Functional herba violae extract and preparation method thereof

Abstract

The invention relates to the technical field of philippine violet herb extraction, in particular to a functional philippine violet herb extract and a preparation method thereof.The preparation method specifically comprises the following steps that S1, philippine violet herb is soaked in a treating agent and pretreated at the closed high temperature and high pressure; s2, performing alcohol extraction under the assistance of ultrasonic waves and microwaves to obtain the high-purity herba violae extract. The herba violae extract obtained through the extraction process has anti-inflammatory, anti-fungal and anti-oxidation effects and also has a bacteriostatic effect on oral pathogenic bacteria such as porphyromonas gingivalis, actinomycetes and porphyromonas, and an environment-friendly extraction solvent and optimized extraction conditions including but not limited to temperature, time, pH value and solvent proportion are adopted, so that the extraction efficiency is improved, and the extraction cost is reduced. Effective components in the herba violae in the extraction process are guaranteed to be reserved to the maximum extent, the activity of the effective components is released, and the purity and the stability of the product are further improved through specific post-treatment steps, ultrafiltration and spray drying.

Description

Technical Field

[0001] The invention relates to the technical field of Viola yedoensis extraction, in particular to a functional Viola yedoensis extract and a preparation method thereof. Background Art

[0002] Viola yedoensis is the dried whole herb of Viola yedoensis Makino, a plant of the Violaceae family. It is harvested in spring and autumn, removed of impurities, washed, chopped, and used fresh or dried. Viola yedoensis is an essential medicine for treating carbuncle. The Compendium of Materia Medica records that "Vila yedoensis is mainly used to treat all carbuncle, carbuncle, scrofula, nameless swelling, and malignant sores"; The Bencao Zhengyi records that "it is a general medicine for carbuncle, carbuncle, and carbuncle". Viola yedoensis tastes bitter and pungent, is cold in nature, and enters the heart and liver meridians. It has the effects of clearing away heat and detoxifying, cooling blood and reducing swelling. It is used for carbuncle, carbuncle, erysipelas, snake bites, etc. The main active ingredients of Viola yedoensis are flavonoid compounds and coumarin compounds. The whole herb contains compounds such as aesculin A, aesculin E, quercetin, luteolin, naringenin, and apigenin. Modern pharmacological tests have shown that Viola yedoensis has antibacterial, anti-inflammatory, antiviral, and anti-endotoxin biological activities. In vitro antibacterial tests have shown that Viola yedoensis coumarin components have different degrees of antibacterial and bactericidal activity against Staphylococcus aureus, Escherichia coli, and Salmonella.

[0003] For example, the invention patent with announcement number CN113398186A discloses a Viola yedoensis extract and its preparation method and application. The Viola yedoensis medicinal material is treated by traditional water decoction, and the aglycones in the extract are released by enzymatic hydrolysis, and then the polar and weakly polar compounds are enriched with ethanol, which lays a good material foundation for formulation. Pharmacological experiments show that the Viola yedoensis extract obtained by this method can improve the cardiac function and myocardial tissue inflammation state of mice with viral myocarditis, indicating that the extract has a good myocardial protective effect on viral myocarditis, and therefore has good practical application value. However, the traditional decoction combined with enzymatic hydrolysis has low extraction efficiency, and the active ingredients in the material cannot be fully released, thereby affecting the yield and purity of the extract. Summary of the invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a functional Viola yedoensis extract and a preparation method thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a functional Viola yedoensis extract comprises the following steps:

[0007] S1 immerses Viola yedoensis into the treatment agent, performs pretreatment under closed high temperature and high pressure, and then instantly releases the pressure to normal pressure;

[0008] S2 is subjected to alcohol extraction under the assistance of ultrasound and microwave, and then ultrafiltration and spray drying are performed to obtain a high-purity Viola yedoensis extract.

[0009] As a further preferred embodiment of the present invention, in S1, the usage ratio of Viola yedoensis to the treatment agent is 1 g: (50-80) mL;

[0010] The pretreatment is carried out at 0.3-0.5 MPa and 115-120° C. for 20-30 min.

