Method for extracting low-residual silymarin and preparation method thereof

Abstract

The application discloses a low-residual extractive method of silymarin and a preparation method thereof. The low-residual extractive method of silymarin comprises the following steps: eluting oil and fat; crushing silybum seed, soaking and eluting oil and fat by using n-hexane, and obtaining a soaking solution; adding ethanol into the soaking solution, filtering after standing, adding water into the concentrated filtrate, and taking the lower layer solution and the precipitate; and crystallizing and drying, filtering after crystallizing again, and drying the silymarin crystals. The low-residual extractive method of silymarin provided by the application has the effect of reducing the solvent residue in silymarin.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plant extract extraction, and in particular relates to a low-residue silymarin extraction method and a preparation method thereof. BACKGROUND

[0002] Silymarin is a mixture of flavonolignans extracted from the dried seeds and fruits of the plant Silybum marianum (Euphorbiaceae). The main components include silybin, isosilybin, silydianin, etc. Silymarin is a pale yellow powder, odorless, slightly bitter, and hygroscopic. It is difficult to dissolve in water and chloroform, easily soluble in alkaline aqueous solution, soluble in methanol and ethanol, and soluble in organic solvents such as acetone and ethyl acetate. Silymarin is considered a safe natural compound with hepatoprotective, antioxidant, anti-inflammatory, and other effects, and is mainly used for the treatment of acute and chronic hepatitis, fatty liver, cirrhosis, alcoholic liver damage, metabolic toxic liver damage, gallstones, and other hepatobiliary diseases.

[0003] There are various methods for extracting silymarin, including organic solvent extraction, supercritical fluid extraction, enzymatic extraction, ultrasonic-assisted extraction, microwave-assisted extraction, etc.

[0004] Organic solvent extraction is the most traditional extraction method, which usually uses organic solvents such as ethanol, acetone, n-hexane, and ethyl acetate. The specific steps are as follows:

[0005] ① The silybum marianum seeds are crushed and mixed with organic solvents.

[0006] ② Silymarin is extracted by heating reflux or room temperature immersion.

[0007] ③ The extract is concentrated, filtered, and other steps to remove impurities to obtain silymarin crude extract.

[0008] ④ Finally, further purification by crystallization or column chromatography, etc. to improve the purity of silymarin.

[0009] The advantages of silymarin organic solvent extraction method are high efficiency, simple operation, low cost, short extraction time, and high extraction rate. These advantages make it have significant economic advantages in industrial production, especially in scenarios where extraction efficiency and cost control are required. However, in the process of silymarin organic solvent extraction, it is difficult to completely remove the organic solvent, and solvent residue is an important quality control problem, especially in the fields of pharmaceuticals, health products, and food additives, etc. Solvent residue may have a significant impact on the safety, effectiveness, and quality of the product. SUMMARY

[0010] In view of the deficiencies of the prior art, the purpose of the present application is to provide a low-residue silymarin extraction method and a preparation method thereof.

[0011] To achieve the aforementioned technical purposes, the technical scheme adopted by the present application comprises:

[0012] A low-residual extractive method of silymarin comprises the following steps:

[0013] Eluting oil and fat: after crushing the silybum marianum seed, the silybum marianum seed is soaked with n-hexane to elute oil and fat, and the soaking solution is obtained;

[0014] Ethanol replacement: ethanol is added to the soaking solution, and after standing, the filtrate is obtained by filtration; after the filtrate is concentrated, water is added and the solution and the precipitate are obtained by standing;

[0015] Crystallization and drying: the solution and the precipitate are concentrated, and then crystallized and dried to obtain silymarin.

[0016] In addition to silymarin, the silybum marianum seed also contains a large amount of lipids, fatty acids and other fat-soluble components. In the present application, n-hexane, as a non-polar solvent, can effectively dissolve the fat-soluble components in the silybum marianum seed, and silymarin itself is a polar substance and is difficult to dissolve in n-hexane.

