A class of sarpagine-type indole alkaloid derivatives, their preparation methods and applications

Abstract

This invention belongs to the field of pharmaceutical technology, specifically relating to a class of sarpagine-type indole alkaloid derivatives, their preparation methods, and applications. The structural formula of this class of compounds is shown in formula (I). They exhibit good antitumor activity, low toxicity to normal cells, and are safe, effective, and low-toxicity candidate antitumor drugs.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to a class of sarpagine-type indole alkaloid derivatives, their preparation methods, and applications. Background Technology

[0002] Malignant tumors are one of the leading causes of death worldwide, posing a serious threat to human health. Current treatments include chemotherapy, radiotherapy, and surgery, but chemotherapy remains the primary treatment. Many chemical drugs are used to treat malignant tumors, such as nitrogen mustard, pyrimidines, platinum compounds, and porphyrins, but the application of most of these drugs is limited due to their high toxicity and low bioavailability. With the development of anti-tumor drugs, new anti-tumor drugs are constantly being developed and updated, playing a significant role in improving cure rates, prolonging survival time, and delaying disease progression. For many years, researchers have continuously developed new anti-tumor drugs and attempted to develop a series of new anti-tumor drug derivatives through structural modification.

[0003] Chemical structure modification of drugs is based on their original basic chemical structure. This involves chemically modifying certain functional groups or combining two or more chemical structures with the same or different activities to obtain new derivatives of these drugs. Structural modification can alter the original physicochemical properties and pharmacological activities, playing a crucial role in clinical applications. Sarpagine-type indole alkaloids, due to their complex structures and diverse physiological activities such as antitumor, antimalarial, anti-inflammatory, and antiarrhythmic effects, have attracted considerable attention from synthetic chemists, and the derivatization of sarpagine-type indole alkaloids holds great potential for innovative drug development. However, the limited variety and abundance of naturally occurring sarpagine-type indole alkaloids hinders the exploration of their mechanisms of action and subsequent drug development research.

[0004] Therefore, it is of great significance to develop a structural derivative that can achieve the diversity of sarpagine-type indole alkaloids. Summary of the Invention

[0005] To address the above problems, one objective of this invention is to provide a structurally modified sarpagine-type indole alkaloid derivative. This type of compound is prepared from L-tryptophan methyl ester hydrochloride via carbamylation, Kulinkovich cyclopropanation, and Bischler-Napieralski cyclization to obtain a cyclopropanol-imine. Subsequently, iron-promoted ring-opening addition of cyclopropanol to the imine achieves rapid construction of an indole-diaza-bridged cyclononane skeleton. Further multi-step transformations complete the final product. This compound, along with its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs, exhibits good antitumor activity and low toxicity to normal cells, making it a safe, effective, and low-toxicity candidate antitumor drug.

[0006] To achieve the above objectives, the present invention can adopt the following technical solutions:

[0007] In one aspect, this invention provides a derivative of the Sarpagine-type indole alkaloid represented by formula (I), and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs.

[0008]

[0009] R1 is arbitrarily selected from: H, 4-Br, 5-Cl, 5-Br, 5-OMe, 6-F, or 6-Br;

[0010] R2 can be selected from:

[0011] R3 can be selected from: -CHO, -COOH, -CH2OH, -CN, or -COCHCH2.

[0012] Another aspect of the present invention provides a method for preparing a tetrahydropyrrolidine compound represented by formula (I) above, comprising: when R3 in the compound represented by formula (I) is selected from -CHO, the preparation method comprises: taking the compound... The THF solution of compound 10 is stirred and mixed with n-BuLi, and then the THF solution of compound 10 is added and stirred to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -CN, the preparation method includes: adding TosMIC to THF / DCE, adding potassium tert-butoxide at 0℃ and stirring and mixing, then adding the THF / DCE solution of compound 10 and MeOH, and then reacting at 0℃ to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -COCHCH2, the preparation method includes: adding to the THF solution of compound (I) with R3 as -CHO at 0℃. The reaction yields the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -COOH, the preparation method includes: at room temperature, mixing and reacting the compound (I) with R3 being -CHO, NIS, K2CO3, and MeOH to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -CH2OH, the preparation method includes: adding NaBH4 to the EtOH solution of the compound (I) with R3 being -CHO at 0°C to obtain the compound shown in formula (I); wherein, the structural formula of compound 10 is... R1 is arbitrarily selected from: H, 4-Br, 5-Cl, 5-Br, 5-OMe, 6-F, or 6-Br; R2 is arbitrarily selected from:

[0013] In another aspect, the present invention provides a pharmaceutical composition comprising the above-described compounds and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs.

