Method for extracting coumarin from cnidium and application thereof

Abstract

The application discloses a method for extracting coumarin from Cnidium monnieri and application thereof. The method comprises the following steps: taking dried Cnidium monnieri as raw material, crushing the raw material to obtain coarse powder, and performing defatting treatment to obtain defatted coarse powder; adding the defatted coarse powder into 85-95% (volume concentration) ethanol aqueous solution, performing ball milling, microwave extraction, filtering to obtain filtrate I, and concentrating to obtain thick paste; then adding the thick paste into mixed solvent A, performing ultrasonic extraction under heating, filtering to obtain extraction liquid; finally, adding the extraction liquid into mixed solvent B, performing extraction, separating to obtain organic phase and aqueous phase, reducing and concentrating the organic phase to obtain solid I, adjusting the pH of the aqueous phase to 7.5-8, filtering to obtain filtrate II, adding hydrochloric acid solution into the filtrate II under stirring until the pH is 2-3, performing cold storage, and performing suction filtration to obtain solid II; and combining the solid I and the solid II, and drying to obtain the product. The method is simple, the total coumarin extraction rate is high, and the content is high. The method can be used for preparation of coumarin drugs, and has good market promotion value.

Description

Technical Field

[0001] This invention belongs to the field of Cnidium monnieri processing technology, specifically relating to a method and application for extracting coumarin from Cnidium monnieri. Background Technology

[0002] Cnidium monnieri (L.) Cuss., a plant belonging to the genus Cnidium in the family Umbelliferae, is the dried, ripe fruit of the plant. Cnidium monnieri is warm in nature, bitter and pungent in taste, and slightly toxic. It has the effects of drying dampness and dispelling wind, killing parasites and relieving itching, and warming the kidneys and strengthening yang. Externally, it dries dampness, kills parasites, and relieves itching; internally, it warms the kidneys, strengthens yang, dispels wind, and dries dampness. It is used to treat eczema and itching, damp-bi syndrome with lower back pain, kidney deficiency and impotence, infertility due to cold uterus, and trichomonal vaginitis. The pharmacological effects of Cnidium monnieri involve the immune, nervous, endocrine, cardiovascular, respiratory, and reproductive systems, mainly manifested as anti-inflammatory, anti-allergic, central nervous system depressant, antiarrhythmic, and antitumor effects.

[0003] The active components of Cnidium monnieri can be divided into coumarins and volatile oils. Among the volatile oils, sesquiterpenes are the most abundant components, along with esters and terpene alcohols. Coumarins are the main physiologically active components of Cnidium monnieri. Currently, six monomeric compounds have been isolated from Cnidium monnieri coumarins, including osthole (Ost), imperatorin (Imp), isopimpinellin, bergapten, xanthotoxol, and xanthotoxin. Pharmacological experiments have shown that total coumarins from Cnidium monnieri possess various biological activities such as anti-inflammatory, antioxidant, antimutagenic, antitumor, and antibacterial effects, thus showing broad clinical application prospects.

[0004] Currently, methods for extracting total coumarins from Cnidium monnieri include solvent extraction, alkali dissolution and acid precipitation, steam distillation, supercritical fluid extraction, membrane separation, and aqueous two-phase extraction. Separation methods often employ column chromatography, requiring elution with varying proportions of organic solvents. This results in large solvent consumption, long processing times, and significant environmental pollution. Supercritical fluid extraction and membrane separation require specialized or expensive equipment, leading to high costs and making them unsuitable for large-scale industrial production.

[0005] Patent application CN108904559A discloses a method for preparing coumarin components from Cnidium monnieri. The steps are as follows: Cnidium monnieri is pulverized, defatted by reflux with ether for 4-6 hours, dried, and then placed in an Erlenmeyer flask. Ethanol with a volume fraction of 85-95% is added, and the mixture is extracted 2-4 times under microwave power of 500-600W for 30-40 minutes each time, and kept at 45-55℃ with shaking for 1-2 hours. The mixture is filtered, and the extracts are combined. The extract is concentrated under reduced pressure to obtain an extract. The extract is separated by macroporous adsorption resin column chromatography. First, it is eluted with 6 column volumes of water, and the water elution fraction is discarded. Then, it is eluted with an ethanol gradient, and the 85% ethanol elution fraction is collected. Then, it is separated by silica gel column chromatography, and successively eluted with methanol-water at volume ratios of 85:1, 65:1, 32:1, and 15:1, and the 32:1 elution fraction is collected and concentrated to obtain the final product. The patent application first separates the components using macroporous adsorption resin column chromatography, followed by ethanol gradient elution, and then separates them again using silica gel column chromatography, followed by elution with methanol aqueous solutions of different concentrations. The consumption of ethanol and methanol is quite staggering, and the processing is lengthy, making it unsuitable for widespread application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method and application for extracting coumarin from Cnidium monnieri. The method is simple and yields high total coumarin content.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0009] (1) First, pulverize the dried Cnidium monnieri to 20-40 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0010] (2) Add the defatted crude powder to an 85-95% ethanol aqueous solution, ball mill, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste.

