Monoterpenoid indole alkaloid, preparation method and application thereof, AChE inhibitor and medicine for preventing and treating neurodegenerative diseases

Abstract

The invention provides monoterpenoid indole alkaloid, a preparation method and application thereof, an AChE inhibitor and a medicine for preventing and treating neurodegenerative diseases, and belongs to the technical field of medicinal chemistry. The structure of the monoterpenoid indole alkaloid provided by the invention is as shown in a formula I or II. The monoterpenoid indole alkaloid provided by the invention is novel in structure, small in polarity, good in lipid solubility, low in toxicity, easy to penetrate through a blood brain barrier, capable of remarkably inhibiting AChE activity and capable of being applied to preparation of AChE inhibitors and prevention and treatment of neurodegenerative diseases. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical chemistry, and in particular to a monoterpenoid indole alkaloid, a preparation method and application thereof, an AChE inhibitor, and a drug for preventing and treating neurodegenerative diseases. Background Art

[0002] Alzheimer's disease (AD) is a degenerative disease of the central nervous system that often occurs in the early and late stages of old age. It is mainly manifested by memory loss and decreased cognitive ability in patients, eventually leading to death.

[0003] There are roughly two types of drugs currently used in clinical treatment of AD: one is acetylcholinesterase (AChE) inhibitors, namely donepezil, galantamine and rivastigmine, as well as domestically developed huperzine A, which are only effective for patients with mild to moderate AD; the other is N-methyl-D-aspartate receptor blockers, namely memantine, which can be used to treat patients with moderate to severe AD. However, the drugs currently used to treat AD can only improve some symptoms or delay the development of AD, and have serious adverse reactions. Existing studies have shown that AChE causes the occurrence of AD by reducing cholinergic neurotransmitters. Therefore, the screening of efficient AChE inhibitors is the basis for the development of drugs to treat neurodegenerative diseases. Summary of the invention

[0004] The purpose of the present invention is to provide a monoterpenoid indole alkaloid and a preparation method and application thereof, an AChE inhibitor, and a drug for preventing and treating neurodegenerative diseases. The monoterpenoid indole alkaloid provided by the present invention has a novel structure, can significantly inhibit the activity of AChE, and can be used in the preparation of AChE inhibitors and drugs for preventing and treating neurodegenerative diseases.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a monoterpenoid indole alkaloid having a structure shown in Formula I or Formula II:

[0007]

[0008] The R 1 is a hydrogen atom, X1, a methyl group, an ethyl group, a hydroxyl group, a methoxy group, a formyloxy group, an acetoxy group, a substituted benzyloxy group or an unsubstituted benzyloxy group; the substituted benzyloxy group has at least one substituent on the benzene ring, and the substituent is X2, a methyl group or a nitro group; X1 and X2 are halogen atoms;

[0009] The R 2It is a hydrogen atom, a carboxyl group, a hydroxymethyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a methylcarbamoyl group, an ethylcarbamoyl group, an propylcarbamoyl group, a benzylcarbamoyl group, a dimethylcarbamoyl group, a diethylcarbamoyl group or a dipropylcarbamoyl group.

[0010] Preferably, X1 and X2 are independently -F, -Cl or -Br.

[0011] Preferably, the monoterpenoid indole alkaloid is any one of the following compounds a1-a12, b1-b2, c1-c5:

[0012]

[0013] The present invention provides a method for preparing the monoterpenoid indole alkaloids described in the above technical solution, comprising the following steps:

[0014] The aglycone of swertiacoside and the reaction reagent Ma are subjected to a first Pictet-Spengeler reaction and a second Pictet-Spengeler reaction under the catalysis of a Lewis acid to obtain a monoterpenoid indole alkaloid having a structure shown in Formula I and Formula II; the Lewis acid is one or more of zinc trifluoromethanesulfonate, trifluoroacetic acid, aluminum trichloride, ferric chloride, boron trifluoride, potassium trifluoromethanesulfonate and lithium trifluoromethanesulfonate;

[0015] The swertiain aglycone has a structure shown in Formula 1, and the reaction reagent Ma has a structure shown in Formula 2:

[0016]

[0017] The R 1 , R 2 As defined in Formula I and Formula II.

[0018] Preferably, the temperature of the first Pictet-Spengeler reaction and the second Pictet-Spengeler reaction are independently 40 to 45° C., and the time is independently 1 to 30 h;

[0019] The first Pictet-Spengeler reaction is carried out in the presence of a first organic solvent, wherein the first organic solvent is one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide and methanol;

[0020] The second Pictet-Spengeler reaction is performed in the presence of a second organic solvent, and the second organic solvent is hexafluoroisopropanol.

[0021] Preferably, the swertiain aglycone is obtained by hydrolyzing swertiain in the presence of β-glucosidase; the temperature of the hydrolysis reaction is 25 to 50° C., and the time is 1 to 48 hours; the hydrolysis reaction is carried out at a pH value of 5.0 to 7.0.

[0022] The present invention provides the use of the monoterpenoid indole alkaloids described in the above technical solution in the preparation of AChE inhibitors.

[0023] The present invention provides the use of the monoterpenoid indole alkaloids described in the above technical solution in the preparation of medicines for preventing and treating neurodegenerative diseases.

[0024] Preferably, the neurodegenerative disease is Alzheimer's disease.

[0025] The present invention provides a drug for preventing and treating neurodegenerative diseases, which uses the monoterpenoid indole alkaloids described in the above technical solution as an active ingredient.

[0026] The present invention provides a monoterpenoid indole alkaloid, which has a novel structure, low polarity, good lipid solubility, low toxicity, is easy to penetrate the blood-brain barrier, can significantly inhibit AChE activity, and can be used in the preparation of drugs for preventing and treating Alzheimer's disease. The embodiment shows that the anti-AChE activity of the monoterpenoid indole alkaloid is screened using a chemical model for inhibiting acetylcholinesterase activity, and a drug treatment experiment is carried out under this condition. It can be seen that the inhibition rates of compounds a2, a3, a7, a8, and b1 on AChE are all greater than 50%, which shows that the monoterpenoid indole alkaloid provided by the present invention has an AChE inhibitory effect and has the potential to prepare drugs for preventing and treating neurodegenerative diseases such as Alzheimer's disease.

[0027] Further, the present invention provides a method for preparing the monoterpenoid indole alkaloids, specifically, a derivative obtained by derivatization of commercially available tryptamine, L-tryptophan or its substitute is used as a reaction reagent (i.e., reaction reagent Ma), and a scutellarin aglycone obtained by hydrolyzing the natural active ingredient scutellarin is used as a synthesis module, and a series of monoterpenoid indole alkaloids are obtained by biomimetic synthesis through Mannich reaction and Pictet-Spengler reaction. The preparation method provided by the present invention not only has the characteristics of diversity-oriented synthesis, but also the reaction reagent and scutellarin aglycone are synthesized into monoterpenoid indole alkaloids through a one-step reaction, which has the characteristics of mild conditions, simple operation, rapid reaction, high efficiency and saving raw materials, and does not exist in the harsh reaction conditions of high temperature, high pressure and strong acid and strong base. Moreover, the reaction raw materials used in the present invention are natural, abundant and easily available compounds, which are suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is a bar graph of absorbance values ​​of different compounds at 405 nm (a5, a10, a1, a6, a2, a7, c2, a3, a8, b1 and c1);

[0030] Figure 2 The bar graphs are the absorbance values ​​of different compounds at 405 nm (a4, a9, c3, a11, b2, a12, c4 and c5);

[0031] Figure 3 is the fitting curve diagram of tacrine;

[0032] Figure 4 is the fitting curve diagram of compound a2;

[0033] Figure 5 is the fitting curve diagram of compound a7;

[0034] Figure 6 is the fitting curve diagram of compound a3;

[0035] Figure 7 It is the fitting curve diagram of compound a8. DETAILED DESCRIPTION

[0036] The present invention provides a monoterpenoid indole alkaloid having a structure shown in Formula I or Formula II:

[0037]

[0038] The R 1 is a hydrogen atom, X1, a methyl group, an ethyl group, a hydroxyl group, a methoxy group, a formyloxy group, an acetoxy group, a substituted benzyloxy group or an unsubstituted benzyloxy group; the substituted benzyloxy group has at least one substituent on the benzene ring, and the substituent is X2, a methyl group or a nitro group; X1 and X2 are halogen atoms;

[0039] The R 2 It is a hydrogen atom, a carboxyl group, a hydroxymethyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a methylcarbamoyl group, an ethylcarbamoyl group, an propylcarbamoyl group, a benzylcarbamoyl group, a dimethylcarbamoyl group, a diethylcarbamoyl group or a dipropylcarbamoyl group.

[0040] In the present invention, X1 and X2 are preferably -F, -Cl or -Br.

[0041] In the present invention, the monoterpenoid indole alkaloid is preferably any one of the following compounds a1-a12, b1-b2, c1-c5:

[0042]

[0043]

[0044] The present invention also provides a method for preparing the monoterpenoid indole alkaloids described in the above technical solution, comprising the following steps:

[0045] The aglycone of swertiacoside and the reaction reagent Ma are subjected to a first Pictet-Spengeler reaction and a second Pictet-Spengeler reaction under the catalysis of a Lewis acid to obtain a monoterpenoid indole alkaloid having a structure shown in Formula I and Formula II; the Lewis acid is one or more of zinc trifluoromethanesulfonate, trifluoroacetic acid, aluminum trichloride, ferric chloride, boron trifluoride, potassium trifluoromethanesulfonate and lithium trifluoromethanesulfonate;

[0046] The swertiacoside aglycone has a structure shown in Formula 1, and the reaction reagent Ma has a structure shown in Formula 2:

[0047]

[0048] The R 1 , R 2 As defined in Formula I and Formula II.

[0049] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared by methods well known to those skilled in the art.

[0050] The invention uses commercially available tryptamine, L-tryptophan or their substitutes to obtain derivatives obtained by derivatization as reaction reagents (i.e. reaction reagent Ma), uses swertiain aglycone obtained by hydrolyzing the natural active ingredient swertiain as a synthesis module, and obtains a series of monoterpenoid indole alkaloids through biomimetic synthesis through specific reactions (Mannich reaction and Pictet-Spengeler reaction).