[0014] In another aspect, the present invention provides a formulation comprising the above-described compound and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs; or the above-described pharmaceutical compositions; and a pharmaceutically acceptable carrier.

[0015] In another aspect, the present invention provides the use of the above-mentioned compounds and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs; or the use of the above-mentioned pharmaceutical compositions as or in the preparation of formulations with anticancer activity.

[0016] The beneficial effects of this invention include: the sarpagine-type indole alkaloid derivatives and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs provided by this invention have good antitumor effects and low toxicity to normal cells, making them safe, effective and low-toxicity candidate antitumor drugs. Detailed Implementation

[0017] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. Singular expressions include plural expressions unless they have a distinct meaning in the context. As used herein, it should be understood that terms such as “comprising,” “having,” “including,” are intended to indicate the presence of a feature, number, operation, material, or combination thereof. The terminology of the invention is disclosed in the specification and is not intended to exclude the possibility that one or more other features, numbers, operations, materials, or combinations thereof may be present or added. As used herein, “ / ” may be interpreted as “and” or “or,” depending on the context.

[0019] This invention provides a derivative of the Sarpagine-type indole alkaloid represented by formula (I) and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs.

[0020]

[0021] R1 is arbitrarily selected from: H, 4-Br, 5-Cl, 5-Br, 5-OMe, 6-F, or 6-Br;

[0022] R2 can be selected from:

[0023] R3 can be selected from: -CHO, -COOH, -CH2OH, -CN, or -COCHCH2.

[0024] It should be noted that the aforementioned sarpagine-type indole alkaloid derivatives and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs possess the ability to kill cancer cells with low cytotoxicity. Furthermore, the terms stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs are conventional technical terms in the art and have no other specific meaning.

[0025] It should also be noted that R 1选择

[0026] In some specific embodiments, the sarpagine-type indole alkaloid derivatives of formula (I) above, and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs may be arbitrarily preferred from any one of the following compounds:

[0027] (6S,10S,11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0028] (6S,10S,11aS)-1-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0029] (6S,10S,11aS)-2-chloro-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0030] (6S,10S,11aS)-2-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0031] (6S,10S,11aS)-2-methoxy-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0032] (6S,10S,11aS)-3-fluoro-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0033] (6S,10S,11aS)-3-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0034] (6S, 10S, 11aS)-5-(phenylsulfonyl)-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0035] (6S,10S,11aS)-5-((4-(trifluoromethyl)phenyl)sulfonyl)-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0036] (6S, 10S, 11aS)-5-((2-bromophenyl)sulfonyl)-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0037] (6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-nitriles;

[0038] 1-((6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,11,11,11a,12-octahydro-6,10-methoxyindol[3,2-b]quinolin-1-yl)prop-2-en-1-one;

[0039] (6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxylic acid;

[0040] ((6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindol[3,2-b]quinoline-11-yl)methanol;

[0041] And its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs.

[0042] In some specific embodiments, the sarpagine-type indole alkaloid derivatives of formula (I) above, and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs may be more preferably selected from any of the following compounds:

[0043] (6S,10S,11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0044] (6S,10S,11aS)-1-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0045] (6S,10S,11aS)-2-chloro-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0046] (6S,10S,11aS)-2-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0047] (6S,10S,11aS)-3-fluoro-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0048] (6S,10S,11aS)-3-bromo-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0049] (6S, 10S, 11aS)-5-(phenylsulfonyl)-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0050] (6S, 10S, 11aS)-5-((2-bromophenyl)sulfonyl)-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-carboxaldehyde;

[0051] (6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,10,11,11a,12-octahydro-6,10-methoxyindole[3,2-b]quinoline-11-nitriles;

[0052] 1-((6S, 10S, 11aS)-5-tolyl-9-vinylidene-5,6,8,9,11,11,11a,12-octahydro-6,10-methoxyindol[3,2-b]quinolin-1-yl)prop-2-en-1-one;

[0053] And its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs.

