Plant extract extraction method

Abstract

The disclosed subject matter is a plant extraction method comprising the following steps: 1) preparing a crude plant extract solution. 2) separating the crude extract solution through a cation resin and an optional anion resin to obtain a collection solution. 3) concentrating the collection solution obtained in step 2); 4) alcoholic precipitation of the concentrated solution obtained in step 3); and optionally, step 5) concentrating and drying. This method can effectively reduce the content of heavy metals in an extract and reduce the amount of ethanol used in extraction, thereby improving product quality and reducing production costs, and improving the efficiency and safety of industrial production. The extract obtained using this method can be used to prepare drugs for lowering blood lipids, treating abnormal glucose tolerance, treating diseases related to abnormal blood sugar, or regulating intestinal flora, and can be processed into food products, health care products, or beverages.

Description

Description Title Plant extract extraction method Technical background The present disclosure belongs to the technical field of plant extract extraction and specifically relates to a plant extract extraction method. Background Natural plant extracts refer to products obtained by using plants as raw materials, and specifically by obtaining or concentrating one or more active components in plants without changing their active structure through physical and chemical extraction and separation based on the use of the final extracted product. Plant extracts contain rich and complex organic compounds, in which most of the organic components have biological activities such as antibacterial activity, bacteriostatic activity, antioxidant activity and immunomodulatory activity. Plant extracts are widely used in fields such as medicines, health care products, cosmetics, food additives, pesticides, feed and daily necessities all over the world because of their environmental friendliness, healthy, safe, efficient and residue-free, etc. China is the cradle of the silkworm industry.Moraceae plants have been used as precious materials as medicine and food since ancient times due to their high nutritional value and medicinal value, which has been recorded in the classics of traditional Chinese medicine in all ages. For example, in the Compendium of Materia Medica, there are explanations about "the decoction of mulberry leaf juice can quench thirst instead of tea" and "drinking after cooking and boiling can quench thirst instead of tea". Modern science has also proven the nutritional components and active medicinal components of Moraceae plants and their mechanisms of action. Research has shown that the chemical compounds in Moraceae plants mainly include flavone compounds, polysaccharide compounds, alkaloids and amino acids, in addition to some volatile oils, tannins, succinic acid, adenine, vitamins and the like, and have antifungal effects, anti-inflammatory effects, hypoglycemic effects, antioxidant effects and the like. Plant extract extraction methods can be classified into classical extraction methods and modern extraction methods. Classical extraction methods do not require special equipment, are simple and easy to operate, have low extraction costs, and mainly include solvent extraction, steam distillation, and the like. Modern extraction methods are extraction methods based on modern advanced instruments or newly developed extraction methods, and mainly include ultrasonic extraction, microwave extraction, enzymatic extraction, solid phase extraction, and the like. The components of plant extracts can be classified into lipophilic components and hydrophilic components, which can be obtained by selecting different solvents or extraction methods for different plant extracts.For example, for lipophilic plant components, organic solvents may be used for permeation, cold washing, ultrasonic extraction, microwave extraction, reflux extraction, and the like; for water-soluble components, a common extraction method is the water extraction and alcohol precipitation method, which is of great importance in terms of refinement and purification, increasing the content of active components, reducing the dosage, and convenience in the production and molding of traditional Chinese medicine extracts. The specific steps include steps such as water extraction, concentration, alcohol precipitation, drying, and the like, where alcohol precipitation refers to adding ethanol to the crude extraction solution until the ethanol concentration reaches a suitable concentration to precipitate the impurities insoluble in ethanol, and then performing solid-liquid separation to achieve purification. For example, Xingjie Chang, et al. extracted the active compounds of Forsythia according to the steps of water extraction (boiling), concentration, ethanol precipitation, and ethanol recovery (Xingjie Chang, Qian Ding.Forsythiaside A, Forsythin and their bacteriostatic activities changes in the preparation process of water extraction and alcohol precipitation of Forsythia [J]. Journal of Traditional Chinese Medicine and Pharmacy Guide, 2018, 24 (9): 39-41.); Aiying Shen, et al. obtained mulberry leaf polysaccharides using water extraction and ethanol precipitation method (Aiying Shen, Ziyu Zhu, Wenliang Zhang. Review of the extraction process of water-soluble polysaccharides from mulberry leaves [J]. Acta Sericologica Sinica, 2004, 30 (3): 277-279.). In order to further concentrate and enrich the active components, resin separation, membrane separation, ultrafiltration, dialysis and the like may also be carried out after alcohol precipitation to achieve the purpose of purification. The increasing demand of consumers for herbal extract products has led to the extensive development of herbal extract extraction processes and the quality of products has been improved. However, compared with developed countries, there are still some outstanding problems in Chinese herbal extracts. In the meantime, product safety issues such as heavy metal and pesticide residues have attracted much attention. It has been found through research that some plants are capable of enriching heavy metals (such as copper, lead, cadmium, zinc, etc.) in the environment. For example, research by Xing Zhang et al. shows that in cases where mulberry is grown in soil containing the following heavy metals, namely copper (593.56 mg / kg); Lead (825.41 mg / kg), Cadmium (8.11 mg / kg), Zinc (705.41 mg / kg) grows, the contents of heavy metals measured in the roots are up to the following values, namely Copper: 33.13 mg / kg, Lead: 33.13 mg / kg, Cadmium: 4.53 mg / kg, Zinc: 317.72 mg / kg, the contents of heavy metals in the leaves are up to the following values, namely Copper: 13.18 mg / kg, Lead: 10.32 mg / kg, Cadmium: 1.90 mg / kg, Zinc: 186.53 mg / kg, which far exceeds the relevant regulations (according to the regulations of the "Green Trade Standards for Medicinal Plants and Medicinal Products for Import and Export", in raw materials, decoctions, extracts and plant products, the total content of heavy metals is 20.0 mg / kg or less, lead is 5 mg / kg or less, cadmium content is 0.3 mg / kg or less, mercury content is 0.2 mg / kg or less, copper content is 20.0 mg / kg or less, and arsenic content is 2.0 mg / kg or less). How to reduce the residues of harmful substances such as heavy metals to the greatest extent is an important aspect that should be considered in studies of plant extract extraction methods. Summary In general research and industrial production processes, water-soluble plant extracts are generally obtained by water extraction and alcohol precipitation, and resin separation, membrane separation, ultrafiltration, dialysis and the like are carried out after alcohol precipitation for further enrichment and purification when investigating the increase in the content of a specific component. However, in the case of plant extracts, especially plants such as Moraceae plants that are prone to heavy metal enrichment in the environment, using this extraction method to obtain the extract is not sufficient to remove heavy metal residues in the extracts. It has been found by the present inventors based on repeated research that during the plant extract extraction process, subjecting the crude extract solution to resin separation, concentration and alcohol precipitation sequentially can not only improve the separation efficiency of active components, but also significantly reduce the heavy metal residues in plant extracts.Based on such a finding, the present inventors propose a novel method for extracting plant extracts that can effectively reduce the content of heavy metals in plant extracts and at the same time reduce the amount of ethanol used in the extraction process, thereby improving product quality while reducing production cost, and improving the efficiency and safety of industrial production to a certain extent. With this in mind, firstly, the present disclosure provides a method for extracting plant extracts, which includes the following steps: Step 1): Preparation of raw plant extraction solution; Step 2): Separation of the crude extraction solution through a cationic resin to collect the effluent (wash product), optionally, separation of the effluent solution through an anionic resin to collect the effluent; Step 3): Concentration of the collection solution obtained in step 2); Step 4): exposing the concentrated solution obtained in Step 3) to alcohol precipitation; and Optionally, step 5): concentration and drying. 1) Preparation of raw plant extraction solutionIn the present embodiment, the plant is preferably a plant of Moraceae, Liliaceae, Campanulaceae or Commelinaceae, also preferably a plant of Morus, Hyacinthus, Adenophora or Commelina, and more preferably the plant is any one or a combination of plants selected from Morus multicaulis Perrott., Morus alba L., Morus atropurpurea Roxb, Morusmizuho Hotta, Morus wittiorum Hand Mazz., Morus laevigata Wall, Morus nigra Linn., Morus cathayana Hemsi., Morus serrata Roxb., Morus Schambid. Koidz., Morus notabilis Schneid., Morus nigriformis Koidz., Morusyunnanensis Koidz., Morus australis Poir., Morus mongolica (Bur.) Schneid var. diabolica Koidz., Morus alba L. var. macrophylla loud, Morus alba Var. Pendula Dippel, Morus alba L. var. venosa Delili, a berry variety bred from the above berry species, a hybrid berry resulting from selective intraspecific or interspecific breeding of the above berry species, Hyacinthus orientalis, Adenophora triphylla var. japonica and Commelina communi.Preferably, the plant is Morus atropurpurea Roxb., Morus multicaulis Perrott., Morus alba L., Morus serrata Roxb., Morus bombycis Koidz., or a hybrid berry, preferably Yuesang No. 11, Guisangyou No. 62 or Guisangyou No. 2. Various parts of the plant may be used, such as leaves, roots, branches, bark, buds, stems and fruit. The plant may be subjected to crude extraction with a solvent such as alcohol-water, water, alkaline aqueous solution, or acidic aqueous solution. Preferably, the solvent used for crude extraction is water. During extraction, it is preferred that the plant is crushed and then the resulting product is added to water to perform thermal extraction, the extraction time is preferably 0.5 hours to 3 hours for each extraction, and the extraction is performed 1 to 3 times. In a preferred mechanism, the crushed plant may be added to an extraction vessel to effect extraction. During extraction, the greater the amount of solvent, the faster the extraction of the plant. However, the excessive amount of solvent added can increase the difficulty of subsequent separation and purification. The added amount of solvent is preferably 3 to 20 times, and preferably 4 to 15 times the weight of the plant raw material used, which is able to obtain the plant extract without excessively increasing the volume of the solution and the difficulty of subsequent processing. Extraction may be carried out using a boiling method, an ultrasonic extraction method or a reflux extraction method, preferably using a boiling method or a reflux extraction method, and more preferably using a boiling method which has more complete industrial equipment. If desired, the extraction may be performed repeatedly and the extraction solutions combined. Preferably, the extracted solution is filtered to remove insoluble materials to obtain a crude solution of the plant extract. 