A peony whitening extract and its preparation method and application

Abstract

The present application proposes a peony whitening extract and its preparation method and application. Peony plants are extracted with Tris buffered saline and then chromatographed and analyzed with a dextran column to obtain an analytical solution; the analytical solution is precipitated with a hydrophilic polymer to obtain a precipitate; the precipitate is resuspended and the supernatant is collected to obtain the peony whitening extract. The extraction process does not use organic reagents, and on the basis of focusing on natural safety and environmental protection, the active ingredients in the plant are retained to the greatest extent possible; the separation method is simple to operate and has low cost, making the production of peony whitening extract more efficient and economical.

Description

Technical Field

[0001] The present application relates to the technical field of natural product extraction, and in particular to a peony whitening extract and a preparation method and application thereof. Background Art

[0002] As global consumers' demand for skin health and beauty continues to increase, the whitening skin care products market is showing a rapid growth trend. The main goal of whitening skin care products is to reduce or inhibit the formation of melanin, so as to achieve the effect of brightening skin color and even skin texture. However, the existing whitening skin care products on the market have various ingredients, different effects, and some potential problems. Traditional whitening ingredients, such as hydroquinone, arbutin, etc., although they have certain whitening effects, long-term use may bring safety hazards such as skin irritation, dependence or rebound effect. In addition, some chemical synthetic ingredients may also pollute the environment, which is not in line with modern consumers' green, environmentally friendly and sustainable consumption concepts. In order to overcome these problems, more and more skin care product research and development have begun to turn to natural plant extracts. Plant extracts have the advantages of wide sources, high safety, and diverse biological activities, and are an important direction for the development of new whitening skin care products.

[0003] Peony, as a traditional precious flower in China, has a long history of medicinal and beauty use. Peony petals are rich in a variety of bioactive ingredients, such as peony glycosides, flavonoids, polyphenols, etc. These ingredients have potential whitening, antioxidant, anti-inflammatory and other effects in the field of skin care. Among them, flavonoids are a class of natural products with a wide range of biological activities that can inhibit the activity of tyrosinase, thereby reducing the production of melanin. Polyphenols have strong antioxidant capacity, can scavenge free radicals, and protect skin cells from oxidative damage.

[0004] However, how to effectively extract the whitening ingredients in peony and apply them to skin care products is a technical problem currently faced by the field of skin care product preparation. On the one hand, the whitening ingredients in peony are at a low content, and efficient extraction technology is needed to improve the extraction efficiency; on the other hand, the activity of the whitening ingredients needs to be maintained during the extraction process to prevent them from being destroyed or degraded. Therefore, it is necessary to develop a preparation method for peony whitening extract, which can not only meet consumers' needs for whitening, health, and environmental protection, but also promote the green development and technological innovation of the skin care industry. Summary of the invention

[0005] The present application provides a peony whitening extract and a preparation method and application thereof to solve the problems existing in the related technology. The technical solution is as follows:

[0006] In a first aspect, the present application provides a method for preparing a peony whitening extract, comprising the following steps:

[0007] Peony plants were extracted with Tris buffered saline, chromatographed on a dextran column, and analyzed to obtain an analytical solution;

[0008] The analytical solution is precipitated by a hydrophilic polymer to obtain a precipitate;

[0009] The precipitate is resuspended and the supernatant is collected to obtain the peony whitening extract.

[0010] In one embodiment, the peony plant is extracted in the form of a powder mixed with Tris buffered saline.

[0011] In one embodiment, the solid-liquid ratio of the peony plant to Tris buffered saline is 1:(1-10).

[0012] In one embodiment, the extraction temperature is 20-30° C. and the stirring is performed for 1-5 hours.

[0013] In one embodiment, the dextran chromatography column filler is Sephadex G25.

[0014] In one embodiment, the conditions for chromatography and analysis are:

[0015] The sample loading volume is 0.2-0.7 times the filling volume of the dextran chromatography column; the volume of the eluent during analysis is 1.8-3.8 times the filling volume of the dextran chromatography column.

[0016] In one embodiment, the eluent is Tris buffered saline.

[0017] In one embodiment, the filling volume of the dextran chromatography column is 8000-10000 mL, and the loading volume is 2000-5000 mL; the eluent volume during analysis is 15000-36000 mL; 2000-3000 mL is taken as one volume, and every three volumes are collected.

[0018] In one embodiment, the hydrophilic polymer is polyacrylamide.

[0019] In one embodiment, the mass ratio of the polyacrylamide to the analytical solution is 1:(5-20).

[0020] In one embodiment, the precipitate is obtained by centrifugation, and the centrifugation conditions are: 10000-15000 rpm for 30-60 min.

[0021] In one embodiment, the resuspending reagent is Tris buffered saline.

[0022] In one embodiment, the supernatant is obtained by resuspension and then centrifugation; the centrifugation conditions are: 8000-12000 rpm for 10-25 min.

[0023] In one embodiment, the supernatant is freeze-dried to obtain the peony whitening extract.

[0024] In one embodiment, freeze drying uses a lyoprotectant, which includes one or a combination of two or more of mannitol, polyethylene glycol, sucrose or dextran 30000.