[0011] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0012] (4) Finally, the extract is added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase is concentrated under reduced pressure to obtain solid I. Solid I is stirred and dispersed in an 85-95% ethanol aqueous solution. The pH is adjusted to 7.5-8. The filtrate II is collected by filtration. While stirring, hydrochloric acid solution is added to filtrate II until the pH is 2-3. The solution is refrigerated and filtered to obtain solid II. The solid II is then dried to obtain the final product.

[0013] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

[0014] Preferably, in step (1), the specific method for degreasing is as follows: add 5 to 6 times its weight of ether to the coarse powder, reflux for degreasing for 4 to 5 hours, and then dry.

[0015] Preferably, in step (2), the ball milling process conditions are: ball-to-material mass ratio of 3 to 4:1, ball milling speed of 500 to 600 r / min, and ball milling time of 2 to 3 hours.

[0016] Preferably, in step (2), the microwave extraction process conditions are: 500-600W microwave treatment for 30-40 minutes.

[0017] Preferably, in step (2), the viscous paste has a relative density of 1.05 to 1.15 at 70°C.

[0018] Preferably, in step (3), the amount of mixed solvent A is 3 to 5 times the mass of the paste, and the mass ratio of 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate, N-methyl,butylpyrrolidine trifluoromethanesulfonate, and deionized water in mixed solvent A is 1:1.5 to 2:7 to 8.

[0019] Preferably, in step (3), the process conditions for heating and ultrasonic extraction are: ultrasonic oscillation treatment at 400-500W for 25-35 minutes at 40-50℃.

[0020] Preferably, in step (4), the amount of mixed solvent B is 3 to 4 times the volume of the extract.

[0021] Preferably, in step (4), the pH is adjusted to 7.5-8 using a sodium hydroxide solution with a mass concentration of 1-2%, and the hydrochloric acid solution has a mass concentration of 1-2%.

[0022] Preferably, in step (4), the refrigeration process conditions are refrigeration at 1-4°C for 12-15 hours.

[0023] Preferably, in step (4), the drying process conditions are: drying at 60-70℃ and 0.07-0.08MPa for 5-7 hours.

[0024] The above method is applied in the preparation of coumarin drugs.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention uses dried Cnidium monnieri as raw material, pulverizing it to 20-40 mesh to obtain coarse powder, which is then defatted to obtain defatted coarse powder. The defatted coarse powder is then added to an 85-95% (v / v) ethanol aqueous solution, ball-milled, microwave-extracted, and filtered to obtain filtrate I, which is concentrated to obtain a thick paste. The thick paste is then added to mixed solvent A, heated, and ultrasonically extracted, and filtered to obtain an extract. Finally, the extract is added to mixed solvent B, extracted, and the organic and aqueous phases are separated. The organic phase is concentrated under reduced pressure to obtain solid I. The pH of the aqueous phase is adjusted to 7.5-8, filtered, and filtrate II is obtained. While stirring, hydrochloric acid solution is added to filtrate II until the pH reaches 2-3. The solution is refrigerated and filtered to obtain solid II. Solids I and II are combined and dried to obtain the final product. This invention's method is simple, with a high extraction rate and high content of total coumarins. This method can be used for the preparation of coumarin-based pharmaceuticals and has significant market potential.

[0027] Microwave extraction is performed after ball milling to fully release the active ingredients in Cnidium monnieri and improve the microwave extraction rate.

[0028] The thick paste obtained by microwave extraction was subjected to ultrasonic extraction under heating in a mixed solvent A. Mixed solvent A was prepared by dispersing 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate in deionized water. Under the action of these two ionic liquids, 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate, the coumarin components in the thick paste were fully extracted.