[0051] In the present invention, the swertiain aglycone is preferably obtained by hydrolysis of swertiain in the presence of β-glucosidase. In the present invention, the molar ratio of swertiain to β-glucosidase is preferably 1:(0.09-0.12), more preferably 1:(0.10-0.11). In the present invention, the hydrolysis reaction is preferably carried out at a pH value of 5.0-7.0, more preferably at a pH value of 6.0. The present invention preferably adjusts the pH value by a citric acid-sodium citrate buffer solution. In the present invention, the hydrolysis reaction is preferably carried out in a protective atmosphere. The present invention does not specifically limit the type of protective gas providing the protective atmosphere, and the conventional gas types in the art can be used. In an embodiment of the present invention, the protective gas is N2. In the present invention, the temperature of the hydrolysis reaction is preferably 25-50°C, more preferably 35-45°C; the time is preferably 1-48h, more preferably 1-12h. After the hydrolysis reaction, the present invention preferably extracts the obtained product system with ethyl acetate, dries the obtained organic phase with anhydrous sodium sulfate, filters, and concentrates the filtrate by rotary evaporation to dryness to obtain swertiaside aglycone. The drying agent used in the present invention is preferably anhydrous Na2SO4.

[0052] Taking Preparation Example 3 of the present invention as an example, the reaction formula of the swertiain aglycone is as follows:

[0053]

[0054] In the present invention, the reaction reagent Ma has a structure shown in Formula 2:

[0055]

[0056] The R 1 , R 2 As defined in Formula I and Formula II.

[0057] In the present invention, the preparation methods and conditions of some types of reaction reagents Ma are as follows:

[0058]

[0059] In the present invention, the preparation method of the compound Mb1 preferably comprises the following steps: mixing L-tryptophan, thionyl chloride and methanol, and performing an esterification reaction to obtain the hydrochloride of the compound Mb1. In the present invention, the molar ratio of L-tryptophan to thionyl chloride is preferably 1:1; the esterification reaction is preferably carried out under reflux conditions, and the reflux temperature is preferably 45°C; the esterification reaction time is preferably 1h. After the esterification reaction, the present invention preferably performs rotary evaporation on the obtained product system to remove methanol and excess thionyl chloride, and the obtained white solid is L-tryptophan methyl ester hydrochloride (i.e., the hydrochloride of Mb1). The hydrochloride of the compound Mb1 is treated with aqueous ammonia to obtain the compound Mb1.

[0060] In the present invention, the method for preparing the compound Mb2 preferably comprises the following steps: 4 and ethanol, and then undergo an ester exchange reaction to obtain compound Mb2. 4 R 4 Preferably methyl; the compound Mb1 and the compound NH2R 4 The molar ratio is based on ensuring that compound Mb1 is fully reacted; the temperature of the amine exchange reaction is preferably room temperature, and the time is preferably 2h. After the amine exchange reaction, the present invention preferably performs rotary evaporation to remove the solvent from the obtained product system, and then performs silica gel column chromatography purification to obtain compound Mb2. In the present invention, the eluting agent used for the silica gel column chromatography purification is preferably ethyl acetate.

[0061] The present invention preferably prepares compounds Mc1 and Mc2 respectively according to the preparation methods of compounds Mb1 and Mb2, the only difference being that the starting material L-tryptophan is replaced by 5-hydroxyL-tryptophan.

[0062] In the present invention, the preparation methods and conditions of some types of reaction reagents Ma are as follows:

[0063]

[0064] In the present invention, the preparation method of the compound Mc4 preferably comprises the following steps:

[0065] Compound Mc1, dichloromethane, triethylamine and di-tert-butyl dicarbonate are mixed and subjected to amino Boc protection reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester;

[0066] The N-Boc-L-5-hydroxytryptophan methyl ester, acetic anhydride and pyridine are mixed and acetylated to obtain a first intermediate;

[0067] The first intermediate, trifluoroacetic acid and dichloromethane are mixed to carry out amino Boc deprotection reaction to obtain compound Mc4;

[0068] The structural formula of the first intermediate is as follows:

[0069]

[0070] The present invention mixes compound Mc1, dichloromethane, triethylamine and di-tert-butyl dicarbonate, and performs amino Boc protection reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester. In the present invention, the molar ratio of the compound Mc1, triethylamine and di-tert-butyl dicarbonate is preferably 1:3:2; the temperature of the amino Boc protection reaction is preferably room temperature, and the time is preferably 1.5 hours. After the amino Boc protection reaction, the present invention preferably mixes the obtained product system with water, extracts the aqueous phase with dichloromethane after separation, and the organic phase obtained by extraction is dried over anhydrous sodium sulfate and then filtered, and the filtrate is vacuum concentrated to obtain a brown-yellow viscous liquid, which is N-Boc-L-5-hydroxytryptophan methyl ester, which can be directly used in the next step reaction without further purification.

[0071] After obtaining N-Boc-L-5-hydroxytryptophan methyl ester, the present invention mixes the N-Boc-L-5-hydroxytryptophan methyl ester, acetic anhydride and pyridine, and performs an acetylation reaction to obtain a first intermediate. In the present invention, the molar ratio of the N-Boc-L-5-hydroxytryptophan methyl ester, acetic anhydride and pyridine is preferably 1: (1-3): 20, and more preferably 1: 2: 20. The acetylation reaction of the present invention is preferably carried out under stirring; the temperature of the acetylation reaction is preferably room temperature; the time is preferably 2-4h, and more preferably 3h. The present invention preferably adds a saturated sodium bicarbonate solution to quench the reaction, extracts the obtained material with dichloromethane, and the organic phase obtained by extraction is dried with anhydrous sodium sulfate, filtered, and the filtrate is concentrated by rotary evaporation under reduced pressure to obtain a first intermediate.

[0072] After obtaining the first intermediate, the present invention mixes the first intermediate, trifluoroacetic acid and dichloromethane, and performs an amino deBoc protection reaction to obtain compound Mc4; in the present invention, the molar ratio of the first intermediate to trifluoroacetic acid is preferably 1: (8-9), more preferably 1: 8.5; the amino deBoc protection reaction is preferably carried out under stirring, the temperature of the amino deBoc protection reaction is preferably room temperature, and the time is preferably 1.5h. After reaching the time of the amino deBoc protection reaction, the present invention preferably adds a saturated sodium bicarbonate solution to quench the reaction, extracts the obtained material with dichloromethane, and dries the obtained organic phase with anhydrous sodium sulfate, filters, and concentrates the filtrate under reduced pressure by rotary evaporation to obtain a yellow solid, which is compound Mc4.

[0073] In the present invention, the preparation method of the compound Mc5 preferably comprises the following steps:

[0074] Compound Mc1, dichloromethane, triethylamine and di-tert-butyl dicarbonate are mixed and subjected to amino Boc protection reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester;

[0075] The N-Boc-L-5-hydroxytryptophan methyl ester and methylamine methanol solution are mixed to carry out an aminoester exchange reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester formamide;

[0076] The N-Boc-L-5-hydroxytryptophan methyl ester formamide, acetone, KOH and methyl iodide are mixed and subjected to an alkylation reaction to obtain a second intermediate;

[0077] The second intermediate, trifluoroacetic acid and dichloromethane were mixed and stirred at room temperature to obtain compound Mc5;

[0078] The structural formula of the second intermediate is as follows:

[0079]

[0080] The present invention mixes compound Mc1, dichloromethane, triethylamine and di-tert-butyl dicarbonate, and performs amino Boc protection reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester. The reaction conditions are the same as those for preparing N-Boc-L-5-hydroxytryptophan methyl ester from Mc1.

[0081] After obtaining N-Boc-L-5-hydroxytryptophan methyl ester, the present invention mixes N-Boc-L-5-hydroxytryptophan methyl ester and methylamine methanol solution, and performs an ester exchange reaction to obtain N-Boc-L-5-hydroxytryptophan methyl ester formamide. In the present invention, the molar ratio of the N-Boc-L-5-hydroxytryptophan methyl ester and the methylamine methanol solution is preferably 1:20; the temperature of the ester exchange reaction is preferably room temperature, and the time is preferably 24 hours. After the ester exchange reaction, the present invention preferably spin-dries the obtained product system, and the obtained brown solid is N-Boc-L-5-hydroxytryptophan methyl ester formamide.

[0082] After obtaining N-Boc-L-5-hydroxytryptophan methyl ester formamide, the present invention mixes the N-Boc-L-5-hydroxytryptophan methyl ester formamide, acetone, KOH and methyl iodide to carry out an alkylation reaction to obtain a second intermediate; in the present invention, the molar ratio of the N-Boc-L-5-hydroxytryptophan methyl ester formamide, KOH and methyl iodide is preferably 1:1:20; the temperature of the alkylation reaction is preferably room temperature, and the time is preferably 2 hours. After the alkylation reaction, the present invention preferably mixes the obtained product system with a saturated ammonium chloride solution to quench the reaction, then adds ethyl acetate for extraction, and the organic phase obtained by extraction is dried over anhydrous sodium sulfate and then filtered, and the filtrate is vacuum concentrated to obtain a yellow solid, which is the second intermediate.

[0083] The second intermediate, dichloromethane and trifluoroacetic acid were mixed and subjected to amino de-Boc protection reaction to obtain compound Mc5. The reaction conditions were the same as those for preparing Mc4 from the first intermediate.

[0084] In the present invention, the method for preparing the monoterpenoid indole alkaloid having the structure shown in Formula I comprises the following steps:

[0085] The swertiacoside aglycone and the reaction reagent Ma are subjected to a first Pictet-Spengeler reaction under the catalysis of Lewis acid to obtain a monoterpenoid indole alkaloid having a structure shown in formula I.

[0086] In the present invention, the molar ratio of the swertiain aglycone to the reaction reagent Ma is preferably 1:(1-1.3), more preferably 1:(1.2-1.3). In the present invention, the Lewis acid is preferably one or more of zinc trifluoromethanesulfonate, trifluoroacetic acid, aluminum trichloride, ferric chloride, boron trifluoride, potassium trifluoromethanesulfonate and lithium trifluoromethanesulfonate, more preferably zinc trifluoromethanesulfonate or trifluoroacetic acid; the molar ratio of the swertiain aglycone to the Lewis acid is preferably 1:(0.09-0.11), more preferably 1:0.1. In the present invention, the first Pictet-Spengeler reaction is preferably carried out in the presence of a first organic solvent; the first organic solvent is preferably one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide and methanol, more preferably dichloromethane or methanol; the present invention has no special limitation on the amount of the organic solvent, as long as the first Pictet-Spengeler reaction is carried out smoothly.

