Method for extracting puerarin from radix puerariae based on resin extraction technology

Abstract

The invention discloses a method for extracting puerarin from radix puerariae based on a resin extraction technology, and relates to the field of plant extraction. The method comprises the following steps: firstly, crushing a radix puerariae raw material, pre-extracting by using a hydrous ethanol liquid, and then carrying out dynamic adsorption and elution treatment by using a modified resin adsorbent. And eluting the puerarin adsorbed by the resin from the eluent by using ethanol with a certain concentration, then removing the ethanol through vacuum concentration, and further purifying to finally obtain the puerarin. Compared with a traditional solvent soaking or water boiling method, the method has the advantages of high extraction efficiency, good purity, short operation time, strong environmental protection property, cost reduction and the like, and is suitable for industrial scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plant extraction, and in particular to a method for extracting puerarin from pueraria lobata based on resin extraction technology. BACKGROUND

[0002] Puerarin is one of the main active ingredients extracted from pueraria lobata and is widely used in traditional Chinese medicine, health products, cosmetics, and food industries. Puerarin has various pharmacological functions such as antioxidant, anti-inflammatory, vasodilation, blood lipid regulation, and cardiovascular and cerebrovascular health improvement, and has high medicinal and economic value. With the increasing awareness of health and the spread of traditional Chinese medicine culture, the demand for puerarin is increasing year by year. Therefore, how to efficiently, environmentally, and cost-effectively extract puerarin has become an important direction for current technical research and development.

[0003] Currently, traditional methods for extracting puerarin include water extraction, solvent extraction, and ultrasonic extraction. Water extraction is generally used for the preliminary extraction of pueraria lobata, but it has low water solubility, low extraction efficiency, and long extraction time. Solvent extraction usually uses solvents such as ethanol and methanol, but this method has problems such as solvent pollution, high energy consumption, and difficulty in solvent recovery. Ultrasonic extraction has improved extraction efficiency, but still has certain energy consumption problems and limited application scope.

[0004] In recent years, resin extraction technology has received widespread attention as an efficient and environmentally friendly separation and extraction method. Resin extraction technology uses highly selective resins to adsorb and enrich target components, has high separation efficiency and strong selectivity, and can extract and enrich target substances in a short time. Compared with traditional solvent extraction methods, resin extraction has the advantages of less solvent usage, simple operation, and high extraction efficiency. Many studies have shown that resin extraction technology has good application prospects in the separation and purification of plant extracts.

[0005] Although existing resin extraction technology has shown advantages in extraction efficiency and environmental friendliness, it still faces some challenges in large-scale industrial production of puerarin, such as the selectivity and adsorption capacity of resins, the concentration and proportion of solvents, the economy and stability of operations, and other issues. Therefore, developing an efficient, environmentally friendly, and large-scale production suitable resin extraction process is still an urgent task. SUMMARY

[0006] Based on the above background technology, the present application proposes a method for extracting puerarin from pueraria lobata based on resin extraction technology, and the technical solution is as follows: A method for extracting puerarin from pueraria lobata based on resin extraction technology, comprising the following steps, in terms of mass fraction: 1000 parts of the raw material of pueraria by mass fraction is crushed into coarse powder, and sieved to 60-80 mesh, and 3500-4500 parts of ethanol solution is added; The modified resin adsorbent is selected as the extraction resin, the addition amount of the extraction resin is 4.5-5.5 times of the mass of the pueraria powder, the resin is loaded into a resin bed, the ethanol solution is passed through the resin bed at a set flow rate in a liquid phase flow extraction mode, the extraction liquid continues to flow out after passing through the resin bed, and the extraction process is continuously carried out for 6-8 hours. The extraction liquid is filtered, and the ethanol is removed by vacuum concentration to obtain a crude extract of puerarin; and the crude extract is purified to obtain a puerarin finished product.

[0007] In an embodiment of the present application, the concentration of the ethanol solution is 60-80 wt%.

