A kind of extraction method of silymarin

Abstract

The invention discloses a method for extracting silymarin, which comprises the steps of polar solvent treatment, acid solution treatment, alkaline solution treatment, and purification; the polar solvent is selected from one or more of chloroform and dichloromethane, and the alkaline solution comprises one or more of sodium hydroxide and potassium hydroxide. The method for extracting silymarin provided by the invention has the effect of reducing the difficulty and cost of extracting silymarin.

Description

Technical Field

[0001] The invention belongs to the technical field of plant extraction, and in particular relates to a method for extracting silymarin. Background Art

[0002] Silymarin is a natural flavonoid lignan compound, a natural active substance extracted from the dried fruit of the Asteraceae plant, Silymarin. The main effect of silymarin is to protect liver cells from toxic substances. It has a strong antioxidant function and can protect liver cells from free radical damage, so it is called a natural liver protector.

[0003] Silymarin is in the form of yellow powder or crystalline powder, and its chemical structure contains four key isomers: silybin, isosilybin, silybin and silybin. In terms of solubility, silymarin is poorly soluble in water and chloroform, but easily soluble in organic solvents such as acetone (ACE), ethyl acetate (EAC) and alkaline solutions. Currently, the organic solvent method is widely used in industry to extract silymarin from crushed milk thistle seeds.

[0004] At present, when silymarin is extracted by organic solvent, it is generally carried out by crushing silymarin seeds and mixing them with acetone, and then extracting them at room temperature or by heating or reflux. However, there are the following shortcomings in the process of dissolving silymarin by organic solvent:

[0005] ① Organic solvents will not only dissolve silymarin, but also other fat-soluble impurities such as oils and waxes. The mixing of these impurities significantly reduces the purity of the extract, resulting in insufficient purity of the obtained extract, which in turn increases the complexity and cost of subsequent purification steps.

[0006] ② The dissolution efficiency of silymarin is directly affected by the fineness of the raw material. Even if an organic solvent is used, it is still difficult to ensure the complete release of silymarin if it only relies on the solubility of the solvent, thus limiting the improvement of the extraction rate.

[0007] Therefore, it is necessary to develop an extraction method for silymarin to improve the purity and extraction rate of silymarin extracted by acetone. Summary of the invention

[0008] In view of the deficiencies of the prior art, the object of the present invention is to provide a method for extracting silymarin.

[0009] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0010] A method for extracting silymarin comprises the following steps:

[0011] S1. The milk thistle seeds are crushed and dried, and then soaked in a polar solvent at 5° C. to 15° C., and the polar solvent in the upper layer is removed several times during the soaking process and a pure polar solvent is added; after the polar solvent soaking is completed, the seeds are dried to obtain a primary treated powder;

[0012] S2, soaking the initially treated powder in an acidic solution with a pH of 1 to 2 at 60° C. to 85° C., wherein the acidic solution contains vitamin C; then filtering, adjusting to neutrality, and drying in an anaerobic environment to obtain a re-treated powder;

[0013] S3, soaking the treated powder in an alkaline solution to obtain a treated solution;

[0014] S4, purifying the treated liquid to obtain silymarin;

[0015] The polar solvent is selected from one or more of chloroform and dichloromethane (DCM), and the alkaline solution is selected from sodium hydroxide solution.

[0016] In the present invention, chloroform and dichloromethane both have good dissolving ability and can dissolve fat-soluble components in milk thistle seed powder, such as oil, wax and some biological molecules. The oil, wax, biological molecules and the like in the milk thistle seed powder are continuously diffused in the polar solvent. Therefore, when the polar solvent in the upper layer is removed and the pure polar solvent is added, the concentration of the oil, wax, biological molecules and the like in the milk thistle seed powder is continuously reduced.

[0017] In the present invention, silymarin is poorly soluble in chloroform and dichloromethane. When the polar solvent on the upper layer is removed and a pure polar solvent is added, the silymarin seed powder sinks to the bottom and silymarin is not easily dissolved.

[0018] In the present invention, the oil, wax, biological molecules and the like in the milk thistle seed powder can be dissolved in the polar solvent and diffuse continuously, so the concentration of the fat-soluble components in the polar solvent is continuously reduced.

[0019] In the present invention, vitamin C has multiple hydroxyl groups and can form a complex with silymarin to increase the solubility of silymarin in the solution, thereby facilitating the improvement of the dissolution effect of silymarin.

