Indolinedione piperazine derivatives, processes for their preparation and use in the preparation of cardioprotective drugs

Abstract

This invention discloses a class of indole-diketopiramate derivatives, their preparation methods, and their applications in the preparation of cardioprotective drugs. The structural formula of the indole-diketopiramate derivative is shown in formula (I) or (II), wherein: in formula (I), R1, R2, and R3 are selected from H, ... ...

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, and in particular to a class of indole-diketopiramate derivatives, their preparation methods, and their application in the preparation of myocardial protective drugs. Background Technology

[0002] Myocardial infarction (MI) is a pathological process caused by sudden blockage of the coronary arteries or a significant reduction in blood flow, leading to local myocardial ischemia and subsequently myocardial cell necrosis. If ischemia persists and blood flow is not restored in time, it may further lead to heart failure and even endanger life. Reperfusion therapy is the main treatment for myocardial infarction, but during the process of restoring blood flow, it may cause further damage to myocardial tissue, manifesting as serious complications such as arrhythmias and cardiac arrest, and exacerbating myocardial necrosis. This phenomenon is called myocardial ischemia-reperfusion injury (MIRI). MIRI is one of the common causes affecting the treatment effect of cardiovascular diseases, hindering the benign progression of the disease, and even leading to treatment failure. However, there has been a lack of clearly effective treatments for MIRI. Therefore, developing safe, effective, and cost-effective small molecule drugs for the treatment of MIRI has significant clinical value and is of great urgency. Summary of the Invention

[0003] The purpose of this invention is to provide a class of indole-diketopiperazine derivatives, their preparation methods, and their applications in the preparation of myocardial protective drugs.

[0004] This invention is achieved through the following technical solutions:

[0005] A class of indole-diketopiramate derivatives, wherein the structural formula of the indole-diketopiramate derivative is shown in formula (I) or (II): ; Wherein: In formula (I), R1, R2, and R3 are selected from H, , , , , , , , , , or R1, R2, and R3 can be the same or different groups, and n = 1-8;

[0006] In formula (II), R4 and R5 are selected from H or R4 and R5 can be the same group or different groups.

[0007] Preferably, the indole-diketone-piperazine derivative has any of the following structures: ; ; ;

[0008] This invention also protects a method for preparing the indole-diketone piperazine derivative, comprising the following steps: ; Among them, R1, R2, and R3 are selected from H, , , , , , or R1, R2, and R3 can be the same or different groups, and n = 1-8;

[0009] Indole-diketopiramate was dissolved in a solvent and placed in a reaction bath at 0-5°C. Sodium hydride and the bromide were added sequentially, and the reaction was continued at this temperature until completion. The reaction process was tracked by TLC. After the reaction was completed, the pH of the reaction solution was adjusted to be weakly acidic. The organic phase obtained by extraction was dried to obtain the crude product. The crude product was then separated by semi-preparative high performance liquid chromatography or by silica gel column chromatography to obtain the target products (HY-1~HY11, HY13~HY-14 and HY19~HY-32).

[0010] Preferably, the solvent is DMF, the molar ratio of sodium hydride to indole-dikepiperazine is 1~8:1, the molar ratio of the brominated product to indole-dikepiperazine is 1~8:1, and the reaction conditions are: 0~5℃ for 1~6 h.

[0011] Preferably, the preparation method of the indole-diketopiperazine derivative includes the following steps: ; Among them, R6 is selected from H, , , or n=2-4;

[0012] The brominated intermediate was dissolved in acetonitrile, and amine reactants and potassium carbonate were added in sequence. The mixture was refluxed and the reaction was monitored by TLC until the reaction was completed. The solvent was evaporated to obtain the crude product, which was then separated by semi-preparative high performance liquid chromatography or silica gel column chromatography to obtain the target product (HY-15~HY-18).

[0013] Further optimization involves a molar ratio of amine reactants to brominated intermediates of 1-6:1, a molar ratio of potassium carbonate to brominated intermediates of 1-6:1, and reaction conditions of 80°C for 2-8 h.

[0014] Further preferred, the amine reactant is selected from one of 1-acetylpiperazine, tetrahydrothiazole, morpholine, and imidazoline.

[0015] This invention also protects a method for preparing the indole-diketone piperazine derivative, comprising the following steps:

[0016] Indole-diketopiramate was mixed with trifluoroacetic acid and stirred in an ice bath to obtain a reaction solution. A potassium carbonate solution was prepared, and an equal volume of dichloromethane was added and stirred in an ice bath to obtain a potassium carbonate / dichloromethane solution. The reaction solution was added to the potassium carbonate / dichloromethane solution, stirred in an ice bath, and the pH was adjusted to 8. The solution was extracted with dichloromethane, the organic phases were combined, dried, filtered, and evaporated to dryness to obtain an intermediate. The intermediate was dissolved in acetic anhydride, and the reaction was refluxed and stirred. The reaction progress was monitored by TLC. After the reaction was completed, the reaction solution was diluted with ethyl acetate, washed, and the obtained organic phase was dried to obtain a crude product. The crude product was purified by column chromatography to obtain the target product (HY-33~HY-37).

[0017] This invention also protects the use of the indole-dikepiperazine derivative in the preparation of myocardial protective drugs.

[0018] This invention also protects a cardioprotective drug, with the aforementioned indole-diketopiramate derivative as the active ingredient.

[0019] The present invention also protects a pharmaceutical composition comprising the indole-dikepiperazine derivative thereof or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipient.

[0020] The present invention also protects the use of the pharmaceutical composition described herein in the preparation of a myocardial protective drug.

[0021] Compared with the prior art, the beneficial effects of the present invention are: the indole-diketopiramate derivative proposed in the present invention has good cardioprotective effects, and provides valuable lead compounds for further structural optimization and the development of cardioprotective drugs. Attached Figure Description

[0022] Figure 1 Results of the compound's cardiomyocyte toxicity;

[0023] Figure 2The study aimed to assess the in vivo efficacy of compound HY-7 in combating myocardial ischemia-reperfusion injury. (A) represents representative echocardiograms from each group; (B) the effect of HY-7 on ejection fraction (EF); (C) the effect of HY-7 on left ventricular shortening rate (FS); and (D) TTC staining to assess infarct area. Data are expressed as mean ± standard deviation (n≥6). Compared with the control group, # P <0.05, ## P <0.01, ### P <0.001. Compared with the OGD / R group, * P <0.05,** P <0.01, *** P <0.001. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available materials and reagents that can be obtained through conventional markets and other commercial channels.

[0025] In the following examples, 60% sodium hydride refers to sodium hydride product (dispersed in mineral oil at a ratio of 60%).

[0026] The synthesis steps of indole-diketopiramate feedstocks (M1, M2, M3, and M4) are shown in the following formula, and the synthesis method includes the following steps:

[0027] Place a 250 mL round-bottom flask in an ice-water bath and add [the following ingredients] to the flask. L A 150 mL solution of 1-tryptophan methyl ester hydrochloride (15 g, 57.71 mmol) was prepared, followed by the dropwise addition of triethylamine (36 mL, 259.70 mmol), and finally the addition of 1-hydroxybenzotriazole (HOBt) (10 g, 86.57 mmol) and Boc- L-Alanine (20 g, 115.42 mmol) was added to the mixture with vigorous stirring. Then, 1-ethyl-3-(3′-dimethylaminopropyl)carboimine hydrochloride (EDC·HCl) (16 g, 86.57 mmol) was added. The round-bottom flask was then placed at room temperature and stirred for 15 h. The reaction was quenched with 1N HCl and extracted twice with an equal volume of DCM. The combined organic phases were washed with saturated NaHCO3 aqueous solution and then back-extracted twice with an equal volume of DCM. The combined organic phases were dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain 23.0 g of a yellow oil. The oil was dissolved in DCM, and the round-bottom flask was placed in an ice-water bath. TFA (15 mL, 195.90 mmol) was slowly added dropwise to the solution. The round-bottom flask was then placed at room temperature and the reaction was stirred for another 2 h. After the reaction was completed, the reaction solution was concentrated under reduced pressure. The resulting residue was dissolved in methanol, and the round-bottom flask was placed in an ice-water bath. Then, 30 mL of dilute ammonia was added dropwise to the flask, and the mixture was stirred at room temperature for 24 h. A large amount of white solid precipitated from the reaction solution. The resulting suspension was cooled in an ice-water bath and filtered while cold. The solution was then washed with cold methanol to obtain a white solid. The white solid was then crushed and dried in an oven at 50 °C for 2 h. 13.6 g of white solid M1 was obtained, with a yield of 90.5%.

[0028] M1, M2, and M4 were prepared by varying the chiral reactants under the same reaction conditions. Specifically, the reactants... L -Tryptophan methyl ester hydrochloride and Boc- D -Alanine yields M2; through reactants D -Tryptophan methyl ester hydrochloride and Boc- L -Alanine yields M3; through reactants D -Tryptophan methyl ester hydrochloride and Boc- D -Alanine yields M4.

[0029] Compounds HY-1~HY-11, HY-13~HY-14 and HY-19~HY-32 were prepared according to the following reaction; ; Among them, R1, R2, and R3 are selected from H, , , , , , or R1, R2, and R3 can be the same or different groups, and n = 1-8;

[0030] Reaction steps: Dissolve the indole-diketopiramate raw material in dry DMF solvent and place it in a reaction bath at 0-5℃. Add sodium hydride (1-8 eq), stir briefly, and then add the bromide (1-8 eq). Continue the reaction at this temperature for 1-6 h until the reaction is complete. Monitor the reaction progress with TLC. After the reaction is complete, slowly add 5% HCl solution until the pH of the reaction solution is weakly acidic (pH≈6). Add distilled water and extract with an equal volume of ethyl acetate. Combine the organic phases and wash with distilled water. Dry the organic phase with anhydrous sodium sulfate, filter, and evaporate to dryness to obtain the crude product. Separate the crude product by semi-preparative high-performance liquid chromatography or silica gel column chromatography to obtain the target compound.

[0031] The brominated derivative is selected from one of ethyl bromoacetate, methyl 3-bromopropionate, ethyl 5-bromopentanoate, ethyl 6-bromohexanoate, ethyl 7-bromoheptanoate, methyl 4-bromomethylcinnamate, 1,4-dibromobutane, bromopropene, 3,3-dimethylallyl bromide, ethyl 7-bromoheptanoate, and ethyl 9-bromononanoate.

[0032] Compound HY-12 is prepared according to the following reaction:

[0033] The indole-diketopiramate compound was dissolved in acetic anhydride, and pyridine (0.8–1.0 eq) was added. The mixture was refluxed at 120 °C with stirring for 1–2 h. The reaction was monitored by TLC. After the reaction was completed, distilled water was added and the mixture was extracted with an equal volume of ethyl acetate. The combined organic phases were washed with distilled water, dried, filtered, and evaporated to dryness to obtain an oily crude product. The crude product was purified by column chromatography to obtain the target compound.

[0034] HY-15~HY-18 are prepared according to the following reaction: ; Among them, R6 is selected from H, , , or n=2-4;

[0035] Reaction steps: Dissolve intermediate HY-14 in acetonitrile, add amine reactants (1-6 eq), add potassium carbonate (1-6 eq) while stirring at 80℃, and reflux at 80℃ for 2-8 h. Monitor the reaction progress by TLC. After the reaction is complete, evaporate directly to dryness to obtain the crude product, which is then separated by semi-preparative high performance liquid chromatography to obtain products HY-15-HY-18.

[0036] The amine reactants are selected from one of 1-acetylpiperazine, tetrahydrothiazole, morpholine, and imidazoline.

[0037] The preparation method of indole-diketopiperazine derivatives (HY-33~HY-37) includes the following steps:

[0038] The indole-diketopiratheine compound starting material was mixed with trifluoroacetic acid and stirred in an ice bath to obtain a reaction solution. A 20% potassium carbonate solution was prepared, and an equal volume of dichloromethane was added. The mixture was stirred in an ice bath to obtain a potassium carbonate / dichloromethane solution. The reaction solution was added to this potassium carbonate / dichloromethane solution, stirred in an ice bath, and the pH was adjusted to 8. The solution was then extracted with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain an intermediate. The intermediate was dissolved in acetic anhydride and refluxed at 120 °C with stirring. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was diluted with ethyl acetate, washed with saturated brine, and the organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain a crude product. This crude product was purified by column chromatography to obtain the target product.

