A C20 ketopregnane alkaloid derivative, its synthesis method and application

Abstract

The invention discloses a C20 keto-pregnane alkaloid derivative and a synthesis method and application thereof. The invention is based on the skeleton structure of active pregnane alkaloids in the Miao medicine Sanliangyin, uses epiandrosterone as a raw material, and obtains a series of C20 keto-pregnane alkaloid derivatives through Wittig reaction, reduction reaction, Corey oxidation, reductive amination, N alkylation and other reactions. The raw materials of the method are cheap and easy to obtain, the reaction conditions are mild, the operation is simple, and the reaction yield is good. The synthesized C20 keto-pregnane alkaloid derivative has excellent anti-tumor activity and anti-inflammatory activity, and can be used in anti-liver cancer, anti-colorectal cancer and anti-inflammatory drugs. It provides a scientific basis for the development and application of new drugs for new anti-tumor and anti-inflammatory pregnane alkaloids.

Description

Technical Field

[0001] The present invention belongs to the technical field of pharmaceutical synthesis, and relates to a C20-ketopregnane-type alkaloid derivative, a synthesis method thereof, and an application thereof. Background Art

[0002] The Miao medicine "Sarcococca ruscifolia" (Miao medicine name: bub jid ngongx), a plant of the genus Sarcococca L. in the family Buxaceae, research shows that its chemical constituents are mainly pregnane-type steroidal alkaloid compounds, which have a wide range of biological activities in aspects such as cholinesterase inhibition, anti-cancer, anti-ulcer, anti-inflammatory, and spasmolysis. The research group previously isolated and identified a series of new pregnane-type steroidal alkaloids from it, and conducted in vitro anti-tumor and anti-inflammatory activity tests on these alkaloids, showing good anti-tumor activity and anti-inflammatory activity. However, previous studies found that the structural diversity of the derivatives naturally produced by these alkaloids is relatively low, which limits the in-depth study of finding highly effective and low-toxic derivatives and their structure-activity relationships. To find highly effective and low-toxic pregnane-type steroidal alkaloid derivatives, based on the pregnane-type alkaloid skeleton structure of the Miao medicine "Sarcococca ruscifolia", using epiandrosterone as a raw material, through a series of reactions such as Wittig reaction, reduction reaction, Corey oxidation, reductive amination, and N-alkylation, a series of C20-ketopregnane-type alkaloid derivatives were obtained. Further through anti-tumor and anti-inflammatory activity evaluations, it was found that the obtained derivatives showed significant anti-tumor and anti-inflammatory activities. The present invention provides a scientific basis for finding novel anti-tumor and anti-inflammatory lead compounds with high selectivity and safety and developing novel anti-tumor and anti-inflammatory drugs. Summary of the Invention

[0003] The purpose of the present invention is to provide a C20-ketopregnane-type alkaloid derivative.

[0004] The purpose of the present invention is to provide a synthesis method of a C20-ketopregnane-type alkaloid derivative.

[0005] Another purpose of the present invention is to provide the application of the C20-ketopregnane-type alkaloid derivative in anti-hepatocellular carcinoma, colorectal cancer, and anti-inflammatory.

[0006] In order to achieve the purpose of the present invention, the present invention is implemented by adopting the following technical solutions and steps:

[0007] The C20-ketopregnane-type alkaloid derivative described in the present invention has a general structural formula shown as (Ⅰ):

[0008]

[0009] Wherein, R1 is selected from aniline, p-toluidine, o-toluidine, m-toluidine, p-chloroaniline, p-methoxyaniline, o-methoxyaniline, m-methoxyaniline;

[0010] R2 is selected from hydrogen, methyl, and ethyl.

[0011] There are 25 kinds of the derivative compounds described in the present invention, which are sequentially denoted as 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4a', 4c', 4d', 4f', 4g', 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 6a, 6b, 6c, 6f, and the corresponding relationships of R1 and R2 are as follows:

[0012]

[0013]

[0014] The synthesis method of the C20-ketopregnane-type alkaloid derivative described in the present invention includes the following steps:

[0015] (1) Synthesis of compound 1: Potassium tert-butoxide and ethyltriphenylphosphonium bromide are added to a flask, evacuated, an appropriate amount of anhydrous tetrahydrofuran is added, stirred at room temperature for 1 h, a pre-prepared solution of epiandrosterone in tetrahydrofuran is added, stirred at room temperature for 3 h, the reaction is monitored by TLC until completion, then saturated ammonium chloride solution is added to the reaction solution to quench the reaction, extracted with ethyl acetate, washed with saturated brine, the organic layer is dried with anhydrous magnesium sulfate, filtered, concentrated under reduced pressure to obtain a crude product, and purified by silica gel chromatography with a mobile phase of petroleum ether: ethyl acetate = 5:1 to obtain compound 1;

[0016] (2) Synthesis of compound 2: BH3-Me2S is added to the tetrahydrofuran solution of compound 1, stirred at 25 °C for 2 h, then ethanol, NaOH, and H2O2 are added dropwise, stirred at 60 °C for 1 h, the mixture is quenched with Na2S2O3, and extracted with ethyl acetate. The synthesized organic solution is washed with saturated brine, dried with Na2SO4, filtered and concentrated to obtain compound 2;

[0017] (3) Synthesis of compound 3: Compound 2, PCC, and an appropriate amount of silica gel are added to DCM, the mixture is stirred at room temperature for 3 h, the mixture is filtered, the filter cake is washed with DCM, the solvent is recovered under reduced pressure, and silica gel column chromatography is carried out with a mobile phase of petroleum ether: ethyl acetate to obtain compound 3;

[0018] (4) Synthesis of compound 4a: Compound 3 is placed in a flask, acetic acid is added, aniline is added by injection, stirred overnight, sodium borohydride is added slowly in batches, stirred at room temperature for 2 h, acetic acid is removed under reduced pressure, water is added to the solid, the pH value is adjusted to 2-3 with dilute hydrochloric acid, extracted with ethyl acetate, the organic layer is adjusted to neutral or weakly alkaline with dilute sodium hydroxide solution, the organic layer is extracted, concentrated under reduced pressure to obtain a crude product, and purified by silica gel chromatography with a mobile phase of petroleum ether: ethyl acetate for gradient elution to obtain compound 4a;

[0019] Synthesis of Compounds 4b - 4h / 4a' / 4c' / 4d' / 4f' / 4g': Operating according to the synthesis procedure of Compound 4a above, reacting Compound 3 with aniline gives Compound 4a'; reacting with p - toluidine gives Compound 4b; reacting with p - anisidine gives Compounds 4c and 4c'; reacting with p - chloroaniline gives Compounds 4d and 4d'; reacting with o - toluidine gives Compound 4e; reacting with m - toluidine gives Compounds 4f and 4f'; reacting with m - anisidine gives Compounds 4g and 4g'; reacting with o - anisidine gives Compound 4h.

[0020] (5) Synthesis of Compound 5a: Place Compound 4a in a flask, add methyl iodide and anhydrous DMF, then add sodium hydride, heat the system to control the temperature at 60 °C - 70 °C, react for 3 h, monitor the completion of the reaction by TLC, cool to room temperature, evaporate DMF under reduced pressure, extract with chloroform, combine the organic phases, wash with saturated brine, dry over anhydrous magnesium sulfate, filter, concentrate under reduced pressure to obtain the crude product, and purify it by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate for gradient elution to obtain Compound 5a;

[0021] Synthesis of Compounds 5b - 5h: Operating according to the synthesis procedure of Compound 5a above, reacting with Compound 4b gives Compound 5b; reacting with Compound 4c gives Compound 5c; reacting with Compound 4d gives Compound 5d; reacting with Compound 4e gives Compound 5e; reacting with Compound 4f gives Compound 5f; reacting with Compound 4g gives Compound 5g; reacting with Compound 4h gives Compound 5h.

[0022] (6) Synthesis of Compound 6a: Place Compound 4a in a flask, add ethyl bromide and anhydrous potassium carbonate, displace with nitrogen three times for protection, add anhydrous DMF, heat the system to control the temperature at 60 °C - 70 °C, monitor the completion of the reaction by TLC, cool to room temperature, evaporate DMF under reduced pressure by rotary evaporation, add water, extract with chloroform (3 × 20 mL), combine the organic phases, wash with saturated brine, dry over anhydrous magnesium sulfate, filter, concentrate under reduced pressure to obtain the crude product, and purify it by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate for gradient elution to obtain Compound 6a.

[0023] Synthesis of Compounds 6b, 6c, 6f: Operating according to the above - mentioned synthesis procedure, reacting with Compound 4b gives Compound 6b; reacting with Compound 4c gives Compound 6c; reacting with Compound 4f gives Compound 6f.