2) Separation by cationic resin and optional anion resin In the present embodiment, the components in the crude plant extract solution are separated using ion exchange resin. In step 2), the crude plant extract solution is loaded onto a cationic resin and separated by the cationic resin. Preferably, after being packed into the column, the cationic resin is subjected to activation by successive washing with an acidic solution, an alkaline solution, and an acidic solution. The resin activation method is also capable of adjusting the pH value of the resin medium, which consequently optimizes the adsorption selectivity of the cationic resin and enhances the separation effect. Preferably, the resin is washed with an alkaline solution until the pH of the wash solution is 8.0 to 9.5, and preferably 8.5 to 9.5. The alkaline solution is preferably an ammonia solution, a sodium hydroxide solution, a potassium hydroxide solution or a sodium carbonate solution, preferably an ammonia solution or a sodium hydroxide solution. Preferably, the concentration of the alkaline solution is 0.5 to 4 mol / L, and preferably 1 to 2 mol / L. Preferably, the resin is washed with an acidic solution so that the pH of the wash solution is 3.0 to 7.0, and preferably 4.5 to 6.5. Preferably, the acidic solution is selected from hydrochloric acid solution, phosphoric acid solution and disodium hydrogen phosphate-citric acid buffer, and is preferably disodium hydrogen phosphate-citric acid buffer. Preferably, the concentration of the acidic solution is 0.5 to 4 mol / L, and preferably 1 to 2 mol / L. When disodium hydrogen phosphate-citric acid buffer is used as the acidic solution, the pH value of the disodium hydrogen phosphate-citric acid buffer is preferably 4.0 to 6.5, and more preferably 4.5 to 5.0. If desired, the cationic resin may be washed with deionized water in a volume of 3 to 5 times the column volume after the final wash with the acidic solution. Preferably, the cation resin is one of or a combination of a strong acidic cation exchange resin, a weak acidic cation exchange resin, and a strong alkaline quaternary ammonium cation resin. Preferably, the cationic resin is selected from one or more of the following resins or combinations: type 732 strongly acidic styrene-based cation exchange resin, type 734 strongly acidic styrene-based cation exchange resin, type 002SC strongly acidic styrene-based cation exchange resin, type D001 strongly acidic macroporous styrene-based cation exchange resin, type D113 weakly acidic macroporous phenylpropene-based cation exchange resin, and type D254 strongly alkaline macroporous quaternary ammonium cation exchange resin. Preferably, the cation resin is a type 732 strongly acidic styrene-based cation exchange resin, a type 734 strongly acidic styrene-based cation exchange resin, and a type D001 macroporous strongly acidic styrene-based cation exchange resin. In this research, it has been determined that the cation exchange resin loading process, especially the concentration of the loading solution and the amount of resin used, without being limited to any theory, has a significant impact on the adsorption and separation effects of plant components. Preferably, the amount of cationic resin used and the plant raw material used have a weight ratio of 1:1 to 1:30, preferably 1:1 to 1:25, and more preferably 1:2 to 1:20. After loading the crude plant extract solution onto the cationic resin, the loaded cationic resin is subjected to washing with a detergent. Preferably, the detergent is a saline solution or an alkaline solution containing a cation, preferably one or more selected from sodium chloride, ammonium chloride, ammonium sulfate, ammonium nitrate, ammonia water, potassium chloride and sodium hydroxide. Preferably, the cations in the detergent have a concentration of 0.04 to 5 mol / L, preferably 0.2 to 3 mol / L, and more preferably 0.5 to 2.5 mol / L. Preferably, the flow rate of the detergent liquid is 1 to 15 BV / h, and preferably 5 to 10 BV / h. Preferably, the weight of detergent used for separation by cationic resin is 0.1 to 30 times the weight of the plant raw material used. Preferably, washing is performed with a detergent whose weight is 0.5 to 10 times the weight of the plant raw material used. Collection begins when the detergent is removed from the cationic resin. The collection start point may be determined by the pH of the effluent from the cationic resin, for example, when an alkaline solution such as ammonia water is used to perform the washing, collection begins when the pH of the effluent from the cationic resin is higher than 7. The collection start point may also be determined by the properties of the components to be separated, for example, the collection start point may be determined by using a chromogenic reaction or a precipitation reaction. The collection start point may also be determined by using detection methods such as high-performance liquid chromatography. Preferably, collection is terminated when the volume of the collection solution reaches 0.1 to 10 times the weight of the loaded plant raw material, and more preferably, collection is terminated when the volume of the collection solution reaches 0.2 to 5 times the weight of the plant raw material used. During the separation through cationic resin, fixed bed ion exchange process as well as continuous ion exchange process may be adopted. Continuous ion exchange process with higher degree of automation is preferably used. In order to improve the separation effect of cationic resin, multiple separations through cationic resin are also possible, for example, 2 to 5 times of separation. Optionally, the collected wash liquid is separated by an anion resin. After separation through the anion resin, the anion resin is subjected to activation by successive washing with alkaline solution, acidic solution and alkaline solution after packing in the column. Preferably, the anionic resin is washed with an acidic solution so that the pH of the washing solution is 3.0 to 7.0, and preferably 4.5 to 6.5. Preferably, the acidic solution is selected from hydrochloric acid solution, phosphoric acid solution and disodium hydrogen phosphate-citric acid buffer, and preferably disodium hydrogen phosphate-citric acid buffer. Preferably, the concentration of the acidic solution is 0.5 to 4 mol / L, and preferably 1 to 2 mol / L. When disodium hydrogen phosphate-citric acid buffer is used as the acidic solution, the pH value of the disodium hydrogen phosphate-citric acid buffer is preferably 4.0 to 6.5, and more preferably 4.5 to 5.0. Preferably, the anion resin is washed with an alkaline solution until the pH of the solution is 8.0 to 9.5, and preferably 8.5 to 9.5. The alkaline solution is preferably an ammonia solution, a sodium hydroxide solution, a potassium hydroxide solution or a sodium carbonate solution, preferably a sodium hydroxide solution. Preferably, the concentration of the sodium hydroxide solution is 0.5 to 4 mol / L, and preferably 1 to 2 mol / L. Preferably, the anion resin is one or a combination of resins selected from a strong alkaline anion exchange resin, a weak alkaline anion exchange resin, and a weak acidic anion exchange resin. Preferably, the anion resin is one or a combination of resins selected from styrene-based strongly alkaline anion exchange resin type 717, styrene-based strongly alkaline anion exchange resin type 711, styrene-based macroporous and strongly alkaline anion exchange resin type D201, acrylic-based macroporous and strongly alkaline anion exchange resin type D218, styrene-based weakly acidic anion exchange resin type D301-G, and styrene-based macroporous and weakly alkaline anion exchange resin type D301. Preferably, the strongly alkaline styrene-based anion exchange resin is type 717, the macroporous and strongly alkaline styrene-based anion exchange resin is type D201, and the macroporous and strongly alkaline acrylic-based anion exchange resin is type D218. Preferably, the amount of anion resin used and the plant raw material used have a weight ratio of 1:1 to 1:80, preferably 1:1 to 1:64, and more preferably 1:1 to 1:32. Collection begins when the liquid is discharged from the anion resin. Preferably, collection is terminated when the volume of the collection solution reaches 0.05 to 10 times the weight of the loaded plant raw material, and more preferably, collection is terminated when the volume of the collection solution reaches 0.1 to 5 times the weight of the loaded plant raw material. Optionally, in order to improve the separation effect of the anion resin, multiple separations through the anion resin are also possible, for example, 2 to 4 times of separation. Preferably, the extraction method further comprises a step of concentrating the crude plant extract solution prior to separation in step 2). Methods for concentrating the crude extraction solution include concentration by heating, concentration by nanofiltration membrane, reverse osmosis membrane, and combinations thereof. Concentration is preferably carried out through heat concentration, reverse osmosis membrane concentration, or a combination thereof to increase the concentration of the crude plant extract solution. Preferably, when using reverse osmosis membrane and nanofiltration membrane to perform concentration, in order to improve concentration efficiency, the impurity may be removed by performing centrifugation, filtration through ultrafiltration membrane, or filtration through microfiltration membrane before concentration through reverse osmosis membrane and nanofiltration membrane. Preferably, the crude plant extract solution is concentrated until the mass concentration of the solid content in the solution is 1% to 15%, and preferably 2% to 10%. Solid content refers to the solid material that remains in the solution after the water is removed. If desired, the concentrated crude extract solution may also be subjected to alcohol precipitation before the resin is separated in step 2). During alcohol precipitation, ethanol is added to the crude extract solution, the mixture is stirred and mixed uniformly, stirring is stopped and the resulting mixture is allowed to stand for a certain period of time to precipitate insoluble materials. Preferably, ethanol is added to the crude plant extract solution in which the volume of ethanol is 0.2 to 20 times the volume of the crude plant extract solution, and preferably 0.4 to 10 times the volume of the crude plant extract solution. More preferably, alcohol precipitation is carried out using an alcohol precipitation tank. Preferably, the stirring speed in the alcohol precipitation is 10 to 600 rpm, preferably 40 to 500 rpm, and most preferably 80 to 400 rpm. 3) Concentration of the collection solution obtained in step 2) Methods for performing the concentration in step 3) include concentration by heating, concentration by nanofiltration membrane, concentration by reverse osmosis membrane, and combinations thereof. Preferably, the impurity may be removed by centrifugation, filtration through an ultrafiltration membrane, or filtration through a microfiltration membrane prior to concentration through the reverse osmosis membrane and nanofiltration membrane. Preferably, the specific gravity of the concentrated liquid obtained in step 3) is 1.0 to 1.3. Specific gravity refers to the mass ratio of concentrated liquid to water under conditions where the concentrated liquid and water have the same volume. 