[0039] Example 1:

[0040] Synthesis of HY-1 and HY2: Compound M1 (55 mg, 0.21 mmol, 1.0 eq) was dissolved in 2 mL of DMF. 60% sodium hydride (22 mg, 0.55 mmol, 2.6 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl bromoacetate (72 µL, 0.65 mmol, 3.1 eq) was added, and the reaction was stirred at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 62.4 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (95 / 5). v / v The system was eluted to give the compounds HY-1 (3.1 mg, 0.01 mmol) and HY-2 (19.7 mg, 0.04 mmol) as pale yellow oils, with yields of 4.8% and 21.6%, respectively.

[0041] Diethyl 2,2'-(( 2S,5S )-2-((1H-indol-3-yl)methyl)-5-methyl-3,6-dioxopiperazine-1,4-diyl) diacetate (HY-1) 1 H NMR (400 MHz, CDCl3) δ 8.27 (s,1H), 7.48 (d, J = 7.8 Hz, 1H), 7.27 (d, J= 8.1 Hz, 1H), 7.13 – 7.08 (m, 1H), 7.08 (d, J = 2.4 Hz, 1H), 7.07 – 7.01 (m, 1H), 4.37 – 4.31 (m, 1H), 4.32 – 4.29 (m, 1H), 4.16 – 4.05 (m, 5H), 3.85 (q, J = 7.1 Hz, 1H), 3.57 (d, J = 17.1 Hz, 1H), 3.51 (d, J = 17.2 Hz, 1H), 3.44 (dd, J = 14.9, 5.2 Hz, 1H), 3.27 (dd, J = 15.0, 4.2 Hz, 1H), 1.19 (td, J = 7.1, 2.3 Hz, 6H), 0.65 (d, J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 168.0 (2xC), 167.3, 165.9, 136.1, 127.5, 124.4, 122.5, 120.1, 118.9, 111.4, 109.3, 62.4, 61.7, 61.7, 56.99, 47.2, 46.2, 29.1, 17.96, 14.22, 14.21. HR-ESI-MS m / z [M+Na] + 452.1798 (calculated 452.1794, C 22 H 27 N3O6Na).

[0042] Diethyl 2,2'-(( 2S,5S )-2-((1-(2-ethoxy-2-oxoethyl)-1H-indol-3-yl)methyl)-5-methyl-3,6-dioxopiperazine-1,4-diyl)diacetate (HY-2) 1 H NMR (400MHz, CDCl3) δ 7.47 (d, J= 7.9 Hz, 1H), 7.17 – 7.11 (m, 2H), 7.06 (ddd, J =8.0, 5.6, 2.4 Hz, 1H), 6.97 (s, 1H), 4.79 – 4.65 (m, 2H), 4.36 (d, J = 17.1Hz, 1H), 4.30 (dd, J = 5.4, 4.3 Hz, 1H), 4.17 – 4.02 (m, 7H), 3.84 (q, J =7.1 Hz, 1H), 3.61 (d, J = 17.2 Hz, 1H), 3.51 (d, J = 17.1 Hz, 1H), 3.39 (dd, J = 15.0, 5.6 Hz, 1H), 3.27 (dd, J = 15.0, 4.0 Hz, 1H), 1.25 – 1.12 (m, 9H), 0.71 (t, J = 5.7 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 168.3, 167.9(2xC), 167.1,165.8, 136.6, 128.6, 128.1, 122.5, 120.1, 119.1, 109.2, 109.1, 62.3, 61.7,61.5, 61.4, 57.0, 47.7, 47.0, 46.2, 28.9, 18.2, 14.2, 14.1, 14.0. HR-ESI-MS m / z [M+H] + 516.2359 (Calculated value 516.2346, C) 26 H 34 N3O8).

[0043] Example 2

[0044] Synthesis of HY-3 and HY4: Compound M1 (164 mg, 0.38 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (42.6 mg, 1.06 mmol, 2.8 eq) was added with stirring at 5 °C. After stirring for 10 minutes, methyl 3-bromopropionate (105 μL, 0.57 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 1 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 222.3 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (92 / 8, 4000 mg / mL). v / v The system was eluted to give yellow oily compound HY-3 (46.6 mg, 0.13 mmol) and pale yellow oily compound HY-4 (20 mg, 0.08 mmol), with yields of 34.1% and 15.3%, respectively.

[0045] Dimethyl 3,3'-(( 2S,5S )-2-((1H-indol-3-yl)methyl)-5-methyl-3,6-dioxopiperazine-1,4-diyl) dipropionate. (HY-3) 1 H NMR (400 MHz, CDCl3) δ 8.79 (s, 1H), 7.55 (d, J = 7.8 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 7.17 (dd, J =13.0, 5.7 Hz, 1H), 7.10 (t, J = 7.4 Hz, 1H), 6.92 (d, J = 2.1 Hz, 1H), 4.41(t, J = 4.1 Hz, 1H), 4.39 – 4.33 (m, 1H), 4.21 – 4.12 (m, 1H), 3.79 (q, J= 7.0 Hz, 1H), 3.69 (s, 3H), 3.64 (s, 3H), 3.54 (m, 1H), 3.51 – 3.44 (m, 1H), 3.32 – 3.23 (m, 2H), 3.21 – 3.12 (m, 1H), 2.79 – 2.61 (m, 4H), 2.24 (ddd, J = 16.5, 8.2, 5.4 Hz, 1H), 0.34 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 172.0, 171.95, 167.3, 165.7, 135.9, 127.5, 123.9, 122.4, 119.9, 119.0, 111.2, 108.8, 61.5, 56.6, 51.97, 51.8, 41.2, 40.9, 31.8, 31.7, 27.8, 17.6. HR-ESI-MS m / z [M+H] + 430.1965 (calcd 430.1978, C 22 H 28 N3O6).

[0046] Dimethyl 3,3'-(( 2S,5S )-2-((1-(3-methoxy-3-oxopropyl)-1H-indol-3-yl)methyl)-5-methyl- 3,6-dioxopiperazine-1,4-diyl)dipropionate. (HY-4) 1 H NMR(400 MHz, CDCl3) δ 7.55 (d, J = 7.9 Hz, 1H), 7.28 (t, J = 4.1 Hz, 1H), 7.21(dd, J = 11.1, 4.0 Hz, 1H), 7.11 (dd, J = 11.0, 3.9 Hz, 1H), 6.89 (s, 1H), 4.38 (dd, J = 9.0, 4.4 Hz, 3H), 4.22 – 4.04 (m, 1H), 3.76 (q, J= 7.0 Hz,1H), 3.70 (s, 3H), 3.68 (s, 3H), 3.64 (s, 3H), 3.57 – 3.43 (m, 2H), 3.25(ddd, J = 14.8, 7.6, 4.6 Hz, 2H), 3.18 – 3.06 (m, 1H), 2.80 – 2.70 (m, 3H), 2.70 – 2.60 (m, 2H), 2.26 (ddd, J = 16.6, 8.2, 5.3 Hz, 1H), 0.31 (d, J = 7.0Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 172.1, 172.0, 171.5, 167.1, 165.7, 135.8,128.3, 127.6, 122.4, 119.99, 119.7, 109.2, 108.3, 61.6, 56.7, 52.1, 52.0,51.9, 41.7, 41.2, 40.9, 34.9, 31.97, 31.9, 27.8, 17.8. HR-ESI-MS m / z [M+H] + 516.2352 (Calculated value 516.2346, C) 26 H 34 N3O8).

[0047] Example 3

[0048] Synthesis of HY-5 and HY-6: Compound M1 (116 mg, 0.45 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (50.4 mg, 1.26 mmol, 2.8 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 5-bromopentanoate (110 μL, 0.68 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 6 h. The reaction progress was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 180 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (90 / 10, 40 / 10, 40 / 10, 40 / 10, 40 / 10) chromatography. v / vThe system was eluted to give colorless oily compound HY-5 (20 mg, 0.05 mmol) and yellow gelatinous compound HY-6 (18 mg, 0.03 mmol), with yields of 11.3% and 7.2%, respectively.

[0049] Ethyl 5-(( 3S,6S )-3-((1H-indol-3-yl)methyl)-6-methyl-2,5-dioxopiperazin-1-yl)pentanoate. (HY-5) 1 H NMR (400 MHz, CDCl3) δ 8.61 (dd, J =9.1, 2.4 Hz, 1H), 7.62 – 7.58 (m, 1H), 7.33 (d, J = 8.1 Hz, 1H), 7.17 (t, J =7.2 Hz, 1H), 7.09 (dd, J = 7.7, 2.8 Hz, 1H), 6.85 (t, J = 3.7 Hz, 1H), 4.28 –4.24 (m, 1H), 4.10 (td, J = 9.2, 7.2 Hz, 4H), 3.77 (q, J = 7.1 Hz, 1H), 3.66– 3.56 (m, 1H), 2.91 – 2.83 (m, 1H), 2.31 (ddd, J = 14.6, 7.4, 4.2 Hz, 3H), 2.03 (s, 1H), 1.82 (p, J = 7.3 Hz, 1H), 1.29 (dd, J = 7.0, 5.1 Hz, 1H), 1.24(t, J = 7.6 Hz, 3H), 0.89 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ173.3, 168.6, 165.4, 136.6, 127.1, 123.8, 122.5, 120.0, 119.0, 111.3, 109.6, 60.5, 56.4, 55.6, 44.4, 33.8, 31.6, 26.96, 22.6, 19.3, 14.3. HR-ESI-MS m / z [M+H] + 386.2098 (calculated value 386.2080, C 21 H 28 N3O4).

[0050] Diethyl 5,5'-(( 2S,5S )-2-((1-(5-ethoxy-5-oxopentyl)-1H-indol-3-yl)methyl)-5-methyl-3,6- dioxopiperazine-1,4-diyl)dipentanoate. (HY-6). 1 H NMR(400 MHz, CDCl3) δ 7.54 (d, J J = 8.0 Hz, 1H), 7.25 (d, J J = 8.2 Hz, 1H), 7.17(t, J J = 7.3 Hz, 1H), 7.08 (t, J J = 7.5 Hz, 1H), 6.83 (s, 1H), 4.26 (t, J J = 4.1Hz, 1H), 4.17 – 4.09 (m, 6H), 4.09 – 4.01 (m, 3H), 3.74 – 3.68 (m, 1H), 3.49(dd, J J = 15.0, 3.9 Hz, 1H), 3.25 (dd, J J = 14.9, 4.4 Hz, 1H), 2.84 (dd, J J =12.6, 6.4 Hz, 1H), 2.79 – 2.69 (m, 1H), 2.38 – 2.17 (m, 6H), 1.85 – 1.76 (m,4H), 1.69 – 1.59 (m, 6H), 1.55 – 1.48 (m, 3H), 1.28 – 1.21 (m, 9H), 0.37 (d, J J = 7.0 Hz, 3H).13 C NMR (100 MHz, CDCl3) δ 173.2(2xC), 173.1, 166.97, 165.4,135.9, 128.2, 127.2, 122.0, 119.5, 109.2, 107.95, 77.4, 77.1, 76.7, 60.5,60.41, 60.39, 60.3, 55.7, 45.9, 44.1, 43.7, 33.8, 33.7, 29.8, 27.7, 26.3,26.2, 22.4, 22.2, 17.9, 14.2 (3xC). HR-ESI-MS m / z [M+H] + 642.3754 (Calculated value 642.3728, C) 35 H 52 N3O8).

[0051] Example 4

[0052] Synthesis of HY-7 and HY-8: Compound M1 (148 mg, 0.58 mmol, 1.0 eq) was dissolved in 2 mL of DMF. 60% sodium hydride (53.4 mg, 1.33 mmol, 2.3 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (26 μL, 1.44 mmol, 2.5 eq) was added, and the reaction was carried out at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 100 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (87 / 13, v / v The system was eluted to give a yellow oily compound HY-7 (41 mg, 0.11 mmol) and a yellow solid HY-8 (20 mg, 0.04 mmol), with yields of 18.5% and 7.4%, respectively.