[0024] The synthesis method of the C20 - keto - pregnane - type alkaloid derivative described in the present invention specifically includes the following steps:

[0025] (1) Synthesis of Compound 1: Weigh 2.34 g of potassium tert-butoxide and 7.67 g of ethyltriphenylphosphonium bromide respectively, add them to a flask, evacuate the air, add an appropriate amount of anhydrous tetrahydrofuran, stir at room temperature for 1 h, add a pre-prepared tetrahydrofuran solution of epiandrosterone (1 g, 3.5 mmol), stir at room temperature for 3 h, monitor the completion of the reaction by TLC, then add saturated ammonium chloride solution to the reaction solution to quench the reaction, extract with ethyl acetate 3 times, 100 ml each time, combine the extracts, wash with saturated brine (2×100 mL), dry the organic layer with anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain a crude product, which is purified by silica gel chromatography with the mobile phase of petroleum ether: ethyl acetate = 5:1 to obtain Compound 1;

[0026] (2) Synthesis of Compound 2: Add BH3-Me2S (7.5 mL, 10 M, 75.0 mmol) to a THF (100 mL) solution of Compound 1 (5 g, 15.0 mmol), stir at 25 °C for 2 h, then add 10 mL of ethanol, NaOH (30 mL, 5 M) and H2O2 (15 mL, 10 M) dropwise, stir at 60 °C for 1 h, quench the mixture with 400 mL of 10% Na2S2O3 solution, and extract with ethyl acetate 2 times, 300 ml each time. Wash the synthesized organic solution with 300 mL of saturated brine, dry with Na2SO4, filter and concentrate to obtain Compound 2;

[0027] (3) Synthesis of Compound 3: Weigh 1 g of Compound 2 and 2.76 g of PCC, add an appropriate amount of silica gel to DCM (100 mL), stir the mixture at room temperature for 3 h, filter the mixture, wash the filter cake with DCM (2×100 mL), recover the solvent under reduced pressure, and perform silica gel column chromatography with the mobile phase of petroleum ether: ethyl acetate to obtain Compound 3;

[0028] (4) Synthesis of Compound 4a: Weigh 100 mg of Compound 3 and place it in a 25 mL flask, add 1 mL of acetic acid, inject 23.70 μL of aniline, stir for 12 h, slowly add 22.70 mg of sodium borohydride in batches, stir at room temperature for 2 h, remove acetic acid under reduced pressure, add water to the solid, adjust the pH value to 2 - 3 with dilute hydrochloric acid, extract with ethyl acetate, adjust the value of the organic layer to neutral or weakly alkaline with dilute sodium hydroxide solution, extract the organic layer, and concentrate under reduced pressure to obtain a crude product, which is purified by silica gel chromatography with the mobile phase of petroleum ether: ethyl acetate and perform gradient elution to obtain Compound 4a;

[0029] Synthesis of Compounds 4b - 4h / 4a' / 4c' / 4d' / 4f' / 4g': Operating according to the synthesis procedure of Compound 4a above, reacting Compound 3 with aniline gives Compound 4a'; reacting with p - toluidine gives Compound 4b; reacting with p - anisidine gives Compounds 4c and 4c'; reacting with p - chloroaniline gives Compounds 4d and 4d'; reacting with o - toluidine gives Compound 4e; reacting with m - toluidine gives Compounds 4f and 4f'; reacting with m - anisidine gives Compounds 4g and 4g'; reacting with o - anisidine gives Compound 4h.

[0030] (5) Synthesis of Compound 5a: Weigh 50 mg of Compound 4a and place it in a 25 - mL flask. Add 22.98 μL of methyl iodide and 2 mL of anhydrous DMF. Then add 3.12 mg of sodium hydride. Heat the system and control the temperature at 60 °C - 70 °C. React for 3 h. Monitor the completion of the reaction by TLC. Cool to room temperature. Evaporate DMF under reduced pressure. Extract with chloroform three times, 20 mL each time. Combine the organic phases. Wash with saturated brine (2×20 mL), dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain the crude product. Purify by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate for gradient elution to obtain Compound 5a.

[0031] Synthesis of Compounds 5b - 5h: Operating according to the synthesis procedure of Compound 5a above, reacting with Compound 4b gives Compound 5b; reacting with Compound 4c gives Compound 5c; reacting with Compound 4d gives Compound 5d; reacting with Compound 4e gives Compound 5e; reacting with Compound 4f gives Compound 5f; reacting with Compound 4g gives Compound 5g; reacting with Compound 4h gives Compound 5h.

[0032] (6) Synthesis of Compounds 6a - 6c / 6: Weigh 50 mg of 4a and place it in a 25 - mL flask. Add 29.09 μL of ethyl bromide and 17.97 mg of anhydrous potassium carbonate. Protect by displacing with nitrogen three times. Add 2 mL of anhydrous DMF. Heat the system and control the temperature at 60 °C - 70 °C. Monitor the completion of the reaction by TLC. Cool to room temperature. Rotate and evaporate DMF under reduced pressure. Add water and extract with chloroform three times, 20 mL each time. Combine the organic phases, wash with saturated brine, dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain the crude product. Purify by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate to obtain Compound 6a.

[0033] Synthesis of Compounds 6b, 6c, 6f: Operating according to the above - mentioned synthesis procedure, reacting with Compound 4b gives Compound 6b; reacting with Compound 4c gives Compound 6c; reacting with Compound 4f gives Compound 6f.

[0034] In step (1) of the present invention, the molar ratio of potassium tert - butoxide, ethyltriphenylphosphonium bromide to epiandrosterone is 6∶6∶1.

[0035] In step (2) of the present invention, the molar ratio of BH3-Me2S to compound 1 is 5:1.

[0036] In step (3) of the present invention, the molar ratio of compound 2 to PCC is 1:4.

[0037] In step (4) of the present invention, the molar ratio of compound 3, aniline to sodium borohydride is 1.6:1.3:3.

[0038] In step (5) of the present invention, the molar ratio of compound 4a, methyl iodide to sodium hydride is 1:3:1; in step (6), the molar ratio of compound 4a, bromoethane to anhydrous potassium carbonate is 1:3:1.

[0039] Application of the C20-ketopregnane-type alkaloid derivative of the present invention in the preparation of anti-hepatocellular carcinoma, anti-colorectal carcinoma and anti-inflammatory drugs.

[0040] Advantages of the present invention:

[0041] 1. The synthesis method of the present invention uses inexpensive and easily available raw materials, has mild reaction conditions, is green and safe, and is easy to operate.

[0042] 2. The C20-ketopregnane-type alkaloid derivative obtained by the present invention is a new compound. The obtained compound is screened for in vitro anti-tumor and anti-inflammatory activities by the CCK8 method, showing that this type of compound has anti-tumor and anti-inflammatory effects. It provides a scientific basis for searching for new anti-tumor and anti-inflammatory lead compounds with high selectivity and safety and developing new anti-tumor and anti-inflammatory drugs. Description of the drawings

[0043] Figure 1a 1H-NMR spectrum of compound 4a 1 1H-NMR spectrum

[0044] Figure 1b 13C-NMR spectrum of compound 4a 13 13C-NMR spectrum

[0045] Figure 2a 1H-NMR spectrum of compound 4b 1 1H-NMR spectrum

[0046] Figure 2b 13C-NMR spectrum of compound 4b 13 13C-NMR spectrum

[0047] Figure 3a 1H-NMR spectrum of compound 4c 1 1H-NMR spectrum

[0048] Figure 3b 13C-NMR spectrum of compound 4c 13 13C-NMR spectrum

[0049] Figure 4a For compound 4d 1 1H-NMR spectrum

[0050] Figure 4b For compound 4d 13 13C-NMR spectrum

[0051] Figure 5a For compound 4e 1 1H-NMR spectrum

[0052] Figure 5b For compound 4e 13 13C-NMR spectrum

[0053] Figure 6a For compound 4f 1 1H-NMR spectrum

[0054] Figure 6b For compound 4f 13 13C-NMR spectrum

[0055] Figure 7a For compound 4g 1 1H-NMR spectrum

[0056] Figure 7b For compound 4g 13 13C-NMR spectrum

[0057] Figure 8a For compound 4h 1 1H-NMR spectrum

[0058] Figure 8b For compound 4h 13 13C-NMR spectrum

[0059] Figure 9a For compound 4a' 1 1H-NMR spectrum

[0060] Figure 9b For compound 4a' 13 13C-NMR spectrum

[0061] Figure 10a For compound 4c' 1 1H-NMR spectrum

[0062] Figure 10b For compound 4c' 13 13C-NMR spectrum

[0063] Figure 11a For compound 4d' 1 1H-NMR spectrum

[0064] Figure 11b For compound 4d'13 C-NMR spectrum

[0065] Figure 12a of Compound 4f' 1 H-NMR spectrum

[0066] Figure 12b of Compound 4f' 13 C-NMR spectrum

[0067] Figure 13a of Compound 4g' 1 H-NMR spectrum

[0068] Figure 13b of Compound 4g' 13 C-NMR spectrum

[0069] Figure 14a of Compound 5a 1 H-NMR spectrum

[0070] Figure 14b of Compound 5a 13 C-NMR spectrum

[0071] Figure 15a of Compound 5b 1 H-NMR spectrum

[0072] Figure 15b of Compound 5b 13 C-NMR spectrum

[0073] Figure 16a of Compound 5c 1 H-NMR spectrum

[0074] Figure 16b of Compound 5c 13 C-NMR spectrum

[0075] Figure 17a of Compound 5d 1 H-NMR spectrum

[0076] Figure 17b of Compound 5d 13 C-NMR spectrum

[0077] Figure 18a of Compound 5e 1 H-NMR spectrum

[0078] Figure 18b of Compound 5e 13 C-NMR spectrum

[0079] Figure 19a of Compound 5f 1 H-NMR spectrum

[0080] Figure 19b For compound 5f 13 C-NMR spectrum

[0081] Figure 20a For compound 5g 1 H-NMR spectrum

[0082] Figure 20b For compound 5g 13 C-NMR spectrum

[0083] Figure 21a For compound 5h 1 H-NMR spectrum

[0084] Figure 21b For compound 5h 13 C-NMR spectrum

[0085] Figure 22a For compound 6a 1 H-NMR spectrum

[0086] Figure 22b For compound 6a 13 C-NMR spectrum

[0087] Figure 23a For compound 6b 1 H-NMR spectrum

[0088] Figure 23b For compound 6b 13 C-NMR spectrum

[0089] Figure 24a For compound 6c 1 H-NMR spectrum

[0090] Figure 24b For compound 6c 13 C-NMR spectrum

[0091] Figure 25a For compound 6f 1 H-NMR spectrum

[0092] Figure 25b For compound 6f 13 C-NMR spectrum

[0093] Figure 26 Cytotoxicity of compounds 4a - 4h

[0094] Figure 27 Cytotoxicity of compounds 5a - 5h

[0095] Figure 28 Cytotoxicity of compounds 4a', 4c', 4d', 4f', 4g', 6a - 6c and 6f