[0054] It should be noted that the pharmaceutically acceptable salts of the compounds of formula (I) above include, but are not limited to, various inorganic or organic acid salts such as hydrochloride, hydrobromide, phosphate, sulfate, citrate, lactate, tartrate, maleate, fumarate, mandelate, and oxalate; and various inorganic or organic base salts such as sodium hydroxide, tris(hydroxymethyl)aminomethane, and N-methylglucosamine.

[0055] It should also be noted that the preferred compounds of formula (I) and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs exhibit stronger killing ability against cancer cells than other compounds; and have lower cytotoxicity.

[0056] Another embodiment of the present invention provides a method for preparing the compound shown in formula (I) above, characterized in that, when R3 in the compound shown in formula (I) is selected from -CHO, the preparation method includes: taking the compound... The THF solution of compound 10 is stirred and mixed with n-BuLi, and then the THF solution of compound 10 is added and stirred to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -CN, the preparation method includes: adding TosMIC to THF / DCE, adding potassium tert-butoxide at 0℃ and stirring and mixing, then adding the THF / DCE solution of compound 10 and MeOH, and then reacting at 0℃ to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -COCHCH2, the preparation method includes: adding to the THF solution of compound (I) with R3 as -CHO at 0℃. The reaction yields the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -COOH, the preparation method includes: at room temperature, mixing and reacting the compound (I) with R3 being -CHO, NIS, K2CO3, and MeOH to obtain the compound shown in formula (I); when R3 in the compound shown in formula (I) is selected from -CH2OH, the preparation method includes: adding NaBH4 to the EtOH solution of the compound (I) with R3 being -CHO at 0°C to obtain the compound shown in formula (I); wherein, the structural formula of compound 10 is... R1 is arbitrarily selected from: H, 4-Br, 5-Cl, 5-Br, 5-OMe, 6-F, or 6-Br; R2 is arbitrarily selected from:

[0057] It should be noted that the compound of formula (I) prepared by the above method can also be purified by conventional purification methods.

[0058] In some specific embodiments, compound 10 can be prepared according to the following reaction formula:

[0059]

[0060] Another embodiment of the present invention provides a pharmaceutical composition comprising the above-described compound of formula (I) and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs.

[0061] It should be noted that the above-mentioned compound of formula (I) and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs can be combined with other active drugs to form a compound for use in combination, thereby enhancing the killing ability against cancer cells or supplementing other therapeutic effects to achieve synergistic effects.

[0062] It should also be noted that the pharmaceutical compositions of the present invention contain 0.1% to 99.9% by weight of the above-described compound of formula (I) as an active ingredient, as well as its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs.

[0063] In another aspect, the present invention provides a formulation comprising a compound of formula (I) above and a pharmaceutically acceptable salt, stereoisomer, tautomer, homologue, solvate, prodrug, or polymorph thereof; or a pharmaceutical composition thereof; and a pharmaceutically acceptable carrier.

[0064] It should be noted that the pharmaceutical carriers in the above-mentioned formulations include, but are not limited to: ion exchange materials, alumina, aluminum stearate, lecithin, self-emulsifying drug delivery systems (SEDDS) such as d-vitamin E polyethylene glycol 1000 succinate, Tween or other similar polymerization media, surfactants used in pharmaceutical formulations, serum proteins such as human serum albumin, buffering substances such as phosphates, glycine, sorbic acid, potassium sorbate, mixtures of saturated vegetable fatty acid partial glycerides, water, salts, electrolytes such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, silica gel, magnesium silicate, etc. Polyvinylpyrrolidone, cellulose substances, polyvinyl alcohol, sodium carboxymethyl cellulose, polyacrylate, ethylene-polyoxyethylene-block polymers and lanolin, cyclodextrins such as α-, β-, γ-cyclodextrin or their chemically modified derivatives such as 2- and 3-hydroxypropyl-β-cyclodextrin, hydroxyalkyl cyclodextrin or other soluble derivatives can all be used to promote drug delivery of the compounds shown in formula (I) above and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs.

