib (IC50). 50 =46 μmol / L) and 18β-glycyrrhetinic acid (IC50) 50 =112 μmol / L), such as Figure 1 As shown in Figures 2 and 3. Flow cytometry results indicated that compound C1 significantly induced apoptosis in HCT-116 cells in a concentration-dependent manner, as shown in Figures 2 and 3. Figure 4 As shown. Cell scratch assay results indicate that compound C1 effectively inhibits the migration of HCT-116 cells, such as... Figure 5 As shown. Computer simulations of molecular docking revealed that PPARγ may be a potential drug target for glycyrrhetinic acid ester derivatives. The high affinity between compound C1 and PPARγ suggests that C1 may act as a PPARγ agonist to regulate tumor signaling pathways, such as... Figure 6 As shown.

[0022] The advantages of this invention compared to existing technologies are as follows:

[0023] In this invention, the obtained 18β-glycyrrhetinic acid derivatives exhibited significant tumor cell inhibitory activity compared to glycyrrhetinic acid. Most of the novel compounds showed significantly better inhibitory activity against two human cancer cell lines (HCT-116 and HCT-8) than their parent molecules. To further investigate the antitumor activity of the 18β-glycyrrhetinic acid derivatives, molecular docking revealed that PPARγ may be a potential drug target for these derivatives. The high affinity between compound C1 and PPARγ suggests that C1 may act as a PPARγ agonist to regulate tumor signaling pathways, providing a possibility for the development of novel oncology drugs. Attached Figure Description

[0024] Figure 1The in vitro proliferation inhibitory activity of 18β-glycyrrhetinic acid derivatives C1~C15 against human colon cancer cell lines HCT-116 and HCT-8 was detected by CCK8 assay.

[0025] Figure 2 The in vitro proliferation inhibitory activity of 18β-glycyrrhetinic acid derivatives C1~C15 against human hepatocyte line L02 was detected by CCK8 assay.

[0026] Figure 3 A diagram showing the in vitro inhibitory activity of 18β-glycyrrhetinic acid derivative C1 on the human colony cancer cell line HCT-116, as determined by the clonogenic assay.

[0027] Figure 4 Figure showing the effect of 18β-glycyrrhetinic acid derivative C1 on apoptosis in human colon cancer cell line HCT-116 as detected by flow cytometry.

[0028] Figure 5 Figure showing the effect of 18β-glycyrrhetinic acid derivative C1 on the migration ability of human colon cancer cell line HCT-116 in a cell scratch assay.

[0029] Figure 6 A schematic diagram illustrating the binding mode of 18β-glycyrrhetinic acid derivative C1 to PPARγ for molecular docking simulation. Detailed Implementation

[0030] A method for preparing 18β-glycyrrhetinic acid ester derivatives, the specific steps of which are as follows:

[0031] Under ice bath conditions, carboxylic acids (B) with different substituents (0.5 mmol), DCC (1 mmol), purified dichloromethane (20 mL), DMAP catalyst (0.1 mmol), and 18β-glycyrrhetinic acid (A) (0.6 mmol) were added sequentially to a 50 mL round-bottom flask. The mixture was stirred for 1 hour, and the reaction was monitored by TLC until complete. The mixture was then separated by silica gel column chromatography (V... 乙酸乙酯 V 石油醚 =1:2) to obtain the corresponding 18β-glycyrrhetinic acid derivatives (C1-C15).

[0032]

[0033] Example 1

[0034]

[0035] Compound C1 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 3-(2,5-dimethylphenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C1 was obtained as a white powder in 80% yield. Compound C1:1 HNMR (600 MHz, CDCl3) δ 8.35 (d, J = 15.2 Hz, 1H), 7.55 (d, J = 10.4 Hz, 1H), 7.50 – 7.39 (m, 1H), 7.31 (t, J = 7.8 Hz, 1H), 7.07 (dd, J = 24.2, 7.6 Hz,2H), 6.79 (d, J = 7.5 Hz, 1H), 6.66 (s, 1H), 5.68 (s, 1H), 4.59 (s, 2H), 4.01(s, 1H), 3.81 (s, 1H), 3.63 (s, 1H), 2.34 – 2.30 (m, 6H), 2.06 – 1.52 (m,16H), 1.44 – 1.09 (m, 24H), 0.82 (s, 1H), 0.77 (s, 1H).