[0017] In the present application, ethanol can dissolve silymarin, and ethanol and n-hexane have good compatibility, and silymarin can be dissolved in the mixed solution of ethanol and n-hexane.

[0018] In the present application, during the ethanol replacement process, after the filtrate is concentrated, water is added and the solution and the precipitate are obtained by standing; cyclohexane is incompatible with water and floats on the water surface, ethanol and water can be mixed in any ratio, and ethanol is dissolved in water in large amounts, so that the content of ethanol in cyclohexane is reduced, which is conducive to the separation of silymarin from cyclohexane into the water-ethanol mixed solution. After part of the silymarin is separated from cyclohexane, it cannot be completely dissolved in the water-ethanol mixed solution and forms a precipitate by crystallization.

[0019] In the present application, in the crystallization and drying step, the lower layer solution and the precipitate cannot be evaporated and crystallized, and during the evaporation and crystallization process, impurities dissolved in water will be mixed into the obtained silymarin, affecting the purity of the obtained silymarin.

[0020] Preferably, in the oil and fat elution step, the silybum marianum seed is crushed, then soaked with n-hexane for 6-10 hours, the amount of n-hexane is 4-6 times the mass of the silybum marianum seed; after the soaking is completed, the upper liquid is removed and an equal volume of n-hexane to the removed upper liquid is added, and then soaked again for 2-3 hours, and the operation is repeated until the upper liquid is colorless and transparent, and then the upper liquid is removed to obtain the soaking solution.

[0021] In the present application, the process of eluting oil and fat can effectively remove the fat-soluble components in the silybum marianum seed and retain silymarin, which is conducive to reducing the difficulty of subsequent extraction of silymarin.

[0022] Preferably, the mass of the soaking liquid is 1.5-2 times the mass of the S. mooreana seeds.

[0023] Preferably, in the ethanol replacement step, the amount of ethanol used is 0.5-1 times the mass of the soaking liquid.

[0024] Preferably, in the ethanol replacement step, the volume of the filtrate after concentration is 0.1-0.25 times the volume before concentration.

[0025] The boiling point of ethanol is 78.4℃, and the boiling point of n-hexane is 69℃. In the present application, during the concentration of the filtrate, because the boiling point of n-hexane is lower than that of ethanol, the evaporation speed of n-hexane is greater than that of ethanol, so that the mass ratio of ethanol to n-hexane is increased after concentration of the filtrate, thereby achieving the removal of a large amount of n-hexane, which is conducive to reducing the volume of the subsequent n-hexane-ethanol phase, thereby facilitating the entry of as much as possible of the silymarin from the n-hexane-ethanol phase into the water-ethanol phase, and further facilitating the reduction of the difficulty of extracting silymarin.

[0026] Preferably, in the ethanol replacement step, the filtrate is evaporated and concentrated at 40℃-60℃.

[0027] Preferably, in the ethanol replacement step, the mass of water is 8-12 times the mass of the filtrate after concentration.

[0028] In the present application, when the amount of water is increased, the amount of ethanol dissolved in water is increased, while the concentration of ethanol in the ethanol-water phase is reduced, and the ability of the ethanol-water phase to dissolve silymarin is reduced, which is conducive to reducing the difficulty of extracting silymarin.

[0029] Preferably, in the crystallization and drying step, the lower layer solution and the precipitate are evaporated and concentrated at 80℃-85℃.

[0030] In the present application, the lower layer solution and the precipitate are evaporated and concentrated at 80℃-85℃, and the ethanol contained therein can be fully evaporated, thereby facilitating the reduction of the residual solvent in the obtained silymarin.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] (1) The low-residual silymarin extraction method provided by the present application is simple to operate, does not require harsh operating conditions, and does not require the participation of strong acid or strong base.

[0033] (2) The low-residual silymarin extraction method provided by the present application, in the ethanol replacement step, the silymarin is transferred from n-hexane to the water phase, and the extraction solvent of silymarin is converted from n-hexane to ethanol and water, thereby facilitating the reduction of the residual n-hexane in the obtained silymarin.