[0065] It should also be noted that, in the above-mentioned formulations, pharmaceutically acceptable carriers also include pharmaceutically acceptable excipients, such as fillers (e.g., anhydrous lactose, starch, lactose beads, and glucose), binders (e.g., microcrystalline cellulose), disintegrants (e.g., croscarmellose sodium, croscarmellose sodium, low-substituted hydroxypropyl cellulose, and croscarmellose PVP), lubricants (e.g., magnesium stearate), absorption enhancers, flavorings, sweeteners, diluents, excipients, wetting agents, solvents, solubilizers, and colorants, which can also be used as pharmaceutically acceptable carriers to prepare formulations from the above-mentioned compounds and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs.

[0066] In some specific embodiments, the pharmaceutical carrier in the above-described formulation is suitable for liquid dosage forms, solid dosage forms, or ointment dosage forms.

[0067] It should be noted that, based on the administration routes of the compounds shown in formula (I) above and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs, suitable pharmaceutical carriers for different dosage forms can be selected. It should also be noted that liquid dosage forms, solid dosage forms, ointment dosage forms, or emulsion dosage forms are known in the art. For example, liquid dosage forms include, but are not limited to, injections, sprays, or oral liquids; solid dosage forms include, but are not limited to, tablets, powders, granules, or capsules; and ointment dosage forms include, but are not limited to, creams or ointments. In some specific implementations, the compounds shown in formula (I) above and their pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs, or polymorphs may be administered via the enteral or non-enteric routes; non-enteric administration preparations include injections, creams, ointments, patches, sprays, etc.; routes of administration include subcutaneous, intradermal, intra-articular, intravenous, intramuscular, intra-articular, intrasynovial, intrathecal, intralesional, intracranial, intralesional, intralesional, intracranial injection or infusion, or oral, local, rectal, nasal, buccal, vaginal, sublingual, intradermal, mucosal, tracheal, or urethral administration, or administration via inhalation aerosol, implantation, or acupuncture.

[0068] In another aspect, the present invention provides the use of the above-described compound of formula (I) and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs; or the use of the above-described pharmaceutical compositions as or in the preparation of formulations with anticancer activity.

[0069] In some specific embodiments, in the above applications, the cancer cells are cancer cells known in the art, preferably human breast cancer cells, human cervical cancer cells, or human melanoma cells.

[0070] It should be noted that the therapeutically effective amount of the compound shown in formula (I) above and its pharmaceutically acceptable salts, stereoisomers, tautomers, homologues, solvates, prodrugs or polymorphs is between 0.001 mg / kg / d and 100 mg / kg / d, and can be used for monotherapy or combination therapy of related diseases, which is within the scope that can be understood by those skilled in the art.

[0071] To better understand the present invention, specific examples are provided below to further illustrate the content of the present invention, but the content of the present invention is not limited to the examples below.

[0072] In the following examples, intermediate compound 10, a sarpagine-type indole alkaloid derivative, was prepared according to the following synthetic route:

[0073]

[0074] The specific steps are as follows:

[0075] (1) Preparation of compound 2

[0076] Take a 500 mL round-bottom flask, weigh out compound 1 (49.0 mmol), dissolve it in methanol (200 mL), slowly add thionyl chloride (11.5 mL) dropwise at 0 °C, heat to 60 °C and stir for 12 h; after concentration under reduced pressure, add ethyl formate (45 mL) and react at 60 °C for 24 h; thin-layer chromatography monitoring showed that the starting material reacted completely; concentration under reduced pressure yielded compound 2, which can be used directly in the next step without further purification.