[0096] Figure 29 Effect of Compounds 4a - 4h on NO in LPS - induced RAW264.7 Cells

[0097] Figure 30 Effect of Compounds 5a - 5h on NO in LPS - induced RAW264.7 Cells

[0098] Figure 31 Effect of Compounds 4a', 4c', 4d', 4f', 4g', 6a - 6c and 6f on NO in LPS - induced RAW264.7 Cells Detailed Implementation Modes

[0099] Example 1: Synthesis Method of C20 - Keto - pregnane - type Alkaloid Derivatives

[0100] 1. Synthesis of Compound 1

[0101] Add potassium tert - butoxide (2.34 g, 21 mmol) and ethyltriphenylphosphonium bromide (7.67 g, 21 mmol) into a flask. Evacuate the flask, add an appropriate amount of anhydrous tetrahydrofuran, stir at room temperature for 1 h, add a pre - prepared tetrahydrofuran solution of epiandrosterone (1 g, 3.5 mmol), stir at room temperature for 3 h, and monitor the completion of the reaction by TLC. Add saturated ammonium chloride (NH4Cl) solution to quench the reaction, extract with ethyl acetate (3×100 ml), wash with saturated sodium chloride NaCl(aq), dry the organic layer with anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain a crude product. Purify it by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate = 5∶1 to obtain Compound 1.

[0102] 2. Synthesis of Compound 2

[0103] Add BH3 - Me2S (7.5 mL, 10 M, 75.0 mmol) to a THF (100 mL) solution of Compound 1 (5 g, 15.0 mmol). After stirring at 25℃ for 2 h, add ethanol (10 mL), NaOH (30 mL, 5 M), and H2O2 (15 mL, 10 M). After stirring at 60℃ for 1 h, quench the mixture with Na2S2O3 (400 mL, 10%), and extract with ethyl acetate (2×300 mL). Wash the synthesized organic solution with saturated sodium chloride (300 mL), dry with Na2SO4, filter and concentrate to obtain Compound 2.

[0104] 3. Synthesis of Compound 3

[0105] Compound 2 (1 g, 2 mmol) and PCC (2.76 g, 8 mmol) were added to DCM (100 mL) along with an appropriate amount of silica gel, and the mixture was stirred at room temperature for 3 h. The mixture was filtered, and the filter cake was washed with DCM. The solvent was recovered under reduced pressure, and silica gel column chromatography was performed to obtain compound 3.

[0106] 4. Synthesis of compound 4a

[0107] Compound 3 (100 mg, 0.32 mmol) was placed in a 25 mL flask, 1 mL of acetic acid was added, and aniline (23.70 μL, 0.26 mmol) was added by injection. The mixture was stirred overnight, and sodium borohydride (22.70 mg, 0.6 mmol) was added slowly in portions. The mixture was stirred at room temperature for 2 h, acetic acid was removed under reduced pressure, water was added to the solid, and the pH was adjusted to 2 - 3 with dilute hydrochloric acid. The mixture was extracted with ethyl acetate, and the organic layer was adjusted to neutral or weakly alkaline with dilute sodium hydroxide solution. The organic layer was extracted and concentrated under reduced pressure to obtain a crude product, which was purified by silica gel chromatography with a mobile phase of petroleum ether∶ethyl acetate to obtain compound 4.

[0108] Synthesis of compounds 4b - 4h / 4a' / 4c' / 4d' / 4f' / 4g': According to the synthesis procedure of compound 4a above, compound 3 was reacted with aniline to obtain compound 4a'; with p - toluidine to obtain compound 4b; with p - anisidine to obtain compounds 4c and 4c'; with p - chloroaniline to obtain compounds 4d and 4d'; with o - toluidine to obtain compound 4e; with m - toluidine to obtain compounds 4f and 4f'; with m - anisidine to obtain compounds 4g and 4g'; with o - anisidine to obtain compound 4h.

[0109] 5. Synthesis of compounds 5a - 5h

[0110] Compound 4a (50 mg, 0.13 mmol) was placed in a 25 mL flask, iodomethane (22.98 μL, 0.39 mmol), anhydrous DMF (2 mL) were added, and sodium hydride (3.12 mg, 0.13 mmol) was added. The temperature of the reaction system was controlled at 60℃ - 70℃ and the reaction was carried out for 3 h. The reaction was monitored by TLC until completion, and then cooled to room temperature. DMF was evaporated under reduced pressure, and the mixture was extracted with chloroform (3×20 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain a crude product, which was purified by silica gel chromatography with a mobile phase of petroleum ether∶ethyl acetate to obtain compound 5a.

[0111] Synthesis of Compounds 5b - 5h: Operate according to the above synthesis procedure of Compound 5a, react with Compound 4b to obtain Compound 5b; react with Compound 4c to obtain Compound 5c; react with Compound 4d to obtain Compound 5d; react with Compound 4e to obtain Compound 5e; react with Compound 4f to obtain Compound 5f; react with Compound 4g to obtain Compound 5g; react with Compound 4h to obtain Compound 5h.

[0112] 6. Synthesis of Compounds 6a - 6c / 6f

[0113] Place 4a (50 mg, 0.13 mmol) in a 25 mL flask, add bromoethane (29.09 μL, 0.39 mmol), anhydrous potassium carbonate (17.97 mg, 0.13 mmol), displace with nitrogen three times for protection, add 2 mL of anhydrously treated DMF, heat the system to control the temperature at 60 °C - 70 °C, monitor the reaction completion by TLC, cool to room temperature, remove DMF by rotary evaporation under reduced pressure, add water, extract with chloroform (3 × 20 mL), combine the organic phases, wash with saturated brine, dry over anhydrous magnesium sulfate, filter, concentrate under reduced pressure to obtain the crude product, and purify by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate to obtain Compound 6a.

[0114] Synthesis of Compounds 6b, 6c, 6f: Operate according to the above synthesis procedure, react with Compound 4b to obtain Compound 6b; react with Compound 4c to obtain Compound 6c; react with Compound 4f to obtain Compound 6f.

[0115] Compound 1: White powder, yield 95%. 1 H-NMR (600 MHz, CDCl3) δ 5.13–5.08 (1H, m), 3.62–3.56 (1H, m), 2.35 (1H, ddt, J = 16.7, 9.1, 1.9 Hz), 2.24 (1H, dt, J = 12.7, 3.5 Hz), 2.19–2.12 (1H, m), 1.80 (1H, dt, J = 14.0, 3.3 Hz), 1.71 (2H, dq, J = 12.0, 3.8 Hz), 1.64 (3H, d, J = 7.4, 1.9 Hz), 1.61–1.47 (5H, m), 1.39 (3H, dddd, J = 19.7, 12.7, 8.1, 4.0 Hz), 1.28 (3H, t, J = 11.6 Hz), 1.20–1.08 (3H, m), 0.95 (2H, dtd, J = 30.4, 12.8, 12.0, 5.0 Hz), 0.86 (3H, s), 0.81 (3H, s), 0.67 (1H, ddd, J = 12.8, 10.5, 4.1 Hz); 1313C-NMR (150 MHz, CDCl3) δ 150.6, 113.4, 71.5, 56.4, 54.5, 45.0, 44.5, 38.3, 37.4, 37.1, 35.7, 35.2, 32.1, 31.7, 31.6, 28.8, 24.5, 21.6, 17.0, 13.2, 12.4.

[0116] The structural formula of Compound 1 is as follows:

[0117]

[0118] Compound 2: White powder, yield 95%. 1 1H-NMR (400 MHz, CD3OD) δ 3.69–3.59 (1H, m), 3.56–3.47 (1H, m), 2.13 (1H, dt, J = 12.8, 3.4 Hz), 1.82–1.57 (6H, m), 1.56–1.49 (2H, m), 1.46–1.34 (3H, m), 1.33–1.26 (4H, m), 1.22–1.12 (4H, m), 1.10 (3H, d, J = 6.1 Hz), 1.04–0.90 (3H, m), 0.84 (3H, s), 0.82 (1H, s), 0.75 (3H, s), 0.71–0.63 (1H, m); 13 13C-NMR (100 MHz, CD3OD) δ 71.9, 70.9, 59.5, 57.5, 56.0, 46.3, 43.8, 41.0, 38.9, 38.3, 36.8, 36.7, 33.4, 32.2, 30.0, 26.8, 25.7, 23.8, 22.2, 12.8.