[0053] Ethyl 6-(3-((( 2S,5S )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)hexanoate. (HY-7). 11H NMR (400 MHz, CDCl3) δ 7.61 (d, J J = 7.9 Hz, 1H), 7.31 (d, J J = 8.2 Hz, 1H), 7.22 (t, J J = 7.5 Hz, 1H), 7.12 (t, J J = 7.4 Hz, 1H), 7.02 (s, 1H), 6.68 (s, 1H), 6.26 (s, 1H), 4.35 – 4.26 (m, 1H), 4.16 – 4.03 (m, 4H), 4.00 (q, J J = 6.9 Hz, 1H), 3.52 (dd, J J = 14.6, 3.5 Hz, 1H), 3.14 (dd, J J = 14.7, 8.7 Hz, 1H), 2.29 (t, J J = 7.3 Hz, 2H), 1.84 (dt, J J = 14.8, 7.2 Hz, 2H), 1.65 (dt, J J = 14.9, 7.3 Hz, 2H), 1.42 – 1.30 (m, 2H), 1.23 (t, J J = 7.1 Hz, 3H), 1.15 (d, J J = 7.0 Hz, 3H). 13 13C NMR (100 MHz, CDCl3) δ 173.7, 168.6, 168.2, 136.6, 127.7, 127.5, 122.2, 119.7, 119.1, 109.7, 107.9, 60.5, 55.5, 50.9, 46.2, 34.2, 30.1, 30.0, 26.7, 24.6, 19.8, 14.3. HR-ESI-MS m / z [M+H]+ + 400.2210 (calcd 400.2236, C 22 H 30 N3O4)

[0054] Ethyl 6-((3 S,6S)-3-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-6-methyl-2,5- dioxopiperazin-1-yl)hexanoate. (HY-8). 1 H NMR (400 MHz, CDCl3) δ 7.51 (d, J = 7.9 Hz, 1H), 7.21 (d, J = 7.8 Hz, 1H), 7.12 (t, J = 7.3 Hz, 1H),7.02 (t, J = 7.4 Hz, 1H), 6.76 (s, 1H), 5.62 (s, 1H), 4.13 (t, J = 4.0 Hz,1H), 4.09 – 3.94 (m, 6H), 3.41 (dd, J = 14.9, 3.5 Hz, 1H), 3.16 (dd, J =14.9, 4.5 Hz, 1H), 2.81 – 2.68 (m, 1H), 2.47 (q, J = 6.9 Hz, 1H), 2.22 (td, J = 7.4, 2.9 Hz, 4H), 1.79 – 1.66 (m, 2H), 1.65 – 1.48 (m, 8H), 1.35 – 1.21 (m,4H), 1.18 (dt, J = 8.6, 7.2 Hz, 6H), 1.05 (d, J = 6.9 Hz, 3H). 13 C NMR (100MHz, CDCl3) δ 173.7, 173.6, 169.0, 167.6, 136.1, 127.96, 127.9, 122.1,119.72, 119.1, 109.5, 107.4, 61.6, 60.5, 60.4, 49.4, 46.2, 44.5, 34.3, 34.2,30.3, 27.3, 27.2, 26.6, 26.5, 24.7, 24.7, 18.9, 14.4, 14.3. HR-ESI-MS m / z [M+H] +542.3189 (Calculated value 542.3230, C) 30 H 44 N3O6).

[0055] Example 5

[0056] Synthesis of HY-9 and HY-10: Compound M1 (354 mg, 1.38 mmol, 1.0 eq) was dissolved in 10 mL of DMF. 60% sodium hydride (138 mg, 3.45 mmol, 2.5 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 7-bromoheptanoate (552 μL, 2.75 mmol, 2.0 eq) was added, and the reaction was allowed to proceed at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 410 mg of crude oil. Purified by column chromatography (methanol-dichloromethane = 1:99 → 1:9), the off-white solid compound HY-9 (69.5 mg, 0.13 mmol) and the yellow oily compound HY-10 (90.3 mg, 0.24 mmol) were obtained, with yields of 9.4% and 18.3%, respectively.

[0057] Ethyl 7-(3-((( 2S,5S )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)heptanoate. (HY-9). 1 H NMR (400 MHz, CDCl3) δ 7.61 (d, J = 7.9 Hz,1H), 7.38 – 7.32 (m, 1H), 7.30 (d, J = 8.2 Hz, 1H), 7.20 (t, J = 7.6 Hz, 1H), 7.09 (t, J = 7.4 Hz, 1H), 7.01 (s, 1H), 6.67 (t, J = 4.4 Hz, 1H), 4.32 – 4.25(m, 1H), 4.13 – 4.07 (m, 2H), 4.04 (dd, J = 7.2, 3.5 Hz, 2H), 3.96 (q,J = 7.1 Hz, 1H), 3.48 (dd, J = 14.7, 3.7 Hz, 1H), 3.17 (dd, J = 14.7, 8.2 Hz, 1H), 2.26 (t, J = 7.4 Hz, 2H), 1.80 (p, J = 7.2 Hz, 2H), 1.60 (t, J = 7.3 Hz, 2H), 1.37 – 1.29 (m, 4H), 1.23 (t, J = 7.1 Hz, 3H), 1.09 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.8, 168.9, 168.4, 136.5, 127.7, 127.5, 122.0, 119.5, 119.1, 109.6, 107.9, 60.3, 55.6, 50.8, 46.3, 34.2, 30.2, 29.98, 28.8, 26.8, 24.8, 19.8, 14.3. HR-ESI-MS m / z [M+H] + 414.2375 (calculated 414.2393, C 23 H 32 N3O4).

[0058] Ethyl 7-(( 3S,6S )-3-((1-(7-methoxy-7-oxoheptyl)-1H-indol-3-yl)methyl)-6-methyl-2,5-dioxopiperazin-1-yl)heptanoate. (HY-10). 1 H NMR (400 MHz, CDCl3) δ 7.59 (d, J = 8.0 Hz, 1H), 7.24 (s, 1H), 7.17 (dd, J = 9.3, 6.2 Hz, 1H), 7.07 (t, J = 7.7 Hz, 1H), 6.95 (s, 1H), 4.25 – 4.22 (m, 1H), 4.10 (t, J=10.1 Hz, 6H), 4.02 (d, J = 9.5, 3.4 Hz, 2H), 3.79 (td, J = 7.2, 2.7 Hz, 1H), 3.66 (dd, J = 13.2, 7.7 Hz, 1H), 3.36 – 3.29 (m, 1H), 3.21 (ddd, J = 14.6,7.6, 2.2 Hz, 1H), 2.81 (td, J = 13.5, 5.4 Hz, 1H), 2.26 (td, J = 7.4, 3.4 Hz,6H), 1.83 – 1.78 (m, 1H), 1.77 – 1.71 (m, 1H), 1.59 (t, J = 7.4 Hz, 6H), 1.55(s, 1H), 1.32 (d, J = 3.7 Hz, 4H), 1.22 (ddd, J = 7.1, 5.0, 1.8 Hz, 6H), 0.94(d, J = 6.7 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.73, 173.69, 168.7, 165.4,136.3, 127.4, 121.95, 119.5, 119.3, 109.5, 108.2, 60.30,60.28, 56.6, 55.5,46.2, 44.6, 34.3, 34.22, 34.20, 30.2, 28.8, 28.7, 26.9, 26.8, 26.6, 24.8,24.8, 18.9, 14.3 (2xC). HR-ESI-MS m / z [M+H] + 570.3516 (Calculated value 570.3543, C) 32 H 48 N3O6).

[0059] Example 6

[0060] Synthesis of HY-11: Compound M1 (150 mg, 0.58 mmol, 1.0 eq) was dissolved in 6 mL of DMF. After stirring for 10 minutes, methyl 4-bromomethylcinnamate (345 mg, 1.33 mmol, 2.3 eq) was added. 60% sodium hydride (58 mg, 1.45 mmol, 2.5 eq) was added while stirring at 5 °C, and the reaction was carried out at 5 °C for 1 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give 476 mg of crude oil. Column chromatography purification (ethyl acetate-petroleum ether = 2:8 → 5:5) yielded a yellow oily compound HY-11 (66.2 mg, 0.10 mmol), with a yield of 18.7%.

[0061] Dimethyl 3,3'-(((( 2S,5S )-2-((1-(4-(( E )-3-methoxy-3-oxoprop-1-en-1-yl)benzyl)-1H-indol-3-yl) methyl)-5-methyl-3,6-dioxopiperazine-1,4-diyl)bis(methylene))bis(4,1-phenylene))(2 E ,2' E )-diacrylate. (HY-11). 1 H NMR (400MHz, CDCl3) δ 7.67 (d, J = 11.6 Hz, 2H), 7.64 (d, J = 4.3 Hz, 1H), 7.61 (s,2H), 7.44 (d, J = 8.1 Hz, 4H), 7.39 (d, J = 8.1 Hz, 2H), 7.30 – 7.25 (m, 1H), 7.22 (t, J = 7.4 Hz, 1H), 7.19 – 7.13 (m, 4H), 7.13 – 7.07 (m, 3H), 6.84 (s,1H), 6.43 (d, J = 10.6 Hz, 1H), 6.41 (d, J= 2.8 Hz, 1H), 6.38 (d, J = 2.6Hz, 1H), 5.33 (d, J = 14.9 Hz, 1H), 5.26 (d, J = 14.8 Hz, 3H), 5.06 (d, J =15.2 Hz, 1H), 4.30 (t, J = 4.5 Hz, 1H), 3.93 (d, J = 14.9 Hz, 1H), 3.81 (s,3H), 3.80 (s, 3H), 3.78 (s, 3H), 3.76 (d, J = 4.9 Hz, 1H), 3.75 – 3.71 (m,1H), 3.54 (dd, J = 14.9, 4.7 Hz, 1H), 3.42 (dd, J = 14.9, 4.4 Hz, 1H), 0.53(d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.30, 167.29, 167.26, 167.25,165.82, 144.05, 143.99(2xC), 139.47, 137.93, 137.88, 136.38, 134.27, 134.05,134.03, 129.01(2xC), 128.58(2xC), 128.56(2xC), 128.53(2xC), 128.48(2xC),128.28, 127.61, 127.48(2xC), 122.61, 120.08, 119.57, 118.33, 118.20, 118.17,109.78, 108.95, 60.12, 54.93, 53.51, 51.79, 51.77(2xC), 49.76, 47.13, 46.69,28.12, 17.94. HR-ESI-MS m / z [M+H] + 780.3293 (Calculated value 780.3285 C) 47 H 46 N3O8).

[0062] Example 7

[0063] Synthesis of HY-12: Compound M1 (110 mg, 0.43 mmol, 1.0 eq) was dissolved in 5 mL of acetic anhydride, and pyridine (33 μL, 0.39 mmol, 0.9 eq) was added. The mixture was refluxed at 120 °C with stirring for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give 150 mg of crude oil. Column chromatography purification (ethyl acetate-petroleum ether = 3:7 → 5:5) gave HY-12 (70 mg, 0.21 mmol) as a yellow oil, with a yield of 47.7%.

[0064] ( 3S,6S )-3-((1H-indol-3-yl)methyl)-1,4-diacetyl-6-methylpiperazine-2,5-dione. (HY-12). 1 H NMR (400 MHz, CDCl3) δ 8.32 (s, 1H), 7.51 (d, J = 7.8 Hz, 1H), 7.30 (dd, J = 8.0, 0.7 Hz, 1H), 7.15 (dt, J = 14.9, 7.0 Hz, 2H), 6.93(d, J = 2.2 Hz, 1H), 5.45 (dd, J = 5.8, 4.7 Hz, 1H), 4.93 (q, J = 7.1 Hz, 1H), 3.58 (dd, J = 14.9, 4.6 Hz, 1H), 3.40 (dd, J = 14.9, 6.0 Hz, 1H), 2.55(s, 3H), 2.48 (s, 3H), 0.71 (d, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ171.6, 171.5, 170.1, 169.1, 136.0, 127.4, 124.1, 122.7, 120.3, 118.8, 111.4,109.4, 59.5, 54.2, 28.95, 27.2, 27.1, 18.8.HR-ESI-MS m / z [M+Na] + 364.1279 (Calculated value 364.1268, C) 18 H 19 N3O4Na).

[0065] Example 8

[0066] Synthesis of HY-13 and HY-14: Starting material M1 (429 mg, 1.67 mmol, 1.0 eq) was dissolved in 11 mL DMF, and 1,4-dibromobutane (500 μL, 4.17 mmol, 2.5 eq) was added. 60% sodium hydride (126.9 mg, 3.17 mmol, 1.9 eq) was added under stirring at 0 °C, and the reaction was carried out at 0 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 460 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (85 / 15, 4 ... v / v The system was eluted to give a pale yellow oily compound HY-13 (25 mg, 0.05 mmol) and a yellow oily compound HY-14 (103.3 mg, 0.26 mmol), with yields of 3.8% and 15.7%, respectively.