4) Alcohol precipitation In the alcoholic precipitation in step 4), the concentrated solution of step 3) is reacted with ethanol. Specifically, ethanol is added to the concentrated solution of step 3, the mixture is stirred and mixed uniformly, the stirring is stopped, and the resulting mixture is allowed to stand for a certain period of time to precipitate insoluble materials. Preferably, in step 4), the ethanol used for alcohol precipitation and the plant raw materials used have a weight ratio of from 1:4 to 1:600, preferably 1:20 to 1:300. Alcohol precipitation is preferably carried out in an alcohol precipitation tank. Preferably, in the alcoholic precipitation in step 4, the stirring speed is 10 to 600 rpm, preferably 40 to 500 rpm, and more preferably 80 to 400 rpm. 5) Condensation and drying If desired, the extraction method can include step 5) concentration and drying. The solution subjected to alcoholic precipitation is filtered to remove insoluble materials and concentrated under reduced pressure to obtain the plant extract as an extract or dried to obtain a dry product. In the second aspect, the present embodiment provides a plant extract obtained based on the above extraction method. Preferably, the plant extract obtained according to the above extraction method provided in this embodiment contains alkaloids with a weight content of 3% or more (preferably containing alkaloids with a weight content of 3% to 99%, more preferably containing alkaloids with a weight content of 15% to 99% and even more preferably containing alkaloids with a weight content of 45% to 99%, such as 35% to 70% or 60% to 75%) and / or contains polysaccharides with a weight content of up to 70% (preferably containing polysaccharides with a weight content of 0.2% to 50% and more preferably containing polysaccharides with a weight content of 0.2% to 35%) and / or contains flavones with a weight content of up to 10% (preferably containing flavones with a weight content of 0.05% to 5%, and more preferably containing flavones with a weight content of 0.05% to 2%) and / or containing amino acids with a weight content of up to 50% (preferably containing amino acids with a weight content of 0% to 40%, more preferably containing amino acids with a weight content of 0% to 25%) and / or other components (with a weight content of preferably 0% to 25% and more preferably 0% to 20%).The total content of each component is 100%, where "each component" refers to all components in the plant extract, including alkaloids, polysaccharides, flavones, and amino acids. That is, in addition to alkaloids, polysaccharides, flavones, and amino acids, there are also other components in the plant extract. Preferably, the herbal extract obtained by the above extraction method in the present embodiment contains each component in the following weight ratios: Alkaloids 3% to 99%; Polysaccharides 0.2% to 70%; Flavones 0% to 10%; Amino acids 0% to 50%; Other components 0% to 25%. Preferably, the herbal extract obtained by the above extraction method in the present embodiment contains each component in the following weight ratios: Alkaloids 5% to 99%; Polysaccharides 0.2% to 50%; Flavones 0.05% to 5%; Amino acids 0% to 40%; Other components 0% to 20% Furthermore, preferably, the herbal extract obtained by the above extraction method contains each component in the following weight ratios: Alkaloids 30% to 99%; Polysaccharides 0.2% to 35%; Flavones 0.05% to 2%; Amino acids 0% to 25%; Other components 0% to 20% Preferably, the alkaloids contain 1-deoxynojirimycin (1-DNJ) with a weight content of 30% to 99%, preferably 50 to 95%, more preferably 55 to 90%, and most preferably 60% to 90%. In a third aspect, the present embodiment provides a pharmaceutical composition comprising the above herbal extract and an optional pharmaceutically acceptable excipient. An excipient is an inactive component that is compatible with the method of administration or mode of administration and has no toxic effects on the human body. The excipient may be a solid or a liquid. For example, solid excipients include sodium lactate, poloxamer, sodium dodecyl sulfate, sodium carboxymethyl cellulose, gelatin, xanthan gum, povidone, starch, magnesium stearate, sodium carboxymethyl starch, and talc. Water, ethanol, syrup, and glycerin are also examples of liquid excipients. Preferably, the dosage form of the pharmaceutical composition comprises a preparation for oral administration. Preferably, the dosage form of the pharmaceutical composition includes tablets, capsules, oral solutions, oral emulsions, coated tablets, and granules. Depending on the patient's age, body weight, health status, diet, method of administration, drugs used in combination with it, course of treatment, and the like, there may be individual differences in the specific dosage prescribed. In a fourth aspect, the present embodiment provides the use of the above herbal extract or pharmaceutical composition in the preparation of a blood sugar lowering medicament. In another aspect, the present disclosure provides the use of the above herbal extract or pharmaceutical composition in the preparation of a medicament for the treatment of abnormal glucose tolerance. In another aspect, the present disclosure provides the use of the above herbal extract or pharmaceutical composition in the preparation of a medicament for the prevention or treatment of a disease related to abnormal blood sugar. These diseases include diabetes, diabetic nephropathy, diabetic foot ulcers, diabetic eye complications, hyperglycemia, hyperuricemia, hyperlipidemia, altered intestinal flora, and cardiovascular and cerebrovascular diseases such as cerebral infarction, cerebral hemorrhage, coronary heart disease, and hypertension. The present disclosure also provides the use of the above herbal extract or pharmaceutical composition in the preparation of a lipid-lowering drug. The present disclosure also provides the use of the above herbal extract or pharmaceutical composition in the preparation of a drug for regulating intestinal flora. In another aspect, the present embodiment provides a food, a health care product, or a beverage comprising the above herbal extract and an optional food, health care product, or beverage acceptable excipient. The present disclosure also provides the use of the above herbal extract in the preparation of a food, health care product or a beverage. Preferably, the food, health care product or beverage is a food, health care product or beverage with a hypoglycemic effect. Plant raw materials in the present embodiment refer to plant raw materials used for extraction, including, but not limited to, fresh or processed plants or plant parts. In the present embodiment, the raw plant extraction solution undergoes the reaction steps of resin separation, concentration, and alcoholic precipitation, which, compared to conventional extraction methods, has the following beneficial effects. 1. The content of heavy metals is significantly reduced. 2. The weight of ethanol used in the conventional water extraction method and alcohol precipitation method is 1 / 4 to 5 times the weight of the plant raw material used, while the amount of ethanol used in the extraction method of the present embodiment may be as low as 1 / 600 of the weight of the plant raw material used, which greatly reduces the amount of ethanol consumed, also reduces the production cost to some extent, facilitates industrial production, and improves the safety of the production process. Brief description of the shapes Figure 1 shows the results of the sucrose tolerance test of the plant extracts obtained in Examples 1, 2, 3, 5 and 6 in mice. Detailed description The present embodiment will be explained in more detail with reference to the figures and examples provided. The features and advantages of the present embodiment will become clearer and more apparent with these examples. Here the specific term “exemplary” means “used as an example, or illustrative example or explanation.” Each “exemplary” example presented here is not necessarily to be construed as superior or better than other examples. Furthermore, the technical features employed in the various mechanisms of the present embodiment described below can be combined as long as they do not conflict with each other. The present representation includes the following identification methods: 1. Determination of alkaloids: An appropriate amount of the extract was taken and added with water to dissolve with ultrasound to prepare the test solution. In addition, an appropriate amount of 1-deoxynojirimycin was accurately weighed as a reference sample and added with water to dissolve and prepare the reference solution. Appropriate volumes of the reference solution and test solution were accurately measured respectively, added with high sodium bicarbonate solution and mixed well by shaking. After that, a solution of 9-fluorovanyl methoxycarbonyl chloride (FMOC-Cl) in acetone was added and heated at 30°C for 30 min. Acetic acid was added to terminate the reaction. The reactant was well mixed by shaking and filtered. A filtrate (filtered material) was successively and accurately absorbed and injected into a liquid chromatography. According to the peak area, the content of 1-deoxynojirimycin and the content of total alkaloids of the test sample were calculated by the external standard method (calculation of chromatographic peaks with relative retention times in the range of 0.4 to 1.7 in terms of 1-deoxynojirimycin) (Reference literature: Xuejun XIA, Renyun WANG, Yuling LIU."Determination of mulberry alkaloids by RP-HPLC with pre-column derivatization" [J]. Chinese Journal of New Drugs, 2008, 17(23): 2044-2047). 2. Determination of amino acids: An appropriate amount of the extract was taken and added with water to dissolve by ultrasound to prepare the test solution. In addition, an appropriate amount of mixed amino acid as a reference sample was accurately weighed and added with water to dissolve and prepare the reference solution. The remaining operation was the same as the operation for determining the amount of alkaloids. 3. Determination of polysaccharides: An appropriate amount of the extract was accurately weighed, added with water, extracted with ultrasound and centrifuged at 4000 rpm for 10 minutes. The supernatant was taken as the test solution. 2 ml of the above test solution was measured and placed in a capped test tube, and 6 ml of 0.1% anthrone-sulfuric acid reagent was added to it. The test tube was heated in a boiling water bath for 15 minutes and placed in an ice water bath for 15 minutes. The corresponding reagent was taken as the control. The absorbance value was measured immediately at 625 nm. The concentration of polysaccharides in the test sample relative to glucose was calculated based on the linear regression equation of glucose, and its value was calculated according to the following relationship: Value =C*D*f / W, where W is the mass of the sample, C is the concentration of polysaccharide relative to glucose, f is the conversion factor (3.38), and D is the dilution factor (Reference literature: Zuofa ZHANG, Jie JIN, Liangen SHI. "Method for the determination of polysaccharide content in Ramulus Mori", Chinese Journal of Materia Medica [J]. 2018, pp.: 33(4). 462-464). 4. Determination of flavanone content: An appropriate amount of the routine reference sample was weighed and dissolved with 60% ethanol to produce the routine reference stock solution. 0.5 ml, 1.0 ml, 3.0 ml, 5.0 ml, and 7.0 ml of the routine reference stock solution were measured into 25 ml volumetric flasks, respectively, to which 10 ml of 5% sodium nitrite solution, 10% aluminum nitrate solution, and 1N NaOH solution were added, respectively, and then diluted to volume with water and mixed well by shaking as a reference solution. A blank reference solution was used as a reference. The absorbance value at a wavelength of 500 nm was measured and the linear regression equation was plotted. An appropriate amount of the extract was accurately weighed, dissolved with 60% ethanol solution by ultrasound, mixed well by shaking and centrifuged for 10 min at 4000 rpm. After that, the supernatant was taken as the flavone extraction solution. 2.0 ml of the flavone extraction solutions were accurately measured, to which 10 ml of 5% sodium nitrite solution, 10% aluminum nitrate solution and 1N NaOH solution were added, respectively, then diluted with water to the scale, mixed well by shaking, left for 15 min and centrifuged for 5 min at 5000 rpm. After that, the supernatant was measured for determination. Another 2.0 ml of the flavone extraction solution was accurately measured and, if there was no color reaction, diluted with water only to 25 ml as the control reference solution. The absorbance values ​​of the reaction solutions were measured at 500 nm. The flavanone concentration was calculated based on the linear regression equation. Then, the flavanone content in the test sample was calculated routinely based on the sample weight and multiple dilution. 5. Determination of heavy metals The total amount of heavy metals was determined by the second method in General Rules 0821 Volume 4 Chinese Pharmacopoeia Edition 2015. The specific method was as follows: (1) Preparation of lead standard solution. 0.1599 g of lead nitrate was weighed and placed in a 1000 ml volumetric flask. After dissolving with 5 ml of nitric acid and 50 ml of water, the solution was diluted with water to the mark and mixed well by shaking as a stock solution. 