[0008] In an embodiment of the present application, the preparation method of the modified resin adsorbent is as follows: 100 parts of dry macroporous sulfonic acid resin and 14-20 parts of indole-3-formyl chloride, 1200-1500 parts of dichloromethane are added into a three-necked flask, 0.9-1.6 parts of 4-dimethylaminopyridine is added, and the reaction is stirred at 25-40°C in the dark for 10-14 hours. After the reaction is completed, the resin is collected by suction filtration, washed with 80-100 parts of dichloromethane, and then washed with 60-80 parts of anhydrous ethanol, and then dried in a vacuum drying oven at 45-55°C for 6-8 hours, the vacuum degree of the drying oven is -0.08~-0.1 MPa, and the modified resin adsorbent is obtained after cooling.

[0009] In an embodiment of the present application, the dry macroporous sulfonic acid resin is selected from D001, D006 or A15 macroporous sulfonic acid resin.

[0010] In an embodiment of the present application, the resin loading mode is a columnar or layered structure, and the height of the resin bed is 20-30 cm.

[0011] In an embodiment of the present application, the extraction temperature of the extraction process is 45-60°C.

[0012] In an embodiment of the present application, the flow rate of the ethanol solution is 1.0-2.0 mL / min, the ethanol solution flows into the top of the resin bed, flows out from the bottom after passing through the resin bed, and the whole process is maintained at a constant flow rate.

[0013] In an embodiment of the present application, the vacuum concentration parameters are as follows: the pressure is 30-150 mmHg, and the temperature is 40-60°C.

[0014] In an embodiment of the present application, the purification step comprises: The crude extract is subjected to column chromatography using silica gel or C18 column, and the eluent is ethanol: water with a volume ratio of 1:1. The eluted liquid is concentrated under vacuum.

[0015] Reaction mechanism Catalytic activation and nucleophilic attack: 4-dimethylaminopyridine (DMAP) is an efficient catalyst for acylation reactions. The nitrogen atom on the pyridine ring can form an active acyl-DMAP complex with the acyl chloride group (-COCl) in indole-3-formyl chloride. This complex can significantly enhance the electrophilicity of the acyl chloride group. Subsequently, the hydroxyl group (-OH, an active group introduced during resin preparation or pretreatment) on the macroporous sulfonic acid resin (D001 / D006 / A15) skeleton acts as a nucleophile, attacking the acyl carbon atom in the acyl-DMAP complex, resulting in a nucleophilic substitution reaction and forming an ester bond (-O-CO-). Simultaneously, DMAP is released, completing the catalytic cycle and achieving the grafting of the indole ring to the resin skeleton through an ester bond.

[0016] Resin skeleton stability guarantee: The cross-linked structure of macroporous sulfonic acid resin (such as styrene-divinylbenzene cross-linked skeleton) has good swelling properties in dichloromethane solvent, which can fully expose the internal hydroxyl group, improving the contact efficiency with indole-3-formyl chloride. The reaction temperature is controlled at 25-40℃, avoiding high temperature-induced degradation or destruction of the resin skeleton, while the low temperature environment can reduce the hydrolysis side reaction of indole-3-formyl chloride, ensuring the directional progress of the acylation reaction.

[0017] The present application uses resin extraction technology to efficiently extract puerarin from pueraria, which has the following significant technical effects: 1. Improve extraction efficiency: By optimizing the selection of resin and extraction process parameters, the extraction efficiency of puerarin is significantly improved. Compared with traditional solvent extraction method, resin extraction method can realize efficient component enrichment in a shorter time, and greatly reduce the time and operation cost required for extraction.

[0018] 2. Improve the purity of puerarin: The modified resin adsorbent has high selectivity and adsorption capacity, which can effectively remove impurities such as sugars and fatty acids in pueraria, improving the purity of puerarin.

[0019] 3. Reduce solvent consumption and environmental friendliness: Compared with traditional solvent extraction method, resin extraction method greatly reduces the amount of solvent used, and the solvent used (such as ethanol) is easy to recover, reducing solvent pollution and environmental burden. In addition, the extraction process does not involve high-temperature heating, which can effectively reduce energy consumption.

[0020] 4. Improve the recovery rate of target product: In the method, the recovery rate of puerarin can reach more than 80%, which is significantly higher than the recovery rate of the traditional method. Through high-efficiency resin adsorption and fine extraction process, there is almost no waste of raw materials in the extraction process, thereby improving the resource utilization rate.