[0087] The present invention preferably mixes swertiacoside aglycone, reaction reagent Ma, Lewis acid and a first organic solvent to carry out a first Pictet-Spengeler reaction. In the present invention, the temperature of the first Pictet-Spengeler reaction is preferably 35 to 45°C; the time is preferably 1 to 30 hours, specifically 1 hour, 2 hours, 3 hours, 4 hours, 10 hours, 20 hours or 30 hours. The present invention preferably uses TLC to monitor the reaction progress. In the present invention, the first Pictet-Spengeler reaction is preferably carried out under stirring conditions. After the first Pictet-Spengeler reaction, the present invention preferably purifies the obtained product system by silica gel column chromatography to obtain a monoterpenoid indole alkaloid having a structure shown in Formula I. In the present invention, the reagent used for the silica gel column chromatography purification is preferably selected according to the specific type of the target compound; in the embodiment of the present invention, a chloroform-methanol mixed reagent or a petroleum ether-ethyl acetate mixed reagent is specifically used, and the volume ratio of chloroform to methanol in the chloroform-methanol mixed reagent is preferably (10-15):1, and more preferably (12-13):1; the volume ratio of petroleum ether to ethyl acetate in the petroleum ether-ethyl acetate mixed reagent is preferably (0.5-6):(5-1), and more preferably (1-2):(2-1).

[0088] In the present invention, the method for preparing the monoterpenoid indole alkaloid having the structure shown in Formula II comprises the following steps:

[0089] The swertiacoside aglycone and the reaction reagent Ma are subjected to a second Pictet-Spengeler reaction under the catalysis of Lewis acid to obtain a monoterpenoid indole alkaloid having a structure shown in formula II.

[0090] In the present invention, the molar ratio of the swertiacoside aglycone to the reaction reagent Ma is preferably 1:(1-1.3), more preferably 1:(1.2-1.3). In the present invention, the second Pictet-Spengeler reaction is preferably carried out in the presence of a second organic solvent; the second organic solvent is preferably hexafluoroisopropanol. In the present invention, the second Pictet-Spengeler reaction is preferably carried out in the presence of a Lewis acid, and the optional type and amount of the Lewis acid required for the second Pictet-Spengeler reaction are preferably the same as those required for the first Pictet-Spengeler reaction, which will not be repeated here.

[0091] The present invention preferably mixes swertiacoside aglycone, reaction reagent Ma, Lewis acid and a second organic solvent to carry out a second Pictet-Spengeler reaction. In the present invention, the conditions of the second Pictet-Spengeler reaction are preferably the same as those of the first Pictet-Spengeler reaction, which will not be repeated here. After the second Pictet-Spengeler reaction, the present invention preferably purifies the obtained product system by silica gel column chromatography to obtain a monoterpenoid indole alkaloid having a structure shown in Formula II. In the present invention, the reagent used for the silica gel column chromatography purification is preferably selected according to the specific type of the target compound; in an embodiment of the present invention, a petroleum ether-ethyl acetate mixed reagent is specifically used, and the volume ratio of petroleum ether to ethyl acetate in the petroleum ether-ethyl acetate mixed reagent is preferably (0.5-3): (2-1), and more preferably (1-2): (2-1).

[0092] The present invention also provides the use of the monoterpenoid indole alkaloids described in the above technical solution in the preparation of AChE inhibitors.

[0093] The present invention also provides the use of the monoterpenoid indole alkaloids described in the above technical solution in the preparation of a drug for preventing and treating neurodegenerative diseases. In the present invention, the neurodegenerative disease is preferably Alzheimer's disease.

[0094] The present invention also provides a drug for preventing and treating neurodegenerative diseases, which uses the monoterpenoid indole alkaloids described in the above technical solution as an active ingredient. In the present invention, the neurodegenerative disease is preferably Alzheimer's disease. In the present invention, the drug preferably also includes a pharmaceutically acceptable excipient. The pharmaceutical excipients of the present invention preferably include one or more of a diluent, an excipient, a filler, a hydrating agent, a wetting agent, a disintegrant, a sodium absorption promoter, a surfactant, an adsorption carrier, a lubricant, a flavoring agent, and a sweetener. The diluent of the present invention preferably includes water; the excipient preferably includes one or more of water, mannitol, magnesium stearate, starch and cyclodextrin; the filler preferably includes starch and / or sucrose; the binder preferably includes one or more of cellulose derivatives, alginate, gelatin and polyvinyl pyrrolidone; the wetting agent preferably includes glycerol; the disintegrant preferably includes one or more of agar, calcium carbonate and sodium bicarbonate; the sodium absorption promoter preferably includes quaternary ammonium compounds; the surfactant preferably includes cetyl alcohol and / or sodium carboxymethyl cellulose; the adsorption carrier preferably includes kaolin and / or saponin; the lubricant preferably includes one or more of talc, calcium stearate, magnesium stearate and polyethylene glycol; the present invention has no special limitation on the flavoring agent and sweetening agent, and the flavoring agent and sweetening agent well known to those skilled in the art can be used.

[0095] The present invention has no particular limitation on the dosage form of the drug, and dosage forms well known to those skilled in the art may be used, such as tablets, granules, capsules, oral liquids, injections, lyophilized injections or powder injections. The present invention has no particular limitation on the preparation of the tablets, granules, capsules, oral liquids, injections, lyophilized injections and powder injections, and preparation methods well known to those skilled in the art may be used.

[0096] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0097] Preparation Example 1

[0098] Synthesis of compound Mc1: 150.4 mg (0.6828 mmol) of 5-hydroxyL-tryptophan, 81.3 mg (0.6828 mmol) of dithionyl chloride and 0.50 mL (12.3594 mmol) of methanol were mixed, and an esterification reaction was carried out at reflux conditions of 45°C for 1 h. The resulting product system was subjected to rotary evaporation to remove methanol and excess dithionyl chloride to obtain the hydrochloride of compound Mc1. The hydrochloride of compound Mc1 was treated with 0.5 mL (12.8571 mmol) of aqueous ammonia to obtain Mc1.

[0099] Synthesis of N-Boc-L-5-hydroxytryptophan methyl ester: 160 mg (0.6828 mmol) of compound Mc1 was placed in a round-bottom flask, 0.8 mL of dichloromethane was added to dissolve, 262 μL (1.8846 mmol) of triethylamine was added dropwise, and the mixture was stirred at room temperature for 10 min. After cooling to 0°C with an ice-water bath, 289 μL (1.2563 mmol) of di-tert-butyl dicarbonate was added dropwise. After the addition was complete, the mixture was stirred for 1.5 h at room temperature and the reaction was monitored by TLC. After the reaction was completed, 10 mL of water was added, the liquids were separated, the aqueous phase was extracted with dichloromethane (20 mL×2), the organic phases were combined, dried over anhydrous sodium sulfate, and then filtered. The filtrate was concentrated in vacuo to obtain a brown-yellow viscous liquid, which was N-Boc-L-hydroxytryptophan methyl ester, with a yield of 221 mg, which could be directly used in the next step without further purification.

[0100] Synthesis of the first intermediate: Take 221 mg (0.6609 mmol) of N-Boc-L-5-hydroxytryptophan methyl ester, dissolve it in 1 mL of pyridine, stir for 10 minutes, add 75 μL (0.7929 mmol) of acetic anhydride dropwise, react at room temperature, monitor the reaction by TLC, and after the reaction is completed, remove the solvent by rotary evaporation, purify by silica gel column chromatography, and use a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 3:1) as the eluent to obtain the first intermediate.

[0101] The first intermediate was dissolved in 2 mL of dichloromethane, 400 μL of trifluoroacetic acid was added dropwise under ice bath conditions, and the mixture was stirred at room temperature. The reaction was monitored by TLC. After the reaction was completed, the reaction was quenched with saturated sodium bicarbonate and extracted with chloroform (10 mL×3). The organic phases were combined, dried over anhydrous sodium sulfate, and then filtered. The filtrate was spin-dried to give compound Mc4 (125.8 mg, yellow viscous liquid, yield 68.9%).

[0102] Compound Mc4 1 The H NMR data are as follows: 1 H NMR(CDCl3,400MHz)δ7.28(d,J=1.4Hz,1H),7.02(d,J=2.3Hz,1H),6.89(dd,J=8.7,2.2Hz,1H),7.29(d,J=2.3Hz,1H) ,3.01(dd,J=14.4,7.7Hz,1H),3.26-3.19(m,1H),3.80(d,J=7.7,4.7Hz,1H),2.34(s,3H),3.71(s,3H),8.57(s,1H); 13 C NMR (100MHz, CDCl3) δ124.65,110.98,127.85,111.32,144.29,116.37,111.86,134.25,30.66,54.89,21.32,52.24,170.77,175.73.

[0103] Preparation Example 2

[0104] Synthesis of N-Boc-L-5-hydroxytryptophan methyl ester carboxamide: Take 221 mg (0.6609 mmol) of N-Boc-L-5-hydroxytryptophan methyl ester, dissolve it in 2 mL of methylamine methanol solution, stir the reaction at room temperature, monitor the reaction by TLC, and after the reaction is completed, remove the excess methylamine methanol solution by rotary evaporation, and purify it by silica gel column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain N-Boc-L-5-hydroxytryptophan methyl ester carboxamide (212.6 mg, light red viscous liquid, yield: 92.6%).

[0105] Synthesis of the second intermediate: Dissolve 210 mg (0.6045 mmol) of N-Boc-L-5-hydroxytryptophan methyl ester formamide in 2.0 mL of acetone, add KOH (33.9 mg, 0.6045 mmol) under ice-water bath, stir for 10 min, then add 225 μL of iodomethane dropwise, warm to room temperature after the addition is complete, stir and react for 6 h, monitor the reaction by TLC, add 10 mL of saturated ammonium chloride solution after the reaction is complete to quench the reaction, then add ethyl acetate for extraction (20 mL×3), combine the organic phases, dry over anhydrous sodium sulfate, and then filter, concentrate the filtrate in vacuo, and separate and purify the residue by silica gel column chromatography, the eluent is a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 2:1), to obtain the second intermediate.

[0106] The second intermediate was dissolved in 2 mL of dichloromethane, and 400 μL of trifluoroacetic acid was slowly added dropwise under ice bath conditions. The mixture was stirred at room temperature and the reaction was monitored by TLC. After the reaction was completed, the reaction was quenched with saturated sodium bicarbonate and extracted with chloroform (10 mL×3). The organic phases were combined, dried over anhydrous sodium sulfate, and then filtered. The filtrate was spin-dried to give compound Mc5 (96.0 mg, yellow viscous liquid, yield 64.2%).