[0029] The extract was obtained using a mixed solvent B, which was prepared by mixing anhydrous ethanol and ethyl acetate in a 1:1 volume ratio. Most of the coumarin components entered the organic phase, while a very small amount of coumarin components in the aqueous phase were separated by an alkaline dissolution and acid precipitation method. Specifically, the pH of the aqueous phase was adjusted to 7.5–8, and the solution was filtered to obtain filtrate II. Hydrochloric acid solution was added to filtrate II while stirring until the pH reached 2–3. The solution was then refrigerated and filtered to obtain solid II. This step further improved the total coumarin extraction rate, resulting in a product with a very high coumarin content. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise specified, all products in this invention were purchased through market channels.

[0032] Example 1

[0033] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0034] (1) First, pulverize the dried Cnidium monnieri to 20 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0035] (2) Add the defatted coarse powder to an 85% ethanol aqueous solution, ball mill, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste.

[0036] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0037] (4) Finally, the extract was added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase was concentrated under reduced pressure to obtain solid I. Solid I was stirred and dispersed in an 85% ethanol aqueous solution. The pH was adjusted to 7.5. The filtrate II was collected by filtration. Hydrochloric acid solution was added to filtrate II while stirring until the pH was 2. The solution was refrigerated and filtered to obtain solid II. The solid II was dried to obtain the final product.

[0038] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

[0039] In step (1), the specific method for degreasing is as follows: add 5 times the weight of the coarse powder to ether, reflux for 4 hours to degrease, and then dry.

[0040] In step (2), the ball milling process conditions are: ball-to-material mass ratio 3:1, ball milling speed 500 r / min, and ball milling time 2 hours.

[0041] In step (2), the microwave extraction process conditions are: 500W microwave treatment for 30 minutes.

[0042] In step (2), the viscous paste has a relative density of 1.05 at 70°C.

[0043] In step (3), the amount of mixed solvent A is 3 times the mass of the paste, and the mass ratio of 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate, N-methyl,butylpyrrolidine trifluoromethanesulfonate and deionized water in mixed solvent A is 1:1.5:7.

[0044] In step (3), the process conditions for heating and ultrasonic extraction are: 400W ultrasonic oscillation treatment for 25 minutes at 40℃.

[0045] In step (4), the amount of mixed solvent B is 3 times the volume of the extract.

[0046] In step (4), the pH is adjusted to 7.5 using a 1% sodium hydroxide solution and the hydrochloric acid solution has a mass concentration of 1%.

[0047] In step (4), the refrigeration process conditions are refrigeration at 1°C for 12 hours.

[0048] In step (4), the drying process conditions are: drying at 60℃ and 0.07MPa for 5 hours.

[0049] Example 2

[0050] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0051] (1) First, pulverize the dried Cnidium monnieri to 40 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0052] (2) Add the defatted coarse powder to a 95% ethanol aqueous solution, ball mill, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste.

[0053] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0054] (4) Finally, the extract was added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase was concentrated under reduced pressure to obtain solid I. Solid I was stirred and dispersed in a 95% ethanol aqueous solution. The pH was adjusted to 8. The filtrate II was collected by filtration. Hydrochloric acid solution was added to the filtrate II while stirring until the pH was 3. The solution was refrigerated and filtered to obtain solid II. The solid II was dried to obtain the final product.

[0055] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

[0056] In step (1), the specific method for degreasing is as follows: add 6 times its weight of ether to the coarse powder, reflux for 5 hours to degrease, and then dry.

[0057] In step (2), the ball milling process conditions are: ball-to-material mass ratio 4:1, ball milling speed 600 r / min, and ball milling time 3 hours.

[0058] In step (2), the microwave extraction process conditions are: 600W microwave treatment for 40 minutes.

[0059] In step (2), the viscous paste has a relative density of 1.15 at 70°C.

[0060] In step (3), the amount of mixed solvent A is 5 times the mass of the paste, and the mass ratio of 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate, N-methyl,butylpyrrolidine trifluoromethanesulfonate and deionized water in mixed solvent A is 1:2:8.

[0061] In step (3), the process conditions for heating and ultrasonic extraction are: 500W ultrasonic oscillation treatment for 35 minutes at 50℃.

[0062] In step (4), the amount of mixed solvent B is 4 times the volume of the extract.

[0063] In step (4), the pH is adjusted to 8 using a 2% sodium hydroxide solution and the hydrochloric acid solution has a 2% mass concentration.