[0067] ( 3S,6S )-3-((1H-indol-3-yl)methyl)-1,4-bis(4-bromobutyl)-6-methylpiperazine-2,5-dione. (HY-13). 1 H NMR (400 MHz, CDCl3) δ 8.43 (s, 1H), 7.57 (d, J = 7.9 Hz, 1H), 7.33 (d, J = 8.0 Hz, 1H), 7.18 (t, J= 7.4 Hz, 1H), 7.11 (t, J = 7.4 Hz, 1H), 6.94 (d, J = 2.1 Hz, 1H), 4.31 (t, J = 4.3 Hz, 1H), 4.17 – 3.98 (m, 1H), 3.75 (q, J = 7.0 Hz, 1H), 3.53 (dd, J = 15.0, 4.1 Hz, 1H), 3.50 – 3.42 (m, 1H), 3.41 (d, J = 5.8 Hz, 2H), 3.38 (d, J = 4.8 Hz, 1H), 3.36 – 3.33 (m, 1H), 3.30 (dd, J = 15.0, 4.5 Hz, 1H), 2.89 (ddd, J = 15.2, 10.5, 6.8 Hz, 1H), 2.85 – 2.70 (m, 1H), 1.94 – 1.71 (m, 7H), 1.70 – 1.53 (m, 1H), 1.49 – 1.31 (m, 1H), 0.43 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.3, 165.6, 135.9, 127.7, 123.8, 122.6, 120.1, 119.2, 111.3, 109.3, 60.5, 55.9, 43.7, 43.3, 33.13, 33.08, 29.98, 29.9, 27.96, 25.6(2xC), 17.9. HR-ESI-MS m / z [M + 2 + H] + 528.0677 (calculated 526.0705, C 22 H 30 Br2N3O2).

[0068] ( 3S,6S )-1,4-bis(4-bromobutyl)-3-((1-(4-bromobutyl)-1H-indol-3-yl)methyl)-6-methylpiperazine-2,5-dione. (HY-14).1 H NMR (400 MHz, CDCl3) δ 7.54(d, J = 7.9 Hz, 1H), 7.27 (d, J = 8.2 Hz, 1H), 7.20 (d, J = 7.1 Hz, 1H), 7.10(d, J = 7.3 Hz, 1H), 6.84 (s, 1H), 4.28 (t, J = 4.2 Hz, 1H), 4.16 – 3.94 (m,3H), 3.73 (q, J = 6.9 Hz, 1H), 3.57 – 3.42 (m, 2H), 3.38 (dt, J = 13.5, 6.3Hz, 6H), 3.27 (dd, J = 15.0, 4.4 Hz, 1H), 2.94 – 2.72 (m, 2H), 1.94 (ddd, J =14.0, 8.8, 5.0 Hz, 2H), 1.89 – 1.80 (m, 4H), 1.80 – 1.69 (m, 4H), 1.69 – 1.55(m, 1H), 1.51 – 1.34 (m, 1H), 0.41 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 166.6, 165.1, 135.5, 127.8, 126.8, 121.8, 119.3, 119.1, 108.9,107.7, 60.1, 55.3, 45.0, 43.2, 42.8, 32.8, 32.7, 32.6, 29.6, 29.5, 29.4,28.6, 27.5, 25.13, 25.10, 17.6. HR-ESI-MS m / z [M+Na] + 682.0216 (Calculated value 682.0255, C) 26 H 37 Br3N3NaO2).

[0069] Example 9

[0070] Synthesis of HY-15: Compound HY-14 (34 mg, 0.06 mmol, 1.0 eq) was dissolved in 2 mL of acetonitrile, and 1-acetylpiperazine (30 μL, 0.21 mmol, 3.5 eq) was added. Potassium carbonate (13.9 mg, 0.10 mmol, 1.68 eq) was added under stirring at 80 °C, and the mixture was refluxed at 80 °C for 3 h. The reaction was monitored by TLC. After the reaction was complete, the product was directly evaporated to dryness to obtain 28 mg of crude product. This crude product was then separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (90 / 10, 4000 mg / mL). v / v The mixture was eluted to give a brown oily compound HY-15 (15.1 mg, 0.02 mmol), with a yield of 37.7%.

[0071] Synthesis of HY-16: Compound HY-14 (20 mg, 0.04 mmol, 1.0 eq) was dissolved in 1.5 mL of acetonitrile, and tetrahydrothiazole (11 μL, 0.14 mmol, 3.5 eq) was added. Potassium carbonate (9 mg) was added while stirring at 80 °C, and the mixture was refluxed at 80 °C for 4 h. 18 mg of the crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (90 / 10, 4000 mg / mL). v / v The mixture was eluted to obtain a brown oily compound HY-16 (10 mg, 0.02 mmol), with a yield of 48.3%.

[0072] Synthesis of HY-17: Compound HY-14 (20.9 mg, 0.04 mmol, 1.0 eq) was dissolved in 1.5 mL of acetonitrile, and morpholine (12 μL, 0.14 mmol, 3.5 eq) was added. Potassium carbonate (9 mg) was added while stirring at 80 °C, and the mixture was refluxed at 80 °C for 2 h. 19 mg of the crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (90 / 10, 4000 mg / mL). v / v The mixture was eluted to obtain a brown colloidal compound HY-17 (16 mg, 0.03 mmol), with a yield of 74.1%.

[0073] Synthesis of HY-18: Compound HY-14 (20 mg, 0.04 mmol, 1.0 eq) was dissolved in 1.5 mL of acetonitrile, and imidazoline (10 μL, 0.14 mmol, 3.5 eq) was added. Potassium carbonate (9 mg) was added while stirring at 80 °C, and the mixture was refluxed at 80 °C for 8 h. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (90 / 10, 4000 ppm). v / v The mixture was eluted to obtain a brown oily compound HY-18 (18 mg, 0.03 mmol), with a yield of 84.2%.

[0074] ( 3S,6S )-1,4-bis(4-(4-acetylpiperazin-1-yl)butyl)-3-((1-(4-(4-acetylpiperazin-1-yl)butyl)-1H-indol-3-yl)methyl)-6-methylpiperazine-2,5-dione. (HY-15). 1 H NMR (400 MHz, CDCl3) δ 7.56 (d, J = 7.9 Hz, 1H), 7.27 (d, J = 8.3 Hz, 1H), 7.18 (t, J = 7.2 Hz, 1H), 7.07 (dd, J = 11.0, 3.9 Hz, 1H),6.83 (s, 1H), 4.27 (t, J = 4.3 Hz, 1H), 4.13 – 3.94 (m, 3H), 3.72 (q, J = 7.0Hz, 1H), 3.60 (m, 6H), 3.53 – 3.38 (m, 8H), 3.27 (dd, J = 15.0, 4.5 Hz, 1H),2.92 – 2.78 (m, 2H), 2.77 – 2.68 (m, 1H), 2.45 – 2.25 (m, 14H), 2.08 (m, 12H)1.80 (dd, J = 14.8, 7.4 Hz, 2H), 1.62 (dt, J = 14.8, 7.4 Hz, 2H), 1.58 – 1.46(m, 4H), 1.39 (dd, J = 14.6, 7.3 Hz, 2H), 1.34 – 1.21 (m, 2H), 0.41 (d, J =7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ168.95 (3xC), 167.0, 165.4, 135.9, 128.2, 127.2, 121.97, 119.5, 109.3, 107.9, 60.3, 57.8 (2xC), 55.6, 53.3 (2xC), 53.2, 52.7 (2xC), 47.5, 46.2, 46.1, 45.8 (3xC), 44.2, 43.8, 42.5, 41.4 (4xC), 28.2, 27.9, 24.7, 24.6, 24.2, 23.99, 21.3 (3xC), 17.9. HR-ESI-MS m / z [M+H] + 804.5473 (calculated 804.5500, C 44 H 70 N9O5).

[0075] ( 3S,6S )-3-methyl-1,4-bis(4-(thiazolidin-3-yl)butyl)-6-((1-(4-(thiazolidin-3-yl)butyl)-1H-indol-3-yl)methyl)piperazine-2,5-dione. (HY-16). 1 H NMR (400 MHz, CDCl3) δ 7.54 (d, J J = 7.8 Hz, 1H), 7.25 (s, 1H), 7.17 (dd, J J = 8.2, 1.2 Hz, 1H), 7.10 – 7.06 (m, 1H), 6.85 (s, 1H), 4.28 (t, J J = 4.3 Hz, 1H), 4.07 (d,<00​​​​​​​​​​= 13.9, 4.9 Hz, 2H), 2.61 – 2.46 (m, 2H), 1.85 (p, J = 7.5 Hz, 3H), 1.56 (dd, J = 6.0, 2.3 Hz, 4H), 1.47(dd, J = 8.0, 6.3 Hz, 2H), 1.36 – 1.33 (m, 1H), 0.90 – 0.84 (m, 1H), 0.38 (d, J = 7.0 Hz, 3H). 13 C NMR (100MHz, CDCl3) δ 167.1, 165.6, 136.1, 128.3, 127.4, 121.99, 119.6(3xC), 109.4, 108.06, 72.3(3xC), 60.6, 58.8, 58.7, 58.6, 55.7, 46.2, 44.2, 44.0, 27.9, 27.5, 27.3, 27.0(3xC), 23.79, 23.76, 17.99. HR-ESI-MS m / z [M+Na] + 709.3381 (calculated 709.3368, C 35 H 54 N6O2S3Na).

[0076] ( 3S,6S )-3-methyl-1,4-bis(4-morpholinobutyl)-6-((1-(4-morpholinobutyl)-1H-indol-3-yl)methyl) piperazine- 2,5-dione. (HY-17). 1 H NMR(400 MHz, CDCl3) δ 7.55 (d, J = 7.9 Hz, 1H), 7.27 (d, J = 8.5 Hz, 1H), 7.17(t, J = 7.2 Hz, 1H), 7.08 (t, J = 7.1 Hz, 1H), 6.83 (s, 1H), 4.27 (t, J = 4.1Hz, 1H), 4.07 (dd,J = 12.3, 5.2 Hz, 3H), 3.72 (dd, J = 16.6, 4.9 Hz, 12H), 3.57 – 3.43 (m, 2H), 3.31 – 3.35 (m, 2H), 2.82 (dt, J = 14.0, 7.1 Hz, 1H), 2.73 (ddd, J = 14.1, 13.4, 8.5 Hz, 1H), 2.40 (d, J = 3.3 Hz, 11H), 2.36 – 2.22 (m, 6H), 1.88 – 1.71 (m, 2H), 1.63 (dd, J = 18.7, 11.3 Hz, 3H), 1.57 – 1.44 (m, 5H), 1.40 (dd, J = 15.0, 7.6 Hz, 3H), 0.40 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.0, 165.4, 135.9, 128.2, 127.2, 121.9, 119.5, 109.3, 107.9, 66.9(6xC), 60.4, 58.4, 58.3, 55.6, 53.7(5xC), 53.7, 46.1, 44.2, 43.9, 28.3, 27.9, 24.7, 24.6, 23.9, 23.8, 17.9. HR-ESI-MS m / z [M+H] + 681.4657(calculated 681.4703, C 38 H 61 N6O5).

[0077] ( 3S,6S )-1,4-bis(4-(imidazolidin-1-yl)butyl)-3-((1-(4-(imidazolidin-1-yl)butyl)-1H-indol-3-yl)methyl)-6-methylpiperazine-2,5-dione. (HY-18). 1 H NMR(400 MHz, CDCl3) δ 7.55 (d, J= 7.9 Hz, 1H), 7.25 (s, 1H), 7.17 (t, J = 7.6Hz, 1H), 7.08 (t, J = 7.4 Hz, 1H), 6.85 (s, 1H), 4.28 (t, J = 4.3 Hz, 1H), 4.07 (p, J = 7.2 Hz, 3H), 3.72 (q, J = 6.9 Hz, 1H), 3.54 (dd, J = 9.3, 6.1Hz, 1H), 3.50 – 3.44 (m, 1H), 3.36 (dd, J = 11.1, 5.7 Hz, 4H), 3.33 – 3.26(m, 12H), 2.90 – 2.79 (m, 1H), 2.77 – 2.66 (m, 1H), 1.90 – 1.80 (m, 2H), 1.67(t, J = 6.7 Hz, 2H), 1.61 (s, 9H), 1.60 – 1.53 (m, 7H), 1.50 – 1.41 (m, 3H), 1.38 -1.30 (m, 1H), 0.39 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.1, 165.6, 136.1, 128.3, 127.4, 122.0, 119.6, 109.4, 108.1, 72.3(3xC),60.6, 58.8, 58.7, 58.6, 55.7, 46.2, 44.2, 44.0, 27.96, 27.5, 27.3, 27.0(2xC),23.80, 23.76, 18.0. HR-ESI-MS m / z [M+K] + 674.4205 (Calculated value 674.4272, C) 35 H 57 N9O2K).