[0034] (3) The low-residual silymarin extraction method provided by the application, in the process of crystallization and drying, ethanol is easy to volatilize, thereby being beneficial to reducing the residual solvent in the obtained silymarin. DETAILED DESCRIPTION

[0035] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have the usual meanings understood by those skilled in the art of the present application, and when there is a conflict, the definition in the specification shall prevail.

[0036] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting the scope of the present application, that is, the content of the present application can be implemented without being limited by any particular theory or mechanism.

[0037] In this document, "the present application" is "the invention", "the disclosure".

[0038] The use of "one", "a", "an", or similar expressions in this document is used to describe the components and technical features of the present application, and such description is only for the convenience of expression and to provide a general meaning to the scope of the present application. Therefore, such description should be understood to include one or at least one, and the singular also includes the plural, unless it is clear that it means otherwise.

[0039] In this document, "or a combination thereof" means "or any combination thereof", "any", "any kind", "any" means "any", "any kind", "any".

[0040] In this document, the terms "comprise," "comprising," "include," "including," "have," "having," "contain," "containing," or any other similar term are intended to be open-ended transitional phrases, which are intended to encompass non-exclusive inclusion. For example, a composition or article that comprises a list of elements is not limited to only those elements but can include other elements not expressly listed or inherent to such composition or article. Further, unless expressly specified, the term "or" refers to a nonexclusive "or" and not an exclusive "or." For example, any of the following are satisfied for "A or B": A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). Also, in this document, the terms "comprise," "comprising," "have," "having," "contain," "containing," "include," "including" are to be construed as specific recitations of the enumerated items or steps they are used to describe, and are not meant to be limiting. For example, a process, product, article, composition or apparatus that "comprises" or "has" one or more steps or one or more components is not necessarily limited to only those steps or those components, but can include additional steps or components not expressly listed or inherent to such process, product, article, composition or apparatus.

[0041] In this document, all features or conditions that are described in terms of a numerical range or a percentage range, such as numerical values, amounts, contents and concentrations, are intended to be merely for convenience and brevity. Thus, a description of a numerical range or a percentage range is intended to encompass and specifically disclose all possible subranges and individual numerical values within the range, including integer and fraction values, particularly integer values, as if each and every such sub-range and individual numerical value were specifically and individually listed. For example, a range description of "1.0 to 8.0" or "between 1.0 and 8.0" or "between 1.0 and 8.0" is intended to specifically disclose 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 is intended to encompass the end points, particularly sub-ranges defined by integer values, and is intended to specifically disclose individual values within the range, such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. The foregoing interpretation applies to all aspects of the application, whether the range is broad or narrow, unless otherwise indicated.

[0042] If an amount, concentration or other numerical value or parameter is expressed in a range, a preferred range (or more preferably a range), or a series of upper and lower limits, it is intended to be a disclosure of all subranges and individual numerical values, including integers and fractions, within the range, whether specifically disclosed or not. Further, unless otherwise indicated, a range of values is intended to encompass both the endpoints of the range and all intermediate values, including integers and fractions, within the range.

[0043] In this document, numerical values are understood to be precise to the number of significant figures used. For example, the number 40.0 is understood to encompass the range 39.50 to 40.49.

[0044] Unless otherwise specified, in this application, a compound refers to a chemical substance formed by the connection of two or more elements through chemical bonds, including small molecule compounds and polymer compounds, and is not limited thereto. In this document, a compound is interpreted not only as a single chemical substance, but also as a same kind of chemical substances having the same component or the same property.

[0045] Unless otherwise specified, in this application, parts by weight represents the relative weight fraction in the composition, which can be any weight unit, such as but not limited to kilogram, kilogram, gram, pound, and the like. For example, 100 parts by weight of polyphenyl ether resin represents 100 kilograms of polyphenyl ether resin or 100 pounds of polyphenyl ether resin.

[0046] It should be understood that the features disclosed in each of the embodiments herein can be combined with each other, forming the technical solutions of the present application, as long as there is no contradiction in the combination of these features.