[0064] In step (4), the refrigeration process conditions are refrigeration at 4°C for 15 hours.

[0065] In step (4), the drying process conditions are: drying at 70℃ and 0.08MPa for 7 hours.

[0066] Example 3

[0067] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0068] (1) First, pulverize the dried Cnidium monnieri to 20 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0069] (2) Add the defatted coarse powder to a 95% ethanol aqueous solution, ball mill, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste.

[0070] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0071] (4) Finally, the extract was added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase was concentrated under reduced pressure to obtain solid I. Solid I was stirred and dispersed in an 85% ethanol aqueous solution. The pH was adjusted to 8. The filtrate II was collected by filtration. Hydrochloric acid solution was added to the filtrate II while stirring until the pH was 2. The solution was refrigerated and filtered to obtain solid II. The solid II was dried to obtain the final product.

[0072] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

[0073] In step (1), the specific method for degreasing is as follows: add 5 times its weight of ether to the coarse powder, reflux for 5 hours to degrease, and then dry.

[0074] In step (2), the ball milling process conditions are: ball-to-material mass ratio 3:1, ball milling speed 600 r / min, and ball milling time 2 hours.

[0075] In step (2), the microwave extraction process conditions are: 600W microwave treatment for 30 minutes.

[0076] In step (2), the viscous paste has a relative density of 1.15 at 70°C.

[0077] In step (3), the amount of mixed solvent A is 3 times the mass of the paste, and the mass ratio of 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate, N-methyl,butylpyrrolidine trifluoromethanesulfonate and deionized water in mixed solvent A is 1:2:7.

[0078] In step (3), the process conditions for heating and ultrasonic extraction are: 400W ultrasonic oscillation treatment for 35 minutes at 50℃.

[0079] In step (4), the amount of mixed solvent B is 3 times the volume of the extract.

[0080] In step (4), the pH is adjusted to 7.5 using a 2% sodium hydroxide solution and the hydrochloric acid solution has a 2% mass concentration.

[0081] In step (4), the refrigeration process conditions are refrigeration at 1°C for 15 hours.

[0082] In step (4), the drying process conditions are: drying at 60℃ and 0.08MPa for 5 hours.

[0083] Example 4

[0084] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0085] (1) First, pulverize the dried Cnidium monnieri to 30 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0086] (2) Add the defatted coarse powder to a 90% ethanol aqueous solution, ball mill, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste;

[0087] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0088] (4) Finally, the extract was added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase was concentrated under reduced pressure to obtain solid I. Solid I was stirred and dispersed in a 90% ethanol aqueous solution. The pH was adjusted to 8. The filtrate II was collected by filtration. Hydrochloric acid solution was added to the filtrate II while stirring until the pH was 2.5. The solution was refrigerated and filtered to obtain solid II. The solid II was dried to obtain the final product.

[0089] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

[0090] In step (1), the specific method for degreasing is as follows: add 5.5 times its weight of ether to the coarse powder, reflux for 4.5 hours to degrease, and then dry.

[0091] In step (2), the ball milling process conditions are: ball-to-material mass ratio of 3.5:1, ball milling speed of 600 r / min, and ball milling time of 2.5 hours.

[0092] In step (2), the microwave extraction process conditions are: 600W microwave treatment for 35 minutes.

[0093] In step (2), the viscous paste has a relative density of 1.10 at 70°C.

[0094] In step (3), the amount of mixed solvent A is 4 times the mass of the paste, and the mass ratio of 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate, N-methyl,butylpyrrolidine trifluoromethanesulfonate and deionized water in mixed solvent A is 1:1.8:7.5.

[0095] In step (3), the process conditions for heating and ultrasonic extraction are: 450W ultrasonic oscillation treatment for 30 minutes at 45℃.

[0096] In step (4), the amount of mixed solvent B is 3.5 times the volume of the extract.

[0097] In step (4), the pH is adjusted to 8 using a 1.5% sodium hydroxide solution and the hydrochloric acid solution has a mass concentration of 1.5%.

[0098] In step (4), the refrigeration process conditions are refrigeration at 2°C for 13 hours.

[0099] In step (4), the drying process conditions are: drying at 65℃ and 0.08MPa for 6 hours.