[0036] Example 2

[0037]

[0038] Compound C2 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 3-(4-fluorophenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C2 was obtained as a white powder in 85% yield. Compound C2: 1 H NMR(600 MHz, CDCl3) δ 8.26 (s, 1H), 7.51 (s, 1H), 7.47 (d, J = 8.1 Hz, 1H), 7.32(t, J = 7.8 Hz, 1H), 7.05 (td, J = 8.1, 2.3 Hz, 3H), 6.98 – 6.90 (m, 2H),5.75 (s, 1H), 4.57 (s, 2H), 4.01 (s, 1H), 3.80 (s, 2H), 1.98 – 1.50 (m, 21H),1.46 – 1.23 (m, 10H), 1.22 – 1.07 (m, 9H), 1.00 (d, J = 4.6 Hz, 1H), 0.80 (d,J = 2.6 Hz, 1H).

[0039] Example 3

[0040]

[0041] Compound C3 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 3-(4-chlorophenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C3 was obtained as a white powder with a yield of 73%. 1 H NMR(600 MHz, CDCl3) δ 8.23 ​​(s, 1H), 7.50 (s, 1H), 7.47 (d, J = 8.1 Hz, 1H), 7.34– 7.29 (m, 3H), 7.04 (d, J = 7.6 Hz, 1H), 6.93 (d, J = 9.0 Hz, 2H), 5.75 (s,1H), 4.58 (s, 2H), 4.01 (s, 1H), 3.80 (s, 2H), 1.97 – 1.51 (m, 20H), 1.43 –1.22 (m, 12H), 1.21 – 1.08 (m, 8H), 1.00 (s, 1H), 0.80 (d, J = 2.8 Hz, 1H).

[0042] Example 4

[0043]

[0044] Compound C4 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 4-(3-chlorophenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C4 was obtained as a white powder in 70% yield. 1 H NMR(600 MHz, CDCl3) δ 8.21 (s, 1H), 7.56 (d, J = 8.4 Hz, 2H), 7.30 – 7.24 (m,3H), 7.09 – 7.04 (m, 1H), 7.02 (t, J = 2.1 Hz, 1H), 6.88 (dd, J = 8.3, 2.3Hz, 1H), 5.61 (s, 1H), 4.59 (s, 2H), 3.95 (t, J = 11.2 Hz, 1H), 3.76 (s, 2H),1.75 (m, 19H), 1.36 (m, 8H), 1.30 – 1.06 (m, 13H), 1.00 (s, 1H), 0.80 (s, 1H).

[0045] Example 5

[0046]

[0047] Compound C5 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 4-(4-fluorophenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C5 was obtained as a white powder with a yield of 71%. 1 H NMR(600 MHz, CDCl3) δ 8.30 (s, 1H), 7.56 (d, J = 8.3 Hz, 2H), 7.25 (d, J = 8.4Hz, 2H), 7.03 (t, J = 8.5 Hz, 2H), 6.94 (dd, J = 8.5, 4.6 Hz, 2H), 5.69 (s,1H), 4.56 (s, 2H), 3.96 (t, J = 11.1 Hz, 1H), 3.75 (s, 2H), 1.97 – 1.56 (m,18H), 1.44 – 1.32 (m, 10H), 1.22 – 1.09 (m, 12H), 1.00 (s, 1H), 0.80 (s, 1H).

[0048] Example 6

[0049]

[0050] Compound C6 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 4-(2-methyl, 4-fluorophenoxyacetamide)phenylacetic acid, while all other conditions remained unchanged. Compound C6 was obtained as a white powder in 65% yield. Compound C6: 1 HNMR (600 MHz, CDCl3) δ 8.25 (s, 1H), 7.54 (t, J = 8.5 Hz, 2H), 7.30 – 7.24(m, 2H), 7.20 (d, J = 2.5 Hz, 1H), 7.14 (ddd, J = 17.2, 8.6, 2.5 Hz, 1H), 6.76 (d, J = 8.7 Hz, 1H), 5.61 (s, 1H), 4.57 (d, J = 3.7 Hz, 2H), 3.95 (t, J= 11.3 Hz, 1H), 3.76 (s, 2H), 2.34 (s, 3H), 1.97 – 1.57 (m, 17H), 1.37 (dd, J= 31.9, 21.6 Hz, 10H), 1.28 – 1.07 (m, 13H), 0.86 – 0.74 (m, 2H).