0.5 ml, 1 ml, 2 ml, 5 ml and 8 ml of the stock solutions were measured into 5 ml volumetric flasks, diluted with water to the mark and mixed well by shaking, and as a result, 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm and 80 ppm lead standard solutions were obtained. (2) Sample Assay 2 g of the sample was taken, gently burned until completely charred, cooled, soaked with exactly 0.5 to 1 ml of sulfuric acid, heated at low temperature to completely remove sulfuric acid, added with 0.5 ml of nitric acid, then evaporated to dryness, cooled after complete removal of nitric oxide vapor, burned at 500°C to 600°C until completely ash, cooled, added with 2 ml of hydrochloric acid, and then evaporated to dryness in a water bath, and then 15 ml of water was added. Ammonia solution was added dropwise until the phenolphthalein indicator solution turned slightly pink, and then 2 ml of acetate buffer (pH3.5) was added. After the substances were dissolved by gentle heating, the solution was transferred to Nessler tubes and diluted with water to 25 ml as a test tube. Another reagent for the formulation of the test solution was taken and evaporated to dryness in a porcelain dish, then mixed with 2 ml of acetate buffer (pH3.5) and 15 ml of water were added and dissolved by gentle heating and then transferred to Nessler tubes, to which a certain amount of the lead standard solution described in (1) was added respectively and then diluted with water to 25 ml as reference tubes. Then 2 ml of thioacetamide test solution was added to the test tubes and reference tubes respectively, mixed well by shaking, left for 2 minutes and placed on white paper at the same time. The test tubes and graduated tubes were observed from top to bottom. The color in the test tubes was compared with the color in the reference tubes to determine the content of heavy metals in the samples. The amount of heavy metals lead, cadmium, mercury and arsenic can be detected using inductively coupled plasma mass spectrometry (ICP-MS method) described in General Rules 0412, Volume IV, 2015 Edition of Chinese Pharmacopoeia. The results of heavy metal detection were compared with those documented in the Green Trade Standards for Medicinal Plants and Preparations for Import and Export. The standards specify that in plant materials, decoctions, extracts and products, the total content of heavy metals ≤20.0 mg / kg, lead ≤5 mg / kg, cadmium ≤0.3 mg / kg, mercury ≤0.2mg / kg, copper ≤20.0 mg / kg and arsenic ≤2.0 mg / kg. The present inventors have compared these two methods for the detection of heavy metals. The results show that the results of both methods are consistent, that is, the heavy metal content of the herbal extracts obtained by the present representation method is in accordance with the provisions of the standards for green trade of medicinal plants and preparation for import and export. Preferably, the heavy metal content of the herbal extracts obtained by the present representation method is at most 20 ppm, more preferably at most 10 ppm, and even more preferably at most 5 ppm. Example 1 100 g of fresh mulberry (Morus alba L.) was taken and crushed, then added with 300 ml of water alcohol in 2 times and extracted by heating under reflux for 1 hour each time. The extraction solutions were combined and filtered to remove insoluble materials, resulting in a crude extraction solution. The crude extraction solution was determined to contain 5 to 10 ppm of heavy metals including 44.5 ppm lead, 38.0 ppm cadmium, 06.0 ppm mercury and 47.0 ppm arsenic. The crude extraction solution was heated until the solid content reached 2%, kept at 25°C and used as a loading solution for the cationic resin column. 5 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column, washed with 2.5 mol / L hydrochloric acid solution until the pH of the washing solution reached 3.5; washed with 1.5 mol / L sodium hydroxide solution until the pH of the solution reached 8.0; washed with 2.5 mol / L hydrochloric acid solution until the pH of the solution reached 3.5; and then washed with 3 times the column volume of deionized water to complete the activation. The concentrated extraction solution was loaded and then washed with 3 liters of 0.1 mol / L ammonia water at a washing rate of 10 BV / h. When the effluent from the cationic resin column was detected at pH > 7, the washing solution was collected. When the collection solution reached 1 liter, the collection was stopped. The collection solution was directly purified on the anion resin column. 1.25 g of macroporous and strongly alkaline acrylic-based anion resin type D218 was loaded into the column, washed with 1.5 mol / L sodium hydroxide solution until the pH of the washing solution became 9.0; washed with 1.5 mol / L hydrochloric acid solution until the pH of the washing solution became 3.5; and washed with 1.5 mol / L sodium hydroxide solution until the pH of the solution became 9.0. And the activation was completed. The liquid from the cationic resin was loaded onto the anion resin. The effluent was collected, and the collection was terminated when the effluent reached 1 liter. The collected solution obtained from the separation was centrifuged through an anion resin column to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.0. It was transferred to an alcohol precipitation tank and 25 g of anhydrous ethanol was added to it while the stirring paddle was at 100 rpm. After the addition of ethanol, the stirring was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and dried in vacuo to obtain the extract. In addition, Ramulus Mori, Cortex Mori, and Folium Mori (Morus alba L.) were prepared and extracted. The extraction method and parameters were the same as those described above. The heavy metal content in the crude extraction solutions obtained from Ramulus Mori, Cortex Mori, and Folium Mori were all 5 to 10 ppm, in which the lead content was 51.5, 87.5, and 12.6 ppm, respectively, the cadmium content was 37.0, 35.0, and 0.41 ppm, the mercury content was 0.07, 0.08, and 0.06 ppm, respectively, and the arsenic content was 0.57, 0.55, and 0.61 ppm, respectively. The amount of components and heavy metal content in the extracts of Hibiscus, Ramulus Mori, Cortex Mori, and Folium Mori obtained are given in Table 1. Table 1 Amount of components and amount of heavy metals in plant extracts obtained in Example 1 Extract Amount of berry extract Ramulus Mori extract Cortex Mori extract Folium Mori extract Alkaloids % 45 48 45 30 Polysaccharides % 28 25 27 34 Flavones % 5 4 6 7 Amino acids % 20 17 18 30 % 1-DNJ in alkaloids 60 62 61 55 Total heavy metals (ppm) <5 <5 <5 <5 Pb (ppm) 0.74 0.70 0.67 0.66 Cd (ppm) 0.05 0.05 0.04 0.04 Hg (ppm) 0.02 0.01 0.02 0.01 As (ppm) 0.17 0.12 0.13 0.15 Example 2 100 g of fresh Folium Mori (Morus atropurpurea Roxb) was taken and crushed, then added with 2000 ml of acid water in 2 times and extracted by boiling for 1 hour each time. The extraction solutions were combined and filtered to remove insoluble materials, resulting in a crude extraction solution. The crude extraction solution was determined to contain 10 to 20 ppm of heavy metals, including 6.13 ppm of lead, 84.0 ppm of cadmium, 16.0 ppm of mercury, and 56.0 ppm of arsenic. The crude extraction solution was centrifuged to remove impurities and then concentrated by filtering through a reverse osmosis membrane until the solid content reached 14.5%. The concentrated crude extraction solution was transferred to an alcohol sedimentation tank, and 80 g (about 100 ml) of anhydrous ethanol was added to it while the paddle was at 300 rpm. After adding ethanol, the solution was stopped stirring and subjected to alcohol precipitation for 24 h. The supernatant was taken as the loading solution for the cationic resin column. 10 g of strongly acidic styrene-based cationic resin type 734 was loaded into the column, washed with 2 mol / L hydrochloric acid solution until the pH of the washing solution was 4.5; washed with 1 mol / L sodium hydroxide solution until the pH of the washing solution was 8.5; washed with 2 mol / L hydrochloric acid solution until the pH of the washing solution was 4.5; and then washed with 5 times the column volume of deionized water to complete the activation. The extraction solution was loaded after concentration and alcohol precipitation, and then washed with 2 liters of 0.5 mol / L ammonia water at a washing rate of 8 BV / h. When the effluent from the cationic resin column was detected at pH > 7, the washing solution was collected. When the collection solution reached 800 ml, the collection was stopped. The collection solution was directly purified on the anion resin column. 8 g of strongly alkaline styrene-based anion resin type 717 was loaded into the column, washed with 1.5 mol / L sodium hydroxide solution until the pH of the washing solution was 9.0; washed with 1.5 mol / L hydrochloric acid solution until the pH of the washing solution was 3.5; and washed with 1.5 mol / L sodium hydroxide solution until the pH of the solution was 9.0 to complete the activation. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected, and the collection was terminated when the effluent reached 750 ml. The collection solution obtained from the separation through the anion resin column was concentrated by heating. The specific gravity of the concentrated liquid was 1.05. It was transferred to an alcohol precipitation tank, and 12.5 g of anhydrous ethanol was added while the stirring paddle was at 200 rpm. After the addition of ethanol, the stirring was stopped and the mixture was subjected to alcohol precipitation for 24 hours. The supernatant was collected and dried in vacuo to obtain the extract. In addition, Ramulus Mori and Cortex Mori (Morus atropurpurea Roxb) were freshly prepared and extracted. The extraction method and parameters were as described above. The heavy metal content in the crude extraction solutions obtained from Ramulus Mori and Cortex Mori were both 10–20 ppm, in which the lead content was 5.14 and 8.15 ppm, respectively, the cadmium content was 78.0 and 77.0 ppm, respectively, the mercury content was 17.0 and 0.18 ppm, respectively, and the arsenic content was 0.57 and 0.55 ppm, respectively. The amount of components and heavy metals in the resulting Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 2. Table 2 Amount of components and amount of heavy metals in plant extracts obtained in Example 2 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 80 75 60 Polysaccharides % 10 14 17 Flavones % 0.3 0.4 0.5 Amino Acids % 5 6 18 % 1-DNJ in Alkaloids 75 69 70 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.65 0.73 1.13 Cd (ppm) 0.03 0.02 0.08 Hg (ppm) 0.01 0.02 0.09 As (ppm) 0.11 0.10 0.25 Example 3 1000 kg of fresh Ramulus Mori (Yuesang No. 11) was taken and crushed, then added with 4000 L of water and extracted by thermal reflux for 2 hours. The extraction solutions were combined and filtered to remove insoluble materials, resulting in a crude extraction solution. The crude extraction solution was determined to contain 40–80 ppm of heavy metals, including 52 ppm of lead, 94.1 ppm of cadmium, 88.0 ppm of mercury, and 11.1 ppm of arsenic. The crude extraction solution was heated until the solid content reached 4%, kept at 50°C, and used as the loading solution for the cationic resin column. 150 kg of phenylpropene-based macroporous weakly acidic cation resin type D113 was loaded into the column, washed with 2 mol / L hydrochloric acid solution until the pH of the solution was 4.5; washed with 1 mol / L sodium hydroxide solution until the pH of the solution was 8.5; washed with 2 mol / L hydrochloric acid solution until the pH of the washing solution was 4.5; and then washed with 5 times the column volume of deionized water to complete the activation. The concentrated extraction solution was loaded and then washed with 1000 L of 2.5 mol / L ammonia water at a washing rate of 6 BV / h. When the effluent from the cation resin column was detected at pH > 7, the washing solution was collected. When the collection solution was up to 900 L, the collection was stopped. The collection solution was directly purified on the anion resin column. 62.5 kg of macroporous, strongly alkaline acrylic-based anion resin type D218 was loaded into the column, washed with 1.5 mol / L sodium hydroxide solution until the pH of the solution reached 9.0; washed with 1.5 mol / L hydrochloric acid solution until the pH of the washing solution reached 3.5; and washed with 1.5 mol / L sodium hydroxide solution until the pH of the solution reached 9.0 to complete the activation. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected, and the collection was terminated when the effluent reached 870 liters. The collection solution obtained from the separation through the anion resin column was filtered through a microfiltration membrane to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.1. It was transferred to an alcohol precipitation tank and 15 kg of anhydrous ethanol was added while the stirring paddle was at 400 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Cortex Mori and Folium Mori (Yesang No. 11) were prepared and extracted. The extraction method and parameters were the same as those described above. The heavy metal content in the crude extraction solutions obtained from Cortex Mori and Folium Mori were both 40–80 ppm, in which the lead content was 48 and 53 ppm, respectively, the cadmium content was 78.1 and 77.1 ppm, respectively, the mercury content was 77.0 and 0.78 ppm, respectively, and the arsenic content was 0.87 and 0.95 ppm, respectively. The amount of components and heavy metals in the resulting Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 3. Table 3 Amount of components and amount of heavy metals in plant extracts obtained in Example 3 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 75 67 50 Polysaccharides % 15 20 27 Flavones % 0.7 0.8 3 Amino Acids % 5 6 16 % 1-DNJ in Alkaloids 72 70 66 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 2.71 2.65 2.60 Cd (ppm) 0.03 0.06 0.05 Hg (ppm) 0.24 0.10 0.12 As (ppm) 0.72 0.45 0.50 Example 4 1000 kg of air-dried Cortex Mori (Guisangyou No. 62) was taken and crushed, then added with 10000 L of water in 2 times and extracted by thermal reflux for 2.5 hours each time. The extraction solutions were combined and filtered to remove insoluble materials, resulting in a crude extraction solution. It was found that the crude extraction solution contained less than 5 ppm of heavy metals, including 57.1 ppm of lead, 23.0 ppm of cadmium, 09.0 ppm of mercury and 58.0 ppm of arsenic. The crude extraction solution was filtered through a microfiltration membrane to remove impurities, and then concentrated through a reverse osmosis membrane until the solid content reached 6%, and served as the loading solution for the cation resin column. 100 kg of macroporous, strongly acidic styrene-based cationic resin type D001 were loaded into the column. The cationic resin was activated according to the method described in Example 3. The concentrated extraction solution was loaded and then washed with 500 liters of 0.2 mol / L ammonium chloride at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and began to collect, producing a white precipitate. When the collection solution reached 200 liters, the collection was terminated. The collection solution was purified directly on the anion resin column. 32 kg of macroporous, strongly alkaline styrene-based anion resin type D201 were packed into the column. The anion resin was activated according to the method described in Example 3. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected and collection was terminated when the effluent reached 100 liters. The collected solution obtained from the separation through the anion resin column was concentrated by heating. The specific gravity of the concentrated liquid was 1.2. It was transferred to an alcohol precipitation tank, and 3 kg of anhydrous ethanol was added while the stirring paddle was at 350 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain an extract. In addition, air-dried Ramulus Mori (Guisangyou No. 62) was prepared and extracted. The extraction method and parameters were the same as those described above. The crude extraction solution obtained from Ramulus Mori contained 5–10 ppm of heavy metals, of which lead was 66.1 ppm, cadmium was 25.0 ppm, mercury was 07.0 ppm, and arsenic was 60.0 ppm. The amount of components and heavy metal content in the resulting Ramulus Mori and Cortex Mori extracts are given in Table 4. Table 4 Amount of components and amount of heavy metals in plant extracts obtained in Example 4 Extract Amount of Ramulus Mori Extract Cortex Mori Extract Alkaloids % 65 58 Polysaccharides % 16 20 Flavones % 0.7 0.5 Amino Acids % 17 20 % 1-DNJ in Alkaloids 69 68 Total Heavy Metals (ppm) <5 <5 Pb (ppm) 0.08 0.04 Cd (ppm) 0.04 0 Hg (ppm) 0.01 0.01 As (ppm) 0.21 0.16 Example 5 10 kg of fresh Ramulus Mori (Sangteyou No. 2) was taken and crushed, and added to 150 L of water in 2 portions and extracted by boiling for 3 h each time. The extraction solutions were combined and filtered to remove insoluble materials. The extraction solution was concentrated by heating until the solid content reached 8%. It was transferred to an alcohol precipitation tank. 2367.9 g of anhydrous ethanol (3 L) was added while the stirring paddle was at 300 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 h. The supernatant was taken as the loading solution for the cationic resin column. 5 kg of strongly acidic styrene-based cation resin type 002SC was loaded into the column. The cation resin was activated according to the method described in Example 3. The extraction solution was loaded after concentration and alcoholic precipitation and then washed with 100 liters of 5 mol / L potassium chloride at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and started to collect, producing a white precipitate. When the collection solution reached 25 liters, the collection was terminated. The collection solution was purified directly on the anion resin column. 10 kg of strongly alkaline styrene-based anion resin type 711 was loaded into the column. The anion resin was activated according to the method described in Example 3. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected and collection was terminated when the effluent reached 15 liters. The collected solution was loaded back onto the cation resin and separated twice through the cation resin and the anion resin respectively according to the methods described above. The resulting collection solution was centrifuged after three-column separation to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.25. It was transferred to an alcohol sedimentation tank, and 125 g of anhydrous ethanol was added to it while the stirring paddle was at 1000 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol sedimentation for 24 h. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Cortex Mori and Folium Mori (Sangteyou No. 2) were prepared and extracted. The extraction method and parameters were the same as those described above. The content of components and the amount of heavy metals in the obtained Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 5. Table 5 Amount of components and amount of heavy metals in plant extracts obtained in Example 5 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 98 95 90 Polysaccharides % 0.2 2 4 Flavones % 0.05 0.1 0.1 Amino Acids % 0 1 3 % 1-DNJ in Alkaloids 99 96 91 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.06 0.05 0.07 Cd (ppm) 0 0 0 Hg (ppm) 0 0 0.01 As (ppm) 0.16 0.12 0.15 Example 6 1 kg of fresh mulberry root (Yesang No. 11) was taken and crushed, then added with 6 liters of alcohol water in 3 times and extracted using ultrasonic method for 1 hour each time. The extraction solutions were combined and filtered to remove insoluble materials to obtain crude extraction solution. The crude extraction solution served as a loading solution for the cationic resin column. 1 kg of macroporous, strongly alkaline quaternary ammonium cation resin type D254 was loaded into the column. The cation resin was activated according to the method described in Example 3. The crude extraction solution was loaded and then washed with 15 L of 3 mol / L sodium chloride at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and started to collect, producing a white precipitate. When the collection solution reached 5 L, the collection was terminated. The collection solution was purified directly on the anion resin column. 1 kg of macroporous, weakly alkaline styrene-based anion resin type D301 was loaded into the column. The anion resin was activated according to the method described in Example 3. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected and collection was terminated when the effluent reached 5 liters. The collected solution was loaded back onto the cation resin and again separated through the cation resin and the anion resin sequentially according to the methods described above. The collection solution obtained from the separation of the two columns was centrifuged to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.2. It was transferred to an alcohol sedimentation tank and 6.3 g of anhydrous ethanol was added to it while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol sedimentation for 24 h. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Ramulus Mori and Folium Mori (Yesang No. 11) were prepared and extracted. The extraction method and parameters were the same as those described above. The amounts of the constituents and the amounts of heavy metals in the extracts of Ramulus Mori, Folium Mori and mulberry root obtained are given in Table 6. Table 6 Amount of components and amount of heavy metals in plant extracts obtained in Example 6 Extract Amount Ramulus Mori Extract Folium Mori Extract Mulberry Root Extract Alkaloids % 97 85 92 Polysaccharides % 0.3 5 3 Flavones % 0.06 0.3 0.1 Amino Acids % 0 5 2 % 1-DNJ in Alkaloids 98 83 95 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.05 0.03 0.05 Cd (ppm) 0 0 0 Hg (ppm) 0 0.02 0 As (ppm) 0.13 0.14 0.14 Example 7 1000 kg of fresh Ramulus Mori (Morus atropurpurea Roxb) was taken and crushed, then added with 11500 L of water and extracted by thermal reflux for 2 hours. The extraction solutions were combined and filtered to remove insoluble materials to obtain the crude extraction solution. The crude extraction solution was centrifuged to remove impurities, then concentrated through a reverse osmosis membrane until the solid content reached 1% and served as the loading solution for the cationic resin column. 150 kg of macroporous, strongly acidic styrene-based cationic resin type D001 were packed into the column. The cationic resin was activated according to the method described in Example 3. The concentrated crude extraction solution was loaded and washed with 5000 liters of 0.04 mol / L ammonium nitrate at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and started to collect, producing a white precipitate. The collection was terminated when the collection solution reached 1000 liters. The collection solution obtained from the cationic resin column separation was concentrated through a nanofiltration membrane. The specific gravity of the concentrated liquid was 1.3. It was transferred to an alcohol precipitation tank, and 1.7 kg of anhydrous ethanol was added when the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Cortex Mori and Folium Mori (Morus atropurpurea Roxb) were prepared and extracted. The extraction method and parameters were as described above. The content of components and heavy metal content in the obtained Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 7. Table 7 Amount of components and amount of heavy metals in plant extracts obtained in Example 7 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 15 10 8 Polysaccharides % 40 42 45 Flavones % 0.7 0.8 0.6 Amino Acids % 40 41 43 % 1-DNJ in Alkaloids 55 50 49 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.12 0.10 0.09 Cd (ppm) 0 0 0 Hg (ppm) 0.02 0.02 0.01 As (ppm) 0.18 0.11 0.15 Example 8 1000 kg of fresh Ramulus Mori (Yuesang No. 11) was taken and crushed, and added to 8000 L of water in 2 batches, and extracted by boiling for 2 hours each time. The extraction solutions were combined and filtered to remove insoluble materials to obtain the crude extraction solution. The crude extraction solution was filtered through a microfiltration membrane to remove impurities, then concentrated through a reverse osmosis membrane until the solid content reached 1% and used as the loading solution for the cationic resin column. 