[0020] In the present invention, the cellulose in the milk thistle seeds can swell and dissolve in an acidic solution, resulting in the rupture of the cellulose chains and the destruction of the integrity of the cell walls, thereby facilitating the release of silymarin from the milk thistle seed powder.

[0021] In the present invention, silymarin is easily soluble in alkaline solution.

[0022] In the present invention, vitamin C will react in an alkaline environment to generate salt and lose its complexing ability with silymarin, thereby facilitating the improvement of the purity of silymarin.

[0023] In the present invention, the boiling point of chloroform is 61.3°C, and the boiling point of dichloromethane is lower than 40°C. In step S1, when the immersion temperature is 5°C to 15°C, it is beneficial to reduce the volatilization of the organic solvent; at the same time, the solubility of silymarin in chloroform and dichloromethane is further reduced at 5°C to 15°C.

[0024] In the present invention, in step S1, the soaking temperature is selected from one of 5°C, 8°C, 10°C, 12°C, and 15°C.

[0025] In the present invention, in step S1, the soaking temperature is specifically selected to be 10°C.

[0026] In the present invention, in step S2, the soaking temperature is selected from one of 60°C, 65°C, 70°C, 75°C, 80°C, and 85°C.

[0027] In the present invention, in step S2, the soaking temperature is specifically selected to be 70°C.

[0028] In the present invention, in step S2, the pH is selected from one of 1.0, 1.2, 1.4, 1.5, 1.6, 1.8, and 2.0.

[0029] In the present invention, in step S2, the pH is specifically selected to be 1.0.

[0030] Preferably, in step S1, the immersion is completed by removing the polar solvent in the upper layer multiple times and replenishing the pure polar solvent so that the polar solvent is clear and transparent.

[0031] Preferably, in step S1, the polar solvent in the upper layer is removed and then an equal volume of pure polar solvent is added.

[0032] Preferably, in step S1, after the polar solvent immersion is completed, the powder is dried and then immersed in water at 5°C to 15°C. During the immersion process, the water in the upper layer is removed several times and deionized water is added. After the water immersion is completed, the powder is dried to obtain the primary treated powder.

[0033] In the present invention, silymarin is poorly soluble in water, and water-soluble impurities in silymarin seed powder can be dissolved in water and removed, thereby facilitating the reduction of impurities in the prepared silymarin and improving the purity of silymarin.

[0034] In the present invention, the temperature for immersion in water is selected from one of 5°C, 8°C, 10°C, 12°C and 15°C.

[0035] In the present invention, the temperature for soaking in water is specifically selected to be 10°C.

[0036] Preferably, in step S1, the immersion is completed by removing the water in the upper layer multiple times and replenishing deionized water so that the refractive index of the aqueous solution in the middle is ≤1.3350.

[0037] Preferably, during the water soaking process, the mass of water is 5 to 10 times the mass of the milk thistle seeds after crushing and drying.

[0038] In the present invention, the mass of water is a multiple selected from 5, 6, 7, 8, 9 and 10 of the mass of the milk thistle seeds after being crushed and dried.

[0039] In the present invention, the mass of water is specifically 10 times the mass of the milk thistle seeds after being crushed and dried.

[0040] Preferably, during the water immersion process, the water in the upper layer is removed and supplemented with an equal volume of deionized water.

[0041] Preferably, in step S3, the treated liquid is evaporated and concentrated, and then purified by acetone to obtain an acetone solution, and then the acetone solution is dried to obtain silymarin.

[0042] In the present invention, silymarin is easily soluble in acetone, and cellulose, alkali cellulose produced by the reaction of cellulose and sodium hydroxide, and sodium hydroxide are all insoluble in acetone, so silymarin can be purified.

[0043] Preferably, in step S3, after the treatment liquid is adjusted to neutral at 5°C to 15°C, it is diluted to 2 to 5 times the volume with deionized water, and then centrifuged to obtain the bottom liquid, which is then evaporated and concentrated.

[0044] In the present invention, the temperature of the treatment liquid is adjusted to one of 5°C, 8°C, 10°C, 12°C and 15°C.

[0045] In the present invention, the temperature of the treatment liquid is adjusted to 10°C.

[0046] In the present invention, the dilution multiple of the treatment solution after adjustment is selected from one of 2, 2.5, 3, 3.5, 4, 4.5, and 5.