[0021] 5. Effect of modified resin adsorbent Improve the adsorption selectivity and capacity of impurities: the indole ring introduced after modification has a conjugated π system, which can specifically adsorb phenolic impurities (such as chlorogenic acid, caffeic acid) and alkaloid impurities in the puerarin extract through π-π stacking action; at the same time, the original sulfonic acid group (-SO3H) of the resin can adsorb sugar impurities through electrostatic action, the double active sites synergistically improve the impurity adsorption capacity, and the adsorption interference rate of puerarin is reduced, thereby ensuring the purity of puerarin. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Figure 1 is a diagram of a puerarin production device; Figure 2 Figure 2 is a diagram of a puerarin beverage. DETAILED DESCRIPTION

[0023] The characteristics of the present application are further illustrated by the following examples, but the protection scope of the patent is not limited by the examples. Example 1

[0024] A method for extracting puerarin from pueraria based on resin extraction technology, comprising the following steps: 1000g of pueraria raw material is crushed into coarse powder, and sieved to 60 mesh, and 3500g of 60wt% ethanol solution is added; A modified resin adsorbent (D001 macroporous sulfonic acid resin) is selected as the extraction resin, and the addition amount of the extraction resin is 4500g (4.5 times the mass of the pueraria powder), the resin is packed in a columnar structure into a resin bed layer, and the height of the resin bed layer is 20cm; liquid phase flow extraction is adopted, the ethanol solution is flowed into the top of the resin bed layer at a flow rate of 1.0mL / min, and flowed out from the bottom after passing through the resin bed layer, and the extraction process is continuously carried out at 45℃ for 6h; The filtrate is obtained, and the ethanol is removed by vacuum concentration under the conditions of 30mmHg pressure and 40℃ to obtain the crude extract of puerarin; The crude extract is purified by column chromatography: a silica gel column is selected, the eluent is ethanol: water (volume ratio 1:1), and the eluted liquid is concentrated by vacuum to obtain the finished product of puerarin.

[0025] The preparation method of the modified resin adsorbent: Put 100 g of dry D001 dry base macroporous sulfonic acid resin, 14 g of indole-3-formyl chloride, and 1200 g of dichloromethane into a three-necked flask, add 0.9 g of 4-dimethylaminopyridine, and stir the reaction at 25°C in the dark for 10 h; After the reaction is completed, the resin is collected by suction filtration, washed with 80 g of dichloromethane, and then washed with 60 g of anhydrous ethanol, and then placed in a 45°C vacuum drying oven (vacuum degree -0.08 MPa) for drying for 6 h. After cooling, the modified resin adsorbent is obtained.

[0026] HPLC analysis shows that the purity of puerarin in the extract is 92.8%, and the recovery rate of puerarin is 85.5%. Example 2

[0027] A method for extracting puerarin from pueraria by resin extraction technology, comprising the following steps: Grind 1000 g of pueraria raw material into coarse powder, sieve to 70 mesh, and add 3800 g of 65 wt% ethanol solution; Select the modified resin adsorbent (D006 macroporous sulfonic acid resin) as the extraction resin, and the amount of resin added is 4800 g (4.8 times the mass of pueraria powder). The resin is packed in a layered structure in the resin bed layer, and the height of the resin bed layer is 23 cm. The ethanol solution is flowed into the top of the resin bed layer at a flow rate of 1.3 mL / min, and flows out from the bottom after passing through the resin bed layer. The extraction process is continuously carried out at 50°C for 6.5 h. Filter to obtain the extract, and remove ethanol by vacuum concentration at a pressure of 60 mmHg and a temperature of 45°C to obtain the crude extract of puerarin; Purify the crude extract by column chromatography: select a C18 column, and use ethanol: water (volume ratio 1:1) as the eluent. The eluted liquid is concentrated under vacuum to obtain the finished product of puerarin.

[0028] The preparation method of the modified resin adsorbent: Put 100 g of dry D006 dry base macroporous sulfonic acid resin, 16 g of indole-3-formyl chloride, and 1300 g of dichloromethane into a three-necked flask, add 1.1 g of 4-dimethylaminopyridine, and stir the reaction at 30°C in the dark for 11 h; After the reaction is completed, the resin is collected by suction filtration, washed with 85 g of dichloromethane, and then washed with 65 g of anhydrous ethanol, and then placed in a 48°C vacuum drying oven (vacuum degree -0.085 MPa) for drying for 6.5 h. After cooling, the modified resin adsorbent is obtained.