[0047] The present application will be described below with specific embodiments and examples. It should be understood that these specific embodiments and examples are merely illustrative and are not intended to limit the scope of the present application and its use.

[0048] The methods, reagents and conditions used in the following preparation examples, comparative examples and examples are conventional methods, reagents and conditions in the art, unless otherwise specified.

[0049] Preparation Example

[0050] Preparation Example 1

[0051] The raw materials used in this preparation example include: 10 kg of Silybum marianum seeds.

[0052] The preparation method of this preparation example includes:

[0053] Z1, the Silybum marianum seeds were placed in 20 kg of water and ultrasonically cleaned for 30 min, then taken out, and the operation was repeated 3 times, and then dried;

[0054] Z2, the dried Silybum marianum seeds were ground in a grinder to a particle size of 400 mesh;

[0055] Z3, the ground Silybum marianum seeds were dried at 80°C for 5h to obtain Silybum marianum powder.

[0056] Example

[0057] Example 1

[0058] The preparation method of the embodiment comprises:

[0059] S1.1, 1 kg of the S. mooreana powder obtained in Preparation Example 1 is soaked with 4 kg of n-hexane at 25°C for 6 h to obtain a primary soaking solution;

[0060] S1.2, after pouring out the upper n-hexane solution of the primary soaking solution, the amount of the poured-out solution is half of the volume of the primary soaking solution, an equal volume of n-hexane to the poured-out primary soaking solution is supplemented, and the soaking is performed again for 2 h, the operation is repeated until the primary soaking solution is colorless and transparent, and then the upper primary soaking solution is removed to obtain a soaking solution, and the mass of the soaking solution is 1.5 kg;

[0061] S2, 0.75 kg of ethanol is added to the soaking solution, and after standing for 2 h, the solution is filtered, and the filtrate is concentrated to 0.25 times the volume at 40°C; then the concentrated filtrate is slowly added to water, and the mass of the water is 8 times the mass of the concentrated filtrate, and after standing for 0.5 h, the lower solution and the precipitate are taken out;

[0062] S3, the lower solution and the precipitate are evaporated and concentrated to 0.2 times the volume of the liquid at 80°C, and then cooled to 2°C to crystallize, filtered, and then dried at 80°C for 4 h to obtain silymarin.

[0063] Example 2

[0064] The difference between the embodiment and Example 1 is that the mass of the soaking solution obtained in step S1.2 is 1.8 kg, and the amount of ethanol used in step S2 is 0.9 kg.

[0065] Example 3

[0066] The difference between the embodiment and Example 1 is that the mass of the soaking solution obtained in step S1.2 is 2.0 kg, and the amount of ethanol used in step S2 is 1 kg.

[0067] Example 4

[0068] The preparation method of the embodiment comprises:

[0069] S1.1, 1 kg of the S. mooreana powder obtained in Preparation Example 1 is soaked with 4 kg of n-hexane at 25°C for 6 h to obtain a primary soaking solution;

[0070] S1.2, after pouring out the upper n-hexane solution of the primary soaking solution, the amount of the poured-out solution is half of the volume of the primary soaking solution, an equal volume of n-hexane to the poured-out primary soaking solution is supplemented, and the soaking is performed again for 2 h, the operation is repeated until the primary soaking solution is colorless and transparent, and then the upper primary soaking solution is removed to obtain a soaking solution, and the mass of the soaking solution is 1.5 kg;

[0071] S2, 1.2 kg of ethanol was added to the soaking solution, and after standing for 2 h, the solution was filtered, and the filtrate was concentrated to 0.1 times the volume at 50°C; then the concentrated filtrate was slowly added to water, and the mass of water was 12 times the mass of the concentrated filtrate, and after standing for 0.5 h, the lower layer solution and the precipitate were taken out;

[0072] S3, the lower layer solution and the precipitate were evaporated and concentrated to 0.2 times the volume of the liquid at 80°C, and then cooled to 2°C to crystallize, filtered, and then dried at 85°C for 4 h to obtain silymarin.