[0047] In the present invention, the dilution multiple of the treatment solution after adjustment is specifically selected to be 3.

[0048] In the present invention, after the treatment liquid is adjusted to neutrality, the sodium hydroxide is converted into salt, and the salt content of the obtained silymarin can be further reduced by dilution and centrifugation, which is beneficial to improving the purity of silymarin.

[0049] Preferably, during the polar solvent soaking process, the mass of the polar solvent is 5 to 10 times the mass of the milk thistle seeds after crushing and drying.

[0050] In the present invention, the mass of the polar solvent is a multiple selected from 5, 6, 7, 8, 9, and 10 of the mass of the dry milk thistle seed powder.

[0051] In the present invention, the mass of the polar solvent is specifically 10 times the mass of the dry milk thistle seed powder.

[0052] Preferably, in step S2, the alkaline solution is heated to 60° C. to 80° C. during the process of soaking the treated powder.

[0053] In the present invention, the heating temperature of the powder after soaking in the alkaline solution is selected from one of 60°C, 65°C, 70°C, 75°C and 80°C.

[0054] In the present invention, the heating temperature for the alkaline solution immersion and reprocessing of the powder is specifically selected to be 70°C.

[0055] In the present invention, heating can accelerate the rate at which sodium hydroxide destroys cellulose, thereby being beneficial to fully destroying the cellulose in the milk thistle seed powder, thereby being beneficial to the dissolution of silymarin.

[0056] Preferably, the pH of the alkaline solution is 8-10.

[0057] In the present invention, the pH of the alkaline solution is selected from one of 8, 8.5, 9, 9.5 and 10.

[0058] In the present invention, the pH of the alkaline solution is specifically 9.5.

[0059] In the present invention, silymarin has good solubility in a solution with a pH value of 8 to 10.

[0060] Preferably, the acidic solution comprises dilute sulfuric acid.

[0061] Preferably, the mass of the alkaline solution is 5 to 10 times the mass of the milk thistle seeds after crushing and drying.

[0062] In the present invention, the mass of the alkaline solution is a multiple selected from 5, 6, 7, 8, 9 and 10 of the mass of the dry milk thistle seed powder.

[0063] In the present invention, the mass of the alkaline solution is specifically 5 times the mass of the dry milk thistle seed powder.

[0064] Preferably, the content of vitamin C in the acidic solution is 0.1% to 0.5%.

[0065] Preferably, the particle size of the milk thistle seeds after crushing is ≥200 mesh.

[0066] In the present invention, the particle size of the milk thistle seeds after crushing is 200-800 meshes.

[0067] In the present invention, the particle size of the crushed milk thistle seeds is specifically 200 meshes.

[0068] Compared with the prior art, the advantages of the present invention include:

[0069] (1) The present invention provides a method for extracting silymarin, wherein the polar solvent can dissolve the oil, wax and biomolecules in the silymarin seed powder, thereby reducing the impurities in the obtained silymarin and improving the purity of the silymarin;

[0070] (2) The present invention provides a method for extracting silymarin, wherein the alkaline solution can destroy the cellulose of the milk thistle seeds and the integrity of the cell walls, thereby facilitating the release of silymarin from the milk thistle seed powder;

[0071] (3) The present invention provides a method for extracting silymarin, which removes impurities in silymarin by using a polar solvent, thereby eliminating the need for complex purification steps when extracting silymarin, thereby reducing the difficulty and cost of extracting silymarin. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0073] Figure 1 The present invention is a schematic diagram of the structure of an extractor involved in a method for extracting silymarin.

[0074] Reference numerals:

[0075] 11. Extraction barrel; 12. Feed port; 13. Inlet; 14. Outlet; 15. Sealing cover; 16. Heat exchange tube. DETAILED DESCRIPTION

[0076] In order to enable those skilled in the art to understand the characteristics and effects of the present application, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present application. In case of conflict, the definitions in this specification shall prevail.

[0077] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present application in any way, that is, the content of the present application can be implemented without being limited by any specific theory or mechanism.

[0078] As used herein, "this application" means "the present invention" or "the present disclosure".

[0079] The use of "one", "an", "a kind" or similar expressions to describe the components and technical features described in this application is merely for the convenience of expression and to provide a general meaning to the scope of this application. Therefore, such description should be understood to include one or at least one, and the singular also includes the plural, unless it is obvious that it refers to another meaning.