[0029] HPLC analysis shows that the purity of puerarin in the extract is 93.4%, and the recovery rate of puerarin is 85.9%. Example 3

[0030] A method for extracting puerarin from pueraria by resin extraction technology, comprising the following steps: 1000g of pueraria raw material is crushed into coarse powder, sieved to 75 mesh, and 4200g of 75wt% ethanol solution is added; A modified resin adsorbent (A15 macroporous sulfonic acid resin) is selected as the extraction resin, and the amount of resin added is 5200g (5.2 times the mass of pueraria powder). The resin is packed into the resin bed in a columnar structure, and the height of the resin bed is 27cm. The ethanol solution is flowed into the top of the resin bed at a flow rate of 1.7mL / min, and flows out from the bottom after passing through the resin bed. The extraction process is carried out continuously at 55℃ for 7.5h. The filtrate is obtained by filtration, and the ethanol is removed by vacuum concentration at a pressure of 120mmHg and a temperature of 55℃ to obtain a crude extract of puerarin; The crude extract is purified by column chromatography: a silica gel column is selected, and the eluent is ethanol:water (1:1 by volume). The eluted liquid is concentrated under vacuum to obtain the finished product of puerarin.

[0031] The preparation method of the modified resin adsorbent: 100g of dried A15 dry-based macroporous sulfonic acid resin, 18g of indole-3-formyl chloride, and 1400g of dichloromethane are added to a three-necked flask, 1.4g of 4-dimethylaminopyridine is added, and the reaction is stirred at 35℃ in the dark for 13h. After the reaction is completed, the resin is collected by suction filtration, washed with 95g of dichloromethane, and then washed with 75g of anhydrous ethanol. It is dried in a vacuum drying oven (vacuum degree-0.095MPa) at 52℃ for 7.5h. After cooling, the modified resin adsorbent is obtained.

[0032] HPLC analysis shows that the purity of puerarin in the extract is 94.0%, and the recovery rate of puerarin is 86.2%. Example 4

[0033] A method for extracting puerarin from pueraria by resin extraction technology, comprising the following steps: 1000g of pueraria raw material is crushed into coarse powder, sieved to 80 mesh, and 4500g of 80wt% ethanol solution is added; A modified resin adsorbent (D001 macroporous sulfonic acid resin) is selected as the extraction resin, and the amount of resin added is 5500g (5.5 times the mass of pueraria powder). The resin is packed into the resin bed in a layered structure, and the height of the resin bed is 30cm. The ethanol solution is flowed into the top of the resin bed at a flow rate of 2.0mL / min, and flows out from the bottom after passing through the resin bed. The extraction process is carried out continuously at 60℃ for 8h. The filtrate was obtained, and the ethanol was removed by vacuum concentration under the condition of 150 mmHg pressure and 60°C to obtain the crude extract of puerarin; The crude extract was purified by column chromatography: a C18 column was selected, the eluent was ethanol: water (1:1 by volume), and the eluted liquid was concentrated by vacuum to obtain the finished product of puerarin.

[0034] The preparation method of the modified resin adsorbent: 100 g of dried D001 dry base macroporous sulfonic acid resin, 20 g of indole-3-formyl chloride, and 1500 g of dichloromethane were added to a three-necked flask, 1.6 g of 4-dimethylaminopyridine was added, and the reaction was stirred at 40°C in the dark for 14 h; After the reaction was completed, the resin was collected by suction filtration, washed with 100 g of dichloromethane, and then washed with 80 g of anhydrous ethanol, and then placed in a vacuum drying oven (vacuum degree -0.1 MPa) at 55°C for 8 h. After cooling, the modified resin adsorbent was obtained.

[0035] HPLC analysis showed that the purity of puerarin in the extract was 94.3%, and the recovery rate of puerarin was 86.7%.