[0119] The structural formula of Compound 2 is as follows:

[0120]

[0121] Compound 3: White powder, yield 71%. 1 1H-NMR (400 MHz, CDCl3) δ 2.52 (1H, t, J = 8.9 Hz), 2.43–2.22 (4H, m), 2.11 (4H, s), 2.07–1.97 (3H, m), 1.80–1.60 (6H, m), 1.44–1.31 (6H, m), 1.28–1.11 (4H, m), 1.00 (3H, s), 0.98 (1H, s), 0.92 (1H, s), 0.78 (1H, td, J = 11.5, 10.8, 4.3 Hz), 0.63 (3H, s); 1313C-NMR (100 MHz, CDCl3) δ 212.1, 209.7, 63.9, 56.6, 53.8, 46.8, 44.8, 44.3, 39.1, 38.7, 38.3, 35.8, 35.5, 31.8, 31.6, 28.9, 24.5, 23.0, 21.6, 13.6, 11.6.

[0122] The structural formula of Compound 3 is as follows:

[0123]

[0124] Compound 4a: Colorless transparent needle crystals, yield 67%. HR-ESI-MS m / z calcd for C 27 H 40 NO ([M + H] + ) 394.3104, found 394.3101; 1 1H-NMR (400 MHz, CDCl3) δ 7.16 (2H, ddd, J = 9.0, 7.3, 2.0 Hz), 6.72–6.56 (3H, m), 3.67 (1H, p, J = 3.3 Hz), 2.57–2.47 (1H, m), 2.11 (3H, s), 1.84–1.04 (24H, m), 0.83 (3H, d, J = 6.3 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 210.0, 147.4, 129.4, 116.8, 113.8, 113.0, 63.9, 56.9, 54.4, 45.7, 44.4, 40.4, 39.2, 36.2, 35.9, 33.0, 32.6, 32.0, 31.7, 28.7, 25.9, 22.8, 21.3, 20.9, 13.6, 12.5, 11.6. See Figure 1a - 1b .

[0125] The structural formula of Compound 4a is as follows:

[0126]

[0127] Compound 4a': White powder, yield 19%. HR-ESI-MS m / z calcd for C 27 H 40 NO ([M + H] + ) 394.3104, found 394.3101; 11H-NMR (400 MHz, CDCl3) δ 7.20–7.13 (2H, m), 6.70–6.55 (3H, m), 3.66 (1H, p, J = 3.2 Hz), 2.53 (1H, t, J = 8.9 Hz), 2.20–2.13 (1H, m), 2.11 (3H, s), 2.05–1.97 (1H, m), 1.74 (2H, dt, J = 10.0, 3.6 Hz), 1.64 (5H, ddt, J = 21.1, 11.9, 3.8 Hz), 1.53 (3H, dt, J = 13.5, 3.9 Hz), 1.36 (3H, ddd, J = 17.9, 10.4, 3.7 Hz), 1.30–1.11 (7H, m), 0.96–0.89 (1H, m), 0.83 (3H, s), 0.81–0.76 (1H, m), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 129.4, 113.1, 64.0, 56.9, 54.5, 44.4, 40.4, 39.2, 36.3, 35.6, 33.1, 32.7, 32.1, 31.7, 28.6, 25.9, 24.5, 22.9, 20.9, 13.6, 11.6. See Figure 9a - 9b .

[0128] The structural formula of compound 4a' is as follows:

[0129]

[0130] Compound 4b: Colorless transparent block crystals, yield 51%. HR-ESI-MS m / z calcd for C 28 H 42 NO ([M + H] + ) 408.3261, found 408.3256; 1 1H-NMR (400 MHz, CDCl3) δ 6.98 (2H, d, J = 8.1 Hz), 6.55 (2H, d, J = 8.1 Hz), 3.64 (1H, q, J = 3.1 Hz), 2.52 (1H, t, J = 9.0 Hz), 2.23 (3H, s), 2.20–2.13 (1H, m), 2.11 (3H, s), 2.00 (1H, dt, J = 11.8, 3.3 Hz,), 1.78–1.45 (10H, m), 1.45–1.24 (5H, m), 1.24–1.11 (5H, m), 0.98–0.86 (1H, m), 0.83 (3H, s), 0.61 (3H, s); 1313C-NMR (100 MHz, CDCl3) δ 209.9, 145.2, 129.9, 113.3, 64.0, 56.9, 54.5, 47.8, 44.4, 40.4, 39.2, 36.2, 35.6, 33.0, 32.7, 32.1, 31.7, 28.6, 25.9, 24.5, 22.9, 20.9, 20.5, 13.6, 11.6. See Figure 2a - 2b 。

[0131] The structural formula of compound 4b is as follows:

[0132]

[0133] Compound 4c: Colorless transparent block crystals, yield 51%. HR-ESI-MS m / z calcd for C 28 H 42 NO2 ([M+H] + ) 424.3210, found 424.3207; 1 1H-NMR (400 MHz, CDCl3) δ 6.78 (2H, d, J = 8.1 Hz), 6.61 (2H, s), 3.74 (3H, s), 3.58 (1H, q, J = 3.9, 3.5 Hz), 2.52 (1H, t, J = 8.9 Hz), 2.11 (3H, s), 2.00 (1H, dt, J = 11.8, 3.3 Hz,), 1.80–1.45 (10H, m), 1.45–1.11 (10H, m), 0.98–0.86 (1H, m), 0.82 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 115.1, 64.0, 56.9, 56.0, 54.4, 44.4, 39.2, 36.2, 35.6, 33.0, 32.1, 31.7, 28.6, 24.5, 22.9, 20.9, 13.6, 11.6. See Figure 3a - 3b 。

[0134] The structural formula of compound 4c is as follows:

[0135]

[0136] Compound 4c': White powder, yield 13%. HR-ESI-MS m / z calcd for C 28 H 42 NO2 ([M+H] + ) 424.3210, found 424.3206; 11H-NMR (400 MHz, CDCl3) δ 6.79 (4H, d, J = 8.3 Hz), 3.76 (3H, s), 3.55 (1H, s), 2.53 (1H, t, J = 8.7 Hz), 2.11 (4H, s), 2.02–1.95 (2H, m), 1.75–1.50 (11H, m), 1.34–1.23 (16H, m), 0.99–0.83 (7H, m), 0.80 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.6, 114.7, 63.7, 56.4, 55.6, 44.1, 38.8, 35.9, 35.3, 31.4, 31.3, 30.0, 29.5, 28.2, 24.2, 22.6, 20.6, 13.3, 11.3. See Figure 10a - 10b .

[0137] The structural formula of compound 4c' is as follows:

[0138]

[0139] Compound 4d: Colorless transparent block crystals, yield 67%. HR-ESI-MS m / z calcd for C 27 H 39 NOCl ([M + H] + ) 428.2715, found 428.2714; 1 1H-NMR (400 MHz, CDCl3) δ 7.13–7.06 (2H, m), 6.57–6.47 (2H, m), 3.61 (1H, t, J = 3.2 Hz), 2.52 (1H, t, J = 9.0 Hz), 2.11 (3H, s), 1.79–1.57 (7H, m), 1.56–1.00 (15H, m), 0.82 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.8, 129.2, 114.2, 64.0, 60.5, 56.9, 54.5, 44.4, 40.4, 39.2, 36.2, 35.6, 33.0, 32.5, 32.0, 31.7, 28.6, 25.7, 24.5, 22.9, 20.9, 13.6, 11.6. See Figure 4a - 4b .

[0140] The structural formula of compound 4d is as follows:

[0141]

[0142] Compound 4d': A white crystalline powder with a yield of 17%. HR-ESI-MS m / z calcd for C 27 H 39 NOCl([M+H] + ) 428.2715, found 428.2710; 1 1H-NMR (400 MHz, CDCl3) δ 7.09 (2H, dd, J = 8.7, 1.8 Hz), 6.51 (2H, dd, J = 10.2, 7.8 Hz), 3.19 (1H, td, J = 11.0, 4.4 Hz), 2.79 (1H, dt, J = 8.5, 2.9 Hz), 2.12 (3H, d, J = 3.5 Hz), 1.89 (2H, tq, J = 9.6, 2.5 Hz), 1.81–1.64 (6H, m), 1.63–1.51 (3H, m), 1.37–1.20 (9H, m), 1.18–1.06 (4H, m), 0.90 (3H, s), 0.80 (3H, d, J = 6.7 Hz); 13 13C-NMR (100 MHz, CDCl3) δ 213.1, 129.2, 114.7, 114.2, 61.5, 53.8, 50.4, 45.9, 45.6, 40.3, 37.7, 35.9, 35.8, 35.5, 33.0, 32.3, 29.8, 29.2, 28.7, 26.0, 25.7, 24.4, 21.2, 21.1, 20.9, 12.4, 11.6. See Figure 11a - 11b .