[0073] Example 5

[0074] The difference between this embodiment and Example 4 is that the amount of ethanol used in step S2 is 1.5 kg.

[0075] Example 6

[0076] The preparation method of this embodiment comprises:

[0077] S1.1, at 25°C, 1 kg of the silybum marianum powder obtained in Preparation Example 1 was soaked with 6 kg of n-hexane for 10 h to obtain a primary soaking solution;

[0078] S1.2, after pouring out the upper layer n-hexane solution of the primary soaking solution, the amount of the poured-out solution was half the volume of the primary soaking solution, and an equal volume of n-hexane was added to the poured-out primary soaking solution, and then soaked again for 2 h, and the operation was repeated until the primary soaking solution was colorless and transparent, and then the upper layer primary soaking solution was removed to obtain a soaking solution, and the mass of the soaking solution was 1.8 kg;

[0079] S2, 0.9 kg of ethanol was added to the soaking solution, and after standing for 2 h, the solution was filtered, and the filtrate was concentrated to 0.1 times the volume at 60°C; then the concentrated filtrate was slowly added to water, and the mass of water was 10 times the mass of the concentrated filtrate, and after standing for 0.5 h, the lower layer solution and the precipitate were taken out;

[0080] S3, the lower layer solution and the precipitate were evaporated and concentrated to 0.2 times the volume of the liquid at 80°C, and then cooled to 2°C to crystallize, filtered, and then dried at 80°C for 4 h to obtain silymarin.

[0081] Example 7

[0082] The difference between this embodiment and Example 6 is that the filtrate is concentrated to 0.25 times the volume in step S2.

[0083] Example 8

[0084] The preparation method of this embodiment comprises:

[0085] S1.1, at 25°C, 1 kg of the silybum marianum powder obtained in Preparation Example 1 was soaked with 6 kg of n-hexane for 10 h to obtain a primary soaking solution;

[0086] S1.2, after pouring out the upper n-hexane solution of the initial leaching solution, the amount of the poured-out solution is half of the volume of the initial leaching solution, and then an equal volume of n-hexane to the poured-out initial leaching solution is supplemented, and the solution is soaked for 2 hours again, the operation is repeated until the initial leaching solution is colorless and transparent, and then the upper initial leaching solution is removed to obtain a soaking solution, and the mass of the soaking solution is 1.5 kg;

[0087] S2, 0.75 kg of ethanol is added to the soaking solution, and after standing for 2 hours, the solution is filtered, and the filtrate is concentrated to 0.15 times the volume at 40°C; then the concentrated filtrate is slowly added to water, the mass of the water is 8 times the mass of the concentrated filtrate, and after standing for 0.5 hours, the lower solution and the precipitate are taken out;

[0088] S3, the lower solution and the precipitate are evaporated and concentrated to 0.2 times the volume of the liquid at 80°C, and then cooled to 2°C to crystallize, filtered, and then dried at 80°C for 4 hours to obtain a silymarin.

[0089] Example 9

[0090] The difference between this example and Example 8 is that in step S2, the mass of the water is 12 times the mass of the concentrated filtrate.

[0091] Table 1: Reagent amounts and process parameters in Examples 1-9

[0092] Test Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Silybum marianum powder / kg 1 1 1 1 1 1 1 1 1 Step S1.1 n-hexane soaking time / h 6 6 6 8 8 10 10 8 8 Step S1.1 n-hexane amount / kg 4 4 4 5 5 6 6 5 5 Mass of soaking liquid / kg 1.5 1.8 2 1.5 1.5 1.8 1.8 1.5 1.5 m 乙醇 / m 浸泡液 ]]> 0.5 0.5 0.5 0.8 1 0.5 0.5 0.5 0.5 Step S2 concentration temperature / °C 40 40 40 50 50 60 60 40 40 Multiple of filtrate concentration 0.25 0.25 0.25 0.1 0.1 0.1 0.25 0.15 0.15 V 水 / V 浓缩后的滤液 ]]> 8 8 8 12 12 10 10 8 12 Step S3 evaporation concentration temperature / °C 80 80 80 85 85 80 80 80 80