[0051] Example 7

[0052]

[0053] Compound C7 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 2,3-dichlorobenzaldehyde lipoic acid, while all other conditions remained unchanged. Compound C7 was obtained as a white powder in 75% yield. Compound C7: 1 H NMR (600MHz, CDCl3) δ 7.60 (d, J = 7.8 Hz, 1H), 7.40 (d, J = 8.0 Hz, 1H), 7.23 (t, J= 7.9 Hz, 1H), 5.64 (s, 1H), 5.57 (d, J = 8.5 Hz, 1H), 4.43-4.38 (m, 1H), 3.09 (m, 3H), 2.33 – 2.28 (m, 2H), 2.21 (d, J = 15.8 Hz, 1H), 1.97 – 1.76 (m,6H), 1.72 – 1.56 (m, 11H), 1.52 – 1.39 (m, 7H), 1.37 (s, 3H), 1.28 (d, J =3.2 Hz, 3H), 1.12 (s, 7H), 1.05 (d, J = 12.9 Hz, 2H), 1.00 (s, 2H), 0.87 (s,3H), 0.85 (s, 3H), 0.81 (s, 2H).

[0054] Example 8

[0055]

[0056] Compound C8 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 2-methylbenzaldehyde lipoic acid, while all other conditions remained unchanged. Compound C8 was obtained as a white powder in 68% yield. Compound C8: 1H NMR (600 MHz, CDCl3) δ 7.57 (d, J = 7.5 Hz, 1H), 7.21 – 7.12 (m, 3H), 5.69 (s, 1H), 5.30(s, 1H), 3.90 (t, J = 10.7 Hz, 1H), 3.07 – 2.95 (m, 3H), 2.44 (s, 3H), 2.40 (t, J = 7.4 Hz, 2H), 2.18 (t, J = 9.2 Hz, 2H), 2.03 – 1.57 (m, 22H), 1.51 –1.41 (m, 5H), 1.37 (d, J = 5.8 Hz, 5H), 1.29 (d, J = 4.2 Hz, 5H), 1.13 (d, J= 2.0 Hz, 5H), 1.00 (s, 2H), 0.86 (s, 2H), 0.81 (s, 2H).

[0057] Example 9

[0058]

[0059] Compound C9 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 4-methoxybenzaldehyde lipoic acid, while all other conditions remained unchanged. Compound C9 was obtained as a white powder with a yield of 73%. Compound C9: 1 H NMR (600MHz, CDCl3) δ 7.38 (d, J = 8.7 Hz, 2H), 6.85 (d, J = 8.7 Hz, 2H), 5.29 (s,1H), 5.12 (s, 1H), 4.11 (t, J = 7.1 Hz, 1H), 3.89 (t, J = 9.5 Hz, 1H), 3.79 (s, 3H), 3.70 – 3.63 (m, 1H), 3.04 – 2.93 (m, 3H), 2.39 (t, J = 7.4 Hz, 2H), 2.18 – 2.12 (m, 1H), 1.97 – 1.57 (m, 20H), 1.56 – 1.44 (m, 3H), 1.42 (s, 1H), 1.36 (dd, J = 23.5, 9.1 Hz, 7H), 1.30 – 1.08 (m, 14H), 1.08 – 0.78 (m, 2H).

[0060] Example 10

[0061]

[0062] Compound C10 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 4-nitrobenzaldehyde lipoic acid, while all other conditions remained unchanged. Compound C10 was obtained as a pale yellow powder in 56% yield. Compound C10: 1 H NMR (600MHz, CDCl3) δ 8.20 (d, J = 8.6 Hz, 2H), 7.64 (d, J = 8.7 Hz, 2H), 5.57 (d, J= 8.3 Hz, 1H), 5.23 (s, 1H), 4.42 – 4.38 (m, 1H), 3.05 – 2.99 (m, 3H), 2.30 (dd, J = 13.0, 5.6 Hz, 2H), 2.07 – 2.01 (m, 3H), 1.94 (dd, J = 16.7, 12.9 Hz, 3H), 1.70 – 1.60 (m, 11H), 1.38 – 1.36 (m, 4H), 1.29 (s, 7H), 1.26 (s, 3H), 1.11 (s, 7H), 1.00 (s, 2H), 0.87 (s, 4H), 0.85 (s, 4H), 0.82 (s, 2H).