41.7 kg of strongly acidic styrene-based cationic resin type 732 were loaded into the column. The cationic resin was activated according to the procedure described in Example 3. The crude extraction solution was loaded and washed with 1000 L of 0.1 mol / L sodium chloride at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and began to collect, producing a white precipitate. Collection was terminated when the collection solution reached 500 L. The collection solution obtained from the cationic resin column separation was concentrated through a nanofiltration membrane. The specific gravity of the concentrated liquid was 1.25. It was transferred to an alcohol precipitation tank, and 15 kg of anhydrous ethanol was added when the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Cortex Mori and Folium Mori (Yesang No. 11) were prepared and extracted. The extraction method and parameters were the same as those described above. The amount of components and heavy metal content in the resulting Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 8. Table 8 Amount of components and amount of heavy metals in plant extracts obtained in Example 8 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 10 8 5 Polysaccharides % 44 50 60 Flavones % 1 1.2 2 Amino Acids % 41 37 30 % 1-DNJ in Alkaloids 54 45 46 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.55 0.30 0.43 Cd (ppm) 0.02 0.01 0.02 Hg (ppm) 0.03 0.01 0.01 As (ppm) 0.11 0.10 0.12 Example 9 100 g of fresh Ramulus Mori (Morus atropurpurea Roxb) was taken and crushed, then added with 600 ml of water, extracted by thermal reflux for 1 h and filtered to remove insoluble materials to obtain a crude extraction solution. The crude extraction solution was first concentrated by heating until the solid content reached 5% and used as the loading solution for the cationic resin column. 3.85 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column. The cationic resin was activated according to the procedure described in Example 3. The crude extraction solution was loaded and washed with 700 ml of 0.15 mol / L ammonium chloride at a wash rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and began to collect by producing a white precipitate. Collection was terminated when the collection solution reached 100 ml. The collection solution obtained from the cationic resin column separation was concentrated by heating. The specific gravity of the concentrated liquid was 1.3. It was transferred to an alcohol precipitation tank, and 25 g of anhydrous ethanol was added to it while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain an extract. In addition, fresh Cortex Mori and Folium Mori (Morus atropurpurea Roxb) were prepared and extracted. The extraction method and parameters were as described above. The amount of components and heavy metal content in the resulting Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 9. Table 9 Amount of components and amount of heavy metals in plant extracts obtained in Example 9 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 8 5 3 Polysaccharides % 45 48 50 Flavones % 1.5 2 3 Amino Acids % 40 40 41 % 1-DNJ in Alkaloids 44 40 38 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.70 0.67 0.60 Cd (ppm) 0.01 0.02 0.01 Hg (ppm) 0.01 0.02 0.01 As (ppm) 0.14 0.10 0.11 Example 10 1000 kg of fresh Ramulus Mori (Sangteyou No. 2) was taken and crushed, then added with 5000 liters of water, extracted by refluxing for 1 hour, and filtered to remove insoluble materials to obtain a crude extraction solution. The crude extraction solution was first concentrated by heating until the solid content reached 10% and used as the loading solution for the cationic resin column. 3.5 g of macroporous, strongly alkaline quaternary ammonium cation resin D254 was loaded into the column. The cation resin was activated according to the procedure described in Example 3. The crude extraction solution was loaded and then washed with 200 L of 0.15 mol / L potassium chloride at a rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and began to collect by producing a white precipitate. Collection was terminated when the collection solution reached 100 L. The collection solution obtained from the cationic resin column separation was concentrated by heating. The specific gravity of the concentrated liquid was 1.05. It was transferred to an alcohol precipitation tank, and 15 kg of anhydrous ethanol was added while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. Fresh Cortex Mori (Sangteyou No. 2) was also prepared and extracted. The extraction method and parameters were the same as those described above. The amount of components and heavy metal content in the obtained Ramulus Mori, Cortex Mori extracts are given in Table 10. Table 10 Amount of components and amount of heavy metals in plant extracts obtained in Example 10 Extract Amount of Ramulus Mori Extract Cortex Mori Extract Alkaloids % 5 3 Polysaccharides % 47 50 Flavones % 2 3 Amino Acids % 41 41 % 1-DNJ in Alkaloids 47 43 Total Heavy Metals (ppm) <5 <5 Pb (ppm) 0.24 0.27 Cd (ppm) 0 0 Hg (ppm) 0.01 0.02 As (ppm) 0.12 0.14 Example 11 1000 g of fresh Ramulus Mori (Morus bombycis Koidz.) was taken and crushed, then added with 10 L of acid water in 3 times, extracted with ultrasound for 2 hours each time, and filtered to remove insoluble materials to obtain a crude extraction solution. The crude extraction solution was filtered through a microfiltration membrane to remove impurities, then concentrated through a reverse osmosis membrane until the solid content reached 4% and used as the loading solution for the cationic resin column. 66.67 g of D001 type macroporous, strongly acidic styrene-based cationic resin was packed into the column. The cationic resin was activated according to the method described in Example 3. The crude extraction solution was loaded and then washed with 12 liters of 1.5 mol / L ammonia water at a washing rate of 5 BV / h. When the effluent from the cationic resin column was detected by high-performance liquid chromatography to contain alkaloids, the washing solution was collected. When the collection solution reached 100 ml, the collection was terminated. The collection solution was purified directly on the anion resin column. 13.3 g of a macroporous, strongly alkaline styrene-based anion resin type D218 was loaded into the column. The anion resin was activated according to the method described in Example 3. The collected eluent from the cation resin was loaded onto the anion resin column. The effluent was collected and collection was terminated when the effluent reached 50 ml. The collection solution obtained from the anion resin column separation was filtered through a microfiltration membrane to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.15. It was transferred to an alcohol precipitation tank, and 25 g of anhydrous ethanol was added to it while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In addition, fresh Cortex Mori and Folium Mori (Morus bombycis Koidz.) were prepared and extracted. The extraction method and parameters were as described above. The content of components and heavy metal content in the resulting Ramulus Mori, Cortex Mori, and Folium Mori extracts are given in Table 11. Table 11 Amount of components and amount of heavy metals in plant extracts obtained in Example 11 Extract Amount Ramulus Mori Extract Cortex Mori Extract Folium Mori Extract Alkaloids % 30 30 15 Polysaccharides % 31 34 40 Flavones % 3 2 1 Amino Acids % 30 28 39 % 1-DNJ in Alkaloids 58 55 53 Total Heavy Metals (ppm) <5 <5 <5 Pb (ppm) 0.26 0.30 0.25 Cd (ppm) 0.01 0.02 0.01 Hg (ppm) 0.01 0 0.02 As (ppm) 0.11 0.12 0.13 Example 12 100 g of fresh Cortex Mori (Guisangyou No. 62) was taken and crushed, then added with 1.2 L of water alcohol, extracted by boiling for 1 hour, and filtered to remove insoluble materials to obtain a crude extraction solution. The crude extraction solution was first concentrated by heating until the solid content reached 8% and used as the loading solution for the cationic resin column. 33.34 g of strongly acidic styrene-based cationic resin type 734 was loaded into the column. The cationic resin was activated according to the method described in Example 3. The crude extraction solution was loaded and then washed with 50 ml of 2.5 mol / L ammonia water at a washing rate of 5 BV / h. When the effluent from the cationic resin column was detected at pH > 7, the washing solution was collected. The collection was terminated when the collection solution reached 10 ml. The collection solution obtained from the cationic resin column separation was centrifuged to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.2. It was transferred to an alcohol precipitation tank and 15 g of anhydrous ethanol was added while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In the Cortex Mori extract, the alkaloid content was 15%, the polysaccharide content was 38%, the flavone content was 2%, and the amino acid content was 40%. In alkaloids, the content of 1-DNJ was 52%. The total heavy metal content was less than 5 ppm, including 29.0 ppm lead, 0 ppm cadmium, 02.0 ppm mercury, and 10.0 ppm arsenic. Example 13 100 g of fresh Ramulus Mori (Morus alba L.) was taken and crushed, then added with 300 ml of alkaline water, extracted by refluxing for 0.5 h, and filtered to remove insoluble matter to obtain a crude extraction solution. The crude extraction solution was centrifuged to remove impurities, then concentrated through a reverse osmosis membrane until the solid content reached 6% and used as the loading solution for the cationic resin column. 3.34 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column. The cationic resin was activated according to the method described in Example 3. The crude extraction solution was loaded and then washed with 3 L of 1.0 mol / L ammonia water at a washing rate of 5 BV / h. The effluent was identified with 20% silicotungstic acid and began to collect by producing a white precipitate. Collection was terminated when the collection solution reached 400 mL. The collection solution obtained from the cationic resin column separation was concentrated by heating. The specific gravity of the concentrated liquid was 1.25. It was transferred to an alcohol precipitation tank, and 5 g of anhydrous ethanol was added while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain the extract. In the obtained Ramulus Mori extract, the alkaloid content was 3%, polysaccharide content was 60%, flavone content was 5%, and amino acid content was 30%. In alkaloids, the content of 1-DNJ was 47%. The total amount of heavy metals less than 5 ppm included 31.0 ppm lead, 0 ppm cadmium, 01.0 ppm mercury, and 14.0 ppm arsenic. Example 14 100 g of fresh Folium Mori (Morus multicaulis Perrott.) was taken and crushed, then added with 500 ml of alcohol water, extracted by boiling for 0.5 h, and filtered to remove insoluble materials to obtain a crude extraction solution. The crude extraction solution was concentrated through a nanofiltration membrane until the solid content reached 12% and used as the loading solution for the cationic resin column. 25 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column. The cationic resin was activated according to the method described in Example 3. The crude extraction solution was loaded and then washed with 2 liters of 2.0 mol / L ammonia water at a washing rate of 5 BV / h. When the effluent from the cationic resin column was detected by high-performance liquid chromatography to contain alkaloids, the washing solution was collected. The collection was terminated when the collection solution reached 800 ml. The collection solution obtained from the cationic resin column separation was concentrated by heating. The specific gravity of the concentrated liquid was 1.14. It was transferred to an alcohol precipitation tank, and 5 g of anhydrous ethanol was added while the stirring paddle was at 600 rpm. After the addition of ethanol, the stirring of the solution was stopped and the solution was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain an extract. In the obtained Folium Mori extract, the alkaloid content was 10%, the polysaccharide content was 43%, the flavone content was 1%, and the amino acid content was 37%. In alkaloids, the content of 1-DNJ was 50%. The total amount of heavy metals less than 5 ppm included 33.0 ppm lead, 01.0 ppm cadmium, 02.0 ppm mercury, and 15.0 ppm arsenic. Example 15 100 g of fresh Hyacinthus orientalis (Hyacinthus orientalis) was collected and crushed, then added with 700 ml of water in 2 portions and extracted with ultrasound for 0.5 h. The extraction solutions were combined and filtered to remove insoluble materials to obtain the crude extraction solution. The crude extraction solution was concentrated through a nanofiltration membrane until the solid content reached 10% and used as the loading solution for the cationic resin column. 3.5 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column. The cationic resin was activated according to the procedure described in Example 3. The concentrated crude extraction solution was loaded and washed with 10 ml of 1.75 mol / L sodium hydroxide solution at a washing rate of 10 BV / h. When the effluent from the cationic resin column was detected at pH > 7, the washing solution was collected. The collection was terminated when the collection solution was up to 10 ml. The collection solution was purified directly on the anion resin column. 