Preparation of a novel indole camptothecin derivative and its use in anti-tumor

Abstract

The present application relates to a kind of preparation of new indole camptothecin derivatives and its use in antitumor, the structure of the compound general formula is shown as follows.In vitro cytotoxic activity screening results show that new indole camptothecin derivatives have broad-spectrum antitumor activity, to human hepatoma cell (HepG2), human non-small cell lung cancer cell (A549), human colon cancer cell (SW480), human intrahepatic cholangiocarcinoma cell (RBE), human breast cancer cell (MCF-7), human pancreatic cancer cell (BxPC3), human bladder cancer cell (T24), human bladder cancer cell (umuc3) show strong inhibitory activity. Among them, the antitumor activity of compound D-18 is most outstanding, and shows strong inhibition to the 8 tumor cell lines measured, IC 50 The range is 0.2585-10.69 μM, significantly better than the control drug irinotecan, and comparable to topotecan activity. Therefore, indole camptothecin derivatives are expected to be developed into a new antitumor drug.

Description

Technical Field

[0001] This invention belongs to the field of natural product chemistry, and relates to the preparation of a novel indole camptothecin derivative and its use in antitumor effects. Background Technology

[0002] Indole rings are among the most widely found heterocyclic compounds in nature. This skeleton exhibits excellent antitumor activity and is commonly found in active ingredients and natural products, such as vincristine, vinblastine, and gelseminate. With the successful development of some indoles and azaindoles into anticancer drugs, the design and synthesis of indole and azaindole derivatives with antitumor activity have received increasing attention and significant progress has been made. Therefore, hybridization of indoles with other active substances is an effective and commonly used strategy for finding and designing novel anticancer drugs.

[0003] Camptothecin is a pentacyclic quinoline alkaloid isolated from the bark and stems of the camptotheca tree. It exerts its antitumor activity by acting on DNA topoisomerase I and has become one of the important lead compounds in the development of anticancer drugs. To date, camptothecin-based drugs such as irinotecan, topotecan, and beloteccan have been approved for marketing for cancer treatment. The structure-activity relationship of camptothecin indicates that modification of the AB ring structure significantly affects its antitumor activity, making it the optimal modification site for further development of novel anticancer drugs.

[0004] Therefore, we employed a skeletal transition design approach, replacing the quinoline AB ring of the camptothecin core with an indole fragment to construct a series of novel indole-based camptothecin derivatives, and tested their inhibitory activity against various tumor cell types. Experimental results showed that the novel indole-based camptothecin derivatives possess broad-spectrum antitumor activity. Among them, the highly active compound D-18 exhibited superior in vitro inhibitory activity against various tumor cell types compared to the clinical drug irinotecan, and its activity was comparable to topotecan, making it a potential novel antitumor drug for development. Summary of the Invention

[0005] This invention provides a novel indole-based camptothecin derivative for preparation and its use in antitumor applications.

[0006] The structural formula of the novel indole camptothecin derivative of this invention is shown below:

[0007]

[0008] The method for preparing the novel indole camptothecin derivative of this invention is carried out according to the following chemical formula 1:

[0009]

[0010] A series of novel indole camptothecin derivatives can be obtained by using the Fischer indole synthesis reaction with phenylhydrazine or phenylhydrazine hydrochloride of different substitutions as raw materials and heating them under reflux for 18-20 hours with tricyclic ketones in an acidic environment.

[0011] This invention relates to a novel indole-based camptothecin derivative that can play a role in the preparation of antitumor drugs, more specifically, in the preparation of drugs for treating human liver cancer, non-small cell lung cancer, colon cancer, cholangiocarcinoma, breast cancer, pancreatic cancer, and bladder cancer. In vitro antitumor activity screening results show that the novel indole-based camptothecin derivative has broad-spectrum antitumor activity, exhibiting strong inhibitory activity against human liver cancer cells (HepG2), human non-small cell lung cancer cells (A549), human colon cancer cells (SW480), human intrahepatic cholangiocarcinoma cells (RBE), human breast cancer cells (MCF-7), human pancreatic cancer cells (BxPC3), human bladder cancer cells (T24), and human bladder cancer cells (umuc3). Among them, compound D-18 exhibits the most prominent antitumor activity, showing strong inhibitory effects on all eight tested tumor cell lines, with an IC50 score of [missing value]. 50 The activity ranged from 0.2585 to 10.69 μM, which was significantly better than the control drug irinotecan and comparable to topotecan.