[0063] Example 11

[0064]

[0065] Compound C11 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with benzyl lipoic acid, while all other conditions remained unchanged. Compound C11 was obtained as a white powder in 60% yield. Compound C11: 1H NMR (600 MHz, CDCl3) δ 7.33 – 7.27 (m, 8H), 7.25 – 7.20 (m, 2H), 5.76 (s, 1H), 4.41 (dd, J= 9.6, 6.7 Hz, 1H), 3.66 (s, 2H), 3.64 (s, 2H), 2.52 – 2.46 (m, 2H), 2.27 –2.23 (m, 2H), 2.09 – 1.87 (m, 5H), 1.86 – 1.56 (m, 14H), 1.55 – 1.51 (m, 1H),1.46 (dd, J = 14.4, 7.3 Hz, 3H), 1.39 – 1.33 (m, 8H), 1.29 (s, 3H), 1.22 –1.16 (m, 4H), 1.14 – 1.10 (m, 6H), 1.00 (s, 1H), 0.88 (d, J = 5.9 Hz, 3H), 0.85 (s, 1H), 0.82 – 0.79 (m, 2H).

[0066] Example 12

[0067]

[0068] Compound C12 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with pentafluorobenzaldehyde thiazolic acid, while all other conditions remained unchanged. Compound C12 was obtained as a white powder in 55% yield. Compound C12: 1 H NMR (600MHz, CDCl3) δ 5.69 (s, 1H), 4.12 (q, J = 7.1 Hz, 1H), 3.23 (dd, J = 11.1, 5.2Hz, 1H), 2.79 (dt, J = 13.5, 3.5 Hz, 1H), 2.33 (s, 1H), 2.17 (dd, J = 13.6,3.6 Hz, 1H), 2.03 – 1.91 (m, 3H), 1.90 – 1.81 (m, 2H), 1.66 (m, 7H), 1.51 –1.39 (m, 6H), 1.36 (s, 4H), 1.30 (s, 3H), 1.14 (s, 7H), 1.01 (s, 3H), 0.86(s, 3H), 0.81 (s, 3H).

[0069] Example 13

[0070]

[0071] Compound C13 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 2-thiophenecarboxylic acid, while all other conditions remained unchanged. Compound C13 was obtained as a white powder in 65% yield. Compound C13: 1 H NMR (600 MHz, CDCl3) δ 7.72 (d, J = 3.6 Hz, 1H), 7.47 (d, J = 4.9 Hz, 1H), 7.03 – 7.01 (m,1H), 5.51 (d, J = 4.6 Hz, 1H), 4.56 – 4.49 (m, 1H), 1.97 (t, J = 10.4 Hz, 4H), 1.77 – 1.72 (m, 4H), 1.31 (d, J = 6.4 Hz, 4H), 1.18 (s, 6H), 1.06 (d, J= 4.8 Hz, 6H), 0.94 (s, 6H), 0.78 (d, J = 3.3 Hz, 6H), 0.76 (s, 6H).

[0072] Example 14

[0073]

[0074] Compound C14 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with 5-chloro-2-thiophenecarboxylic acid, while all other conditions remained unchanged. Compound C14 was obtained as a white powder in 67% yield. 1 H NMR (600 MHz, CDCl3) δ 7.58 (d, J = 3.8 Hz, 1H), 6.93 (d, J = 4.1 Hz, 1H), 5.70 (d, J = 7.7Hz, 1H), 4.70 – 4.65 (m, 1H), 2.00-1.95 (m, 4H), 1.77 – 1.72 (m, 4H), 1.31(d, J = 6.4 Hz, 4H), 1.18 (s, 6H), 1.06 (d, J = 4.8 Hz, 6H), 0.94 (s, 6H),0.78 (d, J = 3.3 Hz, 6H), 0.76 (s, 6H).

[0075] Example 15

[0076]

[0077] Compound C15 was prepared using the same method as above, except that the different substituted carboxylic acids (B) were replaced with indolecarboxylic acid, while all other conditions remained unchanged. Compound C15 was obtained as a white powder in 66% yield. Compound C15: 1 H NMR (600 MHz, CDCl3)δ 8.05 (d, J = 5.3 Hz, 1H), 7.92 – 7.82 (m, 2H), 7.42 (dt, J = 15.1, 7.3 Hz,2H), 5.59 (s, 1H), 4.72 (m, 1H), 2.11 – 1.99 (m, 6H), 1.84 (m, 5H), 1.38 (d,J = 9.4 Hz, 6H), 1.29 – 1.27 (m, 4H), 1.23 – 1.20 (m, 3H), 1.15 – 1.12 (m,6H), 1.05 (d, J = 6.3 Hz, 6H), 0.87 – 0.82 (m, 6H).