[0077] (2) Preparation of compound 3

[0078] Compound 2 (1.0 mmol) was dissolved in THF (10 mL), and under argon protection, freshly prepared [TiCl2(O-)] was added at 0 °C. i [Pr)2] (1.0 mmol). Ethyl magnesium bromide (6.0 mmol) was slowly added dropwise under stirring; the reaction was stirred at room temperature; the reaction progress was determined by TLC analysis, and the reaction was considered complete; the reaction was quenched by adding saturated NH4Cl solution; then filtered through diatomaceous earth and extracted with EtOAc; the organic phases were combined and washed with saturated sodium chloride aqueous solution; then the organic phase was dried with Na2SO4, filtered and concentrated under reduced pressure; the concentrated solution was directly purified by rapid column chromatography (dichloromethane / methanol) to obtain the desired cyclopropanol compound 3.

[0079] (3) Preparation of compound 4

[0080] Compound 3 (1.0 mmol) was dissolved in anhydrous THF (1 mL) under argon protection, and POCl3 (5.0 mmol) was slowly added dropwise at 0 °C. The mixture was heated to room temperature and stirred. The reaction progress was determined by TLC analysis, and the reaction was terminated. The resulting mixture was directly concentrated under reduced pressure, and the crude product was directly purified by rapid column chromatography (dichloromethane / methanol = 10 / 1) to obtain compound 4.

[0081] (4) Preparation of compound 5

[0082] Compound 4 (0.2 mmol) was dissolved in dry 1,4-dioxane (2 mL). Under argon protection, Fe(OTf)3 (0.4 mmol) was rapidly added to the mixed solution, and the mixture was stirred at room temperature for 10 min until the reaction was complete. The reaction was quenched by slow dropwise addition of saturated NaHCO3 solution at 0 °C. The mixture was filtered through diatomaceous earth and extracted with EtOAc. The organic phases were combined, washed with brine, dried over Na2SO4, filtered, and concentrated. Compound 5 was obtained by direct purification using rapid column chromatography (dichloromethane / methanol = 10 / 1).

[0083] (5) Preparation of compound 7

[0084] Compound 6 (0.1 mmol) and K2CO3 (0.2 mmol) were dissolved in dry MeCN (1 mL), and compound 5 (1.2 mmol) was added with stirring. The mixture was stirred at 85 °C for 5 h, quenched with H2O, and filtered through diatomaceous earth. The resulting mixture was extracted with EtOAc. The organic phases were combined, washed with brine, dried over Na2SO4, filtered, and concentrated. The residue was purified by rapid column chromatography (petroleum ether / ethyl acetate = 10 / 1 to 2 / 1) to give compound 7.

[0085] (6) Preparation of compound 8

[0086] Compound 7 (1.0 mmol) and AgNTf2 (1.1 mmol) were dissolved in dry toluene (50 mL), and pyrrolidine (5.0 mmol) was added. The mixture was stirred at 90 °C for 20 min (the reaction progress was determined by TLC analysis), and the reaction was completed. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum, and the residue was purified by rapid column chromatography (petroleum ether / ethyl acetate = 2 / 1) to obtain compound 8.

[0087] (7) Preparation of compound 10:

[0088] Compound 8 (0.1 mmol) was added to a DMSO (1 mL) solution of NaH (60% mineral oil dispersion, 0.2 mmol); the reaction mixture was stirred at room temperature for 30 min, and compound 9 (0.12 mmol) was slowly added dropwise; the reaction mixture was stirred at room temperature (progress was determined by TLC analysis), and the reaction was completed; the reaction mixture was extracted with EtOAc and washed with brine; the organic phases were combined and dried over anhydrous Na2SO4, filtered, and concentrated under vacuum. The residue was directly separated and purified by rapid column chromatography (using petroleum ether / EtOAc = 10 / 1) to obtain compound 10.

[0089] I. Preparation of Compounds

[0090] Example 1

[0091] Compound 10 was prepared according to the above method, wherein compound 1 is... Compound 9 is And target compound 12 was prepared according to the following reaction formula:

[0092]

[0093] The specific operating steps are as follows:

