A method for efficiently extracting rutin from sophora japonica

Abstract

The present invention provides a method for efficiently extracting rutin from sophora japonica flower buds, which relates to the technical field of chemical component extraction. The method includes the steps of: pulverizing sophora japonica flower buds and sieving them to obtain sophora japonica flower bud powder; mixing the sophora japonica flower bud powder with an alcohol solvent, heating for extraction to obtain a rutin extract; combining the obtained extracts, concentrating and drying them to obtain crude rutin; mixing the crude rutin with a low-concentration alcohol solvent, heating for dissolution, stirring at room temperature for crystallization, filtering and drying to obtain refined rutin. The extraction method of the present invention has a high extraction rate and high purity of rutin, and the extraction method has stable product quality of rutin, high repeatability, simple operation in the extraction process, and shortens the overall extraction time.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical component extraction, and particularly relates to a method for efficiently extracting rutin from sophora japonica flower buds. Background Art

[0002] Sophora japonica flower buds are the dried flowers and flower buds of the leguminous plant Sophora japonica L. They are harvested when the flowers bloom or flower buds form in summer, dried in time, and after removing branches, stems and impurities, they are commonly called "sophora japonica flower buds". Sophora japonica flower buds have the functions of cooling blood to stop bleeding, clearing heat and purging fire, moistening the intestines and relaxing bowels, and cooling blood to stop bleeding.

[0003] Among them, the main component in sophora japonica flower buds, rutin, also known as rutoside and quercetin-3-rutinoside, is a type of flavonoid compound. Rutin is also called vitamin P, which has the effects of reducing capillary permeability, antioxidation, anti-inflammation, anti-virus and inhibiting aldose reductase, and can also be used for the adjuvant treatment of cancer; rutin is also a natural antioxidant. In the food industry, rutin can be used as an antioxidant and natural edible yellow pigment. In the cosmetics industry, rutin can be used as a raw material for anti-ultraviolet rays. The market demand for rutin is also increasing day by day. At the same time, people also pay more and more attention to the extraction and utilization of rutin with various biological activities.

[0004] Traditional methods for extracting rutin from sophora japonica flower buds mainly include acid-base extraction method, water extraction method, ultrasonic-assisted water extraction method and microwave method, etc. Among them, the acid-base extraction method is the most widely used method in industry and is also a relatively ideal method, but usually borax needs to be added to improve the yield. However, in domestic food safety, the addition of borax is prohibited, which greatly limits the application of rutin in the food field; the impurities in the water extraction method are difficult to remove and the product purity is not high; although the ultrasonic-assisted water extraction method and the microwave method are safe, have high yields, and the extraction is rapid, the investment is large and the scale is small, and the components are liable to change.

[0005] Chinese Invention Patent CN202210495968 discloses a method for extracting rutin and its application. The rutin extraction steps of this invention include: adding plant raw materials rich in rutin into an aqueous sodium sulfite solution in a slightly boiling state, stirring and extracting, then separating the solid and liquid and collecting the first filtrate and the first filter residue; rinsing the first filter residue with an alkaline solution, separating the solid and liquid and collecting the alkaline rinsing solution and the second filter residue; then extracting the second filter residue with boiling water 2 - 3 times, filtering while it is hot and combining the collected boiling water extraction solutions; mixing the first filtrate, the alkaline rinsing solution and the combined boiling water extraction solutions, keeping warm at 60 - 70 °C and adjusting the pH to 4 - 5 with dilute acid, standing for crystallization at room temperature, filtering, taking the filter residue and washing it with water until the pH is 6 - 7, and drying to obtain crude rutin. Chinese Invention Patent CN201910510946 discloses a method for extracting rutin from sophora japonica. In this extraction process, sophora japonica is directly decocted with water, the decoction is concentrated under reduced pressure, then the pH is adjusted to 4 - 5 with hydrochloric acid, standing to take the precipitate, centrifuging, drying and pulverizing to obtain crude rutin. The above extraction processes need to add chemical reagents such as sodium sulfite, acids and bases, which are likely to contaminate the rutin product.

[0006] Chinese Invention Patent CN101818184A also discloses a method for extracting rutin from sophora japonica. First, sophora japonica is fermented in a closed state with rutin biotransformation enzyme, then stirred and extracted with a mixed solvent of methanol and ethanol, the filtrate is distilled to obtain rutin extract; then rutin is stirred, extracted, filtered and the solvent is recovered by distillation with a mixed solvent of acetone, petroleum ether and n - octanol to obtain purified high - purity rutin. The extraction time of this invention is 16 h, and all extraction and purification work can be completed. However, a large amount of organic solvents are needed in the extraction and purification processes.