[0107] Compound Mc5 1 The HNMR data are as follows: 1 H NMR (CDCl3, 400MHz) δ7.10 (s, 1H), 7.03 (d, J = 2.4Hz, 1H), 6.85 (dd, J = 8.8, 2.4Hz, 1H), 7.25 (d, J = 9.2Hz, 1 H),3.11(dd,J=14.7,7.5Hz,1H),3.31(d,J=15.0Hz,1H),4.39(s,1H),2.67(d,J=4.9Hz,3H),3.87(s,ЗH); 13 CNMR (100MHz, CDCl3) δ123.91,108.48,127.96,100.52,154.38,112.90,112.06,131.35,28.44,55.22,26.38,56.02,172.47.

[0108] Preparation Example 3

[0109] Weigh 3 g of swertiacoside into a hard test tube, add 200 mg of β-glucosidase, dissolve it with 50 mL of citric acid-sodium citrate buffer solution (pH = 6.0), replace the ambient atmosphere with N2, and stir the reaction at 35°C for 4 hours; then pour the resulting product system into a separatory funnel, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the filtrate under reduced pressure by rotary evaporation to obtain 1.6 g of swertiacoside aglycone, with a yield of 92%.

[0110] The reaction formula for preparing the swertiain aglycone is specifically as follows:

[0111]

[0112] Example 1

[0113] Weigh 36.3 mg of swertiain sample in a reaction tube, add 2.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the end, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as the desugaring product; weigh the desugaring product (0.0932 mmol), tryptamine 17.9 mg (0.1118 mmol) and zinc trifluoromethanesulfonate 3.4 mg (0.0093 mmol) was dissolved in 1 mL of hexafluoroisopropanol in a sealed tube, and the reaction was stirred at 35 ° C for 1 h. The reaction was monitored by TLC. After the reaction was completed, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography. The eluent was a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 2:1), and compound a1 (yellow solid, 5.7 mg, two-step yield 17.5%) and compound a6 (yellow solid, 10.6 mg, two-step yield 32.6%) were obtained respectively. The molar ratio of compound a1 to compound a6 was 1:1.81.

[0114] Compound a1: Molecular formula is C 20 H 20 N2O2; HR-ESI-MS(m / z): 321.1597[M+H] + , (calcdfor321.1598); (c=0.1,MeOH); UVλ max (MeOH) 221.3nm; IR (KBr) cm -1 : 3851, 3725, 3178, 2929, 1675, 1553, 1281, 1112 and 771; 1H NMR(400MHz, Acetone-d6)δ:7.48(d,J=2.1Hz,1H),7.37(d,J=7.7Hz,1H),7.27(d,J=8.0Hz,1H),7.02(ddd,J=8.1 ,7.0,1.3Hz,1H),6.95(m,1H),5.75(dt,J=17.2,9.8Hz,1H),5.28(dd,J=17.1,2.0Hz,1H),5.18(dd,J=10.2,2.0Hz ,1H),4.61(d,J=2.3Hz,1H),4.12(ddd,J=11.1,4.1,2.4Hz,1H),3.98(m,2H),3.50(ddd,J=13.4,11.6,4.8Hz,1H), 3.34(dddd,J=9.5,4.3,2.0Hz,1H),2.84(m,1H),2.74(m,1H),2.51(dddd,J=9.8,5.8,4.2,2.0Hz,1H),1.55(m,2H); 13 C NMR(100MHz,Acetone-d6)δ:165.46,145.86,136.58,136.38,132.85,127.52,121.42,119.0 7,117.79,117.29,111.25,108.76,95.68,66.37,58.38,50.93,42.29,29.60,26.51,23.01.

[0115] Compound a6: Molecular formula is C 20 H 20 N2O2; HR-ESI-MS(m / z): 321.1594[M+H] + , (calcdfor321.1598); (c=0.1,MeOH); UVλ max (MeOH) 222nm; IR (KBr) cm -1 : 3847, 3735, 3309, 2923, 1676, 1580, 1446, 1131, 939, 739 and 658; 1HNMR(400MHz, Acetone-d6) δ: 7.54 (d, J = 2.1 Hz, 1H), 7.44 (d, J = 7.7 Hz, 1H), 7.30 (d, J = 7.9 Hz, 1H), 7.03 (dtd, J = 20.5, 7.2, 1.2 Hz, 2H), 5.77 (qd, J = 6.9, 2.2 Hz, 1H), 5.71 (d, J = 2.3 Hz, 1H), 4.26 (ddd, J = 11.2, 4.2, 2.3 Hz, 1H), 4.13 (ddd, J = 13.0, 11.2, 2.0 Hz, 1H), 4.04 (m, 1H), 3.69 (ddd, J = 13.4, 11.7, 4.9 Hz, 1H), 2.92 (dq, J = 11.9, 2.2 Hz, 1H), 2.83 (dddd, J = 14.5, 11.7, 6.1, 2.6 Hz, 1H), 2.71 (dd, J = 15.1, 5.0 Hz, 1H), 2.00 (m, 1H) 1.92 (dd, J = 6.9, 2.1 Hz, 3H), 1.71 (qd, J = 12.7, 4.1 Hz, 1H); 13 C NMR(100MHz, CD3OD) δ: 168.90, 147.70, 136.43, 131.90, 131.61, 127.19, 121.08, 120.66, 118.70, 117.25, 111.01, 107.43, 93.60, 66.88, 53.20, 51.13, 32.16, 25.32, 22.85, 12.71.

[0116] Example 2

[0117] Weigh 42.0 mg of swertiain sample into a reaction tube, add 3.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the reaction, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as a desugaring product; weigh the desugaring product (0.1020 mmol), 23.3 mg (0.1224 mmol) of 5-methoxytryptamine and trifluoromethylsulfonate 3.7 mg (0.0102 mmol) of zinc sulfate was dissolved in 1 mL of hexafluoroisopropanol in a sealed tube, and the reaction was stirred at 35°C for 1 h. The reaction was monitored by TLC. After the reaction, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography. The eluent was a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 2:1), and compound a2 (yellow oil, 8.5 mg, two-step yield 20.6%) and compound a7 (yellow oil, 14.1 mg, two-step yield 34.4%) were obtained respectively. The molar ratio of compound a2 to compound a7 was 1:1.7.

[0118] Compound a2: Molecular formula is C 21 H 22 N2O3; HR-ESI-MS(m / z)351.1698[M+H] + , (calcdfor351.1703); (c=0.1,MeOH); UVλ max (MeOH) 204.7nm; IR (KBr) cm -1 : 3851, 3737, 3620, 3215, 2927, 1667, 1572, 1479, 1291, 1210, 1133, 932, 809 and 669; 1H NMR (400MHz, CDCl3) δ: 8.21 (s, 1H), 7.66 (d, J = 2.0Hz, 1H), 7.24 (d, J = 8.7Hz, 1H), 6.91 (d, J = 2.4Hz, 1H), 6.83 (dd, J = 8.7 ,2.5Hz,1H),5.80(dt,J=17.1,9.8Hz,1H),5.29(m,2H),4.60(d,J=2.5Hz,1H),4.29(ddd,J=11.1,4.1,2.3Hz,1H),4.06 (m,1H),3.88(d,J=5.9Hz,1H),3.85(s,3H),3.50(ddd,J=13.3,11.7,4.7Hz,1H),3.06(ddd,J=9.3,4.2,1.8Hz,1H),2.9 3(dddd,J=14.7,11.7,6.0,2.7Hz,1H),2.76(dd,J=16.2,4.3Hz,1H),2.57(d,J=12.7Hz,1H),1.73(m,1H),1.64(m,1H). 13 C NMR(100MHz, CDCl3)δ:167.66,154.48,147.02,135.79,132.75,130.97,127.86,118.57,112 .46,112.12,109.80,100.32,95.10,67.19,58.56,56.07,51.69,43.30,29.55,26.42,23.50.

[0119] Compound a7: Molecular formula is C 21 H 22 N2O3; HR-ESI-MS(m / z)351.1703[M+H] + , (calcdfor351.1703); (c=0.1,MeOH); UVλ max (MeOH) 205.1nm; IR (KBr) cm -1 : 3850, 3735, 3297, 2932, 1682, 1580, 1467, 1289, 1288, 1129, 801 and 650; 1H NMR (400MHz, CDCl3) δ: 7.67 (d, J = 2.1Hz, 1H), 7.57 (s, 1H), 7.21 (d, J = 8.8Hz, 1H), 6.92 (d ,J=2.5Hz,1H),6.83(dd,J=8.8,2.5Hz,1H),5.78(m,1H),5.55(d,J=2.2Hz,1H),4.40(dd d,J=11.3,4.1,2.3Hz,1H),4.12(td,J=11.9,11.3,2.1Hz,1H),3.90(dd,J=13.4,5.9Hz, 1H),3.85(s,3H),1.98(m,1H),1.95(dd,J=6.9,2.2Hz,3H),1.85(qd,J=12.5,4.0Hz,1H). 13 C NMR(100MHz, CDCl3)δ:166.94,154.50,146.84,132.66,132.46,130.59,128.02,120.42,112 .45,111.99,108.83,100.40,94.89,66.70,56.03,53.07,51.35,32.73,25.76,23.09,14.24.

[0120] Example 3

[0121] Weigh 50.0 mg of swertiain sample into a reaction tube, add 3.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the end, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as a desugaring product; weigh the desugaring product (0.1229 mmol), 26.3 mg (0.1475 mmol) of 5-fluorotryptamine and 4.5 mg (0.0123 mmol) of zinc trifluoromethanesulfonate, Dissolve it in a sealed tube with 1 mL of hexafluoroisopropanol, stir the reaction at 35°C for 1 h, and monitor the completion of the reaction by TLC. After the reaction, drain the solvent from the obtained product system, and purify the residue by silica gel column chromatography. The eluent is a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 2:1), and compound a3 (yellow oil, 6.0 mg, two-step yield 13.2%), compound a8 (yellow oil, 11.0 mg, two-step yield 24.3%) and compound b1 (yellow oil, 8.3 mg, two-step yield 18.3%) are obtained respectively. The molar ratio of compound a3, compound a8 and compound b1 is 1:1.8:1.4.