[0011] As a further preferred embodiment of the present invention, the preparation method of the treatment agent is as follows:

[0012] 1) dissolving alkali lignin in a sodium hydroxide solution, stirring at 200-300 r / min for 30-50 min, then dropping a zinc chloride solution into the system, stirring and reacting at room temperature for 2-5 h, repeatedly washing the precipitate generated by the reaction with distilled water until it is neutral, and freeze-drying to obtain a nanocomposite material;

[0013] 2) The nano-composite material is frozen with liquid nitrogen and then freeze-dried, and then placed in a muffle furnace for graded calcination, and naturally cooled to room temperature to obtain nano-flower-like composite particles, and then the nano-flower-like composite particles are mixed with cellulose nanofibers and added to a sufficient amount of ethanol solution, and stirred at a high speed of 10000-15000r / min for 1-2h, dried after centrifugal separation, and then added to deionized water, stirred and dispersed evenly to obtain a treatment agent with a solid content of 3-7wt%.

[0014] As a further preferred embodiment of the present invention, in step 1), the usage ratio of the alkali lignin, the sodium hydroxide solution, and the zinc chloride solution is (1-3) g: (50-80) mL: (50-80) mL;

[0015] The concentration of the sodium hydroxide solution is 1.0-1.3 mol / L;

[0016] The concentration of the zinc chloride solution is 1.0-1.3 mol / L.

[0017] As a further preferred embodiment of the present invention, in step 2), the graded calcination is specifically: calcining at 120-128°C for 1-2h, calcining at 250-260°C for 2-3h, and calcining at 575-585°C for 2-3h;

[0018] The mass ratio of the nano flower-shaped composite particles to the cellulose nanofibers is 1:(10-18);

[0019] The concentration of the ethanol solution is 70-80 wt %.

[0020] As a further preferred embodiment of the present invention, the preparation method of the cellulose nanofibers is as follows:

[0021] 1) the loofah is fully dried in a 105-110 ℃ of air blast boxes for 2-5h, ground and pulverized by a grinder, immersed in a sodium hydroxide solution, and heated at 60-65 ℃ for 30-50min, fully washed with distilled water and then dried, and then the dried product is immersed in a sodium hypochlorite solution, soaked for 20-30min, and then repeatedly washed with deionized water, and after drying, a pre-treatment loofah powder is obtained;

[0022] 2) The pretreated loofah powder is added to deionized water, and then 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and sodium bromide are added, and sodium hypochlorite solution is added under 100-150W ultrasound, and the reaction is carried out for 1-3 hours. During the reaction, the pH value is adjusted to be stable at 10.0-10.5 using sodium hydroxide solution, and then ethanol is added to terminate the reaction. After continuous stirring for 20-30 minutes, centrifugation is performed, and the mixture is repeatedly washed with deionized water until neutral, and freeze-dried to obtain cellulose nanofibers.

[0023] As a further preferred embodiment of the present invention, in step 1), the concentration of the sodium hydroxide solution is 10-15wt%;

[0024] The concentration of the sodium hypochlorite solution is 12-17 wt %.

[0025] As a further preferred embodiment of the present invention, in step 2), the ratio of the pretreated loofah powder, deionized water, 2,2,6,6-tetramethylpiperidin-1-oxyl radical, sodium bromide, and sodium hypochlorite solution is (1-2) g: (100-150) mL: (0.02-0.05) g: (0.2-0.5) g: (3-6) mL;

[0026] The concentration of the sodium hypochlorite solution is 12-17wt%;

[0027] The concentration of the sodium hydroxide solution is 0.5-0.8 wt %.

[0028] As a further preferred embodiment of the present invention, in S2, in the ultrasound and microwave assistance, the ultrasound frequency is 20-30kHz, and the microwave power is 500-800W;

[0029] The ultrasound and microwave are treated alternately, and each treatment lasts for 10-15 minutes;

[0030] The alcohol extraction is carried out using 99.5-99.8 wt % ethanol solution as solvent, with a solid-liquid mass ratio of 1:(25-30), and the extraction is carried out at 70-75° C. for 40-45 minutes.