[0094] At -78°C, n-BuLi (0.43 mmol) was added dropwise to a 2 mL THF solution of compound 11 (0.5 mmol) and stirred for 30 min; then, a 1 mL THF solution of compound 10 (0.05 mmol) was added and the reaction was stirred for 1 h (the reaction progress was determined by TLC analysis); water was slowly added to quench the reaction; the resulting solution was extracted with EtOAc; the organic phase was washed with saturated sodium chloride aqueous solution, dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product; the crude product was dissolved in 1 mL THF and HCl (2N, 1 mL) was added, and the reaction was stirred at 70°C for 5 h until the reaction was complete; the reaction was quenched with saturated sodium bicarbonate aqueous solution, and the resulting solution was extracted with ethyl acetate; the organic phases were combined, washed with saturated sodium chloride aqueous solution, dried with Na2SO4, and the residue was directly separated and purified by rapid column chromatography (using petroleum ether / EtOAc = 10 / 1) to obtain the target compound 12, whose structural formula is [insert structural formula here].

[0095] Examples 2 to 10

[0096] Target compound 12 was prepared in Examples 2 to 10 according to the method of Example 1 above, wherein the structural formulas of compound 1 and compound 9 are shown in Table 1 below.

[0097] Table 1. Structural formulas of compounds 1 and 9 in Examples 2 to 10

[0098]

[0099]

[0100]

[0101] Example 11

[0102] Compound 10 was prepared according to the above method, wherein compound 1 is... Compound 9 is And target compound 13 was prepared according to the following reaction formula:

[0103]

[0104] The specific operating steps are as follows:

[0105] TosMIC (39.0 mg, 0.2 mmol) was weighed into a round-bottom flask, and 1 mL of dry THF / DCE (1 / 1) was added. Potassium tert-butoxide (22.4 mg, 0.2 mmol) was added at 0 °C, and the mixture was stirred for 30 min. Then, compound 10 (43.0 mg, 0.1 mmol) was dissolved in THF / DCE and added to the above mixture, followed by MeOH (0.7 mmol). The mixture was reacted at 0 °C, and the reaction progress was determined by TLC analysis. The reaction was then quenched with saturated sodium bicarbonate aqueous solution. The resulting solution was extracted with EtOAc. The organic phases were combined, washed with saturated sodium chloride aqueous solution, dried over Na₂SO₄, and the residue was directly purified by rapid column chromatography to obtain target compound 13.

[0106] Example 12

[0107] Compound 14 was prepared from compound 12 obtained in Example 1 according to the following reaction formula:

[0108]

[0109] The specific operating steps are as follows:

[0110] Compound 12 (44.4 mg, 0.1 mmol) prepared in Example 1 was dissolved in THF (1 mL) solution, and the compound was added dropwise at 0 °C. (1.5 mmol), continue stirring until the starting material is consumed, monitor with TLC, and the reaction is complete. Quench the reaction with saturated ammonium chloride, extract with ethyl acetate, wash with saturated brine, dry with anhydrous Na2SO4, and dry under reduced pressure for direct use in the next reaction.

[0111] The crude product obtained above (37.8 mg, 0.08 mmol) was dissolved in CH2Cl2, and DessMartine (50.9 mg, 0.12 mmol) was added to the reaction solution. The mixture was stirred at room temperature. The reaction progress was determined by TLC analysis, and the reaction was considered complete upon termination. The reaction was quenched by adding saturated sodium bicarbonate aqueous solution. The resulting solution was extracted with EtOAc. The organic phases were combined, washed with saturated sodium chloride aqueous solution, dried over Na2SO4, and then purified by column chromatography (petroleum ether / EtOAc = 2 / 1) to obtain the target compound 14.

[0112] Example 13

[0113] Compound 15 was prepared from compound 12 prepared in Example 1 according to the following reaction formula:

[0114]

[0115] The specific operating steps are as follows:

[0116] Compound 12 (89.2 mg, 0.2 mmol), NIS (112.5 mg, 0.5 mmol), and K₂CO₃ (69.2 mg, 0.5 mmol) prepared in Example 1 were placed in a round-bottom flask, and 5 mL of dry MeOH was added. The mixture was stirred at room temperature for 1 h until the reaction was complete. The reaction was quenched by saturated sodium thiosulfate, and methanol was evaporated under reduced pressure and extracted with EtOAc. The combined organic phases were washed with saturated sodium chloride aqueous solution, dried over Na₂SO₄, and dried under reduced pressure to obtain the crude product, which was directly used in the next reaction.