[0007] Therefore, in order to solve the problems existing in the rutin extraction method, such as low extraction efficiency, cumbersome operation, need to add additional chemical components, high cost, etc., it is urgent to establish a rapid and efficient method for extracting rutin from sophora japonica to improve the yield and content of rutin, improve the stability of rutin products, and reduce the pollution of chemical components to rutin products. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a method for efficiently extracting rutin from sophora japonica. High - concentration alcohol solvents are used to thermally extract sophora japonica to obtain crude rutin, and low - concentration alcohol solvents are used to crystallize and purify the crude rutin to finally obtain high - purity rutin products. The extraction method of the present invention has a high extraction rate and high purity of rutin, and the extraction method has stable quality of rutin products, simple operation in the extraction process, and shortens the overall extraction time.

[0009] To achieve the above object, the technical scheme adopted by the present invention is as follows:

[0010] A method for efficiently extracting rutin from sophora japonica flower buds, comprising the steps:

[0011] (1) Crushing the sophora japonica flower buds and sieving to obtain sophora japonica flower bud powder;

[0012] (2) Mixing the sophora japonica flower bud powder with an alcohol solvent and heating for extraction to obtain a rutin extract;

[0013] (3) Concentrating, drying and crushing the rutin extract to obtain crude rutin;

[0014] (4) Mixing the crude rutin with an alcohol solvent and heating for dissolution to obtain a rutin solution;

[0015] (5) Crystallizing the rutin solution by stirring at room temperature, filtering, collecting the solid and drying to obtain high-quality rutin.

[0016] Preferably, in step (1), the mesh number of the sieving is 20 - 200 meshes.

[0017] More preferably, in step (1), the mesh number of the sieving is 40 - 80 meshes.

[0018] In the present invention, the sophora japonica flower buds need to be washed and dried before crushing to reduce the influence of dust and impurities on the surface of the sophora japonica flower buds.

[0019] Preferably, in step (2), the alcohol solvent is selected from at least one of ethanol, methanol, n-butanol, n-octanol, and isooctanol.

[0020] More preferably, the alcohol solvent is selected from at least one of ethanol and methanol.

[0021] Even more preferably, the alcohol solvent is ethanol.

[0022] Preferably, in step (2), the concentration of the alcohol solvent is 70 - 100%, v / v.

[0023] More preferably, the concentration of the alcohol solvent is 80 - 100%, v / v.

[0024] Even more preferably, the concentration of the alcohol solvent is 90%, v / v.

[0025] Preferably, in step (2), the solid-liquid ratio of the sophora japonica flower bud powder to the alcohol solvent is 1 g:4 - 8 mL.

[0026] More preferably, the solid-liquid ratio of the sophora japonica flower bud powder to the alcohol solvent is 1 g:5 - 6 mL.

[0027] Preferably, in step (2), the temperature of the heating extraction is 60 - 90 °C, the extraction times are 2 - 4 times, and the extraction time for each time is 1 - 5 h.

[0028] More preferably, the temperature for heating extraction is 70 - 85°C, the number of extraction times is 2 - 3 times, and the extraction time for each time is 2 - 3 h.

[0029] Even more preferably, the temperature for heating extraction is 80°C, the number of extraction times is 3 times, and the extraction time for each time is 2 h.

[0030] In the present invention, the rutin extract is a combined mixture of all the extracts after extraction with an alcohol solvent 2 - 4 times.

[0031] In the present invention, the rutin extract needs to be dried after recovering the alcohol solvent.

[0032] Preferably, in step (3), the temperature for concentration is 60 - 80°C.

[0033] More preferably, the temperature for concentration is 70°C.

[0034] Preferably, in step (3), the temperature for drying is 60 - 80°C, and the drying time is 4 - 8 h.

[0035] More preferably, the temperature for drying is 75°C, and the drying time is 6 h.

[0036] Preferably, in step (3), the particle size range for pulverization is passing through a 60 - 100 mesh sieve.

[0037] More preferably, the particle size for pulverization is 80 mesh.

[0038] Preferably, in step (4), the alcohol solvent is selected from at least one of ethanol, methanol, n - butanol, n - octanol, and isooctanol.

[0039] More preferably, the alcohol solvent is selected from at least one of ethanol and methanol.

[0040] Even more preferably, the alcohol solvent is ethanol.