[0078] Example 10

[0079] Synthesis of HY-19 and HY-20: Compound M1 (100 mg, 0.39 mmol, 1.0 eq) was dissolved in 3 mL of DMF, and bromopropene (50 μL, 1.13 mmol, 2.9 eq) was added. 60% sodium hydride (46.8 mg, 1.2 mmol, 3.0 eq) was added under stirring at 0 °C, and the reaction was carried out at 0 °C for 1.5 h. The reaction progress was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give 84 mg of crude oil. Crude column chromatography purification (ethyl acetate-petroleum ether = 2:8 → 5:5) yielded light green oily compound HY-19 (68 mg, 0.16 mmol) and yellow oily compound HY-20 (22 mg, 0.04 mmol), with yields of 41.3% and 9.6%, respectively.

[0080] ( 3S,6S )-1,4-diallyl-3-((1-allyl-1H-indol-3-yl)methyl)-6-methylpiperazine-2,5-dione.(HY-19). 1 H NMR (400 MHz, CDCl3) δ 7.57 (d, J = 7.9Hz, 1H), 7.26 (d, J = 7.1 Hz, 1H), 7.18 (t, J = 7.5 Hz, 1H), 7.10 (t, J = 7.4Hz, 1H), 6.88 (s, 1H), 5.92 (ddd, J = 22.5, 10.7, 5.6 Hz, 1H), 5.81 – 5.68(m, 1H), 5.60 (dddd, J = 17.3, 10.2, 7.4, 5.1 Hz, 1H), 5.24 (d, J = 10.1 Hz, 1H), 5.20 (d, J = 11.4 Hz, 1H), 5.17 (d, J = 8.6 Hz, 1H), 5.13 (s, 1H), 5.12– 5.10 (m, 1H), 5.07 (d, J = 17.7 Hz, 1H), 4.76 (dd,J = 15.0, 4.7 Hz, 1H), 4.65 (d, J = 5.5 Hz, 2H), 4.38 – 4.33 (m, 1H), 4.32 (d, J = 4.6 Hz, 1H), 3.79 (q, J = 7.0 Hz, 1H), 3.48 (dd, J = 15.0, 4.5 Hz, 1H), 3.40 (dd, J = 15.0, 7.9 Hz, 1H), 3.34 – 3.21 (m, 2H), 0.45 (d, J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.0, 165.5, 136.2, 133.3, 131.9, 131.6, 128.4, 127.3, 122.1, 119.7, 119.5, 119.3, 118.7, 117.7, 109.6, 108.4, 59.8, 55.0, 48.9, 46.5, 46.4, 27.8, 17.8. HR-ESI-MS m / z [M+H] + 378.2170 (calcd 378.2182, C 23 H 28 N3O2).

[0081] ( 3S,6S )-3-((1H-indol-3-yl)methyl)-1,4-diallyl-6-methylpiperazine-2,5-dione. (HY-20). 1 H NMR (400 MHz, CDCl3) δ 8.56 (s, 1H), 7.59 (d, J = 7.9 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 7.17 (dd, J = 11.1, 3.9 Hz, 1H), 7.11 (t, J = 7.1 Hz, 1H), 6.96 (d, J= 2.3 Hz, 1H), 5.89 – 5.69 (m, 1H), 5.59 (dddd, J =17.4, 10.2, 7.5, 5.0 Hz, 1H), 5.26 (d, J = 10.1 Hz, 1H), 5.18 (d, J = 17.2Hz, 1H), 5.11 (d, J = 10.2 Hz, 1H), 5.07 (dd, J = 17.1, 1.0 Hz, 1H), 4.78(ddd, J = 15.0, 3.2, 1.5 Hz, 1H), 4.40 – 4.33 (m, 2H), 3.80 (q, J = 7.0 Hz, 1H), 3.52 (dd, J = 15.0, 4.2 Hz, 1H), 3.44 (dd, J = 15.0, 7.8 Hz, 1H), 3.31(dd, J = 15.0, 4.6 Hz, 1H), 3.24 (dd, J = 15.2, 7.5 Hz, 1H), 0.42 (d, J = 7.1Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.2, 165.5, 136.0, 131.8, 131.6, 127.7,123.8, 122.5, 119.99, 119.5, 119.3, 118.8, 111.3, 109.4, 59.9, 55.0, 46.6,46.4, 27.8, 17.5. HR-ESI-MS m / z [M+H] + 338.1861 (Calculated value 338.1869, C) 20 H 24 N3O2).

[0082] Example 11

[0083] Synthesis of HY-21 and HY-22: Compound M1 (100 mg, 0.39 mmol, 1.0 eq) was dissolved in 3 mL of DMF, and 3,3-dimethylallyl bromide (150 μL, 1.13 mmol, 2.9 eq) was added. 60% sodium hydride (53.0 mg, 1.33 mmol, 3.4 eq) was added under stirring at 0 °C, and the reaction was carried out at 0 °C for 1.5 h. The reaction progress was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain an oily crude product. Crude column chromatography purification (ethyl acetate-petroleum ether = 2:8 → 3:7) yielded bright yellow oily compound HY-21 (60 mg, 0.17 mmol) and pale yellow oily compound HY-22 (10 mg, 0.03 mmol), with yields of 43.4% and 8.5%, respectively.

[0084] ( 3S,6S )-3-methyl-1,4-bis(3-methylbut-2-en-1-yl)-6-((1-(3-methylbut-2-en-1-yl)-1H-indol-3-yl)methyl)piperazine-2,5-dione. (HY-21). 1 H NMR (400 MHz, CDCl3) δ 7.59 (d, J = 7.9 Hz, 1H), 7.27 – 7.22 (m, 1H), 7.20 – 7.14 (m, 1H), 7.13 – 7.05 (m, 1H), 6.87 (s, 1H), 5.29 (ddd, J = 6.8, 4.1, 1.3 Hz, 1H), 5.15(ddd, J = 7.2, 4.4, 1.3 Hz, 1H), 4.93 – 4.82 (m, 1H), 4.63 (t, J = 7.5 Hz, 3H), 4.28 (t, J = 4.3 Hz, 1H), 4.26 – 4.20 (m, 1H), 3.73 (q, J = 7.0 Hz, 1H), 3.57 (dd, J = 14.7, 8.7 Hz, 1H), 3.50 (dd, J= 14.9, 4.2 Hz, 1H), 3.31 (dd, J = 14.9, 8.2 Hz, 1H), 3.25 (dd, J = 14.9, 4.3 Hz, 1H), 1.81 (s, 3H), 1.74 (s,6H), 1.63 (d, J = 2.9 Hz, 6H), 1.57 (s, 3H), 0.37 (d, J = 7.0 Hz, 3H). 13 C NMR(100 MHz, CDCl3) δ 167.1, 165.6, 137.9, 137.1, 136.3, 135.99, 128.5, 127.0,121.9, 119.96, 119.6, 119.5, 118.4, 118.3, 109.5, 108.2, 59.9, 54.8, 44.2,41.5, 41.4, 27.8, 25.9, 25.7(2xC), 18.1, 17.96, 17.9, 17.7. HR-ESI-MS m / z [M+H] + 462.3103 (calcd 462.3121, C 29 H 40 N3O2).

[0085] ( 3S,6S )-3-((1H-indol-3-yl)methyl)-6-methyl-1,4-bis(3-methylbut-2-en-1-yl)piperazine-2,5-dione. (HY-22). 1 H NMR (400 MHz, CDCl3) δ 8.40 (s, 1H),7.62 (d, J = 7.8 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 7.20 – 7.15 (m, 1H), 7.12(td, J = 7.5, 3.5 Hz, 1H), 6.97 (d, J = 2.3 Hz, 1H), 5.16 (ddd, J = 7.2, 4.3,1.3 Hz, 1H), 4.88 (dd, J= 10.0, 4.0 Hz, 1H), 4.67 (dd, J = 14.7, 5.6 Hz, 1H), 4.31 (t, J = 4.3 Hz, 1H), 4.23 (dd, J = 15.0, 5.9 Hz, 1H), 3.74 (q, J =7.0 Hz, 1H), 3.64 – 3.57 (m, 1H), 3.54 (dd, J = 15.0, 3.8 Hz, 1H), 3.36 –3.30 (m, 1H), 3.27 (dd, J = 15.1, 4.7 Hz, 1H), 1.75 (s, 4H), 1.65 (s, 3H), 1.63 (s, 3H), 1.57 (s, 3H), 0.36 (d, J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 167.4, 165.6, 138.2, 137.2, 135.98, 127.8, 123.8, 122.5, 120.0, 119.5,118.4, 118.2, 111.2, 109.7, 59.7, 54.9, 41.5, 27.7, 25.95, 25.8(2xC), 18.0,17.9, 17.6. HR-ESI-MS m / z [M+H] + 394.2487 (Calculated value 394.2495, C) 24 H 32 N3O2).

[0086] Example 12

[0087] Synthesis of compound HY-23: Compound M2 (150 mg, 0.58 mmol, 1.0 eq) was dissolved in 10 mL DMF, and ethyl 7-bromoheptanoate (552 μL, 1.16 mmol, 2.0 eq) was added. 60% sodium hydride (69.6 mg, 1.74 mmol, 3.0 eq) was added under stirring at 5 °C, and the reaction was carried out at 5 °C for 1.5 h. The reaction progress was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give 136 mg of a white, gelatinous, oily crude product. Crude column chromatography purification (methanol-dichloromethane = 1:99 → 1:9) yielded compound HY-23 (55 mg, 0.13 mmol) in 22.8% yield.

[0088] Ethyl 7-(3-((( 2S,5R )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)heptanoate. (HY-23). 1 H NMR (400 MHz, CDCl3) δ 7.62 (d, J = 7.9 Hz, 1H), 7.32 (d, J = 8.3 Hz, 1H), 7.23 (t, J = 7.6 Hz, 1H), 7.12 (t, J = 7.5 Hz,1H), 6.99 (s, 1H), 5.92 (d, J = 6.4 Hz, 2H), 4.27 (dd, J = 5.2, 2.6 Hz, 1H), 4.16 – 4.03 (m, 4H), 3.55 (d, J = 7.0 Hz, 1H), 3.45 (dd, J = 14.7, 3.7 Hz, 1H), 3.19 (dd, J = 14.6, 8.3 Hz, 1H), 2.28 (t, J = 7.4 Hz, 2H), 1.91 – 1.76(m, 2H), 1.37 (d, J = 7.0 Hz, 3H), 1.35 – 1.31 (m, 3H), 1.24 (t,J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.9, 168.7, 168.2, 136.6, 127.6, 122.2,119.7, 119.1, 109.8, 107.7, 60.4, 55.8, 50.7, 46.4, 34.3, 30.4, 30.2, 28.8,26.8, 24.9, 19.9, 14.4. HR-ESI-MS m / z [M+Na] + 436.2187 (Calculated value 436.2212, C) 23 H 31 N3O4Na).

[0089] Example 13

[0090] Synthesis of HY-24: Compound M2 (400 mg, 1.55 mmol, 1.0 eq) was dissolved in 15 mL of DMF, and ethyl 9-bromononanoate (745 μL, 3.10 mmol, 2.0 eq) was added. 60% sodium hydride (173.6 mg, 4.33 mmol, 2.8 eq) was added under stirring at 5 °C, and the reaction was carried out at 5 °C for 2 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 20 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain an oily crude product. Crude column chromatography was used for purification (methanol-dichloromethane = 1:99 → 1:9) to give a white solid compound HY-24 (230 mg, 0.37 mmol), with a yield of 23.6%.