[0031] A functional Viola yedoensis extract is prepared by adopting the above preparation method.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] In the present invention, alkali lignin is used as a template, zinc chloride is used as a zinc source, and after zinc oxide is loaded, a graded high-temperature calcination method is adopted to obtain nano flower-like composite particles. Since the alkali lignin is used as a zinc oxide carrier, its rich surface functional groups can chelate with metal zinc ions, thereby changing the lattice structure of zinc oxide, so that the structure of the nano flower can still be maintained during the calcination process, and during the calcination process, lignin forms certain holes on the surface of the zinc oxide sheet, further increasing the specific surface area of ​​the nano flower, thereby forming nano flower-like composite particles with a high specific surface area; and then TEMPO oxidation method is used to extract cellulose nanofibers from loofah sponge, and physical combination is formed between the nano flower-like composite particles and the cellulose nanofibers by high-speed stirring, and dispersed in deionized water, thereby obtaining a treating agent; Viola yedoensis is immersed in the treating agent and pretreated under high temperature and high pressure in a closed environment, and superheated water vapor is used. Under the action of high temperature and high pressure, it is forced to enter the interior of the material and fill up the cell gaps. Along with water vapor, the nano-flower-like composite particles and cellulose nanofibers in the treatment agent will also enter the interior of the material together. And because there are certain holes on the surface of the nano-flower-like composite particles, it is beneficial for the cellulose nanofibers to embed into the holes, so that the two can form a combination, and the cellulose nanofibers are connected to each other, so that a network support structure with nano-flower-like composite particles as connecting nodes can form a supporting skeleton inside the material. With the instantaneous reduction of pressure in the later stage, the superheated liquid in the cells instantly vaporizes, the volume expands, the cells rupture into a porous structure, and small molecules are more easily released. And because a supporting skeleton is formed inside the material, the volume structure after expansion will not collapse, and the expanded large volume state will be maintained continuously, so that in the subsequent alcohol extraction process, the active substances in the material can be smoothly released, which helps to improve the extraction rate.

[0034] The preparation method of the Viola yedoensis extract of the present invention comprises the following steps: immersing the Viola yedoensis in a treatment agent and pre-treating the Viola yedoensis under high temperature and high pressure, so that the Viola yedoensis is changed and the interior thereof is in a large volume state expanded for a long time; and under the auxiliary action of microwaves and ultrasound, during the alcohol extraction process, the active substances in the substance are subjected to a lower mass transfer resistance and can be smoothly released, thereby helping to improve the extraction rate and achieving a high yield of the Viola yedoensis extract. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] A method for preparing a functional Viola yedoensis extract comprises the following steps:

[0038] S1: Immerse Viola yedoensis in the treatment agent at a dosage ratio of 1g:50mL, and pre-treat it at a closed high temperature and high pressure of 0.3MPa and 115℃ for 20min, and then instantly release the pressure to normal pressure;

[0039] S2 uses 99.5wt% ethanol solution as solvent, with a solid-liquid mass ratio of 1:25, and is extracted at 70°C for 40 minutes. During the extraction process, ultrasound and microwave assistance are applied alternately, with each treatment time of 10 minutes, an ultrasonic frequency of 20kHz, and a microwave power of 500W. The alcohol extraction product is ultrafiltered and spray-dried to obtain the Viola yedoensis extract.