[0012] Therefore, the novel indole camptothecin derivatives of this invention can be used to prepare antitumor drugs. They have novel structures, inexpensive and readily available raw materials, and high product purity. They also exhibit strong inhibitory effects on the proliferation of various tumor cell lines and have good application prospects.

[0013] The following detailed description of specific embodiments further illustrates the above-mentioned aspects of the present invention. However, this should not be construed as a limitation of the present invention. Detailed Implementation

[0014] To better understand the present invention, the following detailed description of the above-mentioned contents of the present invention is provided through specific embodiments. Unless otherwise specified, the experimental methods described in the following embodiments are conventional methods.

[0015] Example 1: Synthesis of target compound D-1

[0016]

[0017] The synthesis method of compound D-1 described in this invention is carried out according to chemical formula 2:

[0018]

[0019] Synthesis of compound D-1: A tricyclic ketone (200 mg, 0.76 mmol, 1 equivalent) was dissolved in 15 mL of glacial acetic acid, and phenylhydrazine (288 mg, 2.66 mmol, 3.5 equivalent) was added. The mixture was refluxed for 18–20 h under TLC monitoring. After the reaction was complete, the mixture was cooled to room temperature, and the reaction solution was poured into 100 mL of water, resulting in the precipitation of a large amount of solid. The solid was filtered and washed with water. After drying the filter cake, it was subjected to silica gel column chromatography, eluted with a dichloromethane / methanol system, to give a yellow solid, D-1.

[0020] The reaction product test data are as follows: Yield: 66%; Yellow solid; 1 HNMR(400MHz,DMSO)δ12.43(s,1H),7.58(dd,J=9.3,2.3Hz,1H),7.44–7.35(m,1H),7.12(s,1H),6.43(s,1H) ,5.45–5.28(m,2H),4.99(s,2H),1.83(m,J=14.3,7.2Hz,2H),0.88(t,J=7.4Hz,3H); ESI-MSm / z:337.1[M+H] + .

[0021] Example 2: Synthesis of target compound D-2

[0022]

[0023] The experimental procedure was the same as in Example 1, except that 4-fluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 58%; yellow solid; 1 HNMR(400MHz,DMSO)δ12.06(s,1H),7.50(td,J=8.7,3.5Hz,2H),7.09(td,J=9.2,2.7Hz,1H),6.89(s,1H) ,6.38(s,1H),5.40–5.26(m,2H),4.94(s,2H),1.79(m,2H),0.83(t,J=7.4Hz,3H); ESI-MSm / z:355.1[M+H] + .

[0024] Example 3: Synthesis of target compound D-3

[0025]

[0026] The experimental procedure was the same as in Example 1, except that 3-fluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 36%; yellow solid; 1HNMR(400MHz,DMSO)δ12.11(s,1H),7.55(td,J=9.2,3.7Hz,2H),6.96(d,J=14.6Hz,1H),6.46(s,1H), 5.38(d,J=3.8Hz,2H),4.98(s,2H),1.87–1.83(m,2H),0.88(t,J=7.3Hz,3H); ESI-MSm / z:355.1[M+H] + .

[0027] Example 4: Synthesis of target compound D-4

[0028]

[0029] The experimental procedure was the same as in Example 1, except that 2-fluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 55%; yellow solid; 1 HNMR(600MHz,DMSO)δ12.45(s,1H),7.60–7.53(m,1H),7.18–7.10(m,2H),6.99(s,1H),6.44(s ,1H),5.43–5.34(m,2H),5.08–4.98(m,2H),1.84(m,2H),0.90(t,3H); ESI-MSm / z:355.1[M+H] + .

[0030] Example 5: Synthesis of target compound D-5

[0031]

[0032] The experimental procedure was the same as in Example 1, except that 4-bromophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 55%; Orange solid; 1 HNMR (400MHz, DMSO) δ12.21(s,1H),7.98(d,J=2.0Hz,1H),7.53(d,J=8.8Hz,1H),7.39(dd,J=8.8,2.0Hz,1H),6.94(s,1H) ,6.44(s,1H),5.45–5.31(m,2H),4.99(s,2H),1.91–1.74(m,J=7.2Hz,2H),0.87(t,J=7.3Hz,3H); ESI-MSm / z:415.1[M+H] + .