[0143] The structural formula of Compound 4d' is as follows:

[0144]

[0145] Compound 4e: A colorless transparent block crystal with a yield of 41%. HR-ESI-MS m / z calcd for C 28 H 42 NO([M+H] + ) 408.3261, found 408.3258; 11H-NMR (400 MHz, CDCl3) δ 7.13–7.02 (2H, m), 6.60 (2H, d, J = 10.3 Hz), 3.30 (1H, s), 2.56–2.49 (1H, m), 2.16 (2H, d, J = 9.5 Hz), 2.12 (4H, s), 2.0 (2H, dt, J = 11.5, 3.3 Hz), 1.81–1.49 (9H, m), 1.45–1.14 (13H, m), 0.84 (3H, d, J = 2.5 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 130.3, 127.2, 64.0, 56.9, 54.5, 45.8, 44.4, 39.2, 36.1, 35.6, 35.6, 32.1, 32.1, 31.7, 29.8, 28.7, 24.6, 24.5, 22.9, 21.3, 17.8, 13.6, 12.6. See Figure 5a - 5b .

[0146] The structural formula of compound 4e is as follows:

[0147]

[0148] Compound 4f: Colorless transparent block crystals, yield 47%. HR-ESI-MS m / z calcd for C 27 H 42 NO ([M + H] + ) 408.3261, found 408.3261; 1 1H-NMR (400 MHz, CDCl3) δ 7.06 (1H, t, J = 8.5, 7.4 Hz), 6.57–6.38 (3H, m), 3.30–3.20 (1H, m), 2.53 (1H, t), 2.27 (3H, s), 2.12 (4H, s), 2.05–1.92 (2H, m), 1.80–1.46 (8H, m), 1.46–1.00 (12H, m), 0.99–0.85 (2H, m), 0.82 (3H, d, J = 6.5 Hz), 0.77–0.68 (1H, m), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 210.0, 139.2, 129.3, 129.3, 64.0, 56.8, 54.4, 45.7, 44.4, 39.2, 37.7, 36.2, 35.9, 35.6, 32.1, 31.7, 28.6, 24.5, 22.9, 21.8, 21.3, 13.6, 12.5, 11.6. See Figure 12a - 12b .

[0149] The structural formula of compound 4f is as follows:

[0150]

[0151] Compound 4f': Colorless transparent block crystals, yield 17%. HR-ESI-MS m / z calcd for C 27 H 42 NO([M+H] + ) 408.3260, found 408.3255; 1 1H NMR (400 MHz, CDCl3) δ 7.14–7.03 (2H, m), 6.61 (2H, q, J = 5.8, 4.1 Hz), 3.76–3.72 (1H, m), 2.52 (1H, t, J = 8.9 Hz), 2.18 (3H, s), 2.12 (4H, s), 2.01 (1H, dt, J = 11.8, 3.3 Hz), 1.77 (2H, dt, J = 10.9, 3.6 Hz), 1.71–1.60 (4H, m), 1.59–1.51 (4H, m), 1.46–1.14 (13H, m), 0.85 (3H, s), 0.61 (3H, s); 13 13C NMR (100 MHz, CDCl3) δ 209.9, 130.4, 127.3, 64.0, 56.9, 54.7, 44.4, 40.7, 39.2, 36.3, 35.6, 33.4, 32.6, 32.0, 31.7, 28.6, 26.1, 24.5, 22.9, 21.0, 17.7, 13.6, 11.7. See Figure 12a - 12b .

[0152] The structural formula of compound 4f' is as follows:

[0153]

[0154] Compound 4g: Colorless transparent block crystals, yield 39%. HR-ESI-MS m / z calcd for C 28 H 42 NO2([M+H] + ) 424.3210, found 424.3206; 11H-NMR (400 MHz, CDCl3) δ 7.08 (1H, t, J = 8.0 Hz), 6.28 (3H, s), 3.77 (3H, s), 2.52 (1H, t, J = 8.9 Hz), 2.11 (3H, s), 2.00 (1H, dt, J = 12.0, 3.3 Hz), 1.80–1.48 (11H, m), 1.45–1.30 (4H, m), 1.29–1.12 (6H, m), 0.91 (1H, p, J = 5.7, 4.9 Hz), 0.82 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 161.0, 130.2, 64.0, 56.9, 55.3, 44.4, 39.2, 36.2, 35.6, 32.0, 31.7, 28.5, 24.5, 22.9, 20.9, 13.6, 11.6. See Figure 7a - 7b .

[0155] The structural formula of compound 4g is as follows:

[0156]

[0157] Compound 4g': White powder, yield 13%. HR-ESI-MS m / z calcd for C 28 H 42 NO2 ([M + H] + ) 424.3210, found 424.3206; 1 1H-NMR (400 MHz, CDCl3) δ 7.01–6.52 (4H, m), 3.87 (3H, d, J = 7.9 Hz), 3.28 (1H, s), 2.52 (1H, t, J = 8.8 Hz), 2.11 (3H, s), 1.99 (2H, dd, J = 14.2, 10.4 Hz), 1.79–1.47 (12H, m), 1.44–1.12 (13H, m), 0.83 (3H, d, J = 3.1 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 157.9, 132.4, 121.5, 68.2, 66.2, 65.6, 64.0, 58.5, 57.5, 56.9, 55.7, 44.4, 39.2, 36.3, 35.6, 31.7, 25.3, 24.5, 22.9, 21.5, 21.4, 13.6, 12.5. See Figure 13a - 13b .

[0158] The structural formula of compound 4g' is as follows:

[0159]

[0160] Compound 4h: Colorless transparent block crystals, yield 56%. HR-ESI-MS m / z calcd for C 28 H 42 NO2([M+H] + ) 424.3002, found 424.3002; 1 1H-NMR (400 MHz, CDCl3) δ 7.09 (2H, dq, J = 15.1, 7.4, 6.6 Hz), 6.81 (2H, dd, J = 27.8, 7.3 Hz), 3.28 (1H, s), 2.52 (1H, t, J = 8.8 Hz), 2.11 (4H, d, J = 11.0 Hz), 2.00 (2H, d, J = 11.6 Hz), 1.80–1.48 (10H, m), 1.45–1.12 (14H, m), 0.89 (1H, d, J = 10.8 Hz), 0.84 (3H, d, J = 4.5 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 153.7, 127.6, 126.1, 64.0, 56.9, 54.4, 45.7, 44.4, 39.2, 36.0, 35.6, 32.1, 31.7, 29.8, 28.6, 24.5, 22.9, 21.3, 13.6, 12.5, 11.7. See Figure 8a - 8b .

[0161] The structural formula of compound 4h is as follows:

[0162]

[0163] Compound 5a: White powder, yield 42%. HR-ESI-MS m / z calcd for C 28 H 42 NO([M+H] + ) 408.3261, found 408.3257; 1H-NMR (400 MHz, CDCl3) δ 7.25–7.19 (2H, m), 6.97–6.83 (1H, m), 6.77 (1H, d, J = 8.1 Hz), 6.68 (1H, t, J = 7.3 Hz), 2.82 (3H, d, J = 25.3 Hz), 2.56–2.49 (1H, m), 2.17 (1H, tdd, J = 10.1, 4.3, 2.5 Hz), 2.12 (3H, s), 2.01 (1H, dt, J = 11.7, 3.4 Hz), 1.80 (1H, dt, J = 12.9, 3.5 Hz), 1.74–1.57 (7H, m), 1.50 (2H, d, J = 10.1 Hz), 1.46–1.32 (4H, m), 1.31–1.13 (6H, m), 1.01–0.89 (1H, m), 0.83 (3H, d, J = 6.3 Hz), 0.61 (3H, d, J = 3.1 Hz); 13 C-NMR (100 MHz, CDCl3) δ 209.9, 129.2, 129.0, 119.8, 119.1, 116.4, 113.3, 64.0, 58.5, 56.9, 54.4, 46.4, 44.4, 39.2, 38.1, 35.9, 35.7, 32.1, 31.7, 28.9, 28.7, 25.1, 24.6, 22.9, 21.3, 21.0, 13.6, 12.6. See Figure 14a - 14b .

[0164] The structural formula of compound 5a is as follows:

[0165]

[0166] Compound 5b: Yellow powder, yield 53%. HR-ESI-MS m / z calcd for C 29 H 44 NO([M + H] + ) 422.3417, found 422.3414; 11H-NMR (400 MHz, CDCl3) δ 7.07 (2H, d, J = 8.2 Hz), 6.92 (2H, d), 2.75 (3H, s), 2.53 (1H, t, J = 8.9 Hz), 2.29 (3H, s), 2.11 (3H, s), 2.00 (1H, dt, J = 11.9, 3.4 Hz), 1.76 (1H, d, J = 14.6 Hz), 1.69–1.52 (10H, m), 1.44–1.34 (5H, m), 1.27 (5H, d, J = 11.1 Hz), 1.19–1.11 (4H, m), 0.81 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 207.4, 147.8, 128.1, 127.0, 118.8, 61.4, 54.4, 52.6, 52.1, 41.9, 38.1, 37.5, 36.7, 33.4, 33.1, 31.5, 29.6, 29.3, 29.1, 27.2, 26.1, 22.4, 21.9, 20.3, 18.4, 18.2, 11.0, 9.7. See Figure 15a - 15b .