[0040] The preparation method of the treatment agent is as follows:

[0041] 1) the luffa was fully dried in 105 ℃ of air blowers for 2h, ground and pulverized by a grinder, immersed in a sodium hydroxide solution of 10wt%, and heated at 60 ℃ for 30min, dried after fully washing with distilled water, and then immersed in a sodium hypochlorite solution of 12wt% by concentration, soaked for 20min, and then repeatedly washed with deionized water, and dried to obtain a pre-treatment luffa powder;

[0042] 2) 1 g of pretreated loofah powder was added to 100 mL of deionized water, and then 0.02 g of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and 0.2 g of sodium bromide were added, and 3 mL of 12 wt% sodium hypochlorite solution was added under 100 W ultrasound, and the reaction was continued for 1 hour. During the reaction, a 0.5 wt% sodium hydroxide solution was used to adjust the pH value to 10.0, and then ethanol was added to terminate the reaction. After continuous stirring for 20 minutes, the mixture was centrifuged, repeatedly washed with deionized water until neutral, and freeze-dried to obtain cellulose nanofibers;

[0043] 3) Dissolve 1 g of alkali lignin in 50 mL of 1.0 mol / L sodium hydroxide solution, stir at 200 r / min for 30 min, then drop 50 mL of 1.0 mol / L zinc chloride solution into the system, stir at room temperature for 2 h, wash the precipitate generated by the reaction repeatedly with distilled water until it is neutral, and freeze-dry to obtain a nanocomposite material;

[0044] 4) The nano-composite material is frozen with liquid nitrogen and then freeze-dried, and then placed in a muffle furnace for graded calcination, calcined at 120°C for 1h, calcined at 250°C for 2h, and calcined at 575°C for 2h, and naturally cooled to room temperature to obtain nano-flower-like composite particles, and then the nano-flower-like composite particles are mixed with cellulose nanofibers in a mass ratio of 1:10 and added to a sufficient amount of 70wt% ethanol solution, stirred at a high speed of 10000r / min for 1h, dried after centrifugal separation, and then added to deionized water, stirred and dispersed evenly to obtain a treating agent with a solid content of 3wt%.

[0045] Example 2

[0046] A method for preparing a functional Viola yedoensis extract comprises the following steps:

[0047] S1: Immerse Viola yedoensis in the treatment agent at a dosage ratio of 1 g: 70 mL, and pre-treat it at a closed high temperature and high pressure of 0.4 MPa and 117 ° C for 25 minutes, and then instantly release the pressure to normal pressure;

[0048] S2 uses 99.6wt% ethanol solution as solvent, with a solid-liquid mass ratio of 1:28, and is extracted at 72°C for 43min. During the extraction process, ultrasound and microwave assistance are applied alternately, with each treatment time of 12min, an ultrasonic frequency of 25kHz, and a microwave power of 600W. The alcohol extraction product is ultrafiltered and spray-dried to obtain the Viola yedoensis extract.

[0049] The preparation method of the treatment agent is as follows:

[0050] 1) the luffa was fully dried for 3h in 108 ℃ of air blowers, ground and pulverized by a grinder, immersed in a sodium hydroxide solution of 12wt%, and heated at 63 ℃ for 40min, dried after fully washing with distilled water, and then immersed in a sodium hypochlorite solution of 15wt% for 25min, and then repeatedly washed with deionized water, and dried to obtain a pre-treatment luffa powder;

[0051] 2) 1.5 g of pretreated loofah powder was added to 130 mL of deionized water, and then 0.03 g of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and 0.3 g of sodium bromide were added, and 5 mL of 15 wt% sodium hypochlorite solution was added under 120 W ultrasound, and the reaction was continued for 2 h. During the reaction, a 0.7 wt% sodium hydroxide solution was used to adjust the pH value to 10.5, and then ethanol was added to terminate the reaction. After continuous stirring for 25 min, the mixture was centrifuged, repeatedly washed with deionized water until neutral, and freeze-dried to obtain cellulose nanofibers;

[0052] 3) 2 g of alkali lignin was dissolved in 70 mL of 1.2 mol / L sodium hydroxide solution, stirred at 260 r / min for 40 min, and then 70 mL of 1.2 mol / L zinc chloride solution was added dropwise to the system, stirred at room temperature for 3 h, and the precipitate generated by the reaction was repeatedly washed with distilled water until it was neutral, and freeze-dried to obtain a nanocomposite material;

[0053] 4) The nano-composite material is frozen with liquid nitrogen and then freeze-dried, and then placed in a muffle furnace for graded calcination, calcined at 125°C for 1.5 h, calcined at 255°C for 2.5 h, and calcined at 580°C for 2.5 h, and naturally cooled to room temperature to obtain nano-flower-like composite particles, and then the nano-flower-like composite particles are mixed with cellulose nanofibers in a mass ratio of 1:15 and added to a sufficient amount of 75wt% ethanol solution, stirred at a high speed of 13000r / min for 1.5h, dried after centrifugal separation, and then added to deionized water, stirred and dispersed evenly to obtain a treating agent with a solid content of 5wt%.