[0033] Example 6: Synthesis of target compound D-6

[0034]

[0035] The experimental procedure was the same as in Example 1, except that 3-bromophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 33%; Brown solid; 1 HNMR(400MHz,DMSO)δ12.19(s,1H),7.70(s,1H),7.47(m,1H),7.27(m,1H),6.99(d,1H), 6.46(s,1H),5.39(d,2H),5.02(s,2H),1.87(m,2H),0.87(t,3H); ESI-MSm / z:415.1[M+H] + .

[0036] Example 7: Synthesis of target compound D-7

[0037]

[0038] The experimental procedure was the same as in Example 1, except that 2-bromophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 56%; yellow solid; 1 HNMR (400MHz, DMSO) δ12.21(s,1H),7.75(d,J=8.0Hz,1H),7.50(d,J=7.6Hz,1H),7.18(s,1H),7.11(t,J=7.8Hz,1H),6 .43(s,1H),5.45–5.31(m,2H),5.02(s,2H),1.94–1.75(m,J=7.1Hz,2H),0.89(t,J=7.3Hz,3H); ESI-MSm / z:415.1[M+H] + .

[0039] Example 8: Synthesis of target compound D-8

[0040]

[0041] The experimental procedure was the same as in Example 1, except that 4-chlorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product data are as follows: Yield: 45%; Brown solid; 1 HNMR(600MHz,CD3OD)δ7.81(d,J=2.0Hz,1H),7.56(d,J=8.8Hz,1H),7.31(dt,J=8.8,1.7Hz,1H),7.09(s, 1H),5.60–5.53(m,1H),5.41–5.35(m,2H),5.09(s,2H),1.94(m,2H),1.03(t,3H); ESI-MSm / z:371.1[M+H] + .

[0042] Example 9: Synthesis of target compound D-9

[0043]

[0044] The experimental procedure was the same as in Example 1, except that 4-methylphenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 61%; yellow solid; 1 HNMR(600MHz,DMSO)δ11.85(s,1H),7.52–7.48(m,1H),7.43(d,J=8.4Hz,1H),7.11(dd,J=8.5,1.7Hz,1H),6.89(s,1H),6.41(s,1 H),5.40–5.32(m,2H),4.97(d,J=1.8Hz,2H),2.41(s,3H),1.83(m,J=21.4,7.1Hz,2H),0.88–0.85(t,3H); ESI-MSm / z:351.1[M+H] + .

[0045] Example 10: Synthesis of target compound D-10

[0046]

[0047] The experimental procedure was the same as in Example 1, except that 3-methylphenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 37%; yellow solid; 1 HNMR(400MHz,DMSO)δ11.78(s,1H),7.52(d,1H),7.28(s,1H),6.95–6.79(m,2H),6.37(s,1H) ),5.31(m,2H),4.89(d,2H),2.53(s,3H),1.79(m,2H),0.82(t,3H); ESI-MSm / z:351.1[M+H] + .

[0048] Example 11: Synthesis of target compound D-11

[0049]

[0050] The experimental procedure was the same as in Example 1, except that 4-methoxyphenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 45%; Brown solid; 1HNMR(400MHz,DMSO)δ11.88(s,1H),7.44(s,1H),7.24(s,1H),6.92(m,2H),6.43(s,1H), 5.38(d,2H),4.97(s,2H),3.80(s,3H),1.84(m,2H),0.88(t,3H); ESI-MSm / z:367.1[M+H] + .

[0051] Example 12: Synthesis of target compound D-12

[0052]

[0053] The experimental procedure was the same as in Example 1, except that 4-trifluoromethoxyphenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 44%; white solid; 1 H NMR(600MHz,CD3OD)δ7.69(s,1H),7.58(d,1H),7.22(d,1H),7.06(s,1H),5.52(d ,1H),5.34(d,1H),5.07(s,2H),1.92(m,2H),0.98(t,3H); ESI-MSm / z:421.1[M+H] + .

[0054] Example 13: Synthesis of target compound D-13

[0055]

[0056] The experimental procedure was the same as in Example 1, except that 2,4-difluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 47%; Orange solid; 1 HNMR(600MHz,DMSO)δ12.57(s,1H),7.45(dd,J=9.2,2.3Hz,1H),7.22(m,1H),6.99(s,1H),6.45(s,1H), 5.38(d,J=6.6Hz,2H),5.00(t,J=3.3Hz,2H),1.83(m,2H),0.87(t,J=7.4Hz,3H); ESI-MSm / z:373.1[M+H] + .