[0122] Compound a3: Molecular formula is C 20 H 19 FN2O2; HR-ESI-MS(m / z)339.1496[M+H] + , (calcdfor339.1503); (c=0.1,MeOH); UVλ max (MeOH) 224.5nm; IR (KBr) cm -1 : 3718, 2924, 1591, 1269, 808 and 670; 1 H NMR (400MHz, CDCl3) δ: 8.06 (s, 1H), 7.66 (d, J = 2.0Hz, 1H), 7.26 (d, J = 13.1Hz, 1H), 7.11 (dd, J = 9.3, 2.5Hz, 1H), 6 .93(td,J=9.0,2.6Hz,1H),5.81(dt,J=17.1,9.8Hz,1H),5.31(m,2H),4.61(d,J=2.2Hz,1H),4.31(m,1H),4.08( td,J=11.9,10.9,2.2Hz,1H),3.89(m,1H),3.49(d,J=2.0Hz,1H),3.02(dd,J=9.7,4.0Hz,1H),2.92(tdd,J=11.9 ,6.0,2.9Hz,1H),2.76(dd,J=15.4,4.6Hz,1H),2.56(d,J=6.8Hz,1H),1.75(qd,J=12.7,4.0Hz,1H),1.63(m,1H). 13 C NMR (100MHz, CDCl3) δ: 167.48, 160.27, 151.31, 146.89, 135.57, 133.69 (d, J = 2.6Hz), 132.33, 12 4.25,118.73,111.95,110.62,100.09,95.23,67.14,58.37,51.53,43.42,29.59,26.42,23.30.

[0123] Compound a8: Molecular formula is C 20 H 19 FN2O2; HR-ESI-MS(m / z)339.1500[M+H] + , (calcdfor339.1503); (c=0.1,MeOH); UVλ max (MeOH) 220nm; IR (KBr) cm -1: 3860, 2925, 1697, 1533, 1084, 814 and 670; 1 HNMR(400MHz, CDCl3)δ:7.67(d,J=2.1Hz,1H),7.23(dd,J=8.9,4.3Hz,1H),7.12(dd,J=9.3,2.5 Hz,1H),6.92(td,J=9.0,2.5Hz,1H),5.79(qd,J=6.9,2.1Hz,1H),5.55(t,J=2.2Hz,1H),4.40(d dd,J=11.2,4.1,2.3Hz,1H),4.13(m,1H),3.91(m,1H),3.64(ddd,J=13.4,11.7,4.7Hz,1H),2.9 5(dddd,J=14.8,11.7,5.5,2.5Hz,2H),2.80(m,1H),1.95(m,4H),1.85(qd,J=12.6,4.1Hz,1H). 13 C NMR (100MHz, CDCl3) δ: 166.92, 159.27, 146.80, 133.55, 132.46, 132.02, 128.0, 120.68, 111.86 (d, J=10 .2Hz),110.54,109.23,103.65(d,J=23.3Hz),94.94,66.69,52.95,51.23,32.74,25.75,22.93,14.29.

[0124] Compound b1: Molecular formula is C 20 H 19 FN2O2; HR-ESI-MS(m / z)339.1498[M+H] + , (calcdfor339.1503); (c=0.1,MeOH); UVλ max (MeOH) 224.2nm; IR (KBr) cm -1 :: 3725, 2962, 2357, 1714, 1413, 1262, 1036, 806 and 677; 1H NMR(400MHz, Acetone-d6)δ:7.66(d,J=1.7Hz,1H),7.36(dd,J=8.8,4.5Hz,1H),7.18(dd,J=9.8,2.6Hz ,1H),6.87(td,J=9.2,2.6Hz,1H),6.12(dt,J=17.3,9.9Hz,1H),5.47(dd,J=10.3,1.8Hz,1H),5.33(dd ,J=17.2,1.8Hz,1H),4.72(d,J=9.8Hz,1H),4.27(ddd,J=11.1,4.2,2.2Hz,1H),4.13(ddd,J=13.1,11. 1,2.1Hz,1H),3.95(m,1H),3.58(m,2H),3.12(q,J=7.4Hz,1H),2.78(m,1H),2.57(m,1H),1.36(m,2H). 13 C NMR(100MHz, Acetone-d6)δ:166.46,155.66,150.27,147.87,138.86,135.11,128.91,121.18,110.36(d,J =25.1Hz),108.68,103.52(d,J=22.6Hz),101.81,95.18,67.41,56.56,52.22,50.98,27.71,22.64,20.53.

[0125] Example 4

[0126] Weigh 32.2 mg of swertiain sample into a reaction tube, add 2.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the end, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as the desugaring product; weigh the desugaring product (0.0827 mmol), 5-chloro 19.3 mg (0.0992 mmol) of amine and 3.0 mg (0.0080 mmol) of zinc trifluoromethanesulfonate were dissolved in a sealed tube with 2 mL of anhydrous dichloromethane, and the mixture was stirred at 35°C for 1 h. The reaction was monitored to be complete by TLC. After the reaction, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography with a mixture of petroleum ether and ethyl acetate (volume ratio of petroleum ether to ethyl acetate 2:1) as the eluent to obtain compound a5 (light yellow oil, 14.0 mg, two-step yield 43.9%).

[0127] Compound a5: Molecular formula is C20 H 19 ClN2O2; HR-ESI-MS (m / z): 355.1206 [M+H] + , (calcd for 355.1208); (c = 0.1, MeOH); UVλ max (MeOH) 226.4 nm; IR (KBr) cm -1 : 3450, 3722, 1701, 1557, 1465, 1273, 1089, 806 and 606; 1 1H NMR (400 MHz, Acetone-d6) δ: 7.64 (d, J = 2.0 Hz, 1H), 7.43 (d, J = 1.9 Hz, 1H), 7.40 (d, J = 8.6 Hz, 1H), 7.32 (d, J = 2.3 Hz, 1H), 7.08 (dd, J = 8.7, 2.1 Hz, 1H), 5.76 (dt, J = 17.2, 9.9 Hz, 1H), 5.07 (dd, J = 10.3, 2.2 Hz, 1H), 5.01 (dd, J = 17.2, 2.2 Hz, 1H), 4.59 (d, J = 2.3 Hz, 1H), 4.28 (ddd, J = 11.1, 4.3, 2.2 Hz, 1H), 4.18 (m, 1H), 3.66 (m, 2H), 3.08 (ddd, J = 12.3, 7.8, 4.9 Hz, 2H), 2.84 (m, 1H), 2.56 (m, 1H), 1.80 (ddt, J = 13.5, 4.8, 2.3 Hz, 1H), 1.73 (ddd, J = 15.6, 11.2, 4.6 Hz, 1H); 13 13C NMR (100 MHz, Acetone-d6) δ: 166.16, 145.22, 138.55, 135.99, 129.52, 125.89, 124.83, 122.14, 118.81, 117.79, 113.62, 112.66, 95.31, 67.75, 54.86, 50.03, 32.62, 28.70, 26.74, 23.32.

[0128] Example 5

[0129] Weigh 30.3 mg (0.1546 mmol) of swertiarin aglycone, 49.4 mg (0.1855 mmol) of 5-benzyltryptamine and 10.1 mg (0.01546 mmol) of bismuth trifluoromethanesulfonate, put them into a sealed tube, add 1.5 mL of hexafluoroisopropanol, stir and react for 2 h in a water bath at 35 ° C, and monitor the reaction by TLC; after the reaction, drain the solvent in the obtained product system, and purify the residue by silica gel column chromatography, the eluent is a mixture of petroleum ether and ethyl acetate (volume ratio of petroleum ether to ethyl acetate is 2:1), and obtain compound a4 (yellow solid, 13.0 mg, yield is 26.8%) and compound a9 (yellow solid, 19.4 mg, yield is 40.2%), respectively, and the molar ratio of compound a4 to compound a9 is 2:3.

[0130] Compound a4: Molecular formula is C 27 H 26 N2O3; HR-ESI-MS m / z 427.2022[M+H] + (calcd427.2016). 1 H NMR (400MHz, CDCl3) δ7.65 (d, J = 2.1Hz, 1H), 7.47 (m, 2H), 7.39 (m, 2H), 7.32 (m, 1H), 7.24 (s, 0H), 7.00 (d,J=2.4Hz,1H),6.91(dd,J=8.8,2.4Hz,1H),5.80(dt,J=17.1,9.9Hz,1H),5.29(m,2H),5.09(d,J=3 .4Hz,2H),4.59(s,1H),4.29(m,1H),4.06(m,1H),3.87(dd,J=13.2,5.7Hz,1H),3.49(td,J=12.8,4.6 Hz,1H),3.02(dt,J=9.7,3.4Hz,1H),2.91(m,1H),2.75(m,1H),2.59(m,1H),2.01(m,1H),1.72(m,1H); 13 C NMR (101MHz, CDCl3) δ167.60,153.68,147.01,137.59,135.73,132.72,131.10,128.68,127.99,127.69,122.14 ,118.59,113.17,109.98,102.01,95.10,77.16,76.84,71.04,67.16,58.49,51.64,43.42,32.07,26.42,22.84.

[0131] Compound a9: Molecular formula is C 27 H26 N2O3; HR-ESI-MS m / z 427.2019 [M+H] + (calcd 427.2016). 1 1H NMR (400 MHz, CDCl3) δ 7.67 (d, J = 2.2 Hz, 1H), 7.47 (d, J = 8.1 Hz, 2H), 7.39 (m, 2H), 7.32 (m, 1H), 7.22 (d, J = 8.8 Hz, 1H), 7.01 (d, J = 2.6 Hz, 1H), 6.91 (dd, J = 8.7, 2.4 Hz, 1H), 5.77 (dd, J = 6.9, 2.3 Hz, 1H), 5.54 (s, 1H), 5.10 (s, 2H), 4.40 (m, 1H), 4.13 (td, J = 12.7, 12.0, 2.7 Hz, 1H), 3.90 (m, 1H), 3.64 (ddd, J = 13.4, 11.9, 4.8 Hz, 1H), 2.95 (m, 2H), 2.79 (m, 1H), 2.17 (m, 1H), 1.94 (dd, J = 6.8, 2.2 Hz, 3H), 1.85 (qd, J = 12.7, 4.2 Hz, 1H); 13 13C NMR (101 MHz, CDCl3) δ 169.21, 153.67, 146.84, 137.60, 132.68, 132.52, 129.24, 128.68, 127.98, 127.69, 120.42, 116.45, 113.14, 111.95, 108.90, 102.10, 94.89, 71.02, 66.70, 65.63, 53.05, 45.16, 31.12, 25.76, 23.07, 14.25.

[0132] Example 6

[0133] Weigh 60.0 mg of swertiain sample into a reaction tube, add 4.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the end, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as the desugaring product; weigh the desugaring product (0.1425 mmol), 5-hydroxy 30.1 mg (0.1710 mmol) of tryptamine and 5.2 mg (0.0143 mmol) of zinc trifluoromethanesulfonate were dissolved in a sealed tube with 2 mL of DMSO, and the mixture was stirred at 35°C for 2 h. The reaction was monitored to be complete by TLC. After the reaction, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 2:1) as the eluent to obtain compound a10 (white solid, 14.6 mg, two-step yield 25.9%).