[0080] In this document, "or its combination" means "or any combination thereof", and "any one", "any one" means "any one", "any one" or "any one".

[0081] In this article, the terms "comprise", "include", "have", "contain" or any other similar terms are open-ended transitional phrases, which are intended to cover non-exclusive inclusions. For example, a composition or product containing multiple elements is not limited to the elements listed in this article, but may also include other elements that are not explicitly listed but are generally inherent to the composition or product. In addition, unless otherwise explicitly stated, the term "or" refers to an inclusive "or" rather than an exclusive "or". For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), A and B are both true (or exist). In addition, in this article, the interpretation of the terms "comprise", "include", "have", and "contain" should be considered to have been specifically disclosed and simultaneously cover closed transitional phrases such as "consisting of", "consisting of", "the balance is", and "substantially consisting of", "mainly consisting of", "mainly consisting of", "basically containing", "basically consisting of", "basically consisting of", "essentially containing" and other transitional phrases.

[0082] In this article, all features or conditions such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have covered and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions), especially integer values. For example, the range description of "1.0 to 8.0" or "between 1.0 and 8.0" or "between 1.0 and 8.0" should be deemed to have specifically disclosed all sub-ranges such as 1.0 to 8.0, 1.0 to 7.0, 2.0 to 8.0, 2.0 to 6.0, 3.0 to 6.0, 4.0 to 8.0, 3.0 to 8.0, etc., and should be deemed to cover endpoint values, especially sub-ranges defined by integer values, and should be deemed to have specifically disclosed individual values ​​such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. Unless otherwise indicated, the foregoing method of interpretation applies to all contents of the entire application, regardless of whether the scope is broad or not.

[0083] If the quantity, concentration or other numerical value or parameter is expressed as a range, a preferred range (or a better range) or a series of upper and lower limits, it should be understood that all ranges consisting of any pair of the upper limit or preferred value (or a better value) of the range and the lower limit or preferred value (or a better value) of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, if a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0084] In this document, numerical values ​​should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range of 39.50 to 40.49.

[0085] Unless otherwise specified, in this application, parts by weight represent relative parts by weight in a composition, which may be any weight unit, such as but not limited to kilograms, kilograms, grams, pounds, etc. For example, 100 parts by weight of polyphenylene ether resin may represent 100 kilograms of polyphenylene ether resin or 100 pounds of polyphenylene ether resin.

[0086] It should be understood that the features disclosed in the various embodiments herein may be arbitrarily combined to form the technical solution of the present application, as long as there is no contradiction in the combination of these features.

[0087] The present application will be described below with specific implementations and examples. It should be understood that these specific implementations and examples are merely illustrative and are not intended to limit the scope of the present application and its use.

[0088] Unless otherwise stated, the methods, reagents and conditions used in the following preparation examples, comparative examples and examples are conventional methods, reagents and conditions in the art.

[0089] In the following descriptions:

[0090] Deuterated chloroform (CDCl3): purity ≥ 99.8%;

[0091] Dichloromethane (CH2Cl2): purity ≥99.9%;

[0092] Extractor:

[0093] See also Figure 1 The extractor involved in the silymarin extraction method of the present invention includes an extraction barrel 11, which has a height and is vertical. A feed port 12 is provided on the top of the extraction barrel 11. A sealing cover 15 for sealing the feed port 12 is also connected to the top of the extraction barrel 11 by screws.

[0094] An inlet 13 and an outlet 14 are provided at the upper end of the extraction barrel 11, and both the inlet 13 and the outlet 14 are connected to the interior of the extraction barrel 11. The inlet 13 and the outlet 14 are respectively located on both sides of the extraction barrel 11, and the outlet 14 is located above the inlet 13; when the liquid level in the extraction barrel 11 reaches the outlet 14, the volume of the liquid in the extraction barrel is 100L.

[0095] By injecting liquid from the inlet 13, the liquid can flow out from the outlet 14. Figure 1 In the figure, the direction indicated by the arrow is the direction of liquid flow.

[0096] A heat exchange tube 16 is fixedly mounted on the outer wall of the extraction barrel 11, and the heat exchange tube 16 is spirally wound on the extraction barrel 11 along the outer wall of the extraction barrel 11. By injecting hot liquid or cold liquid into the heat exchange tube, the temperature in the extraction barrel 11 can be controlled.