[0057] Example 14: Synthesis of target compound D-14

[0058]

[0059] The experimental procedure was the same as in Example 1, except that 2-chloro-4-fluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 52%; yellow solid; 1 HNMR(400MHz,DMSO)δ12.43(s,1H),7.58(dd,J=9.3,2.3Hz,1H),7.44–7.35(m,1H),7.12(s,1H),6.4 3(s,1H),5.45–5.28(m,2H),4.99(s,2H),1.83(m,2H),0.88(t,J=7.4Hz,3H); ESI-MSm / z:389.1[M+H] + .

[0060] Example 15: Synthesis of target compound D-15

[0061]

[0062] The experimental procedure was the same as in Example 1, except that 2,4-dichlorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product data are as follows: Yield: 48%; yellow solid; 1 HNMR (400MHz, DMSO) δ12.55(s,1H),7.86(d,J=1.8Hz,1H),7.48(d,J=1.9Hz,1H),7.13(s,1H),6.44(s,1 H),5.39(d,J=4.2Hz,2H),5.01(s,2H),1.87–1.80(m,2H),0.88(t,J=7.2Hz,3H); ESI-MSm / z:405.1[M+H] + .

[0063] Example 16: Synthesis of target compound D-16

[0064]

[0065] The experimental procedure was the same as in Example 1, except that 2,5-dichlorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 38%; yellow solid; 1 HNMR(400MHz, CDCl3)7.71(d,1H),7.58(d,1H),7.06(s,1H),6.81(s,1H),5 .60(d,2H),5.13(s,2H),1.87(m,2H),0.88(t,3H); ESI-MSm / z:405.1[M+H] + .

[0066] Example 17: Synthesis of target compound D-17

[0067]

[0068] The experimental procedure was the same as in Example 1, except that 3-chloro-4-fluorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product detection data are as follows: Yield: 31%; Orange solid; 1 HNMR (400MHz, DMSO) δ12.24 (s, 1H), 7.75 (d, J = 8.9Hz, 1H), 7.37 (d, 1H), 6.99 (s, 1H), 6. 44(s,1H),5.39(m,2H),5.13(s,2H),1.84(m,2H),0.96(t,3H); ESI-MSm / z:389.1[M+H] + .

[0069] Example 18: Synthesis of target compound D-18

[0070]

[0071] The experimental procedure was the same as in Example 1, except that 3,4-dichlorophenylhydrazine hydrochloride was used instead of phenylhydrazine. The product analysis data are as follows: Yield: 36%; Brown solid; 1 HNMR(400MHz,DMSO)δ12.31(s,1H),8.06(s,1H),7.88(s,1H),7.00(s,1H),6.44(s,1H), 5.46–5.35(m,2H),4.99(s,2H),1.87–1.80(m,2H),0.92(t,3H); ESI-MSm / z:405.1[M+H] + .

[0072] Example 19: Test methods and results of the antitumor activity of novel indole camptothecin derivatives

[0073] In vitro antitumor assays were performed using the standard MTT assay. Irinotecan and topotecan were used as positive controls to test the inhibitory activity of novel indole camptothecin derivatives against human hepatocellular carcinoma cells (HepG2), human non-small cell lung cancer cells (A549), human colon cancer cells (SW480), human intrahepatic cholangiocarcinoma cells (RBE), human breast cancer cells (MCF-7), human pancreatic cancer cells (BxPC3), human bladder cancer cells (T24), and human bladder cancer cells (umuc3). The compounds were dissolved in DMSO to prepare a 10 mM stock solution, which was then diluted to appropriate concentrations using different culture media. The DMSO concentration in the diluent should be less than 0.01% (v / v) to reduce DMSO toxicity to cells and minimize testing errors. Tumor cells of different cell lines were cultured in RPMI-1640 or DMEM high-glucose medium containing 10% fetal bovine serum (FBS). Log-growing cancer cells were collected, digested with trypsin / EDTA digestion solution, and prepared into appropriate cell suspensions. 100 μL of cell suspension was added to 96-well plates (typically 5000 cells per well) and incubated at 37°C with 5% CO2 for 24 h. Then, different concentrations of the test compound solutions were added, and after 48 h of incubation, the old culture medium was discarded, and the cells were washed twice with PBS. 25 μL of fresh LMT (5 mg / mL) was added, and the cells were incubated for another 4 h. Afterward, the culture medium was discarded, and 200 μL of LDMSO was added. The plates were shaken for 15 min on a shaker until the formazan was completely dissolved. Finally, the absorbance at 490 nm was measured using a microplate reader, and the IC50 was calculated. 50 Values. All experiments were conducted in triplicate or in three replicates. The cytotoxic activity results of the novel indole camptothecin derivatives are shown in Table 1.