[0167] The structural formula of compound 5b is as follows:

[0168]

[0169] Compound 5c: Yellow powder, yield 41%. HR-ESI-MS m / z calcd for C 29 H 44 NO2([M + H] + ) 438.3367, found 438.3366; 1 1H-NMR (400 MHz, CDCl3) δ 7.08–7.02 (2H, m) 6.86–6.80 (2H, m), 3.78 (3H, s), 2.65 (3H, s), 2.53 (1H, t, J = 8.8 Hz), 2.11 (3H, s), 1.99 (1H, dt, J = 12.0, 3.4 Hz), 1.72–1.56 (8H, m), 1.46–1.23 (9H, m), 1.22–1.07 (5H, m), 0.80 (3H, s), 0.60 (3H, s); 1313C-NMR (100 MHz, CDCl3) δ 210.0, 155.8, 147.0, 125.1, 114.2, 64.0, 57.4, 57.0, 55.6, 54.6, 44.5, 42.5, 39.6, 39.3, 36.2, 35.7, 33.4, 32.2, 31.9, 31.7, 28.6, 25.1, 24.5, 22.9, 21.0, 13.6, 12.3. See Figure 16a - 16b 。

[0170] The structural formula of compound 5c is as follows:

[0171]

[0172] Compound 5d: Yellow needle-like crystals, yield 59%. HR-ESI-MS m / z calcd for C 28 H 41 NOCl ([M + H] + ) 442.2871, found 442.2860; 1 1H-NMR (400 MHz, CDCl3) δ 7.14 (2H, d, J = 8.9 Hz), 6.67 (2H, d, J = 8.7 Hz), 3.61–3.51 (1H, m), 2.75 (3H, s), 2.53 (1H, t, J = 8.8 Hz), 2.11 (3H, s), 2.01 (1H, dt, J = 11.6, 3.2 Hz), 1.80 (1H, dt, J = 13.1, 3.5 Hz), 1.72–1.51 (9H, m), 1.43–1.14 (14H, m), 0.99–0.86 (2H, m), 0.83 (3H, s), 0.73 (1H, td, J = 11.4, 4.1 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 208.9, 129.0, 114.4, 100.9, 64.0, 58.8, 56.8, 54.4, 46.4, 44.4, 39.2, 38.6, 35.9, 35.6, 32.1, 31.7, 29.8, 28.8, 24.6, 22.9, 22.8, 21.3, 13.6, 12.6. See Figure 17a - 17b 。

[0173] The structural formula of compound 5d is as follows:

[0174]

[0175] Compound 5e: Yellow powder, yield 60%. HR-ESI-MS m / z calcd for C 29H 44 NO([M+H] + ) 422.3417, found 422.3415; 1 H-NMR (400 MHz, CDCl3) δ 7.20–7.10 (2H, m), 7.05 (1H, dd, J = 8.0, 1.4 Hz), 6.94 (1H, td, J = 7.3, 1.4 Hz), 2.66 (3H, s), 2.55–2.47 (2H, m), 2.28 (3H, s), 2.16 (1H, d, J = 3.9 Hz), 2.11 (4H, d, J = 2.2 Hz), 1.99 (1H, dt, J = 11.3, 3.0 Hz), 1.76–1.56 (10H, m), 1.40–1.16 (11H, m), 0.80 (3H, d, J = 3.6 Hz), 0.59 (3H, s); 13 C-NMR (100 MHz, CDCl3) δ 209.9, 152.3, 133.8, 131.2, 126.1, 122.6, 121.8, 64.0, 62.0, 56.9, 54.5, 46.2, 44.4, 39.3, 38.1, 36.0, 35.6, 35.1, 32.2, 31.7, 31.1, 28.9, 24.9, 24.5, 22.9, 21.3, 18.5, 13.6, 12.6. See Figure 18a - 18b 。

[0176] The structural formula of compound 5e is as follows:

[0177]

[0178] Compound 5f: yellow powder, yield 48%. HR-ESI-MS m / z calcd for C 29 H 44 NO([M+H] + ) 422.3417, found 422.3413; 11H-NMR (400 MHz, CDCl3) δ 7.10 (1H, t, J = 8.2 Hz), 6.58 (2H, s), 6.51 (1H, d, J = 7.4 Hz), 2.77 (3H, s), 2.53 (1H, t, J = 8.8 Hz), 2.31 (3H, s), 2.11 (3H, s), 2.01 (1H, dt, J = 11.5, 3.1 Hz), 1.80 (1H, d, J = 13.0 Hz), 1.72–1.53 (8H, m), 1.44–1.31 (4H, m), 1.31–1.20 (5H, m), 1.17 (2H, p, J = 5.8 Hz), 0.92 (1H, d, J = 11.7 Hz), 0.84 (3H, s), 0.74 (1H, t, J = 10.8 Hz), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 150.8, 138.9, 129.1, 117.4, 114.1, 110.6, 77.4, 64.0, 58.5, 56.9, 54.5, 46.4, 44.4, 39.2, 38.1, 37.8, 35.9, 35.7, 32.2, 31.7, 28.9, 25.1, 24.6, 22.9, 22.1, 21.3, 13.6, 12.6. See Figure 19a - 19b .

[0179] The structural formula of compound 5f is as follows:

[0180]

[0181] Compound 5g: Yellow powder, yield 42%. HR-ESI-MS m / z calcd for C 29 H 44 NO2([M + H] + ) 438.3367, found 438.3363; 1H-NMR (400 MHz, CDCl3) δ 7.18–7.10 (1H, m), 6.55–6.23 (3H, m), 3.79 (3H, d, J = 1.3 Hz), 2.89–2.75 (3H, m), 2.53 (1H, td, J = 8.9, 4.3 Hz), 2.11 (3H, d, J = 1.2 Hz), 2.04–1.97 (1H, m), 1.84–1.76 (1H, m), 1.76–1.56 (6H, m), 1.55–1.44 (3H, m), 1.39–1.33 (2H, m), 1.31–1.22 (5H, m), 1.22–1.09 (4H, m), 0.91 (1H, d, J = 2.7 Hz), 0.85–0.79 (3H, m), 0.61 (2H, d, J = 2.3 Hz); 13 C-NMR (100 MHz, CDCl3) δ 209.9, 160.5, 129.8, 129.5, 110.9, 104.4, 103.9, 63.9, 64.0, 56.9, 55.2, 44.4, 40.8, 39.2, 38.1, 35.8, 35.8, 35.6, 32.1, 31.9, 31.6, 28.7, 24.9, 24.5, 22.9, 21.0, 13.6, 12.4. See Figure 20a - 20b .

[0182] The structural formula of compound 5g is as follows:

[0183]

[0184] Compound 5h: yellow powder, yield 42%. HR-ESI-MS m / z calcd for C 29 H 44 NO2 ([M + H] + ) 438.3367, found 438.3368; 1 H-NMR (400 MHz, CDCl3) δ 6.96 (2H, td, J = 9.4, 2.0 Hz), 6.91–6.82 (2H, m), 3.85 (3H, s), 2.73 (3H, s), 2.51 (1H, t, J = 8.9 Hz), 2.10 (4H, s), 1.99 (1H, dt, J = 11.4, 3.1 Hz), 1.78–1.56 (9H, m), 1.42–1.20 (9H, m), 1.17–1.04 (3H, m), 0.99–0.86 (2H, m), 0.80 (3H, s), 0.60 (3H, s); 1313C-NMR (100 MHz, CDCl3) δ 209.9, 153.2, 142.0, 122.5, 121.2, 120.6, 111.4, 64.0, 61.3, 56.9, 55.6, 54.5, 46.2, 44.4, 39.3, 38.2, 35.9, 35.6, 33.9, 32.2, 31.7, 30.8, 28.9, 24.7, 24.5, 22.9, 21.3, 13.6, 12.5. See Figure 21a - 21b 。

[0185] The structural formula of compound 5h is as follows:

[0186]

[0187] Compound 6a: White powder, yield 23%. HR-ESI-MS m / z calcd for C 29 H 44 NO([M + H] + ) 422.3417, found 422.3413; 1 1H-NMR (400 MHz, CDCl3) δ 7.25–7.21 (2H, m), 7.01–6.95 (2H, m), 6.90 (1H, ddd, J = 7.3, 6.2, 1.1 Hz), 3.25 (2H, q, J = 7.0 Hz), 2.52 (1H, t, J = 8.9 Hz), 2.11 (3H, s), 1.99 (1H, dt, J = 11.9, 3.3 Hz), 1.81–1.74 (1H, m), 1.68–1.58 (4H, m), 1.57 (2H, d, J = 3.0 Hz), 1.46 (1H, d, J = 3.7 Hz), 1.43–1.39 (1H, m), 1.34 (4H, tt, J = 8.1, 4.2 Hz), 1.29 (1H, t, J = 3.2 Hz,), 1.26 (3H, s), 1.17 (2H, td, J = 6.6, 6.1, 2.6 Hz), 1.14–1.09 (2H, m), 0.97–0.89 (4H, m), 0.81 (3H, s), 0.60 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 210.0, 150.2, 128.7, 122.5, 120.8, 64.1, 57.0, 54.7, 51.5, 45.1, 44.5, 40.0, 39.3, 36.0, 35.7, 33.9, 32.2, 31.7, 31.7, 28.7, 24.8, 24.5, 22.9, 21.0, 13.6, 12.5, 11.7. See Figure 22a - 22b 。

[0188] The structural formula of Compound 6a is as follows:

[0189]

[0190] Compound 6b: White powder, yield 19%. HR-ESI-MS m / z calcd for C 30 H 46 NO([M+H] + ) 436.3574, found 436.3573; 1 1H-NMR (400 MHz, CDCl3) δ 7.02 (2H, d, J = 8.2 Hz), 6.66 (2H, d, J = 8.5 Hz), 3.23 (2H, q, J = 7.0 Hz), 2.53 (1H, t, J = 8.9 Hz), 2.24 (3H, s), 2.12 (3H, s), 2.01 (2H, dt, J = 11.8, 3.2 Hz), 1.78 (1H, dd, J = 13.1, 3.5 Hz), 1.63 (10H, dddd, J = 29.6, 12.5, 9.4, 3.3 Hz), 1.42 (2H, s), 1.29 (4H, d, J = 3.5 Hz), 1.26 (10H, d, J = 3.8 Hz), 1.13 (4H, t, J = 7.0 Hz), 0.83 (4H, s), 0.61 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 209.9, 146.5, 129.8, 125.3, 113.7, 64.0, 58.2, 56.9, 54.5, 46.5, 44.4, 39.6, 39.2, 38.2, 36.0, 35.7, 32.5, 31.7, 29.8, 29.4, 28.9, 25.8, 24.6, 22.9, 21.3, 20.3, 15.4, 14.3, 13.6, 12.7. See Figure 23a - 23b .