[0097] When the milk thistle seed powder is soaked with a polar solvent, the polar solvent is continuously or intermittently injected into the extraction barrel 11 from the inlet 13, and the polar solvent flowing in the extraction barrel 11 can take away the substances dissolved by the polar solvent above the inlet 13, thereby continuously diluting the concentration of the solution in the extraction barrel 11. At the same time, since the polar solvent only flows from the inlet 13 to the outlet 14, the milk thistle seed powder at the bottom of the extraction barrel 11 will not be stirred. The substances dissolved in the polar solvent in the milk thistle seed powder continuously move to the top of the extraction barrel 11 under the action of molecular diffusion, and are finally taken out of the extraction barrel 11.

[0098] When the milk thistle seed powder is soaked in water, water is continuously or intermittently injected into the extraction barrel 11 from the inlet 13, and the water flowing in the extraction barrel 11 can carry away the water-dissolved substances located above the inlet 13, thereby continuously diluting the concentration of the solution in the extraction barrel 11. At the same time, since the water only flows from the inlet 13 to the outlet 14, the milk thistle seed powder located at the bottom of the extraction barrel 11 will not be stirred. The water-dissolved substances in the milk thistle seed powder continuously move to the top of the extraction barrel 11 under the action of molecular diffusion, and are finally taken out of the extraction barrel 11.

[0099] Preparation Example

[0100] Preparation Example 1

[0101] The raw materials used in this preparation example include: 10 kg of milk thistle seeds.

[0102] The preparation method of this preparation example includes:

[0103] Z1. Place the milk thistle seeds in 30 kg of deionized water and ultrasonically clean them for 20 min, then dry them;

[0104] Z2, putting the dried milk thistle seeds into a grinder for grinding, grinding to a particle size of 200 mesh to obtain primary powder;

[0105] Z3. Dry the primary powder at 70° C. for 12 h to obtain milk thistle seed powder.

[0106] Example

[0107] Example 1

[0108] The raw materials used in this example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0109] The preparation method of this embodiment includes:

[0110] S1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 to the inlet 13 and allowed to stand for 1 hour.

[0111] S1.2, at 10°C, inject dichloromethane into the inlet 13, recover the dichloromethane flowing out from the outlet 14, and inject at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 is clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0112] S2, soaking the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filtering, adjusting to neutrality, and drying under a nitrogen atmosphere to obtain a re-treated powder;

[0113] S3, mixing the reprocessed powder into 500g NaOH solution, adjusting the pH to 9.5 with 15g / ml NaOH solution, and then heating to 70°C and keeping warm for 2h to obtain a treated solution;

[0114] S4. Dry the treated liquid at 70° C. to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0115] Example 2

[0116] The raw materials used in this example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0117] The preparation method of this embodiment includes:

[0118] S1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 to the inlet 13 and allowed to stand for 1 hour.

[0119] S1.2, at 10°C, inject dichloromethane into the inlet 13, recover the dichloromethane flowing out from the outlet 14, and inject at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 is clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0120] S2, soaking the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.5%; then filtering, adjusting to neutrality, and drying under a nitrogen atmosphere to obtain a re-treated powder;

[0121] S3, mixing the reprocessed powder into 500g NaOH solution, adjusting the pH to 9.5 with 15g / ml NaOH solution, and then heating to 70°C and keeping warm for 2h to obtain a treated solution;

[0122] S4. Dry the treated liquid at 70° C. to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0123] Example 3

[0124] The raw materials used in this example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and deuterated chloroform.

[0125] The preparation method of this embodiment includes:

[0126] S1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of deuterated chloroform were mixed in a blender and then placed in an extraction barrel 11. Deuterated chloroform was added to the extraction barrel 11 to the inlet 13 and allowed to stand for 1 hour.

[0127] S1.2, at 10°C, inject deuterated chloroform into the inlet 13, recover the deuterated chloroform flowing out of the outlet 14, and inject at a rate of 500 ml / L until the deuterated chloroform in the extraction barrel 11 is clear and transparent; dry the substance in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0128] S2, soaking the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filtering, adjusting to neutrality, and drying under a nitrogen atmosphere to obtain a re-treated powder;

[0129] S3, mixing the reprocessed powder into 500g NaOH solution, adjusting the pH to 9.5 with 15g / ml KOH solution, and then heating to 70°C and keeping warm for 2h to obtain a treated solution;

[0130] S4. Dry the treated liquid at 70° C. to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0131] Example 4

[0132] The raw materials used in this example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0133] The preparation method of this embodiment includes:

[0134] S1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 to the inlet 13 and allowed to stand for 1 hour.