[0100] Comparative Example 1

[0101] A method for extracting coumarin from Cnidium monnieri, the specific steps of which are as follows:

[0102] (1) First, pulverize the dried Cnidium monnieri to 20 mesh to obtain coarse powder, and then degrease it to obtain degreased coarse powder;

[0103] (2) Add the defatted crude powder to an 85% ethanol aqueous solution, microwave extract, filter to obtain filtrate I, and concentrate to obtain a thick paste.

[0104] (3) Then add the viscous paste to mixed solvent A, heat and extract with ultrasonication, and filter to obtain the extract;

[0105] (4) Finally, the extract was added to mixed solvent B for extraction and separation to obtain the organic phase. The organic phase was concentrated under reduced pressure to obtain solid I. Solid I was stirred and dispersed in an 85% ethanol aqueous solution. The pH was adjusted to 7.5. The filtrate II was collected by filtration. Hydrochloric acid solution was added to filtrate II while stirring until the pH was 2. The solution was refrigerated and filtered to obtain solid II. The solid II was dried to obtain the final product.

[0106] Wherein, the mixed solvent A is obtained by adding 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate and N-methyl,butylpyrrolidine trifluoromethanesulfonate to deionized water and stirring to disperse them evenly; the mixed solvent B is obtained by mixing anhydrous ethanol and ethyl acetate in a volume ratio of 1:1.

Claims

1. A method of extracting coumarin from Cnidium monnieri, characterized by, The specific steps are as follows: (1) first, the dried Cnidii Fructus is crushed to 20-40 meshes to obtain coarse powder, and the coarse powder is defatted to obtain defatted coarse powder; The specific method of defatting treatment is as follows: the coarse powder is added into 5-6 times of weight of ethyl ether, and refluxed for 4-5 hours, and then dried to obtain the defatted coarse powder; (2) then, the defatted coarse powder is added into 85-95% (volume concentration) ethanol aqueous solution, ball-milled, and subjected to microwave extraction, and then filtered to obtain filtrate I, and concentrated to obtain thick paste; The process conditions of microwave extraction are as follows: 500-600W microwave treatment for 30-40 minutes; the relative density of the thick paste is 1.05-1.15 at 70℃; the process conditions of ball-milling are as follows: the mass ratio of ball to material is 3-4:1, the ball-milling speed is 500-600r / min, and the ball-milling time is 2-3 hours; (3) then, the thick paste is added into mixed solvent A, and subjected to heating ultrasonic extraction, and then filtered to obtain extraction liquid; The process conditions of heating ultrasonic extraction are as follows: 400-500W ultrasonic oscillation treatment for 25-35 minutes at 40-50℃; (4) finally, the extraction liquid is added into mixed solvent B, and subjected to extraction, and then separated to obtain organic phase, and then reduced pressure concentrated to obtain solid I, and then the solid I is dispersed in 85-95% (volume concentration) ethanol aqueous solution, and then the pH value is adjusted to 7.5-8, and then filtered to obtain filtrate II, and then the filtrate II is added with hydrochloric acid solution while stirring until the pH value is 2-3, and then subjected to cold storage, and then subjected to suction filtration to obtain solid II, and then dried to obtain the product; wherein, the mixed solvent A is prepared by adding 1-butyl-2,3-dimethylimidazole trifluoromethanesulfonate and N-methyl, butyl pyrrolidine trifluoromethanesulfonate into deionized water and stirring to disperse uniformly; the mixed solvent B is prepared by mixing anhydrous ethanol and ethyl acetate according to a volume ratio of 1:1; The amount of the mixed solvent A is 3-5 times of the mass of the thick paste, and the mass ratio of 1-butyl-2,3-dimethylimidazole trifluoromethanesulfonate, N-methyl, butyl pyrrolidine trifluoromethanesulfonate and deionized water in the mixed solvent A is 1:1.5-2:7-8, and the amount of the mixed solvent B is 3-4 times of the volume of the extraction liquid.

2. The method of claim 1, wherein, In step (4), the pH value is adjusted to 7.5-8 by using 1-2% (mass concentration) sodium hydroxide solution, and the mass concentration of the hydrochloric acid solution is 1-2%.

3. The method of claim 1, wherein, In step (4), the process conditions of cold storage are as follows: cold storage for 12-15 hours at 1-4℃; in step (4), the process conditions of drying are as follows: drying for 5-7 hours at 60-70℃ and 0.07-0.08MPa.

4. The use of the method according to any one of claims 1-3 in the preparation of coumarin drugs.