[0117] The crude product obtained above was dissolved in 1 mL of MeOH / H2O (2 / 1). LiOH (4.8 mg, 0.2 mmol) was added to the mixed solution, and the mixture was stirred at room temperature. The reaction progress was determined by TLC analysis, and the reaction was considered complete. Methanol was evaporated under reduced pressure, and the resulting solution was extracted with EtOAc. The organic phases were combined, washed with saturated sodium chloride aqueous solution, dried over Na2SO4, and the residue was purified by rapid column chromatography (petroleum ether / EtOAc = 2 / 1) to obtain the target compound 15.

[0118] Example 14

[0119] Compound 16 was prepared from compound 12 prepared in Example 1 according to the following reaction formula:

[0120]

[0121] The specific operating steps are as follows:

[0122] Compound 12 (44.6 mg, 0.1 mmol) prepared in Example 1 was dissolved in EtOH (1 mL) solution. NaBH4 (18.9 mg, 0.5 mmol) was added dropwise at 0 °C, and the reaction was stirred for 1 hour. The reaction was monitored by TLC until completion. The reaction was quenched by adding saturated sodium bicarbonate aqueous solution. The resulting solution was extracted with EtOAc; the organic phases were combined, washed with saturated sodium chloride aqueous solution, dried over Na2SO4, and then subjected to column chromatography (eluting with petroleum ether / EtOAc = 2 / 1) to obtain the target compound 16.

[0123] II. Characterization of Compound I

[0124] The names, structural formulas, yields, and proton nuclear magnetic resonance data of the target compounds prepared in Examples 1 to 14 are shown in Table 2 below.

[0125] Table 2 Characterization data of the target compounds prepared in Examples 1 to 14

[0126]

[0127]

[0128]

[0129]

[0130]

[0131] III. In vitro antitumor activity and cytotoxicity assay of compound I

[0132] The MTT assay [3-(4,5)-bismethyl-2-thiazolyl-(2,5)-phenyltetrazolium bromide blue] was used to determine the half maximal inhibitory concentration (IC50) of the target compounds (compound I) prepared in Examples 1 to 14 when they achieved a 50% inhibition rate against human breast cancer cells (MDA-MB-231), human cervical cancer cells (HeLa), and human melanoma cells (A375). 50 ); and cytotoxicity to human hepatocytes (L02), the toxicity of each compound being measured by the concentration (CC) at which L02 cell viability was inhibited to 50%. 50 To express.

[0133] The specific steps are as follows:

[0134] (1) Preparation of culture medium: 89% DMEM (basal culture medium), 10% fetal bovine serum, 1% penicillin-streptomycin solution (10000 IU / mL, 10000 μg / mL);

[0135] (2) Culture of four types of cells: Using the culture medium prepared in (a) (the volume of the culture medium is about 1 / 10 of the capacity of the culture flask), human breast cancer cells (MDA-MB-231), human cervical cancer cells (HeLa), human melanoma cells (A375), and human hepatocytes (L02) were cultured in a 37℃, 5% CO2 incubator. The passage time was determined based on the growth status of the cells.

[0136] (3) Preparation of different drug concentrations: The stock solution was prepared using DMEM (with a small amount of DMSO as a dissolving agent). The final concentration of DMSO in the cell suspension in each well after drug addition was generally no more than 0.05%-0.1%. The stock solution was diluted with DMEM to six concentration gradients (100μM, 50μM, 10μM, 1μM, 0.1μM and 0.01μM) and stored in a -20℃ freezer for later use.

[0137] (4) Cell incubation: Take tumor cells in the logarithmic growth phase and adjust the cell suspension concentration to 5 × 10⁻⁶.4 Mix well and add to a 96-well plate (100 μL / well), and incubate at 37°C in a 5% CO2 incubator for 24 h.

[0138] (5) Drug addition: The diluted drugs of different concentration gradients were added to the 96-well culture plates, with 3 replicates for each concentration gradient, and cultured for 72 hours. The experiment was divided into experimental group (culture medium, cells and compound I), control group (culture medium and cells) and blank group (culture medium only).