[0135] S1.2, at 10°C, inject dichloromethane into the inlet 13, recover the dichloromethane flowing out from the outlet 14, and inject at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 is clear and transparent; dry the material in the extraction barrel 11 at 70°C, and treat the powder with an organic solvent;

[0136] S1.3, at 10°C, put the organic solvent treated powder and 200g of deionized water into a stirrer and mix them evenly, then put them into the extraction barrel 11, add deionized water into the extraction barrel 11 to the inlet 13, and let it stand for 0.5h;

[0137] S1.4, at 10°C, inject deionized water into the inlet 13, and recover the deionized water flowing out of the outlet 14, with an injection rate of 500 ml / L, until the refractive index of the aqueous solution in the extraction barrel 11 located between the inlet 13 and the bottom of the extraction barrel 11 is ≤1.3350; dry the substance in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0138] S2, soaking the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filtering, adjusting to neutrality, and drying under a nitrogen atmosphere to obtain a re-treated powder;

[0139] S3, mixing the reprocessed powder into 500g NaOH solution, adjusting the pH to 9.5 with 15g / ml NaOH solution, and then heating to 70°C and keeping warm for 2h to obtain a treated solution;

[0140] S4. Dry the treated liquid at 70° C. to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0141] Comparative Example

[0142] Comparative Example 1

[0143] The raw materials used in this comparative example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1.

[0144] The preparation method of this comparative example comprises:

[0145] D1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of deionized water were mixed in a blender and then placed in an extraction barrel 11. Deionized water was added to the extraction barrel 11 up to the inlet 13 and allowed to stand for 1 hour.

[0146] D1.2. Inject deionized water into the inlet 13 at 10°C, and recover the deionized water flowing out of the outlet 14 at a rate of 500 ml / L until the deionized water in the extraction barrel 11 becomes clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0147] D2. Soak the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filter, adjust to neutrality, and dry under a nitrogen atmosphere to obtain a re-treated powder;

[0148] D3, mixing the reprocessed powder into 500 g of NaOH solution, adjusting the pH to 9.5 with 15 g / ml of NaOH solution, and then heating to 70° C. and keeping the temperature for 2 h to obtain a treated solution;

[0149] D4. Dry the treated liquid at 70°C to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70°C to obtain silymarin.

[0150] Comparative Example 2

[0151] The raw materials used in this comparative example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0152] The preparation method of this comparative example comprises:

[0153] D1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 up to the inlet 13 and allowed to stand for 1 hour.

[0154] D1.2. At 10°C, inject dichloromethane into the inlet 13, and recover the dichloromethane flowing out from the outlet 14 at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 becomes clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0155] D2. Soak the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filter, adjust to neutrality, and dry under a nitrogen atmosphere to obtain a re-treated powder;

[0156] D3. Add the reprocessed powder into acetone with a mass ratio of the reprocessed powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0157] Comparative Example 3

[0158] The raw materials used in this comparative example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0159] The preparation method of this comparative example comprises:

[0160] D1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 up to the inlet 13 and allowed to stand for 1 hour.

[0161] D1.2. At 10°C, inject dichloromethane into the inlet 13, and recover the dichloromethane flowing out from the outlet 14 at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 becomes clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0162] D2. Soak the initially treated powder in a dilute sulfuric acid solution with a pH of 1.0 at 70° C. for 1 hour, wherein the vitamin C concentration in the dilute sulfuric acid solution is 0.1%; then filter, adjust to neutrality, and dry under a nitrogen atmosphere to obtain a re-treated powder;

[0163] D2, mixing the reprocessed powder into 500 g of NaOH solution, adjusting the pH to 9.5 with 15 g / ml of NaOH solution, and then heating to 70° C. and keeping the temperature for 2 h to obtain a treated solution;

[0164] D3. Dry the treated liquid at 70°C to obtain silymarin.

[0165] Comparative Example 4

[0166] The raw materials used in this comparative example include: 1 kg of milk thistle seed powder obtained in Preparation Example 1 and dichloromethane.