[0091] Ethyl 9-(3-((( 2S,5R )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)nonanoate. (HY-24). 1 H NMR (400 MHz, CDCl3) δ 7.62 (d, J = 7.9 Hz, 1H), 7.32 (d, J = 8.2 Hz, 1H), 7.26 – 7.18 (m, 1H), 7.13 (dd, J= 14.9, 7.8Hz, 1H), 6.99 (s, 1H), 6.43 (s, 1H), 6.15 (s, 1H), 4.27 (dd, J = 5.0, 2.7 Hz,1H), 4.16 – 4.10 (m, 2H), 4.10 – 4.03 (m, 2H), 3.54 (d, J = 6.9 Hz, 1H), 3.49– 3.39 (m, 1H), 3.19 (dd, J = 14.6, 8.2 Hz, 1H), 2.27 (t, J = 7.5 Hz, 2H),1.86 – 1.74 (m, 2H), 1.66 – 1.56 (m, 4H), 1.36 (d, J = 7.0 Hz, 3H), 1.30 (d, J = 4.1 Hz, 7H), 1.25 (t, J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.6,168.8, 168.5, 136.2, 127.3, 127.2, 121.8, 119.2, 118.7, 109.4, 107.4, 59.98,55.5, 50.1, 46.1, 34.1, 30.1, 29.95, 28.9, 28.8, 28.79, 26.7, 24.6, 19.3,14.0. HR-ESI-MS m / z [M+H] + 442.2688 (Calculated value 442.2706, C) 25 H 36 N3O4).

[0092] Example 14

[0093] Synthesis of HY-25 and HY-26: Compound M2 (140 mg, 0.54 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (54 mg, 1.35 mmol, 2.5 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (150 μL, 0.81 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 100 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (87 / 13, v / v The system was eluted to give a pale yellow oily compound HY-25 (16 mg, 0.03 mmol) and a white gelatinous solid HY-26 (50 mg, 0.13 mmol), with yields of 5.4% and 23.2%, respectively.

[0094] Ethyl 6-(( 3S,6R )-3-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-6-methyl-2,5-dioxopiperazin-1-yl)hexanoate. (HY-25). 1 H NMR (400 MHz, CDCl3) δ 7.52 (d, J = 7.9 Hz, 1H), 7.26 (d, J = 8.3 Hz, 1H), 7.17 (dd, J = 13.0, 5.1Hz, 1H), 7.05 (t, J = 7.4 Hz, 1H), 6.93 (s, 1H), 5.72 (s, 1H), 4.21 – 4.13(m, 1H), 4.10 – 3.96 (m, 6H), 3.80 – 3.70 (m, 2H), 3.66 (dd, J = 14.8, 3.4Hz, 1H), 2.94 – 2.87 (m, 1H), 2.87 – 2.81 (m, 1H), 2.23 (td, J = 7.4, 4.0 Hz, 4H), 1.77 (dd, J= 15.1, 7.4 Hz, 2H), 1.60 (dt, J = 15.1, 7.4 Hz, 4H), 1.54 –1.40 (m, 2H), 1.35 (d, J = 7.0 Hz, 3H), 1.29 (ddd, J = 22.7, 10.1, 5.4 Hz,4H), 1.20 (t, J = 6.0 Hz, 3H), 1.16 (t, J = 6.0 Hz, 3H). 13 C NMR (100 MHz,CDCl3) δ 173.6, 173.5, 169.1, 166.1, 136.8, 127.4, 127.2, 122.4, 119.6,118.9, 109.9, 108.3, 60.4, 56.6, 53.4, 46.3, 44.8, 34.2, 34.1, 30.1, 28.9,27.3, 26.6, 26.5, 24.7, 24.6, 17.96, 14.4, 14.3. HR-ESI-MS m / z [M+H] + 542.3202(calculated 542.3230, C 30 H 44 N3O6).

[0095] Ethyl 6-(3-((( 2S,5R )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)hexanoate. (HY-26). 1 H NMR (400 MHz, CDCl3) δ 7.55 (d, J = 7.9 Hz,1H), 7.23 (d, J = 8.2 Hz, 1H), 7.14 (t, J = 7.6 Hz, 1H), 7.03 (t, J = 7.4 Hz,2H), 6.93 (s, 1H), 6.55 (s, 1H), 4.24 – 4.14 (m, 1H), 4.07 – 3.96 (m, 4H),3.40 (q, J= 7.0 Hz, 1H), 3.34 (dd, J = 14.6, 3.7 Hz, 1H), 3.15 (dd, J =14.6, 7.7 Hz, 1H), 2.20 (t, J = 7.4 Hz, 2H), 1.80 – 1.69 (m, 2H), 1.56 (dt, J = 15.1, 7.4 Hz, 2H), 1.27 (d, J = 7.0 Hz, 3H), 1.23 (m, 2H), 1.15 (t, J = 7.1Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.6, 169.2, 168.8, 136.5, 127.7, 127.6,122.1, 119.6, 119.1, 109.6, 107.8, 60.4, 55.96, 50.4, 46.2, 34.1, 30.2, 30.1,26.5, 24.6, 19.5, 14.3. HR-ESI-MS m / z [M+H] + 400.2219 (Calculated value 400.2236, C) 22 H 30 N3O4).

[0096] Example 15

[0097] Synthesis of compounds HY-27 and HY-28: Compound M3 (158 mg, 0.61 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (63.4 mg, 1.60 mmol, 2.6 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (167 μL, 0.92 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 186 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) with a methanol / water ratio of 87 / 13. v / vThe system was eluted to give a pale yellow oily compound HY-27 (18 mg, 0.03 mmol) and a white gelatinous solid HY-28 (60 mg, 0.15 mmol), with yields of 5.4% and 24.6%, respectively.

[0098] Ethyl 6-(( 3R,6S )-3-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-6-methyl-2,5-dioxopiperazin-1-yl) hexanoate. (HY-27). 1 H NMR (400 MHz, CDCl3) δ7.58 (d, J = 7.9 Hz, 1H), 7.27 (t, J = 4.1 Hz, 1H), 7.19 (t, J = 7.5 Hz, 1H), 7.08 (t, J = 7.4 Hz, 1H), 6.83 (s, 1H), 6.11 (s, 1H), 4.20 (t, J = 3.9 Hz,1H), 4.16 – 4.03 (m, 7H), 3.48 (dd, J = 14.9, 3.5 Hz, 1H), 3.23 (dd, J =14.9, 4.5 Hz, 1H), 2.86 – 2.71 (m, 1H), 2.55 (q, J = 6.8 Hz, 1H), 2.31 – 2.23(m, 4H), 1.84 – 1.71 (m, 2H), 1.63 (tdd, J = 19.1, 9.5, 5.7 Hz, 6H), 1.39 –1.28 (m, 3H), 1.28 – 1.21 (m, 7H), 1.13 (d, J = 6.9 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ173.7, 173.6, 169.4, 167.6, 136.1, 127.9, 127.9, 122.1, 119.7, 119.1, 109.5, 107.4, 61.5, 60.5, 60.4, 49.3, 46.2, 44.5, 34.2, 34.1, 30.3, 27.2, 27.1, 26.5, 26.4, 24.6, 24.5, 18.8, 14.4, 14.3. HR-ESI-MS m / z [M+H] + 542.3202(calculated 542.3230, C 30 H 44 N3O6).

[0099] Ethyl 6-(3-((( 2R,5S )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)hexanoate. (HY-28). 1 H NMR (400 MHz, CDCl3) δ 7.62 (d, J J = 7.9 Hz,1H), 7.32 (d, J J = 8.2 Hz, 1H), 7.23 (t, J J = 7.6 Hz, 1H), 7.12 (t, J J = 7.4 Hz,1H), 7.00 (s, 1H), 6.38 (s, 1H), 6.16 (s, 1H), 4.28 (d, J J = 5.5 Hz, 1H), 4.10(q, J J = 7.2 Hz, 4H), 3.53 (dd, J J = 13.4, 6.6 Hz, 1H), 3.44 (dd, J J = 14.5, 3.1Hz, 1H), 3.20 (dd, J J = 14.5, 8.0 Hz, 1H), 2.29 (t, J J = 7.3 Hz, 2H), 1.90 –1.79 (m, 2H), 1.73 (d, J J = 5.5 Hz, 2H), 1.65 (dt, J J = 15.1, 7.4 Hz, 2H), 1.36(d,J = 6.9 Hz, 3H), 1.23 (t, J = 7.1 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.7, 168.9, 168.4, 136.5, 127.7, 127.6, 122.2, 119.7, 119.1, 109.7, 107.8,60.5, 55.9, 50.6, 46.3, 34.2, 30.4, 30.1, 26.6, 24.6, 19.8, 14.4. HR-ESI-MS m / z [M+H] + 400.2217 (Calculated value 400.2236, C) 22 H 30 N3O4).

[0100] Example 16

[0101] Synthesis of compounds HY-29 and HY-30: Compound M4 (150 mg, 0.58 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (58 mg, 1.45 mmol, 2.5 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (165 μL, 0.87 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 1.5 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 173 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) with a methanol / water ratio of 87 / 13. v / v The system was eluted to give a pale yellow oily compound HY-29 (22 mg, 0.04 mmol) and a white solid HY-30 (58 mg, 0.14 mmol), with yields of 7.0% and 25.1%, respectively.

[0102] Eehyl 6-(( 3R,6R )-3-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-6-methyl-2,5-dioxopiperazin-1-yl)hexanoate. (HY-29).1 1H NMR (400 MHz, CDCl3) δ 7.60 (d, J J = 7.7 Hz, 1H), 7.32 – 7.26 (m, 1H), 7.20 (dd, J J = 15.0, 7.1 Hz, 1H), 7.11 (t, J J = 7.4 Hz, 1H), 7.00 – 6.94 (m, 1H), 6.15 (s, 1H), 4.27 – 4.19 (m, 1H), 4.16 – 4.04 (m, 6H), 3.83 (q, J J = 7.0 Hz, 1H), 3.76 – 3.64 (m, 1H), 3.38 (dd, J J = 14.4, 3.3 Hz, 1H), 3.17 (dd, J J = 14.3, 8.3 Hz, 1H), 2.91 – 2.80 (m, 1H), 2.28 (td, J J = 7.4, 2.8 Hz, 4H), 1.89 – 1.77 (m, 2H), 1.64 (dd, J J = 16.7, 9.3 Hz, 4H), 1.41 – 1.28 (m, 5H), 1.24 (dt, J J = 10.2, 7.1 Hz, 7H), 1.07 (d, J J = 7.0 Hz, 3H). 13 13C NMR (100 MHz, CDCl3) δ 173.6, 173.5, 168.6, 165.4, 136.4, 127.7, 127.4, 122.1, 119.6, 119.3, 109.6, 108.3, 60.5, 60.4, 56.7, 55.6, 46.2, 44.6, 34.2, 34.1, 31.8, 30.1, 26.9, 26.6, 26.5, 24.7, 24.6, 19.1, 14.4, 14.3. HR-ESI-MS m / z [M+H]+ + 542.3202 (calcd 542.3230, C 30 H 44 N3O6).

[0103] Ethyl 6-(3-(((2R,5R )-5-methyl-3,6-dioxopiperazin-2-yl)methyl)-1H-indol-1-yl)hexanoate. (HY-30). 1 1H NMR (400 MHz, CDCl3) δ 7.61 (d, J J = 7.9 Hz, 1H), 7.31 (d, J J = 8.2 Hz, 1H), 7.22 (t, J J = 7.5 Hz, 1H), 7.11 (t, J J = 7.4 Hz, 1H), 7.01 (s, 1H), 6.80 (s, 1H), 6.33 (s, 1H), 4.30 (d, J J = 5.4 Hz, 1H), 4.10 (dt, J J = 13.8, 7.0 Hz, 4H), 3.99 (dd, J J = 13.7, 6.8 Hz, 1H), 3.51 (dd, J J = 14.6, 3.3 Hz, 1H), 3.14 (dd, J J = 14.6, 8.6 Hz, 1H), 2.29 (t, J J = 7.3 Hz, 2H), 1.82 (dd, J J = 14.8, 7.3 Hz, 2H), 1.65 (dt, J J = 14.9, 7.3 Hz, 2H), 1.40 – 1.31 (m, 2H), 1.23 (t, J J = 7.1 Hz, 3H), 1.14 (d, J J = 6.9 Hz, 3H). 13 13C NMR (100 MHz, CDCl3) δ 173.7, 168.7, 168.3, 136.5, 127.7, 127.5, 122.1, 119.6, 119.1, 109.7, 107.9, 60.4, 55.6, 50.8, 46.2, 34.1, 30.1, 30.0, 26.6, 24.6, 19.8, 14.3. HR-ESI-MS m / z [M+H] + 400.2208 (calcd 400.2236, C22 H 30 N3O4).