[0139] (6) Detection of viable cells: 20 μL of MTT (5 mg / mL) was added to each well of a 96-well plate after 72 h of culture; after incubation at 37 °C for 4 h, the supernatant was removed, 200 μL of DMSO was added to each well, and the plate was shaken until all formazan crystals were dissolved; the optical density (OD value) of each well was detected at a wavelength of 570 nm using an automated microplate reader.

[0140] (7) Calculation of inhibition rate: The killing ability of compound I prepared in Examples 1 to 14 against cancer cells (MDA-MB-231, HeLa and A375) and the toxicity to normal cells (L02) were calculated using the following formulas.

[0141] Growth inhibition rate = (1 - survival rate) × 100% = [1 - (OD experiment - OD blank) / (OD control - OD blank)] × 100%, where OD experiment is the average optical density of the experimental group, OD control is the average optical density of the control group, and OD blank is the average optical density of the blank group.

[0142] (8) Calculate the IC50 based on the concentration of compound I and the growth inhibition rate of different cancer cells (MDA-MB-231, HeLa, and A375). 50 Unit: μM; Calculate the CC value based on the concentration of compound I and the growth inhibition rate of normal cells (L02). 50 The unit is μM; the results are shown in Table 3 below.

[0143] Table 3. Cancer cell killing ability and normal cell toxicity data of Compound I prepared in Examples 1 to 14

[0144]

[0145] Note: In Table 3, IC 50 Half-maximal inhibitory concentration (IC50) indicates the compound's ability to kill cancer cells; CC 50 Half-maximal toxicity concentration (WMC) is the toxicity of a compound to normal cells.

[0146] The above results indicate that the sarpagine-type indole alkaloid derivatives (compound I) prepared in Examples 1 to 14 all have antitumor effects and low toxicity to normal cells.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. Derivatives of Sarpagine-type indole alkaloids represented by Formula I and their pharmaceutically acceptable salts, characterized in that, The general structural formula of the Sarpagine-type indole alkaloid derivatives is as follows: I； The derivatives of the Sarpagine-type indole alkaloids are selected from the following structures: 、 、 、 、 、 、 、 、 。 2. The method for preparing the Sarpagine-type indole alkaloid derivative and its pharmaceutically acceptable salt as described in claim 1, characterized in that, , , , , , and The preparation method is as follows: The compound is prepared by... The THF solution of compound 10 was mixed with n-BuLi by stirring, and then the THF solution of compound 10 was added and the reaction was stirred to obtain the compound shown in formula I; the structural formula of compound 10 is as follows. R1 is selected from: H, 4-Br, 5-Cl, 5-Br, 6-F, or 6-Br; R2 is selected from: , or ; The preparation method is as follows: TosMIC is added to THF / DCE, potassium tert-butoxide is added and stirred at 0°C, then a THF / DCE solution of compound 10 and MeOH are added, and the mixture is reacted at 0°C to obtain the compound shown in Formula I; the structural formula of compound 10 is... R1 is H; R2 is ; The preparation method is as follows: at 0°C, add to the THF solution of compound 12 The reaction yields the compound shown in Formula I, and the structural formula of compound 12 is as follows: .

3. The preparation method according to claim 2, characterized in that, The preparation method of compound 10 is as follows: .

4. A pharmaceutical composition, characterized in that, This includes derivatives of Sarpagine-type indole alkaloids as described in claim 1 and their pharmaceutically acceptable salts.

5. A formulation, characterized in that, This includes derivatives of Sarpagine-type indole alkaloids as described in claim 1 and their pharmaceutically acceptable salts, or the pharmaceutical composition as described in claim 4, and pharmaceutically acceptable carriers.

6. The formulation according to claim 5, characterized in that, Pharmaceutical carriers are suitable for liquid, solid, or ointment dosage forms.

7. The use of the Sarpagine-type indole alkaloid derivative of claim 1 and its pharmaceutically acceptable salt, or the pharmaceutical composition of claim 4, in the preparation of formulations with anticancer cell activity, characterized in that... The cancer cells were selected from human breast cancer cells, human cervical cancer cells, or human melanoma cells.

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