[0054] Example 3

[0055] A method for preparing a functional Viola yedoensis extract comprises the following steps:

[0056] S1: Immerse Viola yedoensis in the treatment agent at a dosage ratio of 1g:80mL, and pre-treat it at a closed high temperature and high pressure of 0.5MPa and 120℃ for 30min, and then instantly release the pressure to normal pressure;

[0057] S2 uses 99.8wt% ethanol solution as solvent, with a solid-liquid mass ratio of 1:30, and is extracted at 75°C for 45 minutes. During the extraction process, ultrasound and microwave assistance are applied alternately, with each treatment time of 15 minutes, an ultrasonic frequency of 30kHz, and a microwave power of 800W. The alcohol extraction product is ultrafiltered and spray-dried to obtain the Viola yedoensis extract.

[0058] The preparation method of the treatment agent is as follows:

[0059] 1) the luffa was fully dried in 110 ℃ of air blast boxes for 5h, ground and pulverized by a grinder, immersed in a sodium hydroxide solution of 15wt%, and heated at 65 ℃ for 50min, dried after fully washing with distilled water, and then immersed in a sodium hypochlorite solution of 17wt% for 30min, and then repeatedly washed with deionized water, and dried to obtain a pre-treatment luffa powder;

[0060] 2) adding 2 g of pretreated loofah powder to 150 mL of deionized water, then adding 0.05 g of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and 0.5 g of sodium bromide, and adding 6 mL of 17 wt % sodium hypochlorite solution under 150 W ultrasound, reacting for 3 h, and during the reaction, adjusting the pH value to 10.5 with a 0.8 wt % sodium hydroxide solution, then adding ethanol to terminate the reaction, and stirring for 30 min, centrifuging, repeatedly washing with deionized water until neutral, and freeze-drying to obtain cellulose nanofibers;

[0061] 3) 3 g of alkali lignin was dissolved in 80 mL of 1.3 mol / L sodium hydroxide solution, stirred at 300 r / min for 50 min, and then 80 mL of 1.3 mol / L zinc chloride solution was added dropwise to the system, stirred at room temperature for 5 h, and the precipitate generated by the reaction was repeatedly washed with distilled water until it was neutral, and freeze-dried to obtain a nanocomposite material;

[0062] 4) The nano-composite material is frozen with liquid nitrogen and then freeze-dried, and then placed in a muffle furnace for graded calcination, calcined at 128°C for 2h, calcined at 260°C for 3h, and calcined at 585°C for 3h, and naturally cooled to room temperature to obtain nano-flower-like composite particles, and then the nano-flower-like composite particles are mixed with cellulose nanofibers in a mass ratio of 1:18 and added to a sufficient amount of ethanol solution with a concentration of 80wt%, stirred at a high speed of 15000r / min for 2h, dried after centrifugal separation, and then added to deionized water, stirred and dispersed evenly to obtain a treating agent with a solid content of 7wt%.

[0063] Comparative Example 1: The specific implementation is the same as Example 1, except that it does not contain a treating agent.

[0064] Comparative Example 2: The specific implementation method is the same as that of Example 1, except that steps 1)-2) are omitted in the preparation of the treating agent.

[0065] Comparative Example 3: The specific implementation method is the same as that of Example 1, except that steps 3)-4) are omitted in the preparation of the treating agent.

[0066] Comparative Example 4: The specific implementation method is the same as that of Example 1, except that the high temperature and high pressure pretreatment is omitted.