[0041] Preferably, in step (4), the concentration of the alcohol solvent is 20 - 60% (v / v).

[0042] More preferably, the concentration of the alcohol solvent is 25 - 40% (v / v).

[0043] Even more preferably, the concentration of the alcohol solvent is 30% (v / v).

[0044] Preferably, in step (4), the solid - liquid ratio of the crude rutin to the alcohol solvent for mixing is 1 g:2 - 7 mL.

[0045] Further preferably, the solid-liquid ratio of the crude rutin mixed with the alcohol solvent is 1 g: 4-6 mL.

[0046] Even more preferably, the solid-liquid ratio of the crude rutin mixed with the alcohol solvent is 1 g: 5 mL.

[0047] Preferably, in step (4), the temperature for heating and dissolving is 60-90 °C.

[0048] Further preferably, the temperature for heating and dissolving is 70-85 °C.

[0049] Preferably, in step (5), after the rutin solution is filtered while it is hot, the liquid is cooled to room temperature, stirred for crystallization, filtered, and the solid is collected.

[0050] Preferably, in step (5), the temperature for drying is 60-80 °C, and the drying time is 4-8 h.

[0051] The present invention also provides the rutin prepared by the above method.

[0052] The present invention also provides the application of the above method in extracting rutin from sophora flower buds.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The rutin extraction method of the present invention is simple in operation, short in time consumption, high in yield and purity; the extraction method of the present invention has high repeatability, and the yield and purity results of rutin are stable; the instrument and equipment required by the process of the present invention are simple, easy to operate, and suitable for large-scale industrial production. Description of the Drawings

[0055] Figure 1 is a schematic flow chart of the method for extracting rutin from sophora flower buds of the present invention.

[0056] Figure 2 is the liquid chromatogram of the refined rutin obtained in Example 2 of the present invention.

[0057] Figure 3 is the liquid chromatogram of the rutin reference substance. Detailed Embodiments

[0058] The following non-limiting examples can enable those of ordinary skill in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. The following content is only an exemplary illustration of the scope claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention according to the disclosed content, and it should also fall within the scope claimed by the present invention.

[0059] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0060] The present invention will be further described below by way of specific embodiments. All kinds of chemical reagents used in the embodiments of the present invention are obtained through conventional commercial channels unless otherwise specified. For the chemical reagents and raw materials described in the present invention, products from different manufacturers have no significant impact on the effects.

[0061] The embodiments of the present invention are carried out according to Figure 1 the flow schematic diagram shown for the extraction of rutin from sophora japonica flower buds.

[0062] Example 1

[0063] (1) Clean and crush the sophora japonica flower buds, sieve through 50 meshes to obtain sophora japonica flower bud powder;

[0064] (2) Add 100 kg of the sophora japonica flower bud powder to the extraction tank, add 5 times 90% ethanol, 500 L, extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract;

[0065] (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, and dry the concentrated solution at 75 °C to obtain 51.3 kg of crude rutin;

[0066] (4) Mix the crude rutin with 5 times the amount, i.e., 250 L, of 30% ethanol, dissolve completely at 80 °C to obtain a rutin solution;

[0067] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 42.5 kg of refined rutin.

[0068] Example 2

[0069] (1) Clean and crush the sophora japonica flower buds, sieve through 50 meshes to obtain sophora japonica flower bud powder;

[0070] (2) Add 250 kg of the sophora japonica flower bud powder to the extraction tank, add 5 times 90% ethanol, 1250 L, extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract;

[0071] (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, and dry the concentrated solution at 75 °C to obtain 125.7 kg of crude rutin;

[0072] (4) Mix the crude rutin with 5 times the amount, i.e., 630 L, of 30% ethanol, and dissolve it completely at 80 °C to obtain a rutin solution.

[0073] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 108.1 kg of high-quality rutin.

[0074] Example 3

[0075] (1) Clean and crush the sophora flower buds, sieve them through a 50-mesh sieve to obtain sophora flower bud powder.

[0076] (2) Add 500 kg of the sophora flower bud powder to an extraction tank, add 5 times, i.e., 2500 L, of 90% ethanol, and extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract.

[0077] (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover the ethanol, and dry the concentrated solution at 75 °C to obtain 251.3 kg of crude rutin.

[0078] (4) Mix the crude rutin with 5 times the amount, i.e., 1260 L, of 30% ethanol, and dissolve it completely at 80 °C to obtain a rutin solution.

[0079] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 215.2 kg of high-quality rutin.