[0134] Compound a10: Molecular formula: C 20 H 20 N2O3; English name: (13bS,14aS,E)-14-ethylidene-10-hydroxy-1,2,7,8,13,13b,14,14a-octahydro-4H-indolo[2,3-a]pyrano[3,4-g]quinolizin-4-one; HR-ESI-MS(m / z): 335.1400[M+H] + , (calcd for 335.1401); (c=0.1,MeOH); UVλ max (MeOH) 226.3nm; IR (KBr) cm -1 : 3844, 3731, 3619, 3254, 2955, 1667, 1573, 1461, 1206, 1124, 804 and 670; 1HNMR(400MHz,CD3OD)δ:7.63(d,J=1.9Hz,1H),7.08(d,J=8.6Hz,1H),6.71(d,J=2.3Hz,1H),6.56(dd,J=8.7,2.4Hz,1H),5.77( qd,J=6.9,2.1Hz,1H),5.64(d,J=2.0Hz,1H),4.32(ddd,J=11.1,4.1,2.2Hz,1H),4.11(ddd,J=13.0,11.1,2.0Hz,1H),3.94(dd, J=13.3,5.9Hz,1H),3.66(ddd,J=12.9,11.5,4.8Hz,1H),2.92(dq,J=11.9,2.2Hz,1H),2.83(dddd,J=14.5,11.7,6.1,2.6Hz,1 H),2.71(dd,J=15.1,5.0Hz,1H),1.99(ddd,J=13.2,5.4,2.5Hz,1H),1.88(dd,J=6.8,2.1Hz,3H),1.72(qd,J=12.7,4.1Hz,1H); 13 C NMR(100MHz,CD3OD)δ:170.33,151.51,149.09,134.05,133.04,132.61,129.30,121.90, 112.84,112.25,108.10,103.04,94.87,68.29,54.67,52.58,33.55,26.73,24.31,14.10.

[0135] Example 7

[0136] 31.8 mg (0.1622 mmol) of swertiarin aglycone, 33.9 mg (0.1947 mmol) of compound 5-methyltryptamine and 5.9 mg (0.0162 mmol) of zinc trifluoromethanesulfonate were weighed and placed in a sealed tube. After vacuum replacement with N2, 2 mL of hexafluoroisopropanol was added, and the reaction was stirred at 35 ° C in an oil bath for 1 h. The reaction was monitored by TLC. After the reaction was completed, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography. The eluent was a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 1.5:1), and compound a11 (yellow oil, 11.5 mg, yield 21.2%) and compound b2 (yellow oil, 23.0 mg, yield 42.5%) were obtained, respectively, and the molar ratio of compound a11 to compound b2 was 1:2.

[0137] Compound a11: Molecular formula is C 21 H 22N2O2; HR-ESI-MS m / z 335.1759[M+H] + (calcd335.1754). 1 H NMR (400MHz, MeOD) δ7.64(d,J=2.0Hz,1H),7.57(s,1H),7.21(m,2H),6.93(dd,J=8.3,1.8Hz,1H),5.78(qd,J=6. 9,2.3Hz,1H),5.61(t,J=2.3Hz,1H),4.37(m,1H),4.11(ddd,J=13.1,11.2,2.1Hz,1H),3.94(dd,J=13.3,5.5Hz,1 H),3.68(ddd,J=13.3,11.7,4.9Hz,1H),2.96(dddd,J=15.4,11.7,5.2,2.5Hz,2H),2.83(ddd,J=15.4,4.0,1.7Hz ,1H),2.39(s,3H),2.01(ddt,J=13.3,4.5,2.4Hz,1H),1.92(dd,J=6.9,2.1Hz,3H),1.80(qd,J=13.0,4.2Hz,1H); 13 C NMR(101MHz,MeOD)δ169.55,148.49,135.12,132.60,132.14,129.06,127.96,123.82,121. 42,118.06,111.72,107.92,94.36,67.71,54.07,52.21,32.87,26.00,23.84,21.62,14.14.

[0138] Compound b2: Molecular formula is C 21 H 22 N2O2; HR-ESI-MS m / z 335.1756[M+H] + (calcd335.1754). 1H NMR (400MHz, CDCl3) δ7.81(d,J=1.8Hz,1H),7.27(m,1H),7.19(d,J=8.2Hz,1H),7.01(dd,J=8.4,1.9Hz,1H),6.03(dt,J =17.4,9.8Hz,1H),5.62(dd,J=10.3,1.5Hz,1H),5.41(dd,J=17.2,1.6Hz,1H),4.58(d,J=10.0Hz,1H),4.40(ddd,J=11.2 ,4.2,2.2Hz,1H),4.20(ddd,J=13.1,11.2,2.1Hz,1H),3.78(dd,J=13.0,5.3Hz,1H),3.61(td,J=11.6,4.0Hz,1H),2.90 (dddd,J=14.1,11.6,5.4,2.4Hz,1H),2.77(m,1H),2.51(m,1H),2.44(d,4H),1.98(m,1H),1.45(qd,J=12.7,4.2Hz,1H); 13 C NMR (101MHz, CDCl3) δ167.47,147.96,139.01,134.09,131.77,129.27,126.50,124.09,121. 48,118.07,110.81,109.04,90.90,67.30,55.64,52.06,49.81,35.43,29.84,27.55,21.92.

[0139] Example 8

[0140] Weigh 27.2 mg (0.1388 mmol) of swertiarin aglycone, 29.7 mg (0.1666 mmol) of 6-fluorotryptamine and 5.1 mg (0.0140 mmol) of zinc trifluoromethanesulfonate into a sealed tube, replace the vacuum with N2, add 1.5 mL of hexafluoroisopropanol, stir and react for 1 h in an oil bath at 35 ° C, and monitor the reaction by TLC. After the reaction is completed, the solvent in the obtained product system is drained, and the residue is purified by silica gel column chromatography with a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 2:1) as the eluent to obtain compound a12 (yellow oil, 23.1 mg, yield 49.1%).

[0141] Compound a12: Molecular formula is C 20 H 19 FN2O2; HR-ESI-MS m / z 339.1503[M+H] + (calcd339.1503); 1H NMR (400MHz, MeOD) δ7.65(d,J=2.1Hz,1H),7.32(dd,J=8.7,5.3Hz,1H),7.02(dd,J=9.9,2.4Hz,1H),6.77 (m,1H),5.80(d,J=7.0Hz,1H),5.62(d,J=2.3Hz,1H),4.39(ddd,J=11.1,4.2,2.3Hz,1H),4.15(m,1H),3.9 6(ddd,J=13.2,5.9,2.3Hz,1H),3.69(tdd,J=13.4,5.0,2.2Hz,1H),2.96(dddd,J=14.7,11.9,6.2,3.1Hz, 2H),2.83(dd,J=14.6,5.4Hz,1H),2.01(m,1H),1.92(dt,J=7.0,1.8Hz,3H),1.81(qd,J=12.9,4.2Hz,1H); 13 C NMR (101MHz, MeOD) δ169.66,161.68,159.33,148.56,137.09,132.54(d,J=89.9Hz),124.53,121.72,119.05(d,J=10 .3Hz),108.54,108.25(d,J=24.2Hz),98.33(d,J=25.7Hz),94.56,67.80,54.03,52.15,32.95,26.12,23.80,14.15.

[0142] Example 9

[0143] Weigh 50.0 mg of swertiain sample into a reaction tube, add 3.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir in a 36°C water bath for 40 min; after the reaction, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as a desugaring product; weigh the desugaring product (0.1214 mmol), compound (Mb2) 31.7 mg (0.1457 mmol) and trifluoroacetic acid 1 μL (0.0121 mmol) were dissolved in a sealed tube with 1 mL of anhydrous methanol and stirred at 35°C for 12 h. The reaction was monitored to be complete by TLC. After the reaction, the solvent in the obtained product system was drained and the residue was purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 1:1) as the eluent to obtain compound c1 (yellow oil, 11.5 mg, two-step yield 21.9%).

[0144] Compound c1: Molecular formula is C 22 H 23 N3O3; HR-ESI-MS(m / z)378.1809[M+H] + , (calcdfor378.1812); (c=0.1,MeOH); UVλ max (MeOH) 222nm; IR (KBr) cm -1 : 3844, 3729, 3313, 2927, 1667, 1569, 1460, 1399, 1233, 1129, 940, 748 and 670; 1 H NMR(400MHz, Acetone-d6)δ:7.55(d,J=2.2Hz,1H),7.47(m,1H),7.28(dd,J=7.5,1.5Hz,1H),7.03(dtd,J=17 .3,7.2,1.4Hz,2H),5.78(qd,J=6.8,2.2Hz,1H),5.72(s,1H),4.76(d,J=7.1Hz,1H),4.28(ddd,J=11.2,4.2, 2.3Hz,1H),4.17(ddd,J=13.1,11.1,2.0Hz,1H),4.05(q,J=7.2Hz,1H),3.66(dd,J=15.8,1.9Hz,1H),3.00(m ,2H),2.81(d,J=4.6Hz,3H),1.88(dd,J=6.8,2.1Hz,3H),1.71(dd,J=12.7,4.2Hz,1H),1.19(t,J=7.1Hz,1H); 13 CNMR(100MHz,Acetone-d6)δ:169.73,165.74,147.92,137.24,132.96,132.36,128.45,122.21,121. 56,119.81,118.69,112.17,107.97,98.37,79.19,67.01,63.12,49.86,33.83,26.58,22.57,13.97.

[0145] Example 10

[0146] Weigh 51.0 mg of swertiain sample into a reaction tube, add 3.0 mg of β-glucosidase, dissolve with 2 mL (pH = 6.0) of citric acid-sodium citrate buffer solution, and stir the reaction in a 36°C water bath for 40 min; after the reaction, add ethyl acetate to extract the reaction solution, repeat three times, combine the organic phases, add anhydrous sodium sulfate to dry the organic phase, filter, and concentrate the obtained filtrate by rotary evaporation under reduced pressure to obtain a crude product containing swertiain aglycone, which is recorded as the desugaring product; weigh the desugaring product (1295 mmol), L-5-hydroxytryptophan methyl ester (Mc1) 36.4 mg (0.1554 mmol), zinc trifluoromethanesulfonate 4.7 mg (0.0130 mmol), dissolved in 1 mL of hexafluoroisopropanol in a sealed tube, stirred at 35 ° C for 12 h, and the reaction was completed after monitoring by TLC; after the reaction, the solvent in the obtained product system was drained, and the residue was purified by silica gel column chromatography, the eluent was a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate was 1:2), to obtain compound c2 (yellow oil, 11.4 mg, two-step yield 20.3%).