[0067] Comparative Example 5: The specific implementation method is the same as that of Example 1, except that the ultrasound and microwave assistance are omitted.

[0068] Test experiment:

[0069] The same batch of Viola yedoensis was extracted by the preparation methods provided in Examples 1-3 and Comparative Examples 1-5. The quality results of the Viola yedoensis extract prepared were shown in Table 1. The contents of flavonoids and coumarins in the Viola yedoensis extract were calculated. The contents of flavonoids and coumarins in the Viola yedoensis extract were determined by HPLC. The specific method was as follows: (1) Chromatographic conditions: the chromatographic column was filled with octadecylsilane bonded silica gel; the injection volume was 10 μl, the column temperature was 30°C, and the detection wavelength was 290 nm; the mobile phase A was acetonitrile; the mobile phase B was 14 mmol / L ammonium acetate aqueous solution; gradient elution (0-10 min, A10-25%; 10-20 min, A25-60%); (2) Reference solution: accurately weigh aesculin, Fraxinus ethylenic acid, quercetin, luteolin and naringenin were placed in the same volumetric flask, and methanol was added to prepare mixed solutions with concentrations of 100 μg / ml, 100 μg / ml, 50 μg / ml, 50 μg / ml and 25 μg / ml, respectively, as mixed reference solutions; (3) Test solution: 5 mg of Viola yedoensis extract powder was accurately weighed and placed in a volumetric flask, methanol was added, ultrasonically dissolved, diluted to the scale, shaken, filtered, and the filtrate was taken as the test solution; (4) Content determination: The reference solution and the test solution were accurately aspirated, respectively, injected into a liquid chromatograph, and determined to obtain the contents of flavonoids and coumarins in Viola yedoensis extract, wherein the flavonoids include quercetin, luteolin and naringenin, and the coumarins include fraxinus ethylenic acid and fraxinus ethylenic acid. The results are shown in Table 2.

[0070] Table 1

[0071] Example 1 Example 2 Example 3 Comparative Example 1 Viola yedoensis extract mg 45.7 46.5 46.1 30.2 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Viola yedoensis extract mg 34.9 34.3 37.6 36.4

[0072] Table 2

[0073] Example 1 Example 2 Example 3 Comparative Example 1 Fraxinin% 17.1 17.8 17.5 12.5 Fraxin % 20.4 20.9 20.6 15.2 Quercetin % 9.3 9.8 9.5 6.1 Luteolin% 12.2 12.6 12.4 8.8 Naringenin % 5.7 6.1 5.9 3.1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Fraxinin% 14.8 14.1 16.4 15.7 Fraxin % 17.5 17.9 19.3 18.6 Quercetin % 7.2 7.5 8.6 8.1 Luteolin% 9.4 9.9 11.2 10.7 Naringenin % 3.8 4.1 4.9 4.6

[0074] It can be seen from Table 1 and Table 2 that the preparation method of the present invention can effectively promote the full release of active substances in Viola yedoensis, thereby improving the extraction efficiency of Viola yedoensis and achieving a high yield of Viola yedoensis extract.

[0075] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a functional Viola yedoensis extract, It is characterized in that The specific steps include: S1 immerses Viola yedoensis into the treatment agent, performs pretreatment under closed high temperature and high pressure, and then instantly releases the pressure to normal pressure; S2 is subjected to alcohol extraction under the assistance of ultrasound and microwave, and then ultrafiltration and spray drying are performed to obtain a high-purity Viola yedoensis extract.

2. A method for preparing a functional Viola yedoensis extract according to claim 1, It is characterized in that In S1, the dosage ratio of Viola yedoensis to the treatment agent is 1 g: (50-80) mL; The pretreatment is carried out at 0.3-0.5 MPa and 115-120° C. for 20-30 min.