[0074] Table 1. In vitro cytotoxic activity of novel indole-based camptothecin derivatives

[0075]

[0076]

[0077] Note: (1) Screening method: standard MTT colorimetric method; (2) Action time: 48 hours; (3) Compound numbers D-1 to D-18 are the products obtained in Examples 1 to 18 above.

[0078] In vitro cytotoxicity screening results showed that the novel indole camptothecin derivatives possess broad-spectrum antitumor activity, exhibiting strong inhibitory activity against human hepatocellular carcinoma cells (HepG2), human non-small cell lung cancer cells (A549), human colon cancer cells (SW480), human intrahepatic cholangiocarcinoma cells (RBE), human breast cancer cells (MCF-7), human pancreatic cancer cells (BxPC3), human bladder cancer cells (T24), and human bladder cancer cells (umuc3). Among them, compound D-18 showed the most prominent antitumor activity, exhibiting strong inhibitory effects on all eight tested tumor cell lines, with an IC50 score of [missing value]. 50 The concentration ranged from 0.2585 to 10.69 μM, significantly superior to the control drug irinotecan, and comparable in activity to topotecan. Therefore, indole camptothecin derivatives hold promise for development into novel antitumor drugs.

Claims

1. An indole-based camptothecin derivative, characterized in that, The structures of compounds D-1 to D-18 are shown in the formula: 。 2. A method for preparing an indole-type camptothecin derivative according to claim 1, characterized in that, The method includes: The Fischer indole synthesis reaction was used, with phenylhydrazines or their hydrochlorides of different substitutions as raw materials. Under acidic conditions, (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyranO[3,4-F]indoleazine-3,6,10(4H)-one was heated under reflux for 18-20 hours to obtain indole camptothecin derivatives D-1 to D-18.

3. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human liver cancer HepG2; wherein, The indole camptothecin derivatives are D-1, D-2, D-3, D-4, D-5, D-6, D-7, D-9, D-10, D-11, D-13, D-14, D-15, D-16, D-17 or D-18.

4. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human non-small cell lung cancer A549; wherein, The indole camptothecin derivatives are D-2, D-3, D-4, D-5, D-6, D-7, D-9, D-10, D-13, D-14, D-15, D-16, D-17 or D-18.

5. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human colon cancer SW480; wherein, The indole camptothecin derivatives are D-3, D-4, D-5, D-6, D-9, D-10, D-13, D-14, D-16, D-17, or D-18.

6. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human intrahepatic cholangiocarcinoma cells (RBE); wherein, The indole camptothecin derivative is D-16 or D-18.

7. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human breast cancer MCF-7; wherein, The indole camptothecin derivatives are D-1, D-2, D-3, D-4, D-5, D-6, D-7, D-8, D-9, D-10, D-11, D-12, D-13, D-14, D-15, D-16, D-17 or D-18.

8. The use of an indole camptothecin derivative according to claim 1 in the preparation of a medicament for treating human pancreatic cancer BxPC3; wherein, The indole camptothecin derivatives are D-1, D-2, D-3, D-4, D-5, D-6, D-7, D-8, D-9, D-10, D-11, D-12, D-13, D-14, D-15, D-16, D-17 or D-18.

9. The use of an indole-based camptothecin derivative according to claim 1 in the preparation of a medicament for treating human bladder cancer T24; wherein, The indole camptothecin derivatives are D-2, D-3, D-6, D-7, D-9, D-10, D-12, D-13, D-14, D-15, D-16, D-17 or D-18.

10. The use of an indole camptothecin derivative according to claim 1 in the preparation of a medicament for treating human bladder cancer umuc3; wherein, The indole camptothecin derivatives are D-2, D-3, D-6, D-7, D-8, D-9, D-10, D-12, D-13, D-14, D-15, D-16, D-17 or D-18.

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