[0147] Compound c2: molecular formula is C 22 H 22 N2O5; HR-ESI-MS(m / z)395.1604[M+H] + , (calcdfor395.1601); (c=0.1, MeOH); UVλmax (MeOH) 205.2nm; IR (KBr) cm -1 : 3730, 3414, 2944, 1702, 1581, 1458, 1260, 1108, 806 and 668; 1 HNMR (400MHz, CD3OD) δ: 7.61 (d, J = 2.0Hz, 1H), 7.09 (d, J = 8.6Hz, 1H), 6.73 (d, J = 2.3Hz, 1H), 6. 61(dd,J=8.6,2.4Hz,1H),5.84(ddd,J=17.1,10.3,9.0Hz,1H),5.41(m,1H),5.26(dd,J=10.3, 1.8Hz,1H),4.86(d,J=3.2Hz,1H),4.27(dt,J=11.2,3.5Hz,1H),4.09(ddd,J=15.2,12.0,7.9H z,2H),3.77(m,1H),3.67(s,3H),3.61(d,J=9.7Hz,1H),3.05(m,1H),2.54(m,1H),1.69(m,2H); 13C NMR(100MHz,CD3OD)δ:171.71,168.75,161.23,149.05,140.6,136.8,133.25,131.0,118.76,1 12.70,112.6,107.23,103.05,96.44,72.90,68.73,63.06,56.02,53.06,43.52,30.79,27.20.

[0148] Embodiment 11

[0149] Weigh 22.7 mg (0.1158 mmol) of swertiarin aglycone, 32.4 mg (0.1390 ​​mmol) of compound Mc2 and 4.2 mg (0.0116 mmol) of zinc trifluoromethanesulfonate into a sealed tube, replace the vacuum with N2, add 2 mL of hexafluoroisopropanol, stir and react at 35 °C in an oil bath for 24 h, and monitor the reaction by TLC. After the reaction is completed, drain the solvent in the obtained product system, and purify the residue by silica gel column chromatography with a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 1:2) as the eluent to obtain compound c3 (yield 28.3 mg, yield 62.1%).

[0150] The compound c3 is a yellow solid; the molecular formula is C 22 H 23 N3O4; HR-ESI-MS(m / z)394.1769[M+H] + , (calcd for 394.1761); 1 HNMR(400MHz,MeOD)δ7.64(d,J=2.1Hz,1H),7.05(d,J=8.7Hz,1H),6.74(d,J=2.3Hz,1H), 6.56(dd,J=8.7,2.4Hz,1H),5.78(dd,J=6.8,2.1Hz,1H),5.65(d,J=2.2Hz,1H),4.66(d,J= 7.1Hz,1H),4.33(d,J=10.0Hz,1H),4.14(t,J=11.1Hz,1H),3.37(m,1H),2.92(m,2H),2.71 (s,3H),2.00(d,J=11.4Hz,1H),1.84(dd,J=6.8,2.1Hz,3H),1.73(qd,J=12.7,4.0Hz,1H); 13C NMR(101MHz,MeOD)δ171.93,169.91,151.49,149.89,132.85,132.78,132.67,129.23,122.39,1 12.81,112.36,106.94,103.16,97.63,68.47,63.90,50.84,33.84,26.70,26.63,23.66,14.05.

[0151] Example 12

[0152] Weigh 36.0 mg (0.2041 mmol) of swertiarin aglycone, 2.1 mg (0.2250 mmol) of Mc46 and 7.4 mg (0.0204 mmol) of zinc trifluoromethanesulfonate into a sealed tube, replace the vacuum with N2, add 2 mL of hexafluoroisopropanol, stir and react for 24 h in an oil bath at 35 ° C, and monitor the reaction by TLC. After the reaction is completed, the solvent in the obtained product system is drained, and the residue is purified by silica gel column chromatography with a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 1:1) as the eluent to obtain compound c4 (yellow solid, 24.2 mg, yield is 27.2%).

[0153] The compound c4 has a molecular formula of C 24 H 24 N2O6; HR-ESI-MS(m / z)437.1716[M+H] + , (calcdfor437.1707); 1 H NMR (400MHz, CDCl3) δ7.77(s,1H),7.57(d,J=2.6Hz,1H),7.19(d,J=2.6Hz, 1H),6.87(dd,J=8.7,2.6Hz,1H),6.00(s,1H),5.81(m,1H),4.57(d,J=7.1Hz ,1H),4.41(dt,J=11.4,3.8Hz,1H),4.15(m,1H),3.76(s,3H),3.39(d,J=15 .7Hz,1H),3.21(m,1H),2.97(m,1H),2.32(s,3H),1.96(m,4H),1.87(m,1H); 13C NMR (101MHz, CDCl3) δ170.68,170.30,166.53,146.76,144.60,133.55,132.49,132.41,127.77,121.35, 116.62,111.72,110.85,107.24,97.23,66.82,61.43,52.93,49.22,33.01,25.59,24.50,21.30,14.35.

[0154] Example 13

[0155] Weigh 30.4 mg (0.1551 mmol) of swertiarin aglycone, 46.2 mg (0.1861 mmol) of Mc5 and 5.63 mg (0.0155 mmol) of zinc trifluoromethanesulfonate into a sealed tube, replace the vacuum with N2, add 2 mL of hexafluoroisopropanol, stir and react for 1 d in an oil bath at 45 °C, and monitor the reaction by TLC. After the reaction is completed, the solvent in the obtained product system is drained, and the residue is purified by silica gel column chromatography with a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 1:1) as the eluent to obtain compound c5 (yellow solid, 22.7 mg, yield is 35.8%).

[0156] Compound c5: Molecular formula is C 23 H 25 N3O4; HR-ESI-MS(m / z)408.1925[M+H] + , (calcdfor408.1918); 1 H NMR (400MHz, MeOD) δ7.71(dt,J=4.6,2.0Hz,1H),7.37(dt,J=8.8,1.6Hz,1H),7.03(d,J=2.6Hz,1H),6.88( dd,J=8.8,2.4Hz,1H),6.36(ddd,J=17.7,10.1,8.1Hz,1H),5.58(m,2H),4.96(dt,J=4.2,2.0Hz,1H),4.62( d,J=6.1Hz,1H),4.52(m,1H),4.32(m,1H),3.94(s,3H),3.54(d,J=15.7Hz,1H),3.17(m,1H),2.96(dd,J=1 7.4,12.7Hz,1H),2.88(d,J=4.3Hz,3H),2.65(m,1H),2.15(dt,J=11.0,2.9Hz,1H),1.71(d,J=12.0Hz,1H); 13C NMR (101MHz, CDCl3) δ170.60,168.76,154.24,149.34,136.16,131.80,131.34,127.22,120.62,112 .57,112.46,108.65,100.34,99.40,68.53,63.24,56.18,53.94,46.59,32.00,28.30,26.61,23.36.

[0157] Test Example 1

[0158] 1. Experiment on the inhibitory activity of compounds on AChE

[0159] Acetylcholine (ACh) is an important neurotransmitter. When the acetylcholine content decreases, it will cause neurodegenerative diseases such as Alzheimer's disease. Acetylcholinesterase (AChE) is a specific cholinesterase that hydrolyzes acetylcholine. Therefore, the screening of efficient AChE inhibitors is the basis for the development of drugs for the treatment of neurodegenerative diseases. AChE can catalyze the degradation of its substrate analog iodine thioacetylcholine to generate thiocholine and acetic acid. The reaction product reacts with the color developer DTNB to generate a yellow substance with specific light absorption at 405nm. The mixed solution of the compound and AChE reacts at 37℃. If the compound has an inhibitory effect on AChE, the amount of AChE-catalyzed degradation of the substrate analog iodine thioacetylcholine will decrease, and the corresponding yellow compound generated by the reaction with DTNB will decrease, that is, the light absorption value at 405nm will decrease, so as to screen compounds with inhibitory activity.

[0160] Tacrine was selected as the positive control drug, and the direct inhibitory effect of the compound on acetylcholinesterase activity in vitro was detected by Ellman method. Experimental method references Ellman, GL; Courtney, KD; Andres, VJ; Featherstone, RMB Biochem Pharmacol, 1961, 7, 88-95.

[0161] 1.1 Experimental reagents and instruments

[0162] The experimental reagents and instruments used in this test example are shown in Table 1:

[0163] Table 1 Experimental reagents and instruments

[0164] Reagents company <![CDATA[Na2HPO4]]> Sigma-Aldrich Corporation <![CDATA[NaH2PO4]]> Sigma-Aldrich Corporation Acetylcholinesterase Sigma-Aldrich Corporation Thioacetylcholine iodide Sigma-Aldrich Corporation DTNB Sigma-Aldrich Corporation Tacrine Sigma-Aldrich Corporation Multiskan FC Thermo

[0165] 1.2 Experimental method for determining AChE inhibition rate

[0166] 1. Use phosphate buffer (each 100 mL of phosphate buffer contains 94.7 mL of 0.1 M Na2HPO4 solution; 5.3 mL of 0.1 M NaH2PO4 solution, and the pH is adjusted to 8.0) to dilute AChE to a 0.1 U / mL working solution;

[0167] 2. Prepare a 6.25 mM solution (working solution) of iodinated thioacetylcholine and DTNB in ​​phosphate buffer;

[0168] 3. The compound and crude extract were diluted with DMSO and water to 1mM and 2mg / mL working solutions respectively, ensuring that the DMSO concentration in the compound solutions of different concentrations was the same (all 2%), the final concentration of DMSO in the final reaction system was 0.1%, the final concentration of the compound was 50μM, and the final concentration of the crude extract was 100μg / mL. The positive control was tacrine, with a final concentration of 0.333μM; the negative control group (NC group) was a 2% DMSO solvent control.

[0169] 4. The reaction was carried out in a 96-well plate. The following reagents were added to the 96-well plate in sequence (the volume of the added reagents was the volume of one reaction), and each sample was repeated 3 times.

[0170] Plating: 200uL / well, the final concentration of the compound in each well is 50μM, the final concentration of the crude extract is 100μg / mL, and the final concentration of tacrine is 0.333μM.