[0080] Example 4

[0081] (1) Clean and crush the sophora flower buds, sieve them through a 50-mesh sieve to obtain sophora flower bud powder.

[0082] (2) Add 250 kg of the sophora flower bud powder to an extraction tank, add 5 times, i.e., 2500 L, of 80% methanol, and extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract.

[0083] (3) Combine the rutin extracts obtained from the above 3 extractions, heat and distill at 80 °C, separate and recover the methanol, and dry the concentrated solution at 75 °C to obtain 112.5 kg of crude rutin.

[0084] (4) Mix the crude rutin with 5 times the amount, i.e., 562.5 L, of 30% methanol, and dissolve it completely at 80 °C to obtain a rutin solution.

[0085] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 93.2 kg of high-quality rutin.

[0086] Example 5

[0087] (1) Clean and process the sophora flower buds, crush them, and sieve through 50 meshes to obtain sophora flower bud powder.

[0088] (2) Add 250 kg of sophora flower bud powder to the extraction tank, add 2500 L of 5 times 70% ethanol, and extract at 60 °C for 3 times, 2 hours each time, to obtain rutin extract.

[0089] (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, and dry the concentrated solution at 75 °C to obtain 107.5 kg of crude rutin.

[0090] (4) Mix the crude rutin with 5 times the amount, i.e., 540 L of 20% ethanol, and dissolve completely at 80 °C to obtain a rutin solution.

[0091] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 97.5 kg of high-quality rutin.

[0092] Example 6

[0093] (1) Clean and process the sophora flower buds, crush them, and sieve through 50 meshes to obtain sophora flower bud powder.

[0094] (2) Add 250 kg of sophora flower bud powder to the extraction tank, add 500 L of 8 times 90% ethanol, and extract at 90 °C for 3 times, 3 hours each time, to obtain rutin extract.

[0095] (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, and dry the concentrated solution at 80 °C to obtain 125.2 kg of crude rutin.

[0096] (4) Mix the crude rutin with 2 times the amount, i.e., 250.4 L of 50% ethanol, and dissolve completely at 60 °C to obtain a rutin solution.

[0097] (5) Filter the rutin solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 101.2 kg of high-quality rutin.

[0098] Comparative Example 1

[0099] Different from Example 1, the extraction solvent is water, and the pH is adjusted to 10 with sodium bicarbonate. The remaining steps and parameters are the same as those in Example 1, specifically:

[0100] (1) Clean and process the sophora flower buds, crush them, and sieve through 50 meshes to obtain sophora flower bud powder.

[0101] (2) Add 100 kg of sophora flower bud powder to the extraction tank, add 500 L of water at 5 times the amount, adjust the pH to 10 with sodium bicarbonate, and extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract solution;

[0102] (3) Combine the rutin extract solutions obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, and dry the concentrated solution at 75 °C to obtain 42.1 kg of crude rutin;

[0103] (4) Mix the crude rutin with 210 L of 30% ethanol at 5 times the amount, dissolve completely at 80 °C to obtain a rutin dissolution solution;

[0104] (5) Filter the rutin dissolution solution while it is hot, crystallize the liquid by stirring at room temperature, filter, and collect the filter cake; dry the filter cake in a blast dryer at 70 °C to obtain 34.2 kg of refined rutin.

[0105] Comparative Example 2

[0106] Differing from Example 1, in step (2), the concentration of the ethanol used is 60% (v / v), and the remaining steps and parameters are the same as those in Example 1.

[0107] Finally, 37.1 kg of crude rutin was obtained from 100 kg of sophora flower bud powder, and after dissolution and recrystallization of the crude rutin, 30.2 kg of refined rutin was obtained.

[0108] Comparative Example 3

[0109] Differing from Example 1, in step (2), the extraction temperature is 50 °C. The remaining steps and parameters are the same as those in Example 1.

[0110] Finally, 34.1 kg of crude rutin was obtained from 100 kg of sophora flower bud powder, and after dissolution and recrystallization of the crude rutin, 29.5 kg of refined rutin was obtained.

[0111] Comparative Example 4

[0112] Differing from Example 1, in step (4), the organic solvent used to dissolve the crude rutin is replaced with petroleum ether, and the remaining steps and parameters are the same as those in Example 1.

[0113] Finally, 10.2 kg of refined rutin was obtained from 100 kg of sophora flower bud powder.

[0114] Comparative Example 5

[0115] Differing from Example 1, in step (4), the concentration of the ethanol is replaced with 10% (v / v). The remaining steps and parameters are the same as those in Example 1.