[0167] The preparation method of this comparative example comprises:

[0168] S1.1. At 10°C, 1 kg of milk thistle seed powder and 500 g of dichloromethane were mixed in a blender and then placed in an extraction barrel 11. Dichloromethane was added to the extraction barrel 11 to the inlet 13 and allowed to stand for 1 hour.

[0169] S1.2, at 10°C, inject dichloromethane into the inlet 13, recover the dichloromethane flowing out from the outlet 14, and inject at a rate of 500 ml / L until the dichloromethane in the extraction barrel 11 is clear and transparent; dry the material in the extraction barrel 11 at 70°C to obtain a primary treated powder;

[0170] S2, mixing the primary treated powder into 500g NaOH solution, adjusting the pH to 9.5 with 15g / ml NaOH solution, and then heating to 70°C and keeping warm for 2h to obtain a treated solution;

[0171] S3. Dry the treated liquid at 70° C. to obtain a coarse powder; add the coarse powder to acetone with a mass ratio of the coarse powder to acetone of 1:2, and then filter to obtain an acetone solution; dry the acetone solution at 70° C. to obtain silymarin.

[0172] Performance Testing

[0173] The purity of silymarin obtained in Examples 1 to 4 and Comparative Examples 1 to 4 was determined by spectrophotometry, unit: %.

[0174]

[0175] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, some simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for extracting silymarin, characterized in that: The steps include: S1. The milk thistle seeds are crushed and dried, and then soaked in a polar solvent at 5° C. to 15° C., and the polar solvent in the upper layer is removed several times during the soaking process and a pure polar solvent is added; after the polar solvent soaking is completed, the seeds are dried to obtain a primary treated powder; S2, soaking the initially treated powder in an acidic solution with a pH of 1 to 2 at 60° C. to 85° C., wherein the acidic solution contains vitamin C; then filtering, adjusting to neutrality, and drying in an anaerobic environment to obtain a re-treated powder; S3, soaking the treated powder in an alkaline solution to obtain a treated solution; S4, purifying the treated liquid to obtain silymarin; The polar solvent is selected from one or more of chloroform and dichloromethane, and the alkaline solution is selected from sodium hydroxide solution.

2. A method for extracting silymarin according to claim 1, characterized in that: In the step S1, the immersion is completed by removing the polar solvent in the upper layer multiple times and replenishing the pure polar solvent, so that the polar solvent is clear and transparent; And / or, in step S1, the polar solvent in the upper layer is removed and then an equal volume of pure polar solvent is added.

3. A method for extracting silymarin according to claim 1, characterized in that: In the step S1, after the polar solvent immersion is completed, the powder is dried and then immersed in water at 5°C to 15°C. During the immersion process, the water in the upper layer is removed several times and deionized water is added. After the water immersion is completed, the powder is dried to obtain the primary treated powder.

4. A method for extracting silymarin according to claim 3, characterized in that: In the step S1, the immersion is completed by removing the water in the upper layer several times and adding deionized water so that the refractive index of the aqueous solution in the middle is ≤1.3350; and / or, during the water soaking process, the mass of the water is 5 to 10 times the mass of the milk thistle seeds after crushing and drying; And / or, during the water immersion process, remove the water in the upper layer and add an equal volume of deionized water.

5. A method for extracting silymarin according to claim 1, characterized in that: In step S4, the treated liquid is evaporated and concentrated, and then purified by acetone to obtain an acetone solution, and then the acetone solution is dried to obtain silymarin.

6. A method for extracting silymarin according to claim 5, characterized in that: In step S4, the treatment liquid is adjusted to neutral at 5°C to 15°C, diluted to 2 to 5 times the volume with deionized water, and then centrifuged to obtain the bottom liquid, which is then evaporated and concentrated.

7. A method for extracting silymarin according to claim 1, characterized in that: During the polar solvent soaking process, the mass of the polar solvent is 5 to 10 times the mass of the milk thistle seeds after crushing and drying; and / or, in step S3, the alkaline solution is heated to 60° C. to 80° C. during the soaking of the reprocessed powder; And / or, the pH of the alkaline solution is 8 to 10; and / or, the acidic solution comprises dilute sulfuric acid; And / or, the mass of the alkaline solution is 5 to 10 times the mass of the milk thistle seeds after crushing and drying; And / or, the content of the vitamin C in the acidic solution is 0.1% to 0.5%; And / or, the particle size of the milk thistle seeds after crushing is ≥200 mesh.

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