[0191] The structural formula of Compound 6b is as follows:

[0192]

[0193] Compound 6c: White powder, yield 22%. HR-ESI-MS m / z calcd for C 30 H 46 NO2([M+H] + ) 452.3528, found 452.3520; 11H-NMR (400 MHz, CDCl3) δ 7.05–7.00 (2H, m), 6.84–6.79 (2H, m), 3.78 (3H, s), 3.01 (2H, q, J = 7.0 Hz), 2.52 (1H, t, J = 8.8 Hz), 2.11 (3H, s), 1.99 (1H, dt, J = 12.0, 3.4 Hz), 1.62 (8H, dtd, J = 23.5, 9.9, 8.8, 3.6 Hz), 1.53–1.46 (1H, m), 1.44–1.13 (17H, m), 1.06 (2H, tt, J = 9.5, 3.8 Hz), 0.79 (3H, s), 0.59 (3H, s); 13 13C-NMR (100 MHz, CDCl3) δ 210.0, 155.7, 144.0, 127.3, 113.9, 64.1, 57.0, 55.5, 54.6, 53.7, 46.9, 44.5, 39.3, 39.3, 36.2, 35.7, 33.1, 32.3, 31.8, 31.7, 28.6, 25.0, 24.5, 22.9, 21.0, 13.6, 12.3, 11.5. See Figure 24a - 24b .

[0194] The structural formula of compound 6c is as follows:

[0195]

[0196] Compound 6f: White powder, yield 17%. HR-ESI-MS m / z calcd for C 30 H 46 NO([M + H] + ) 436.3574, found 436.3576; 1 1H-NMR (400 MHz, CDCl3) δ 7.13–7.05 (1H, m), 6.54 (2H, d, J = 6.6 Hz), 6.48 (1H, d, J = 7.4 Hz), 3.26 (2H, q, J = 7.0 Hz), 2.54 (1H, t, J = 8.7 Hz), 2.30 (3H, s), 2.12 (3H, s), 2.04–1.99 (1H, m), 1.83–1.77 (1H, m), 1.73–1.56 (8H, m), 1.46–1.41 (4H, m), 1.31–1.24 (13H, m), 1.16 (5H, t, J = 7.0 Hz), 0.84 (3H, s), 0.61 (3H, s); 1313C-NMR (100 MHz, CDCl3) δ 209.9, 148.7, 139.0, 129.2, 116.8, 113.5, 110.0, 64.0, 57.6, 56.9, 54.5, 46.5, 44.4, 39.3, 38.2, 36.0, 35.7, 32.6, 32.2, 31.7, 29.8, 28.9, 25.8, 24.6, 22.9, 22.2, 21.3, 15.5, 13.6, 12.7. See Figure 25a - 25b .

[0197] The structural formula of compound 6f is as follows:

[0198]

[0199] Test Example 1: The present invention screened the cytotoxic activities of the newly synthesized C20-ketopregnane alkaloids against human liver cancer cells (HepG2, SK-Hep1) and human colorectal cancer cells (HCT116, SW480, DLD-1), and further illustrated the present invention through the following embodiments.

[0200] I. Study on the cytotoxic activity of the compounds of the present invention:

[0201] 1. Experimental principle: The full English name of CCK-8 is Cell Counting Kit-8. The main chemical drug is WST-8, with the chemical name of sodium 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt. Its core group is the same as that of MTT, and it is an upgraded version of MTT. In the presence of an electron coupling reagent (that is, the cells are alive, have respiration, and have energy metabolism), it can be oxidized and reduced by NAD+ to form a water-soluble yellow formazan product. The more live cells there are, the more formazan is produced and the darker the color will be.

[0202] 2. Experimental steps: Take cells in the logarithmic growth phase, digest them with 0.25% EDTA (1×) trypsin until the cells are in a suspended state, then add a serum-containing medium to dilute the trypsin concentration and terminate the digestion. Prepare a density of 2×10 4cells / mL single cell suspension was inoculated into 96-well plates at 100 μL / well. 100 μL of PBS buffer was added to the outer cell culture wells to reduce the influence of edge effects on the experimental results. It was statically cultured in an incubator at 37 °C and 5% CO2 for 24 h. After observing cell adhesion, 100 μL of culture medium containing the alkaloid derivative to be tested was added. The concentration range of the alkaloid derivative test solution was set as: 20, 10, 5, 2.5, 1.25, 0.625 μM, and 3 replicate wells were set for each concentration. Three wells with only cell culture medium were reserved as blank controls, and the culture medium wells with only DMSO without adding drugs were used as negative controls. After culturing for 72 h, the supernatant was discarded, 100 μL of CCK-8 working solution containing 10% CCK-8 was added, and it was continued to be placed in the incubator for 2 h. Then, the absorbance value was measured at a wavelength of 450 nm using an enzyme-linked immunosorbent detector. After all absorbance values were first subtracted by the blank control value, the relative cell inhibition rate of the experimental group drug was obtained by comparing with the control group value. The drug cell inhibition rate = [OD control - OD experiment] / [OD control - OD negative] × 100%. The concentration of the drug that can inhibit the cell growth rate by 50% of the same drug at different concentrations, that is, the half-maximal inhibitory concentration IC 50 . Since each alkaloid derivative at the same concentration occupies 3 wells in the 96-well plate, that is, the same concentration acts on cells three times on average and takes the average value, and each experiment is repeated three times. The obtained data was expressed as "mean + standard error" (mean + SEM), and significant analysis was performed by Student's t-test. A significant difference was considered when P < 0.05.

[0203] 3. Experimental results:

[0204] Table 1 IC of compounds against HepG2, SK-HEP-1, HCT-116, SW480, DLD-1 50 (Unit: μmol / mL)

[0205]

[0206] Note: * The IC of the compound 50 is better than the positive control

[0207] The test results of the target derivatives against liver cancer cells (HepG2, SK-Hep1) showed (Table 1): The IC 50 values of compounds 5b and 6c against HepG2 cells were 0.36 μmol / mL and 0.43 μmol / mL respectively, which were better than the positive control sorafenib; the IC 50Superior to the positive control sorafenib; The test results of the target derivatives against colorectal cancer cells (HCT116, SW480, DLD-1) show (Table 1): Compound 4c' has good inhibitory activity against both HCT116 and SW480 cells, and the IC 50 values are 0.04 μmol / mL and 0.22 μmol / mL respectively, both superior to the positive control; Compounds 4e, 4f, 4c', 5c, 5d, and 6b have significant inhibitory effects on colorectal cancer cell SW480.

[0208] Experimental Example 2: The present invention conducts in vitro anti-inflammatory activity screening on the newly synthesized C20-ketopregnane-type alkaloids, tests the activity effects of the synthesized derivatives on RAW264.7 cells, and then, from the perspective of inflammation theory, uses lipopolysaccharide to induce the mouse monocyte macrophage cell line (RAW264.7) to establish an inflammatory cell model. Subsequently, whether the synthesized compounds have anti-inflammatory effects is judged by detecting the nitric oxide release amount of the cells. And the present invention is further illustrated through the following implementation.

[0209] 1. Experimental principle: The basic principle of the CCK-8 method is the same as above. NO is extremely easy to be oxidized to NO2- in vivo or in an aqueous solution environment, etc. Under acidic conditions, NO can undergo a series of reactions to generate a special pink substance, which has a maximum absorption peak at 540 nm, and the NO concentration can be deduced from the OD value.

[0210] 2. Experimental steps:

[0211] (1) The experimental steps for the cytotoxicity of pregnane alkaloid derivatives against RAW264.7 cells are the same as above.