[0104] Example 17

[0105] Synthesis of compound HY-31: Compound M1 (60 mg, 0.23 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (33.1 mg, 0.83 mmol, 3.6 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (85 μL, 0.46 mmol, 2.0 eq) was added, and the reaction was carried out at 5 °C for 2 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 84 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (87 / 13, v / v The system was eluted to give a pale yellow oily compound HY-31 (10 mg, 0.01 mmol), with a yield of 6.3%.

[0106] Diethyl 6,6'-(( 2S,5S )-2-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-5-methyl-3,6-dioxopiperazine-1,4-diyl)dihexanoate. (HY-31). 1 H NMR (400 MHz, CDCl3) δ 7.55 (d, J = 7.9 Hz, 1H), 7.25 (d, J = 8.2 Hz, 1H), 7.17(t, J = 7.5 Hz, 1H), 7.08 (t, J = 7.4 Hz, 1H), 6.82 (s, 1H), 4.25 (t, J = 4.1Hz, 1H), 4.18 – 4.07 (m, 7H), 4.04 (dd, J = 14.4, 7.4 Hz, 2H), 3.74 – 3.61(m, 1H), 3.49 (dd, J= 14.9, 3.9 Hz, 1H), 3.25 (dd, J = 15.0, 4.5 Hz, 1H), 2.83 (dt, J = 14.0, 7.1 Hz, 1H), 2.77 – 2.66 (m, 1H), 2.27 (dt, J = 14.6, 7.4Hz, 6H), 1.85 – 1.72 (m, 4H), 1.62 (ddd, J = 21.4, 12.6, 6.3 Hz, 7H), 1.54 –1.44 (m, 3H), 1.41 – 1.30 (m, 1H), 1.29 – 1.19 (m, 13H), 0.35 (d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 173.5, 173.4, 173.3, 166.9, 165.4, 135.9,128.2, 127.2, 121.9, 119.5, 119.4, 109.2, 107.9, 60.5, 60.23, 60.2,60.1,55.7, 46.0, 44.4, 43.9, 34.1, 34.0(3xC), 30.1, 27.7, 26.52,26.50, 26.48,26.4, 24.5(3xC), 17.9, 14.6(3xC). HR-ESI-MS m / z [M+H] + 684.4178 (Calculated value 684.4224 C) 38 H 58 N3O8).

[0107] Example 18

[0108] Synthesis of compound HY-32: Compound M2 (140 mg, 0.54 mmol, 1.0 eq) was dissolved in 4 mL of DMF. 60% sodium hydride (54.0 mg, 1.35 mmol, 2.5 eq) was added with stirring at 5 °C. After stirring for 10 minutes, ethyl 6-bromohexanoate (150 μL, 0.82 mmol, 1.5 eq) was added, and the reaction was carried out at 5 °C for 2 h. The reaction was monitored by TLC. After the reaction was complete, 5% HCl solution was slowly added dropwise until the pH of the reaction solution was weakly acidic (pH≈6). 15 mL of distilled water was added, and the mixture was extracted three times with the same volume of ethyl acetate. The organic phases were combined and washed four times with 10 mL of distilled water. The organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 160 mg of crude oil. The crude product was separated by semi-preparative high-performance liquid chromatography (HPLC) using methanol / water (87 / 13, v / v The system was eluted to give a pale yellow oily compound HY-32 (10 mg, 0.01 mmol), with a yield of 2.6%.

[0109] Diethyl 6,6'-(( 2S,5R )-2-((1-(6-ethoxy-6-oxohexyl)-1H-indol-3-yl)methyl)-5-methyl-3,6- dioxopiperazine-1,4-diyl)dihexanoate. (HY-32). 1 H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 7.9 Hz, 1H), 7.18 (d, J = 8.2 Hz, 1H), 7.09(t, J = 7.5 Hz, 1H), 7.00 (t, J = 7.4 Hz, 1H), 6.66 (s, 1H), 4.17 (t, J = 3.4Hz, 1H), 4.14 – 4.01 (m, 8H), 3.96 (dt, J = 21.1, 7.0 Hz, 2H), 3.45 (dt, J =16.6, 8.3 Hz, 1H), 3.08 (ddd, J = 11.4, 7.8, 4.4 Hz, 2H), 2.79 (dt, J = 23.3,8.4 Hz, 1H), 2.74 (s, 1H), 2.49 (q,J = 6.9 Hz, 1H), 2.29 – 2.15 (m, 4H), 2.11 (dd, J = 15.2, 7.7 Hz, 2H), 1.77 – 1.64 (m, 3H), 1.64 (s, 9H), 1.34(dddd, J = 30.1, 21.8, 14.1, 5.9 Hz, 8H), 1.20 (d, J = 7.6 Hz, 3H), 1.19 (s, 9H). 13 C NMR (100 MHz, CDCl3) δ 173.7, 173.62, 173.59, 167.7, 166.5, 136.0,128.0, 127.8, 122.1, 119.6, 119.5, 109.3, 107.2, 60.4(3xC), 60.4, 53.7, HR-ESI-MS m / z [M+H] + 684.4193 (Calculated value 684.4224, C) 38 H 58 N3O8).

[0110] Example 19

[0111] Synthesis of compound HY-33: Compound M1 (400 mg, 1.56 mmol, 1.0 eq) was added to 1 mL of trifluoroacetic acid in an ice bath and stirred for 1–2 minutes. A 56 mL solution of 20% potassium carbonate was prepared, and 56 mL of dichloromethane was added and stirred in an ice bath. The reaction mixture was then added to this (potassium carbonate / dichloromethane) solution, stirred in an ice bath, and the pH was adjusted to 8. Extraction was performed with dichloromethane (50 mL × 3). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give a white solid compound HY-33 (330 mg, 1.28 mmol), with a yield of 82.5%.

[0112] ( 3S)-3-methyl-2,3,6,10b,11,11a-hexahydro-4H-pyrazino[1',2':1,5]pyrrolo[2,3-b]indole-1,4(5aH)-dione.(HY-33). 1 H NMR (400 MHz, CDCl3) δ 7.14(d, J = 7.4 Hz, 1H), 7.08 (t, J = 7.6 Hz, 1H), 6.77 (t, J = 7.4 Hz, 1H), 6.60(d, J = 7.8 Hz, 1H), 6.54 (s, 1H), 5.74 (d, J = 6.7 Hz, 1H), 4.06 (dq, J =14.7, 7.2 Hz, 3H), 2.70 (dd, J = 13.0, 6.4 Hz, 1H), 2.46 (ddd, J = 13.0,11.1, 7.3 Hz, 1H), 1.47 (d, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 169.95,166.9, 149.4, 128.7, 127.5, 124.2, 119.4, 109.3, 75.96, 58.3, 51.4, 44.3,33.7, 16.2. HR-ESI-MS m / z [M+H] + 258.1229 (Calculated value 258.1243, C) 14 H 16 N3O2).

[0113] Example 20

[0114] Synthesis of compound HY-34: Compound M2 (400 mg, 1.56 mmol, 1.0 eq) was added to 1 mL of trifluoroacetic acid in an ice bath and stirred for 1–2 minutes. A 56 mL solution of 20% potassium carbonate was prepared, and 56 mL of dichloromethane was added and stirred in an ice bath. The reaction mixture was then added to this (potassium carbonate / dichloromethane) solution, stirred in an ice bath, and the pH was adjusted to 8. Extraction was performed with dichloromethane (50 mL × 3). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give a white solid, compound HY-34 (300 mg, 1.17 mmol), in 75.0% yield.

[0115] ( 3S )-3-methyl-2,3,6,10b,11,11a-hexahydro-4H-pyrazino[1',2':1,5]pyrrolo[2,3-b]indole-1,4(5aH)-dione.(HY-34). 1 H NMR (400 MHz, CDCl3) δ 7.14(d, J = 7.4 Hz, 1H), 7.08 (t, J = 7.6 Hz, 1H), 6.77 (t, J = 7.4 Hz, 1H), 6.60(d, J = 7.8 Hz, 1H), 6.54 (s, 1H), 5.74 (d, J = 6.7 Hz, 1H), 4.06 (dq, J =14.7, 7.2 Hz, 3H), 2.70 (dd, J = 13.0, 6.4 Hz, 1H), 2.46 (ddd, J = 13.0,11.1, 7.3 Hz, 1H), 1.47 (d, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 169.95,166.94, 149.4, 128.7, 127.5, 124.2, 119.4, 109.3, 75.96, 58.3, 51.4, 44.3,33.7, 16.2. HR-ESI-MS m / z [M+H] + 258.1229 (Calculated value 258.1243, C) 14 H16 N3O2).

[0116] Example 21

[0117] Synthesis of compounds HY-35, HY-36, and HY-37: Compound HY-33 (30 mg, 0.12 mmol, 1.0 eq) was dissolved in 0.5 mL of acetic anhydride and refluxed at 120 °C with stirring for 5 h. The reaction was monitored by TLC. After the reaction was complete, the reaction solution was diluted with 10 mL of ethyl acetate, washed three times with saturated brine (10 mL × 3), dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give 50 mg of crude orange liquid. Column chromatography purification (ethyl acetate-petroleum ether = 2:8 → 8:2) yielded white oily compound HY-35 (12 mg, 0.04 mmol), white solid HY-36 (9 mg, 0.03 mmol), and pale yellow solid HY-37 (7 mg, 0.02 mmol), with yields of 30%, 25%, and 20%, respectively.

[0118] ( 3S )-2,6-diacetyl-3-methyl-2,3,6,10b,11,11a-hexahydro-4H-pyrazino[1',2':1,5]pyrrolo[2,3-b]indole-1,4(5aH)-dione. (HY-35). 1 H NMR (400 MHz, CDCl3) δ 8.10 (d, J = 7.8 Hz, 1H), 7.22 (d, J = 7.5 Hz, 1H), 7.18 (d, J = 8.4 Hz, 1H), 7.06 (td, J = 7.5, 0.8 Hz, 1H), 6.65 (d, J = 7.6 Hz, 1H), 4.97 (q, J = 7.0Hz, 1H), 4.15 (t, J = 7.7 Hz, 1H), 4.07 (dd, J = 12.5, 4.9 Hz, 1H), 2.54 (dd, J= 12.1, 4.9 Hz, 1H), 2.41 (s, 3H), 2.41 (s, 3H), 2.20 – 2.10 (m, 1H), 1.47(d, J = 7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 170.9, 170.7, 168.0, 167.9,143.7, 129.3, 129.2,124.9, 124.6, 117.3, 76.5, 59.2, 53.1, 44.1, 38.96, 26.5,24.4, 21.9. HR-ESI-MS m / z [M+H] + 342.1445 (calcd 342.1454, C 18 H 20 N3O4).

[0119] ( 3S )-2-acetyl-3-methyl-2,3,6,10b,11,11a-hexahydro-4H-pyrazino[1',2':1,5]pyrrolo[ ,3-b]indole-1,4(5aH)-dione. (HY-36). 1 H NMR (400 MHz, CDCl3) δ 7.83 (d, J = 6.4 Hz, 1H), 7.63 (d, J = 7.6 Hz, 1H), 7.24 (t, J = 7.8 Hz, 1H),7.10 (t, J = 7.5 Hz, 1H), 6.31 (d, J = 5.9 Hz, 1H), 5.83 (d, J = 1.6 Hz, 1H),4.87 (q, J = 7.1 Hz, 1H), 4.32 (s, 1H), 3.84 (d, J = 6.1 Hz, 1H), 2.51 (s,3H), 2.35 (s, 3H), 2.24 (s, 3H), 1.59 (d, J = 7.1 Hz,3H).< / / 13 [[ID= / / 43]]C NMR ( / / 100 MHz,CDCl3)[[ID= / / 44]] δ It should be noted that there seems to be an error in the original text where the closing bracket in the chemical structure description in line 19 is not properly formatted. Also, the " / / " added in the translation for lines 43 and 44 is just to mark the potential error in the original text for better understanding. The translation is otherwise done according to the rules.171.4, 168.7, 165.9, 141.1, 129.4, 125.6, 125.4, 86.7, 76.4, 55.5,50.99, 27.7, 24.3, 21.2, 19.8. HR-ESI-MS m / z [M+H] + 300.1341 (Calculated value 300.1348, C) 16 H 18 N3O3).