4 g of macroporous, strongly alkaline styrene-based anion resin type D218 was packed into the column. The anion resin was activated according to the method described in Example 3. The liquid from the cation resin was loaded onto the anion resin. The effluent was collected and collection was terminated when the effluent reached 5 ml. The collected solution obtained from the separation through the anion resin column was concentrated by heating. The specific gravity of the concentrated liquid was 1.1. It was transferred to an alcohol precipitation tank and 0.4 g of anhydrous ethanol was added to it while the stirring paddle was at 100 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and dried in vacuo to obtain Hyacinthus orientalis bulb extract. In Hyacinthus orientalis onion extract, the alkaloid content was 3%, the polysaccharide content was 68%, the flavone content was 2%, and the amino acid content was 25%. In alkaloids, the amount of 1-DNJ was 30%. The total amount of heavy metals was less than 5 ppm, including 08.0 ppm lead, 01.0 ppm mercury, and 15.0 ppm arsenic, in which cadmium was not detected. Example 16 100 g of fresh Commelina communi leaves (Commelina communi) were collected and crushed, then added with 500 ml of alcohol water in 2 portions and extracted by heating under reflux for 1 hour each time. The extraction solutions were combined and filtered to remove insoluble materials. The extracted solution was concentrated by heating to a solid content of 10% at 30°C and used as the loading solution for the cationic resin column. 3.5 g of strongly acidic styrene-based cationic resin type 732 was loaded into the column. The cationic resin was activated according to the method described in Example 3. The concentrated extraction solution was loaded and then washed with 800 ml of 2.3 mol / L ammonia water at a washing rate of 10 BV / h. When the effluent from the cationic resin column was detected at pH > 7, the washing solution was collected. Collection was terminated when the collection solution reached 300 ml. The collection solution obtained from the cationic resin column separation was filtered through an ultrafiltration membrane to remove impurities and then concentrated through a reverse osmosis membrane. The specific gravity of the concentrated liquid was 1.2. It was transferred to an alcohol precipitation tank, and 5 g of anhydrous ethanol was added when the stirring paddle was at 500 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and dried in vacuo to obtain Commelina communi leaf extract. In Commelina communi leaf extract, the alkaloid content was 10%, the polysaccharide content was 27%, the flavones content was 10%, and the amino acid content was 50%. In alkaloids, the amount of 1-DNJ was 50%. The total amount of heavy metals was less than 5 ppm, including 0.5 ppm lead and 17.0 ppm arsenic, in which cadmium and mercury were not detected. Comparative Example 1 1000 kg of fresh Ramulus Mori (Morus serrata Roxb.) was taken from the same batch as used in Example 3 and subjected to crude extraction according to the method described in Example 3. The crude extraction solution was concentrated by heating. The specific gravity of the concentrated liquid was 1.1. It was transferred to an alcohol precipitation tank and 62 kg of anhydrous ethanol was added while the stirring paddle was at 400 rpm. After the addition of ethanol, the stirring of the solution was stopped and subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain Ramulus Mori extract. The alkaloid content was 15%, the polysaccharide content was 40%, the flavone content was 5.2% and the amino acid content was 30%. In alkaloids, the amount of 1-DNJ was 55%. The total amount of heavy metals was 30 to 40 ppm, including 11.29 ppm lead, 50.1 ppm cadmium, 76.0 ppm mercury, and 0.1 ppm arsenic, in which the levels of lead, cadmium, and mercury exceeded the content standards. Without the cationic resin column and anion resin column separation steps, this comparative example showed a decrease in alkaloid content, a significant increase in heavy metal content, and a 3-fold increase in ethanol content compared to Example 3. Comparative Example 2 1000 kg of fresh Ramulus Mori (Morus serrata Roxb.) from the same batch as used in Example 3 was weighed and subjected to crude extraction, heat concentration and separation through cation resin and anion resin according to the method described in Example 3. 870 L of the collection solution obtained from the anion resin column separation was transferred to an alcohol precipitation tank and 135 kg of anhydrous ethanol was added thereto while the stirring paddle was at 400 rpm. After the addition of ethanol, the stirring of the solution was stopped and it was subjected to alcohol precipitation for 24 hours. The supernatant was collected and concentrated under reduced pressure to obtain Ramulus Mori extract. The alkaloid content was 62%, the polysaccharide content was 18%, the flavone content was 1.1% and the amino acid content was 12%. In alkaloids, the amount of 1-DNJ was 68%. The total amount of heavy metals was 10 to 20 ppm, including 01.10 ppm lead, 70.0 ppm cadmium, 44.0 ppm mercury, and 83.0 ppm arsenic, in which the amount of lead, cadmium, and mercury exceeded the content standards. Without a concentration step between resin separation and alcohol precipitation, this comparative example showed an increase in heavy metal content and an 8-fold increase in ethanol content compared to Example 3. Comparative Example 3 1000 kg of fresh Ramulus Mori (Morus serrata Roxb.) from the same batch as used in Example 3 was weighed and subjected to crude extraction, heat concentration and separation through cation resin and anion resin according to the method described in Example 3. 870 liters of the collection solution obtained from the anion resin column separation was concentrated under reduced pressure to obtain Ramulus Mori extract. The alkaloid content was 52%, the polysaccharide content was 22%, the flavone content was 0.8% and the amino acid content was 20%. In alkaloids, the amount of 1-DNJ was 60%. The total amount of heavy metals was 20 to 40 ppm, including 15.22 ppm lead, 45.1 ppm cadmium, 65.0 ppm mercury, and 89.0 ppm arsenic, in which the levels of lead, cadmium, and mercury exceeded the content standards. Without the alcoholic precipitation step after resin separation, this comparative example showed a reduced alkaloid content and a significant increase in heavy metal content compared to Example 3. Comparative Example 4 1000 kg of fresh Ramulus Mori (Morus serrata Roxb.) from the same batch as used in Example 3 was taken and crushed, then added with 4 times the amount of water alcohol (4000 L) and extracted by heating under reflux for 2 hours. The extraction solutions were combined and filtered to remove insoluble materials. The crude extraction solution was concentrated by heating. The specific gravity of the concentrated liquid was 1.1. It was transferred to an alcohol precipitation tank and 62 kg of anhydrous ethanol was added while the stirring paddle was at 400 rpm. After the ethanol was added, the solution was stopped stirring and subjected to alcohol precipitation for 24 hours. The supernatant was collected and loaded onto a cationic resin. According to the method described in Example 3, 150 kg of cationic resin was packed into the column and subjected to cationic resin separation and anion resin separation. The collected solution from the anion resin column separation was concentrated under reduced pressure to obtain Ramulus Mori extract. The alkaloid content was 51%, the polysaccharide content was 25%, the flavone content was 0.5%, and the amino acid content was 20%. In alkaloids, the amount of 1-DNJ was 55%. The total amount of heavy metals was 10 to 20 ppm, including 11.11 ppm lead, 82.0 ppm cadmium, 50.0 ppm mercury, and 53.0 ppm arsenic, in which the levels of lead, cadmium, and mercury exceeded the content standards. In this comparative example, alcohol precipitation was performed before the cationic resin separation step and, compared to Example 3, showed a decrease in alkaloid content, an increase in heavy metal content, and a 3-fold increase in ethanol content. Comparative Example 5 1000 kg of fresh Ramulus Mori (Morus serrata Roxb.) was taken from the same batch as used in Example 3 and subjected to crude extraction and heat concentration according to the method described in Example 3. The concentrated crude extraction solution was directly loaded onto an anion resin and subjected to anion resin separation according to the method described in Example 3. 3000 liters of effluent was collected. The collection solution resulting from the anion resin column separation was centrifuged to remove impurities and then concentrated through a nanofiltration membrane. The specific gravity of the concentrated liquid was 1.1. It was transferred to an alcohol sedimentation tank and 46 kg of anhydrous ethanol was added while the stirring paddle was at 400 rpm. After the addition of ethanol, the stirring of the solution was stopped and the alcohol sedimentation was carried out for 24 hours. The supernatant was taken and concentrated under reduced pressure to obtain Ramulus Mori extract. In the Ramulus Mori extract, the alkaloid content was 40%, the polysaccharide content was 35%, the flavone content was 1.5%, and the amino acid content was 22%. In alkaloids, the amount of 1-DNJ was 50%. The total amount of heavy metals was 30 to 40 ppm, including 01.30 ppm lead, 24.1 ppm cadmium, 21.0 ppm mercury, and 85.0 ppm arsenic, in which the amount of lead, cadmium, and mercury exceeded the content standards. Without the cationic resin separation step, this comparative example showed reduced alkaloid content, a significant increase in heavy metal content, and a 2-fold increase in ethanol content compared to Example 3. Experimental example 1 Sustainability study The mulberry extract prepared in Example 1, the Folium Mori extracts prepared in Examples 2, 8 and 9, the Ramulus Mori extracts prepared in Examples 3 and 5-7, and the Cortex Mori extracts prepared in Examples 4 and 10 were sealed and packaged in composite film bags, then placed at a temperature of 25°C±2°C and a relative humidity of RH60%±10% for 24 months, and then the amount of alkaloids contained therein was tested. The results are given in Table 1 below. Table 1: Amount / % Item Example 1 Berry Extract Example 2 Folium Mori Extract Example 3 Ramulus Mori Extract Example 4 Cortex Mori Extract Example 5 Ramulus Mori Extract Example 6 Ramulus Mori Extract Example 7 Ramulus Mori Extract Example 8 Folium Mori Extract Example 9 Folium Mori Extract Example 10 Cortex Mori Extract Total Alkaloids 44.8 59.5 74.3 57.2 97.2 96.7 14.8 4.9 2.9 2.9 1-DNJ 59.4 68.8 71.3 66.9 98.1 97.5 54.9 45.7 37.7 42.8 It is clear from Table 1 that the plant extracts obtained by the extraction method in the present embodiment have good stability. Test sample 2 Residual organic solvents Gas chromatography was used to detect residual resin including n-hexane, methylcyclohexane, divinylbenzene, toluene, benzene, xylene and styrene. The herbal extracts prepared in Examples 1 to 9 were tested and none of them were detected as extracts containing residual resin. Experimental Example 3 Effectiveness Test Normal male ICR mice were randomly divided into 6 groups (n=10) according to body weight and fasted overnight before the experiment. One group was orally administered sucrose solution (4.0 g / kg) as the control (normal) group, while the remaining 5 groups were orally administered sucrose as well as Cortex Mori extract sample prepared in Example 1, Folium Mori extract sample prepared in Example 2 and Ramulus Mori extract samples prepared in Examples 3, 5 and 6 (10 mg / kg each in terms of total alkaloids) as the treatment groups. Blood glucose levels were measured before administration (0 min) and at 30 min, 60 min and 120 min after administration. Blood glucose time-curves were plotted and the area under the curve (AUC) of blood glucose was calculated. The results were as shown in Fig. 1. The results show that plant extracts obtained by the present herbal extraction method lead to a significant reduction in the increase in blood glucose in healthy mice after sucrose loading. The present embodiment has been described above with reference to preferred mechanisms, which, however, are exemplary and illustrative only. Accordingly, various alternatives and improvements to the present embodiment may be made, all of which fall within the scope of the present embodiment.