[0171] In this test example, the reagents used in the Blank group, NC group, Tacrine group, and compound group, the order of adding samples, and the reaction termination concentrations of various reagents are shown in Table 2:

[0172] Table 2 Reagents used in each group and the order of sample addition

[0173]

[0174] 5. Within 1 hour after adding the color developer and substrate, measure the absorbance at 405 nm every 30 seconds.

[0175] 6. Select the sample absorbance value when the average absorbance value of the NC group is about 1, calculate the average absorbance value of the compound (compound measurement value-background value), and calculate the compound AChE inhibition rate according to (NC-compound absorbance average value) / NC*100%.

[0176] 1.3 AChE inhibition rate experimental results

[0177] (1) 405nm absorbance bar graph

[0178] The absorbance bar graph of different compounds at 405 nm is as follows Figure 1 and Figure 2 As shown, Figure 1 It is a bar graph of absorbance values ​​of compounds a5, a10, a1, a6, a2, a7, c2, a3, a8, b1 and c1 at 405 nm; Figure 2 It is a bar graph of the absorbance values ​​of compounds a4, a9, c3, a11, b2, a12, c4 and c5 at 405 nm.

[0179] (2) Inhibition rate

[0180] The calculation formula of inhibition rate is: inhibition rate = (NC-average absorbance value of compound) / NC*100%

[0181] The AChE inhibition rates of tacrine and compounds a5, a10, a1, a6, a2, a7, c2, a3, a8, b1 and c1 are shown in Table 3:

[0182] Table 3 AChE inhibition rate of different compounds

[0183]

[0184]

[0185] Note: The final concentration of tacrine reaction is 0.333 μM, and the final concentration of compound reaction is 50 μM;

[0186] “++” indicates that the inhibition rate is between 20% and 60%; “+++” indicates that the inhibition rate is >60%.

[0187] The AChE inhibition rates of tacrine and compounds a4, a9, c3, a11, b2, a12, c4 and c5 are shown in Table 4:

[0188] Table 4 AChE inhibition rate of different compounds

[0189] sample Inhibition rate (%) SD Inhibitory activity TA 60.19 1.62 — a4 47.51 1.63 ++ a9 36.21 0.34 ++ c3 17.22 1.82 + a11 15.89 3.84 + b2 41.84 2.71 ++ a12 17.97 2.29 + c4 25.33 2.1 ++ c5 19.29 4.16 +

[0190] Note: The final concentration of tacrine reaction is 0.333 μM, and the final concentration of compound reaction is 50 μM;

[0191] "+" indicates that the inhibition rate is between 10% and 20%; "++" indicates that the inhibition rate is between 20% and 60%.

[0192] 1.4AChE IC 50 Determination experimental method

[0193] 1. Use phosphate buffer (each 100 mL of phosphate buffer contains 94.7 mL of 0.1 M Na2HPO4 solution; 5.3 mL of 0.1 M NaH2PO4 solution, and the pH is adjusted to 8.0) to dilute AChE to a 0.1 U / mL working solution;

[0194] 2. Prepare a 6.25 mM solution (working solution) of iodinated thioacetylcholine and DTNB in ​​phosphate buffer;

[0195] 3. The compound was diluted with DMSO to form a concentration gradient. The positive control was tacrine, which was diluted with DMSO to form a concentration gradient; the negative control group (NC group) was a 2% DMSO solvent control.

[0196] 4. The reaction was carried out in a 96-well plate, with 200uL / well plate, and 3 replicates for each sample;

[0197] (1) Setting of compound and tacrine concentration gradient (diluted with 1% DMSO):

[0198] The specific data for setting the compound and tacrine concentration gradient are shown in Table 5:

[0199] Table 5 Compound and tacrine concentration gradient settings

[0200] TA concentration gradient setting Compound concentration gradient setting 2μM 100μM 1μM 50μM 0.5μM 30μM 0.2μM 10μM 0.04μM 3μM 0.008μM 1μM 0.0016μM 0.2μM

[0201] (2) Plate laying: 200uL / well, the final concentration of DMSO in each well was 0.1%, and 3 replicate wells were made for each sample.

[0202] In this test example, the reagents used in the Blank group, NC group, Tacrine group, and compound group, the order of adding samples, and the reaction termination concentrations of various reagents are shown in Table 6:

[0203] Table 6 Reagents used in each group and sample addition order

[0204]

[0205] 5. Within 1 hour after adding the colorimetric reagent and substrate, measure the absorbance at 405 nm every 30 seconds

[0206] 6. Select the sample absorbance value when the average absorbance value of the NC group is about 1, calculate the average absorbance value of the compound (compound measurement value-background value), and calculate the compound AChE inhibition rate according to (NC-compound absorbance average value) / NC*100%.

[0207] 1.5AChE IC 50 Experimental Results

[0208] 1. Inhibition rate:

[0209] The calculation formula of the inhibition rate is: inhibition rate = (NC-average value of compound absorbance) / NC*100%.

[0210] The AChE inhibition rates of different concentrations of tacrine and compounds a2, a7, a3 and a8 are shown in Tables 7 to 11:

[0211] Table 7 AChE inhibition rate of different concentrations of tacrine

[0212] TA (concentration μM) Inhibition rate (%) SD 2 87.546 0.333 1 82.090 0.459 0.5 74.177 0.770 0.2 55.449 0.115 0.04 25.861 0.185 0.008 2.453 0.536 0.0016 0.817 1.714

[0213] Table 8 AChE inhibition rate of compound a2 at different concentrations

[0214] a2(concentration μM) Inhibition rate (%) SD 100 70.909 1.009 50 62.841 0.626 30 35.146 0.985 10 12.725 3.196 3 3.036 1.032 1 -0.820 0.885 0.2 -6.068 0.746

[0215] Table 9 AChE inhibition rate of compound a7 at different concentrations

[0216]

[0217]

[0218] Table 10 AChE inhibition rate of compound a3 at different concentrations

[0219] a3 (concentration μM) Inhibition rate (%) SD 100 70.182 1.761 50 63.919 0.479 30 37.133 2.558 10 14.997 1.618 3 7.569 2.732 1 3.092 1.678 0.2 0.238 1.646

[0220] Table 11 AChE inhibition rate of compound a8 at different concentrations

[0221] a8 (concentration μM) Inhibition rate (%) SD 100 75.496 2.938 50 68.251 2.819 30 63.019 1.772 10 43.667 3.229 3 17.903 2.068 1 8.495 1.624 0.2 6.931 0.736

[0222] 2. AChE IC 50 result

[0223] AChE IC of tacrine and compounds a2, a7, a3, and a8 50 The results are shown in Table 12.

[0224] Table 12 AChE IC of tacrine and compounds a2, a7, a3 and a8 50 result

[0225] sample TA a2 a7 a3 a8 <![CDATA[IC 50 (μM)]]> 0.160 38.950 26.540 37.435 14.467 SD(μM) 0.003 1.073 1.579 0.953 1.176

[0226] The fitting curves of tacrine and compounds a2, a7, a3, and a8 were made using origin8 software. Figures 3 to 7 As shown. According to the analysis of IC 50 result.

[0227] According to the sample screening and IC 50 The results of the assay show that the inhibition rates of compounds a2, a7, a3, and a8 are substantially similar to those of tacrine at a final concentration of 50 μM, which demonstrates that the monoterpenoid indole alkaloids provided by the present invention can significantly inhibit AChE activity and have good application prospects.

[0228] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A monoterpenoid indole alkaloid having a structure shown in Formula I or Formula II: The R 1 is a hydrogen atom, X1, a methyl group, an ethyl group, a hydroxyl group, a methoxy group, a formyloxy group, an acetoxy group, a substituted benzyloxy group or an unsubstituted benzyloxy group; the substituted benzyloxy group has at least one substituent on the benzene ring, and the substituent is X2, a methyl group or a nitro group; X1 and X2 are halogen atoms; The R 2 It is a hydrogen atom, a carboxyl group, a hydroxymethyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a methylcarbamoyl group, an ethylcarbamoyl group, an propylcarbamoyl group, a benzylcarbamoyl group, a dimethylcarbamoyl group, a diethylcarbamoyl group or a dipropylcarbamoyl group.

2. The monoterpenoid indole alkaloid according to claim 1, characterized in that The X1 and X2 are independently -F, -Cl or -Br.

3. The monoterpenoid indole alkaloid according to claim 1 or 2, characterized in that The monoterpenoid indole alkaloid is any one of the following compounds a1-a12, b1-b2, c1-c5:

4. The method for preparing the monoterpenoid indole alkaloid according to any one of claims 1 to 3, comprising the following steps: The aglycone of swertiacoside and the reaction reagent Ma are subjected to a first Pictet-Spengeler reaction and a second Pictet-Spengeler reaction under the catalysis of a Lewis acid to obtain a monoterpenoid indole alkaloid having a structure shown in Formula I and Formula II; the Lewis acid is one or more of zinc trifluoromethanesulfonate, trifluoroacetic acid, aluminum trichloride, ferric chloride, boron trifluoride, potassium trifluoromethanesulfonate and lithium trifluoromethanesulfonate; The swertiacoside aglycone has a structure shown in Formula 1, and the reaction reagent Ma has a structure shown in Formula 2: The R 1 , R 2 As defined in Formula I and Formula II.

5. The preparation method according to claim 4, characterized in that: The temperature of the first Pictet-Spengeler reaction and the second Pictet-Spengeler reaction are independently 35 to 45° C., and the time is independently 1 to 30 h; The first Pictet-Spengeler reaction is carried out in the presence of a first organic solvent, wherein the first organic solvent is one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide and methanol; The second Pictet-Spengeler reaction is performed in the presence of a second organic solvent, and the second organic solvent is hexafluoroisopropanol.

6. The preparation method according to claim 4, characterized in that: The swertiain aglycone is obtained by hydrolyzing swertiain in the presence of β-glucosidase; the temperature of the hydrolysis reaction is 25-50° C., the time is 1-48 hours; and the hydrolysis reaction is carried out at a pH value of 5.0-7.

0.

7. Use of the monoterpenoid indole alkaloid according to any one of claims 1 to 3 in the preparation of AChE inhibitors.

8. Use of the monoterpenoid indole alkaloid according to any one of claims 1 to 3 in the preparation of a medicament for preventing and treating neurodegenerative diseases.

9. The use according to claim 7, characterized in that: The neurodegenerative disease is Alzheimer's disease.

10. A drug for preventing and treating neurodegenerative diseases, comprising the monoterpenoid indole alkaloid according to any one of claims 1 to 3 as an active ingredient.

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