[0116] Finally, 20.2 kg of refined rutin was obtained from 100 kg of sophora flower bud powder.

[0117] Comparative Example 6

[0118] Different from Example 1, in step (1), after the sophora flower buds were crushed, they were not sieved and directly underwent subsequent extraction and recrystallization steps. The remaining steps and parameters were the same as those in Example 1.

[0119] Finally, 40.2 kg of crude rutin was obtained from 100 kg of sophora flower bud powder. The crude rutin was dissolved and recrystallized to obtain 37.2 kg of refined rutin.

[0120] Comparative Example 7

[0121] Different from Example 1, the purification method in steps (4)-(5) was different, and the heating and recrystallization steps were not carried out. The remaining steps and parameters were the same as those in Example 1.

[0122] Steps (4)-(5) were specifically as follows: The crude rutin obtained in step (3) was mixed evenly with 5 times the amount of acetone, and fully stirred for the purification extraction of rutin. After filtration, the filtrate was collected. After recovering the solvent by reduced pressure distillation, it was dried to obtain 20.2 kg of purified refined rutin.

[0123] Experiment 1 Determination of rutin content and yield

[0124] 1. According to the content determination method of sophora flower in the first part of the Pharmacopoeia of the People's Republic of China (2020 Edition), the rutin content was detected.

[0125] The rutin content was determined according to the high performance liquid chromatography method (General Rule 0512).

[0126] Chromatographic conditions and system suitability test: Octadecylsilane chemically bonded silica gel was used as the filler; methanol: 1% glacial acetic acid solution (32:68) was used as the mobile phase; the detection wavelength was 257 nm. The number of theoretical plates calculated based on the rutin peak should not be less than 2000.

[0127] Preparation of reference substance solution: An appropriate amount of rutin reference substance was accurately weighed and dissolved in methanol to prepare a solution containing 0.1 mg per 1 mL, that is, obtained.

[0128] Preparation of test solution: Take 2 portions of the refined rutin from the above examples and comparative examples (accurately weighed, placed in a stoppered conical flask, accurately add 10 mL of methanol, weigh, ultrasonically treat (power 250 W, frequency 25 kHz) for 15 minutes, let it cool, weigh again, make up the lost weight with methanol, shake well, filter, that is, obtained. Determination method: Accurately pipette 10 μL of the reference substance solution and the test solution respectively, inject into the liquid chromatograph, and determine, that is, obtain the refined product content.

[0129] The rutin fine product of Example 2 and the rutin reference substance used in this experiment were characterized and analyzed. The liquid chromatograms are shown respectively in Figures 2 - 3 , Figure 2 is the liquid chromatogram of the rutin fine product obtained in Example 2 of the present invention; Figure 3 is the liquid chromatogram of the rutin reference substance.

[0130] 2. Detection method for rutin yield:

[0131] Rutin yield (%) = weight of rutin fine product (kg) / (weight of sophora japonica flower buds × 0.45); the 0.45 refers to the theoretical rutin content (purity) in sophora japonica flower buds.

[0132] The detection results of rutin content and yield in Examples 1 - 6 and Comparative Examples 1 - 7 are shown in Table 1.

[0133] Table 1

[0134]

[0135]

[0136] Based on the detection of rutin samples in each example and comparative example, with 2 parallel measurements, the detection results show that the rutin content in the examples is not only high, but also the yield is high. The rutin obtained by the extraction method of the present invention has high stability and good repeatability of the rutin extraction method.

[0137] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention shall not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for efficiently extracting rutin from sophora japonica flower buds, characterized in that, it includes the steps: (1) Clean and crush the sophora japonica flower buds, sieve through 50 mesh to obtain sophora japonica flower bud powder; (2) Mix the sophora japonica flower bud powder with 5 times of 90% ethanol, extract at 80 °C for 3 times, 2 hours each time, to obtain a rutin extract; (3) Combine the rutin extracts obtained from the above 3 extractions, concentrate under reduced pressure at 70 °C, separate and recover ethanol, dry the concentrated solution at 75 °C to obtain crude rutin; (4) Mix the crude rutin with 5 times the amount of 30% ethanol, dissolve completely at 80 °C to obtain a rutin solution; (5) Filter the rutin solution while it is hot, stir the liquid for crystallization at room temperature, filter, collect the solid, and dry it in a blast dryer at 70 °C to obtain refined rutin.

2. Use of the method according to claim 1 in the extraction of rutin from sophora japonica flower buds.

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