Claims

W hat is claimed is:

1. A plant extraction method comprising the following step s of : step 1): preparing a crude plant extraction solution; step 2): separating the crude extraction solution via a cation resin and an anion resin to obtain a collection solution; wherein the cation resin in step 2) is any one or a combination of more selected from a strongly acidic cation exchange resin , a weakly acidic cation exchange resin , and a strongly alkaline quaternary ammonium-type cation resin ; the cation resin and a charged plant raw material has a weight ratio ranging from 1:1 to 1:30；a eluent of the cation resin is a salt solution or an alkaline solution containing cations ; the eluent is one or more selected from sodium chloride, ammonium chloride, ammonium sulfate, ammonium nitrate, ammonia water, potassium chloride and sodium hydroxide ；the cation in the eluent has a concentration ranging from 0.04 to 5 mol / L； a starting point of a collection is determined according to a pH of a effluent obtained from the cation resin is higher than 7 or a precipitation reaction; the collection is terminated when a volume of a collection solution obtained from the cation resin reaches 0.1 to 10 times the weight of the charged plant raw material ; a weight of the eluent used in the separation via the cation resin in step 2) is 0.1 to 30 times ; wherein the anion resin in step 2) is one or a combination of more selected from a strongly alkaline anion exchange resin, a weakly alkaline anion exchange resin, and a weakly acidic anion exchange resin ; the anion resin and the charged plant raw material has a weight ratio ranging from 1:1 to 1:80 ; a collection is terminated when a volume of a collection solution obtained from the anion resin reaches 0.05 to 10 times the weight of the charged plant raw material ; step 3): concentrating the collection solution obtained in step 2); step 4): subjecting the concentrated solution obtained in step 3) to alcohol precipitation ; and optional ly, step 5 ) : concentrating and drying; wherein the plant is a plant of Moraceae ; ethanol used for the alcohol precipitation in step 4) and the charged plant raw material has a weight ratio ranging from 1:4 to 1:600; a plant extract obtained by the extraction method contains each component in the following weight ratios: alkaloids 30% to 99%; polysaccharides 0.2% to 35%; flavones 0.05% to 2%; amino acids 0% to 25%; other components 0% to 20% ; a heavy metal content of the plant extract obtained by the method is not more than 10 ppm .

2. The extraction method according to claim 1, wherein the plant further comprises a plant of Liliaceae , Campanulaceae , or Commelinaceae ; preferably, the plant is a plant of Morus , Hyacinthus , Adenophora , or Commelina ; preferably, the plant is any one or a combination of more selected from Morus multicaulis Perrott. , Morus alba L. , Morus atropurpurea R oxb , Morusmizuho Hotta , Morus wittiorum Hand Mazz. , Morus laevigata Wall , Morus nigra Linn., Morus cathayana Hemsi., Morus serrata Roxb., Morus mongolica Schneid., Morus bo mbycis Koidz . , Morus notabilis Schneid., Morus nigriformis Koidz . , Morus yunnanensis Koidz . , Morus australis Poir., Morus mongolica (Bur.) Schneid var. diabolica Koidz., Morus alba L. var. macrophylla loud , Morus al ba Var.Pendula Dippel, Morus alba L. var. venosa Delili , a mulberry variety bred from the above mulberry species, a hybrid mulberry obtained from selective intra-species or inter-species breeding of the above mulberry species, Hyacinthus orientalis , Adenophora . triphylla var． japonica , and Commelina communi ; preferably, the plant is Morus atropurpurea Roxb, Morus multicaulis Perrott., Morus alba L., Morus serrata Roxb., Morus bombycis Koidz., or a hybrid mulberry, the hybrid mulberry is preferably Yuesang No.11, Guisangyou No.62 or Sangteyou No.2.

3. The extraction method according to claim 1 or 2, wherein the extraction method further comprises a step of concentrating the crude plant extraction solution prior to the separation in step 2) .

4. The extraction method according to any one of claim s 1 to 3 , wherein the cation resin is any one or a combination of more selected from 732-type strongly acidic styrene-based cation exchange resin, 734-type strongly acidic styrene-based cation exchange resin, 002SC-type strongly acidic styrene-based cation exchange resin, D001-type macroporous and strongly acidic styrene-based cation exchange resin, D113-type macroporous and weakly acidic phenylpropene-based cation exchange resin, and D254-type macroporous and strongly alkaline quaternary ammonium-type cation exchange resin; preferably, the cation resin is 732-type strongly acidic styrene-based cation exchange resin, 734-type strongly acidic styrene-based cation exchange resin and D001-type macroporous and strongly acidic styrene-based cation exchange resin; preferably, upon separation via the cation resin in step 2) , the cation resin and the charged plant raw material has a weight ratio ranging from 1:1 to 1:25, and more preferably 1:2 to 1:20; preferably, a weight of the eluent used in the separation via the cation resin in step 2) is 0.5 to 10 times the weight of the charged plant raw material.

5. The extraction method according to any one of claim s 1 to 4 , wherein the anion resin is one or a combination of more selected from 717-type strongly alkaline styrene-based anion exchange resin, 711-type strongly alkaline styrene-based anion exchange resin, D201-type macroporous and strongly alkaline styrene-based anion exchange resin, D218 -type macroporous and strongly alkaline acrylic-based anion exchange resin, D301-G-type macroporous and weakly acidic styrene-based anion exchange resin, and D301-type macroporous and weakly alkaline styrene-based anion exchange resin ; and preferably, the anion resin is 717-type strongly alkaline styrene-based anion exchange resin, D201-type macroporous and strongly alkaline styrene-based anion exchange resin andD218 -type macroporous and strongly alkaline acrylic-based anion exchange resin ; preferably, upon separation via the anion resin in step 2) , the anion resin and the charged plant raw material has a weight ratio ranging from 1: 1 to 1: 64, and more preferably 1: 1 to 1: 32.

6. The extraction method according to any one of claims 1 to 5, wherein ethanol used for the alcohol precipitation in step 4) and the charged plant raw material has a weight ratio ranging from 1:20 to 1:300.

7. A plant extract obtained by the extraction method of any one of claims 1 to 6.8 . A pharmaceutical composition comprising the plant extract of claim 7 and an optional pharmaceutically acceptable excipient; preferably, a dosage form of the pharmaceutical composition includes an oral solid preparation and a liquid preparation ; and preferably, the dosage form of the pharmaceutical composition includes a tablet, a capsule, an oral solution, an oral emulsion, a pill and a granule.9 . Use of the plant extract of claim 7 or the pharmaceutical composition of claim 8 in preparation of a h ypoglycemic drug .

10. Use of the plant extract of claim 7 or the pharmaceutical composition of claim 8 in preparation of a drug for treating abnormal glucose tolerance .

11. Use of the plant extract of claim 7 or the pharmaceutical composition of claim 8 in preparation of a drug for preventing and / or treating a disease related to abnormal blood glucose.

12. Use of the plant extract of claim 7 or the pharmaceutical composition of claim 8 in preparation of a lipid-lowing drug.

13. Use of the plant extract of claim 7 or the pharmaceutical composition of claim 8 in preparation of a drug for regulating intestinal flora .

14. A food , a health care product or a drink , comprising the plant extract of claim 7 .

15. Use of the plant extract of claim 7 in preparation of a food , a health care product or a drink .

Images