[0120] ( 3S )-6-acetyl-3-methyl-2,3,6,10b,11,11a-hexahydro-4H-pyrazino[1',2':1,5]pyrrolo[2,3-b]indole-1,4(5aH)-dione.(HY-37). 1 H NMR (400 MHz, CDCl3) δ 7.94(d, J = 7.1 Hz, 1H), 7.23 (s, 1H), 7.18 (d, J = 7.3 Hz, 3H), 7.07 (t, J = 7.5Hz, 1H), 6.29 (d, J = 6.1 Hz, 1H), 6.10 (s, 1H), 5.23 (s, 0H), 4.15 – 3.98(m, 2H), 3.89 (dd, J = 11.3, 5.7 Hz, 1H), 2.68 (dd, J = 12.9, 5.7 Hz, 1H), 2.60 (s, 3H), 2.36 – 2.26 (m, 1H), 1.40 (d, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 170.7, 168.9, 166.4, 143.0, 128.9, 125.1, 123.7, 119.0, 58.5, 51.4,44.0, 34.4, 29.8, 23.9, 16.7. HR-ESI-MS m / z [M+H] + 300.1341 (Calculated value 300.1348, C) 16 H 18N3O3).

[0121] Experimental Example 1

[0122] The toxicity of the compound to cardiomyocytes and its protective effect against OGD / R-induced cardiomyocytes.

[0123] 1. In vitro experimental section

[0124] (1) Preparation of H9c2 cardiomyocytes

[0125] H9c2 cardiomyocytes (ATCC-derived) were cultured in DMEM medium containing 10% fetal bovine serum (FBS) and 1% penicillin / streptomycin, and routinely cultured in a 37°C, 5% CO2 saturated humidity incubator. The medium was changed every two days, and the cells were passaged after 3-5 days. For oxygen-glucose deprivation / reoxygenation (OGD / R) treatment, H9c2 cells in the logarithmic growth phase and in good growth condition were digested with trypsin and then divided into cells at 2 × 10⁶ cells per well. 5 H9c2 cells were seeded in 6-well plates and incubated overnight. After the cells were fully adhered, the complete culture medium of H9c2 cells was aspirated, the cells were washed twice with PBS, and the culture medium was replaced with sugar-free DMEM. The cells were then cultured at 37°C in an incubator containing 95% N2 and 5% CO2 for 3 h.

[0126] (2) Cytotoxicity test

[0127] Take H9c2 cells in the logarithmic growth phase and in good growth condition, and divide them into groups of 8 × 10⁸ cells per well. 4 Cells were seeded at a density in 96-well plates and incubated overnight until complete cell adhesion. The original culture medium was discarded, and 100 μL of complete culture medium containing the drug (10 μM test compound) was added to each well for 24 h. The original culture medium was then discarded, and 100 µL of prepared MTT working solution (prepared with complete culture medium, concentration 0.5 mg / mL) was added to each well, and the plates were incubated at 37°C for 4 h. The MTT working solution was then removed, and 150 µL of DMSO was added to each well. The plates were then shaken in the dark for 10 min.

[0128] (3) Experiment on cardioprotective effect

[0129] H9c2 cells were subjected to OGD treatment (100 μL of glucose-free medium was added, and the cells were placed in an anoxic environment for 6 h of glucose and oxygen deprivation). The medium was then replaced with 100 μL of complete medium containing the drug (10 μM of the test compound HY series and the positive control drug 100 μM diazoxide), and cultured in a normal incubator for 12 h. The original medium was discarded, and 100 µL of prepared MTT working solution (prepared with complete medium at a concentration of 0.5 mg / mL) was added to each well. The cells were incubated at 37°C for 4 h. The MTT working solution was then removed, and 150 µL of DMSO was added to each well. The cells were shaken in the dark for 10 min.

[0130] (4) Cytotoxicity results ( Figure 1 The results showed that, except for compound HY-20 which exhibited cytotoxicity, the other compounds did not show significant differences. Overall, this series of indole-diketopiperazine derivatives showed low cardiocytotoxicity.

[0131] (5) The results of the myocardial protection experiment are shown in Table 1. Among the tested indole diketopiperazine derivatives, compounds HY-5, HY-7, HY-16~HY18 and HY-26 showed significant myocardial protection activity, and their myocardial protection activity was better than that of the positive control group diazoxide. This indicates that the indole diketopiperazine derivatives have a good balance between high myocardial cell protection activity and low cytotoxicity, which is of great significance for the development of myocardial protection drugs with good activity.

[0132] Table 1. Protective effects of compounds (10 μM) on cardiomyocytes.

[0133] Note: Data are expressed as mean ± standard deviation (n=5). Compared with the control group, # P < 0.05 ## P < 0.01, ### P < 0.001. Compared with the OGD / R group, *P < 0.05, **P < 0.01, ***P < 0.001. Diazide (100 μM)

[0134] 2. In vivo activity test

[0135] This experiment used the LAD ligation method to establish a mouse model of myocardial ischemia-reperfusion injury (MIRI) and investigated the protective effect of compound HY-7 against myocardial injury.

[0136] (1) Animal grouping and administration methods

[0137] C57BL / 6 mice (Guangdong Vital River Laboratory Animal Technology Co., Ltd.) weighing 22–25 g were randomly divided into 6 groups: sham surgery group, MIRI model group, low, medium, and high dose (7.5, 15.0, 30.0 mg / kg) HY-7 groups, and a positive control group (diazide). Before sham surgery or MIRI, mice were intraperitoneally injected with saline, diazide (10 mg / kg / day), or compound HY-7.

[0138] (2) Animal model construction

[0139] Preoperative fasting (but water intake allowed) was maintained for 10-12 hours. Mice were anesthetized with 0.25% sodium pentobarbital, their chest fur was shaved, and they were fixed on a surgical board (with an electric blanket for warmth). Endotracheal intubation was performed, and a small animal ventilator was connected for assisted breathing. The surgical area was disinfected with iodine, and the second rib was located using the manubrium of the sternum as a landmark. The surgical incision was made at the third intercostal space on the left side. The skin and pectoralis major muscle were incised sequentially to expose the ribs. The pleura was opened, and the left lung was slightly pushed to the side and back with sterile, defatted cotton. The pericardium was torn open with forceps to expose the heart. The left anterior descending coronary artery was ligated with a 6 / 0 atraumatic suture needle. A 1 cm long PP tube (Φ0.5×0.9 mm) was placed at the ligation site, between the left atrial appendage and the pulmonary conus, 2-3 mm from the origin of the coronary artery. The PP tube was removed 30 minutes after ligation to allow blood reperfusion. The ribs, pectoralis major muscle, and skin were sutured sequentially, and the incision was disinfected. The Sham group underwent open-chest LAD suture insertion but not ligation; all other procedures were the same as the other groups. The animal experiment concluded 24 hours after reperfusion, with cardiac function assessed, and whole blood, plasma, and heart tissue collected for subsequent experiments.

[0140] (3) Evaluation of cardiac function

[0141] Non-invasive echocardiography was performed on mice using the Feinuo small animal ultrasound system to measure cardiac function. The left ventricular end-systolic / end-diastolic diameter and volume were calculated based on the M-mode images to obtain the left ventricular ejection fraction (EF) and fractional shortening (FS) values.

[0142] (4) Measurement of infarct area

[0143] Mice were anesthetized 24 h after reperfusion. The heart was then removed and frozen at -80°C. After 8 minutes, the heart was cut into 5 short-axis sections and immersed in a 1% 2,3,5-triphenyltetrazolium chloride (TTC) incubator at 37°C for 15 min. The sections were photographed and the infarct area was assessed using ImageJ software.

[0144] (5) Results Analysis

[0145] The in vivo efficacy of compound HY-7, which exhibits good cardioprotective activity, against myocardial ischemia-reperfusion was evaluated. For example...Figure 2 AC echocardiography results showed: MIRI group had an ejection fraction (EF) of 25.93 ± 2.46% and a left ventricular shortening rate (FS) of 11.75 ± 1.16%; HY-7 low-dose (7.5 mg / kg) group had an EF of 48.40 ± 3.48% and an FS of 24.0 ± 2.09%; medium-dose group (15.0 mg / kg) had an EF of 72.36 ± 2.75% and an FS of 40.61 ± 2.41%; in the high-dose group (30.0 mg / kg), 4 out of 6 mice died; the positive control group had an EF of 57.08 ± 7.12%. TTC staining revealed significant myocardial infarction in the MIRI group, while the perforation area decreased in the low-dose group, and the infarct area was significantly reduced in the medium-dose group. Figure 2 (D) Compared with the MIRI group, low and medium doses of HY-7 significantly reversed the decrease in ejection fraction (EF) and left ventricular shortening rate (FS) caused by MIRI, improved cardiac function, and were superior to the positive control drug diazoxide. HY-7 administration significantly reduced the infarct area.

[0146] The above results indicate that HY-7 exhibits certain cardioprotective effects across different indicators, providing a valuable lead compound for further structural optimization and the development of cardioprotective drugs.

[0147] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A class of indole-diketopiperazine derivatives, characterized in that, The aforementioned indole-dione-piperazine derivative has the structural formula shown in formula (I) or formula (II): ； Wherein: In formula (I), R1, R2, and R3 are selected from H, , , , , , , , , , or R1, R2, and R3 can be the same or different groups, and n = 1-8; In formula (II), R4 and R5 are selected from H or R4 and R5 can be the same group or different groups.

2. The indole-diketopiperazine derivative according to claim 1, characterized in that, The indole-dione-piperazine derivatives described herein have any of the following structures: ； ； ； 。 3. The method for preparing the indole-diketone piperazine derivative according to claim 1 or 2, characterized in that, Includes the following steps: ； Among them, R1, R2, and R3 are selected from H, , , , , , or R1, R2, and R3 can be the same or different groups, and n = 1-8; Indole-diketopiramate was dissolved in a solvent and placed in a reaction bath at 0-5°C. Sodium hydride and the bromide were added sequentially, and the reaction was continued at this temperature until completion. The reaction process was tracked by TLC. After the reaction was completed, the pH of the reaction solution was adjusted to be weakly acidic. The organic phase obtained by extraction was dried to obtain the crude product. The crude product was then separated by semi-preparative high performance liquid chromatography or by silica gel column chromatography to obtain the target product.

4. The method for preparing the indole-diketone piperazine derivative according to claim 3, characterized in that, Includes the following steps: ； Among them, R6 is selected from H, , , or n=2-4; The brominated intermediate was dissolved in acetonitrile, and amine reactants and potassium carbonate were added sequentially. The mixture was refluxed and the reaction was monitored by TLC until the reaction was completed. The solvent was evaporated to obtain the crude product, which was then separated by semi-preparative high performance liquid chromatography or silica gel column chromatography to obtain the target product.

5. The method for preparing the indole-diketone piperazine derivative according to claim 1 or 2, characterized in that, Includes the following steps: ； Indole-diketopiramate was mixed with trifluoroacetic acid and stirred in an ice bath to obtain a reaction solution. A potassium carbonate solution was prepared, and an equal volume of dichloromethane was added and stirred in an ice bath to obtain a potassium carbonate / dichloromethane solution. The reaction solution was added to the potassium carbonate / dichloromethane solution, stirred in an ice bath, and the pH was adjusted to 8. The mixture was extracted, the organic phases were combined, and dried to obtain an intermediate. The intermediate was then dissolved in acetic anhydride, and the mixture was refluxed and stirred. The reaction progress was monitored by TLC. After the reaction was completed, the reaction solution was diluted with ethyl acetate, washed, and the resulting organic phase was dried to obtain a crude product. The crude product was purified by column chromatography to obtain the target product.

6. The use of the indole-dikepiperazine derivative according to claim 1 or 2 or the indole-dikepiperazine derivative obtained by the preparation method according to any one of claims 3-5 in the preparation of cardioprotective drugs.

7. A cardioprotective drug, characterized in that, The active ingredient is the indole-dikepiperazine derivative as described in claim 1 or 2, or the indole-dikepiperazine derivative obtained by the preparation method described in any one of claims 3-5.

8. A pharmaceutical composition, characterized in that, It comprises the indole-dikepiperazine derivative of claim 1 or 2 or the indole-dikepiperazine derivative obtained by the preparation method of any one of claims 3-5, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipient.

9. The use of the pharmaceutical composition of claim 8 in the preparation of a myocardial protective drug.

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