[0036] Comparative Example 1 A method for extracting puerarin from pueraria based on resin extraction technology, comprising the following steps: 1000 g of pueraria raw material was crushed into coarse powder, sieved to 60 mesh, and 3500 g of 60 wt% ethanol solution was added; D001 macroporous sulfonic acid resin was selected as the extraction resin, and the amount of resin added was 4500 g (4.5 times the mass of pueraria powder). The resin was packed in a columnar structure in the resin bed layer, and the height of the resin bed layer was 20 cm. The liquid phase flow extraction method was used, and the ethanol solution was flowed into the top of the resin bed layer at a flow rate of 1.0 mL / min, and flowed out from the bottom after passing through the resin bed layer. The extraction process was continuously carried out at 45°C for 6 h. The filtrate was obtained, and the ethanol was removed by vacuum concentration under the condition of 30 mmHg pressure and 40°C to obtain the crude extract of puerarin; The crude extract was purified by column chromatography: a silica gel column was selected, the eluent was ethanol: water (1:1 by volume), and the eluted liquid was concentrated by vacuum to obtain the finished product of puerarin.

[0037] HPLC analysis showed that the purity of puerarin in the extract was 89.6%, and the recovery rate of puerarin was 83.6%.

[0038] Comparative Example 2 A method for extracting puerarin from pueraria based on resin extraction technology, comprising the following steps: 1000g of the raw material of puerariae radix is crushed into coarse powder, which is sieved to 60 mesh, and 3500g of 60wt% ethanol solution is added; A modified resin adsorbent (D001 macroporous sulfonic acid resin) is selected as the extraction resin, and the amount of resin added is 4500g (4.5 times the mass of the puerariae radix powder). The resin is packed into the resin bed in a columnar structure, and the height of the resin bed is 20cm. In the liquid phase flow extraction mode, the ethanol solution is flowed into the top of the resin bed at a flow rate of 1.0mL / min, and flows out from the bottom after passing through the resin bed. The extraction process is continuously carried out at 45℃ for 6h. The extraction liquid is filtered, and the ethanol is removed by vacuum concentration under the conditions of 30mmHg pressure and 40℃ to obtain the crude extract of puerarin; The crude extract is purified by column chromatography: a silica gel column is selected, and the eluent is ethanol: water (volume ratio 1:1). The eluted liquid is concentrated under vacuum to obtain the finished product of puerarin.

[0039] The preparation method of the modified resin adsorbent is as follows: 100g of dried D001 dry-based macroporous sulfonic acid resin and 1200g of dichloromethane are added to a three-necked flask, 0.9g of 4-dimethylaminopyridine is added, and the reaction is stirred at 25℃ in the dark for 10h. After the reaction is completed, the resin is collected by suction filtration, washed with 80g of dichloromethane, and then washed with 60g of anhydrous ethanol. The resin is dried in a vacuum drying oven (vacuum degree-0.08MPa) at 45℃ for 6h. After cooling, the modified resin adsorbent is obtained.

[0040] HPLC analysis shows that the purity of puerarin in the extraction liquid is 91.0%, and the recovery rate of puerarin is 84.2%.

[0041] Comparative Example 3 A method for extracting puerarin from puerariae radix based on resin extraction technology, comprising the following steps: 1000g of the raw material of puerariae radix is crushed into coarse powder, which is sieved to 60 mesh, and 3500g of 60wt% ethanol solution is added; A modified resin adsorbent (D001 macroporous sulfonic acid resin) is selected as the extraction resin, and the amount of resin added is 4500g (4.5 times the mass of the puerariae radix powder). The resin is packed into the resin bed in a columnar structure, and the height of the resin bed is 20cm. In the liquid phase flow extraction mode, the ethanol solution is flowed into the top of the resin bed at a flow rate of 1.0mL / min, and flows out from the bottom after passing through the resin bed. The extraction process is continuously carried out at 45℃ for 6h. The extraction liquid is filtered, and the ethanol is removed by vacuum concentration under the conditions of 30mmHg pressure and 40℃ to obtain the crude extract of puerarin; The crude extract is purified by column chromatography: a silica gel column is selected, the eluent is ethanol: water (1:1 by volume), the eluted liquid is concentrated by vacuum, and the puerarin finished product is obtained.

[0042] The preparation method of the modified resin adsorbent: 100 g of dried D001 dry base macroporous sulfonic acid resin, 14 g of indole-3-formyl chloride, and 1200 g of dichloromethane are added to a three-necked flask, and stirred at 25°C in the dark for 10 h; After the reaction is completed, the resin is collected by suction filtration, washed with 80 g of dichloromethane, and then washed with 60 g of anhydrous ethanol, and then dried in a vacuum drying oven (vacuum degree -0.08 MPa) at 45°C for 6 h, and then cooled to obtain the modified resin adsorbent.