[0212] (2) Determination of NO secretion in RAW264.7 cells by the Griess method

[0213] Take cells in the logarithmic growth phase, prepare a single-cell suspension with a density of 1×10 5 cells / mL, inoculate 100 μL / well into a 96-well plate, and add 100 μL of PBS buffer to the outer cell culture wells to reduce the influence of edge effects on the experimental results. Incubate statically in a 37°C, 5% CO2 incubator for 20 h, and observe after the cells adhere. Add 100 μL of the culture medium containing the alkaloid derivatives to be tested. The concentration range of the alkaloid derivative test solution is set as: 200, 100, 50, 25, 12.5, 6.25 μM, and each concentration has 3 replicate wells. Leave three wells with only the cell culture medium as the normal group, and use the culture medium well with only DMSO added without drugs as the blank group. After incubating statically in a 37°C, 5% CO2 incubator for 1 h, add LPS with a concentration of 1 μg / mL to stimulate the production of inflammation, and finally place it in a 37°C, 5% CO2 incubator for 20 h.

[0214] Take out Griess Reagent I and II, allow them to return to room temperature, prepare a standard curve according to the reagent instruction manual. Add the standard products and samples into a new 96-well plate at 50 μL / well for the culture supernatant of the cells. Add Griess Reagent I to each well at 50 μl / well first, then add Griess Reagent II. Finally, measure the absorbance at 540 nm using an enzyme-linked immunosorbent assay (ELISA) reader, and calculate the concentration of nitric oxide in the sample according to the standard curve of the standard products.

[0215] 3. Experimental Results

[0216] The cell viability of C20-ketopregnane alkaloids on RAW264.7 cells was determined by the CCK8 assay at 6 different concentrations. As Figure 26 - 28 shown: For compounds 4a - 4h, except for compound 4b, the remaining compounds had no effect on macrophage RAW264.7 at doses of 100 μM - 6.25 μM; for compounds 5a - 5h, when the administration concentration of compound 5a was below 200, there was no significant difference compared with the normal group and no cytotoxicity. Compounds 5e, 5f, and 5h had no effect on macrophage RAW264.7 at doses below 25 μM; compounds 4a', 4c', 4d', 4g', and 4f' had no cytotoxicity only at the minimum concentration of about 6.25 μM; compound 6b had strong cytotoxicity; the safety concentration ranges of all target compounds varied greatly.

[0217] Nitric oxide (NO) is a signaling molecule that plays a key role in the pathogenesis of inflammation. It is a pro-inflammatory mediator that is over-secreted under abnormal conditions and then causes inflammation. When RAW264.7 cells are stimulated with lipopolysaccharide (LPS), a large amount of NO is released from the cells into the culture medium and exists in the form of nitrite, and the content of nitrite can be measured using Griess reagent. Since the cell viabilities of different compounds are different, we set different concentration gradients within their safe concentration ranges to explore the effects of the compounds on the NO expression levels in the RAW264.7 cell inflammation model stimulated with LPS (1 μg / mL) for 24 h. The experimental results showed that all compounds could reduce the secretion of NO to a certain extent. As Figure 29 - 31 shown: Among them, for compounds 4a and 4e, except at 12.5 μM, there was no significant difference compared with the model group at other administration concentrations, and they could inhibit the generation of NO; for compound 4h, except at 6.25 μM, there was no significant difference compared with the model group at other administration concentrations, and it could inhibit the generation of NO; for compound 4g', except at 200 μM, there was no significant difference compared with the model group at other administration concentrations, and it could inhibit the generation of NO.

[0218] Although the present invention has been described in detail above with general descriptions, specific embodiments and experiments, some modifications or improvements can be made thereto based on the present invention, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A C20 ketopregnane-type alkaloid derivative, characterized in that, The structural general formula is shown as (Ⅰ): The specific derivative compounds are 25 kinds, which are sequentially denoted as 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4a', 4c', 4d', 4f', 4g', 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 6a, 6b, 6c, 6f, and the corresponding relationships of R1 and R2 are as follows: 。 2. A method for synthesizing a C20 ketopregnane-type alkaloid derivative as described in claim 1, characterized in that, It includes the following steps: (1) Synthesis of compound 1: Weigh 2.34 g of potassium tert-butoxide and 7.67 g of ethyltriphenylphosphonium bromide respectively, add them to a flask, evacuate, add 15 mL of anhydrous tetrahydrofuran, stir at room temperature for 1 h, add a pre-prepared tetrahydrofuran solution of 3.5 mmol of epiandrosterone, stir at room temperature for 3 h, monitor the completion of the reaction by TLC, then add saturated ammonium chloride solution to the reaction solution to quench the reaction, extract with ethyl acetate 3 times, 100 mL each time, combine the extracts, wash with saturated brine 3 times, 100 mL each time, dry the organic layer with anhydrous magnesium sulfate, filter, concentrate under reduced pressure to obtain a crude product, and purify it by silica gel chromatography, with the mobile phase being petroleum ether∶ethyl acetate = 5∶1, to obtain compound 1; (2) Synthesis of compound 2: Add 7.5 mL of BH3-Me2S to a 100 mL THF solution of 15 g of compound 1, stir at 25 °C for 2 h, then dropwise add 10 mL of ethanol, 30 mL of NaOH, and 15 mL of H2O2, stir at 60 °C for 1 h, quench the mixture with 400 mL of 10% Na2S2O3 solution, and extract with ethyl acetate 2 times, 300 mL each time. Wash the synthesized organic solution with 300 mL of saturated brine, dry with Na2SO4, filter and concentrate to obtain compound 2; (3) Synthesis of compound 3: Weigh 1 g of compound 2 and 2.76 g of PCC, add an appropriate amount of silica gel to 100 mL of DCM, stir the mixture at room temperature for 3 h, filter the mixture, wash the filter cake with 100 mL of DCM 2 times, recover the solvent under reduced pressure, and perform silica gel column chromatography, with the mobile phase being petroleum ether∶ethyl acetate, to obtain compound 3; (4) Synthesis of compound 4a: Weigh 100 mg of compound 3 and place it in a 25 mL flask, add 1 mL of acetic acid, inject 23.70 μL of aniline, stir overnight, slowly add 22.70 mg of sodium borohydride in batches, stir at room temperature for 2 h, remove acetic acid under reduced pressure, add water to the solid, adjust the pH value to 2 - 3 with dilute hydrochloric acid, extract with ethyl acetate 3 times, 30 mL each time, adjust the organic layer to neutral or weakly alkaline with dilute sodium hydroxide solution, dry with Na2SO4, concentrate under reduced pressure to obtain a crude product, and purify it by silica gel chromatography, with the mobile phase being petroleum ether∶ethyl acetate, and perform gradient elution to obtain compound 4a; Synthesis of Compounds 4b - 4h / 4a' / 4c' / 4d' / 4f' / 4g': According to the synthesis procedure of Compound 4a described above, reacting Compound 3 with aniline gives Compound 4a'; reacting with p-toluidine gives Compound 4b; reacting with p-anisidine gives Compounds 4c and 4c'; reacting with p-chloroaniline gives Compounds 4d and 4d'; reacting with o-toluidine gives Compound 4e; reacting with m-toluidine gives Compounds 4f and 4f'; reacting with m-anisidine gives Compounds 4g and 4g'; reacting with o-anisidine gives Compound 4h; (5) Synthesis of Compound 5a: Weigh 50 mg of Compound 4a and place it in a 25 mL flask. Add 22.98 μL of methyl iodide and 2 mL of anhydrous DMF. Then add 3.12 mg of sodium hydride. Heat the system and control the temperature at 60°C - 70°C for 3 h. Monitor the completion of the reaction by TLC. After cooling to room temperature, evaporate DMF under reduced pressure. Extract with chloroform three times, 20 mL each time. Combine the organic phases, wash with saturated brine twice, 20 mL each time. Dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain the crude product. Purify by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate for gradient elution to obtain Compound 5a; Synthesis of Compounds 5b - 5h: According to the synthesis procedure of Compound 5a described above, reacting with Compound 4b gives Compound 5b; reacting with Compound 4c gives Compound 5c; reacting with Compound 4d gives Compound 5d; reacting with Compound 4e gives Compound 5e; reacting with Compound 4f gives Compound 5f; reacting with Compound 4g gives Compound 5g; reacting with Compound 4h gives Compound 5h; (6) Synthesis of Compound 6a: Weigh 50 mg of 4a and place it in a 25 mL flask. Add 29.09 μL of ethyl bromide and 17.97 mg of anhydrous potassium carbonate. Replace the air with nitrogen three times for protection. Then add 2 mL of anhydrous DMF. Heat the system and control the temperature at 60°C - 70°C. Monitor the completion of the reaction by TLC. After cooling to room temperature, evaporate DMF by rotary evaporation under reduced pressure. Add water and extract with chloroform three times, 20 mL each time. Combine the organic phases, wash with saturated brine twice, 20 mL each time. Dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain the crude product. Purify by silica gel chromatography with the mobile phase of petroleum ether∶ethyl acetate for gradient elution to obtain Compound 6a; Synthesis of Compounds 6b, 6c, 6f: According to the above synthesis procedure, reacting with Compound 4b gives Compound 6b; reacting with Compound 4c gives Compound 6c; reacting with Compound 4f gives Compound 6f.

3. The synthesis method of the C20 ketone pregnane-type alkaloid derivative according to claim 2, characterized in that, In the step (2), the molar ratio of BH3-Me2S to Compound 1 is 5∶1.

4. Use of the C20-oxo-pregnane alkaloid derivative according to Claim 1 in the preparation of anti-hepatocellular carcinoma, anti-colorectal cancer and anti-inflammatory drugs.

Images