[0093] Comparative Example

[0094] Comparative Example 1

[0095] The preparation method of the comparative example comprises:

[0096] D1.1, 1 kg of the water fly powder obtained in Preparation Example 1 is soaked with 4 kg of n-hexane at 25°C for 6 hours to obtain an initial leaching solution;

[0097] D1.2, after pouring out the upper n-hexane solution of the initial leaching solution, the amount of the poured-out solution is half of the volume of the initial leaching solution, and then an equal volume of n-hexane to the poured-out initial leaching solution is supplemented, and the solution is soaked for 2 hours again, the operation is repeated until the initial leaching solution is colorless and transparent, and then the upper initial leaching solution is removed to obtain a soaking solution, and the mass of the soaking solution is 1.5 kg;

[0098] D2, after the soaking solution is dried at 50°C, 0.75 kg of ethanol is added, and after standing for 2 hours, the solution is filtered, and the upper clear liquid is taken out;

[0099] D3, the upper clear liquid is evaporated and concentrated to 0.2 times the volume of the liquid at 80°C, and then cooled to 2°C to crystallize, filtered, and then dried at 80°C for 4 hours to obtain a silymarin.

[0100] Experimental results

[0101] The content of the silymarin obtained in Examples 1-9 and Comparative Example 1 was detected, and the ethanol residual amount and the n-hexane residual amount were detected according to the US Pharmacopoeia, and the detection procedure was CGJT / JFB21002.

[0102] Table 2 Parameters of the silymarin obtained in Examples 1-9 and Comparative Example 1

[0103] Test Example n-hexane residual amount / ppm ethanol residual amount / ppm silymarin purity % Example 1 33 78.65 46.47 Example 2 37 78.00 46.55 Example 3 39 78.65 46.66 Example 4 24 74.10 48.31 Example 5 16 75.40 48.34 Example 6 42 84.50 47.67 Example 7 34 79.95 47.61 Example 8 38 80.60 46.52 Example 9 36 78.65 47.93 Comparative Example 1 106 114.00 29.73

[0104] It should be understood that the above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable the person skilled in the art to understand the content of the present application and to implement it, and it cannot be considered that the specific implementation of the present application is limited to these descriptions. For ordinary skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can also be made, and any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A method for extracting low-residue silymarin, characterized in that, Includes the following steps: Oil removal: Milk thistle seeds were crushed, soaked in n-hexane and the oil was removed to obtain a soaking solution; Ethanol replacement: Add ethanol to the soaking solution, let it stand, filter it, concentrate the filtrate, add water and let it stand, and take the lower layer solution and precipitate. Crystallization and drying: The lower layer solution and precipitate are concentrated, recrystallized and filtered, and then dried to obtain silymarin; In the step of washing away oil, milk thistle seeds are crushed and soaked in n-hexane for 6-10 hours. The amount of n-hexane used is 4-6 times the mass of milk thistle seeds. After soaking, the upper liquid is removed and then an equal volume of n-hexane is added. The mixture is soaked again for 2-3 hours. This process is repeated until the upper liquid is colorless and transparent after soaking. The upper liquid is then removed to obtain the soaking liquid. In the ethanol replacement step, the volume of the concentrated filtrate is 0.1 to 0.25 times that before concentration. In the ethanol replacement step, the filtrate is evaporated and concentrated at 40℃~60℃; In the ethanol replacement step, the mass of water is 8 to 12 times the mass of the concentrated filtrate. In the crystallization drying step, the lower layer solution and precipitate are evaporated and concentrated at 80℃~85℃.

2. The extraction method for low-residue silymarin according to claim 1, characterized in that: The mass of the soaking solution is 1.5 to 2 times the mass of the milk thistle seeds.

3. The extraction method for low-residue silymarin according to claim 1, characterized in that: In the ethanol replacement step, the amount of ethanol used is 0.5 to 1 times the mass of the soaking solution.