[0043] HPLC analysis shows that the purity of puerarin in the extract is 91.4%, and the recovery rate of puerarin is 84.5%.

[0044] The above examples, comparative examples, and test results verify the technical effects of the resin extraction method of the present application, especially the significant advantages in improving extraction efficiency, purity, and reducing solvent consumption.

[0045] It is easy to understand that, based on the several embodiments provided in the present application, a person skilled in the art can combine, split, recombine, etc. the embodiments of the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0046] The above specific embodiments further detail the purposes, technical solutions, and beneficial effects of the embodiments of the present application. It should be understood that the above is only a specific embodiment of the present application, and is not intended to limit the protection scope of the embodiments of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A method for extracting puerarin from Pueraria montana var. lobata by resin extraction technique, characterized by, The method comprises the following steps, in terms of mass fraction: 1000 parts of ginseng raw material is crushed into coarse powder, which is sieved to 60-80 mesh, and 3500-4500 parts of ethanol solution is added; The modified resin adsorbent is selected as the extraction resin, and the addition amount of the extraction resin is 4.5-5.5 times the mass of the ginseng powder. The extraction resin is loaded into a resin bed layer. The ethanol solution is passed through the resin bed layer at a set flow rate by using liquid phase flow extraction. The extraction liquid continues to flow out after passing through the resin bed layer. The extraction process is continuously carried out for 6-8 hours. The extraction liquid is filtered, and the ethanol is removed by vacuum concentration to obtain a crude extract of ginsenoside. The crude extract is purified to obtain a ginsenoside finished product. The modified resin adsorbent is prepared by reaction of dry base macroporous sulfonic acid resin, indole-3-carbonyl chloride and 4-dimethylaminopyridine.

2. A method of extracting puerarin from Pueraria montana by resin extraction technology as claimed in claim 1, wherein: The concentration of the ethanol solution is 60-80 wt%.

3. A method of extracting puerarin from Pueraria montana by resin extraction technology as claimed in claim 1, wherein: The preparation method of the modified resin adsorbent is as follows: 100 parts of dry dry base macroporous sulfonic acid resin, 14-20 parts of indole-3-carbonyl chloride, 1200-1500 parts of dichloromethane are added to a three-necked flask, 0.9-1.6 parts of 4-dimethylaminopyridine is added, and the reaction is carried out at 25-40°C under light shielding and stirring for 10-14 hours. After the reaction is completed, the resin is collected by suction filtration, washed with 80-100 parts of dichloromethane, and then washed with 60-80 parts of anhydrous ethanol. The resin is dried in a vacuum drying oven at 45-55°C for 6-8 hours. The vacuum degree of the drying oven is -0.08~-0.1MPa. After cooling, the modified resin adsorbent is obtained.

4. A method of extracting puerarin from Pueraria montana by resin extraction technology according to claim 3, characterized in that: The dry base macroporous sulfonic acid resin is selected from D001, D006 or A15 macroporous sulfonic acid resin.

5. The method for extracting puerarin from kudzu root based on resin extraction technology according to claim 1, characterized in that: The resin loading mode is columnar or layered structure, and the height of the resin bed layer is 20~30 cm.

6. A method of extracting puerarin from Pueraria montana by resin extraction technology as claimed in claim 1, wherein the said method comprises the steps of: The extraction temperature of the extraction process is 45-60°C.

7. A method of extracting puerarin from pueraria root based on resin extraction technology as claimed in claim 1, wherein: The set flow rate of the ethanol solution is 1.0-2.0 mL / min. The ethanol solution flows into the top of the resin bed layer and flows out from the bottom after passing through the resin bed layer. The whole process is kept at a constant flow rate.

8. A method of extracting puerarin from Pueraria montana by resin extraction technology as claimed in claim 1, wherein: The vacuum concentration parameters are: pressure 30–150 mmHg, temperature 40–60°C.

9. The method for extracting puerarin from kudzu root based on resin extraction technology according to claim 1, characterized in that: The purification step comprises: The crude extract is subjected to column chromatography, and silica gel or C18 column is selected. The eluent is ethanol:water with a volume ratio of 1:

1. The eluted liquid is concentrated under vacuum.

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