[0078] Example 16

[0079] Using human colon cancer cell lines HCT-116 and HCT-8 as detection lines and the CCK-8 colorimetric assay as the detection method, the in vitro tumor cell inhibitory activity of type I 18β-glycyrrhizin derivatives was studied. The results showed that these novel structural derivatives exhibited significant in vitro tumor cell inhibitory activity. C1 showed the strongest inhibitory activity against HCT-116 cells, and its inhibitory activity was superior to the positive control gefitinib. (See attached figure for results.) Figure 1 Meanwhile, this type of derivative did not show significant inhibitory effect on the proliferation of human hepatocyte cell line L02, with an IC50 value of [missing information]. 50 The values ​​were all greater than 100 μmol / L, indicating that the toxicity of this type of derivative to normal cells was significantly lower than that of its parent nucleus structure, 18β-glycyrrhetinic acid. The results are shown in the appendix. Figure 2 .

[0080] Table 1. Antiproliferative activity of 18β-glycyrrhetinic acid derivatives against human colon cancer cells

[0081]

[0082] Furthermore, colony formation assays were performed on compound C1, which exhibited the best activity. The results showed that C1 significantly inhibited the number and size of HCT-116 cell clones, suppressing the proliferation of the HCT-116 cell line in a concentration-dependent manner, demonstrating superior anti-proliferative activity. (See attached figure for details.) Figure 3Apoptosis experiments showed that, at the same molar concentration, compound C1 effectively induced apoptosis in HCT-116 cells, with significantly better results than the parent compound glycyrrhetinic acid and the positive control drug gefitinib. The results are as follows: Figure 4 Furthermore, cell scratch assays showed that compound C1 at 20 μmol / L effectively inhibited HCT-116 migration; results are attached. Figure 5 .

[0083] Example 17: Compound C1 has a high affinity for PPARγ protein.

[0084] Molecular docking was used to simulate the binding of compounds with PPARγ. The results are shown in Table 2. Compounds C1-C15 all showed good binding energies with PPARγ, with C1 exhibiting the lowest binding energy at -8.7762 kcal / mol, indicating the strongest affinity. Molecular docking suggests that PPARγ may be a potential drug target for 18β-glycyrrhetinic acid ester derivatives. The high affinity between compound C1 and PPARγ suggests that C1 may act as a PPARγ agonist to regulate tumor signaling pathways. (See attached table for details.) Figure 6 .

[0085] Table 2. Binding energy of 18β-glycyrrhetinic acid derivatives to PPARγ protein

[0086]

[0087] Based on the above conclusions, this type of compound has the potential to be used as a PPARγ agonist and can be prepared into an anti-tumor drug.

Claims

1. 18β-glycyrrhetinic acid ester derivatives, characterized in that: The 18β-glycyrrhetinic acid derivative is one of the following structural formulas: 、 、 、 。 2. A method for preparing the 18β-glycyrrhetinic acid ester derivative as described in claim 1, characterized in that: The preparation method includes dissolving carboxylic acids with different substituents, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine in anhydrous dichloromethane, stirring at room temperature for 30 minutes to obtain a reaction mixture; then adding 18β-glycyrrhetinic acid to the reaction mixture, stirring at room temperature for more than 12 hours, evaporating to remove the solvent, and purifying the residue by silica gel column chromatography to obtain 18β-glycyrrhetinic acid ester derivatives; the carboxylic acids with different substituents are as follows: 。 3. The method for preparing 18β-glycyrrhetinic acid ester derivatives according to claim 2, characterized in that: The molar ratio of the different substituents of the carboxylic acid, dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and 18β-glycyrrhetinic acid is 1:2:0.2:1.

2.

4. The method for preparing 18β-glycyrrhetinic acid ester derivatives according to claim 2, characterized in that: The molar concentration of the different substituents in the reaction mixture is 25 mmol / L.

5. The method for preparing 18β-glycyrrhetinic acid ester derivatives according to claim 2, characterized in that: The eluent for purification consisted of ethyl acetate and petroleum ether in a volume ratio of 1:

2.

6. The use of the 18β-glycyrrhetinic acid ester derivative as described in claim 1 in the preparation of antitumor drugs, characterized in that, The tumor is colon cancer.

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