3. The method for preparing a functional Viola yedoensis extract according to claim 1, It is characterized in that The preparation method of the treatment agent is as follows: 1) dissolving alkali lignin in a sodium hydroxide solution, stirring at 200-300 r / min for 30-50 min, then dropping a zinc chloride solution into the system, stirring and reacting at room temperature for 2-5 h, repeatedly washing the precipitate generated by the reaction with distilled water until it is neutral, and freeze-drying to obtain a nanocomposite material; 2) The nano-composite material is frozen with liquid nitrogen and then freeze-dried, and then placed in a muffle furnace for graded calcination, and naturally cooled to room temperature to obtain nano-flower-like composite particles, and then the nano-flower-like composite particles are mixed with cellulose nanofibers and added to a sufficient amount of ethanol solution, and stirred at a high speed of 10000-15000r / min for 1-2h, dried after centrifugal separation, and then added to deionized water, stirred and dispersed evenly to obtain a treatment agent with a solid content of 3-7wt%.

4. A method for preparing a functional Viola yedoensis extract according to claim 3, It is characterized in that In step 1), the usage ratio of the alkali lignin, the sodium hydroxide solution, and the zinc chloride solution is (1-3) g: (50-80) mL: (50-80) mL; The concentration of the sodium hydroxide solution is 1.0-1.3 mol / L; The concentration of the zinc chloride solution is 1.0-1.3 mol / L.

5. The method for preparing a functional Viola yedoensis extract according to claim 3, It is characterized in that In step 2), the graded calcination is specifically: calcining at 120-128°C for 1-2h, calcining at 250-260°C for 2-3h, and calcining at 575-585°C for 2-3h; The mass ratio of the nano flower-shaped composite particles to the cellulose nanofibers is 1:(10-18); The concentration of the ethanol solution is 70-80 wt %.

6. The method for preparing a functional Viola yedoensis extract according to claim 3, It is characterized in that The preparation method of the cellulose nanofiber is as follows: 1) the loofah is fully dried in a 105-110 ℃ of air blast boxes for 2-5h, ground and pulverized by a grinder, immersed in a sodium hydroxide solution, and heated at 60-65 ℃ for 30-50min, fully washed with distilled water and then dried, and then the dried product is immersed in a sodium hypochlorite solution, soaked for 20-30min, and then repeatedly washed with deionized water, and after drying, a pre-treatment loofah powder is obtained; 2) The pretreated loofah powder is added to deionized water, and then 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and sodium bromide are added, and sodium hypochlorite solution is added under 100-150W ultrasound, and the reaction is carried out for 1-3 hours. During the reaction, the pH value is adjusted to be stable at 10.0-10.5 using sodium hydroxide solution, and then ethanol is added to terminate the reaction. After continuous stirring for 20-30 minutes, centrifugation is performed, and the mixture is repeatedly washed with deionized water until neutral, and freeze-dried to obtain cellulose nanofibers.

7. The method for preparing a functional Viola yedoensis extract according to claim 6, It is characterized in that In step 1), the concentration of the sodium hydroxide solution is 10-15wt%; The concentration of the sodium hypochlorite solution is 12-17 wt %.

8. The method for preparing a functional Viola yedoensis extract according to claim 6, It is characterized in that In step 2), the ratio of the pretreated loofah powder, deionized water, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide, and sodium hypochlorite solution is (1-2) g: (100-150) mL: (0.02-0.05) g: (0.2-0.5) g: (3-6) mL; The concentration of the sodium hypochlorite solution is 12-17wt%; The concentration of the sodium hydroxide solution is 0.5-0.8 wt %.

9. The method for preparing a functional Viola yedoensis extract according to claim 1, It is characterized in that In S2, in the ultrasound and microwave assistance, the ultrasound frequency is 20-30kHz and the microwave power is 500-800W; The ultrasound and microwave are treated alternately, and each treatment lasts for 10-15 minutes; The alcohol extraction is carried out using 99.5-99.8 wt % ethanol solution as solvent, with a solid-liquid mass ratio of 1:(25-30), and the extraction is carried out at 70-75° C. for 40-45 minutes.

10. A functional Viola yedoensis extract, It is characterized in that The preparation method is described in any one of claims 1 to 9.