[0025] In one embodiment, the composition of the Tris buffered saline is 100 mM Tris, 100 mM NaCl, 10 mM EDTA; and the pH is 7.2.

[0026] In a second aspect, an embodiment of the present application provides a peony whitening extract, wherein the peony whitening extract is prepared by any of the above-mentioned methods for preparing a peony whitening extract.

[0027] In a third aspect, the embodiments of the present application provide the application of the peony whitening extract in whitening products.

[0028] The advantages or beneficial effects of the above technical solution include at least:

[0029] The preparation method of the peony whitening extract of the present application does not use organic reagents during the preparation process, is more natural and safe, reduces potential irritation, is more in line with environmental protection requirements, reduces pollution to the environment, and embodies the concept of sustainable production; at the same time, the active ingredients in the plant are better retained. The dextran column chromatography impurity removal technology also has the characteristics of simple operation and low cost, avoiding cumbersome separation steps and expensive equipment investment, making the production of peony whitening extract more efficient and economical.

[0030] The peony whitening extract prepared in the present application has excellent tyrosinase inhibition rate and whitening effect, and has outstanding whitening performance. DETAILED DESCRIPTION

[0031] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the description is considered to be exemplary rather than restrictive in nature.

[0032] Natural plant extracts have unique advantages in the field of skin care products. They are not only widely available, highly safe, but also have excellent performance. However, there are also problems such as complex extraction process and low extraction yield. Therefore, the present application provides a peony whitening extract and its preparation method and application, and provides a safe, effective and stable preparation method of the whitening extract to meet consumers' needs for whitening, health and environmental protection and promote the green development and technological innovation of the skin care industry.

[0033] A method for preparing a peony whitening extract comprises the following steps:

[0034] Peony plants were extracted with Tris buffered saline, chromatographed on a dextran column, and analyzed to obtain an analytical solution;

[0035] The analytical solution is precipitated by a hydrophilic polymer to obtain a precipitate;

[0036] The precipitate is resuspended and the supernatant is collected to obtain the peony whitening extract.

[0037] Tris buffered saline is used for extraction, and no organic reagents are used in the preparation process, making the extracted product more natural and safe, reducing potential irritation; at the same time, the extraction process is more in line with environmental protection requirements, reducing pollution to the environment, and embodying the concept of sustainable production. The dextran column chromatography is simple to operate and has low cost, avoiding cumbersome separation steps and expensive equipment investment, making the production of peony whitening extract more efficient and economical.

[0038] In particular, extraction with Tris-buffered saline is combined with dextran column chromatography to better retain the active ingredients in the plant.

[0039] In one embodiment, the peony plant is mixed with Tris buffered saline in the form of powder for extraction. The peony plant is in the form of powder, which can make the plant cells contact and dissolve better with Tris buffered saline, thereby improving the extraction efficiency.

[0040] In one embodiment, the composition of the Tris buffered saline is 100 mM Tris, 100 mM NaCl, 10 mM EDTA; and the pH is 7.2.

[0041] The composition of the Tris buffered saline is stable, low-cost and low-toxic, has good biocompatibility, and does not produce significant toxicity or side effects to organisms. Therefore, the present application uses Tris buffered saline as an extraction reagent, so that the extracted product is stable and does not change, and the extraction is more natural and safe, reducing potential risks; at the same time, compared with other organic reagents for extraction, the extraction process is more in line with environmental protection requirements and reduces pollution to the environment.

[0042] In one embodiment, the solid-liquid ratio of the peony plant to Tris buffered saline is 1:(1-10). At this solid-liquid ratio, the active substances in the peony plant are better dissolved in the Tris buffered saline, which will neither cause excessive Tris buffered saline to increase the burden of subsequent treatment; nor will the peony plant be incompletely leached due to too little Tris buffered saline. Preferably, the solid-liquid ratio of the peony plant to Tris buffered saline is 1:8. At this solid-liquid ratio, a better extraction efficiency is achieved.

[0043] In one embodiment, the extraction temperature is 20-30°C and stirred for 1-5h. The extraction temperature and time have a certain influence on the extraction efficiency, and the temperature is related to the stability of the active substance. Therefore, the present application can efficiently extract while maintaining the stability of the active substance at 20-30°C and stirring for 1-5h. Preferably, the extraction temperature is room temperature and the stirring time is 2h. The room temperature is suitable, the stirring extraction time is not too long, and the leaching efficiency of plant active substances is high.

[0044] In one embodiment, the filler of the dextran chromatography column is Sephadex G25. Different specifications and models of dextran are represented by the English letter G, and the Arabic number after G is generally 10 times the water value of the gel; this application uses G25 regular dextran, which absorbs 2.5 grams of water per gram of gel when expanded. Sephadex G25 has a separation range of 1000-5000 and is suitable for desalting, separation of peptides and other small molecules; therefore, the dextran chromatography column filled with Sephadex G25 is used in this application to remove impurities and specifically separate the active ingredients in the peony Tris buffered saline extract. In this embodiment, Sephadex G25 is used to obtain the activity belonging to the plant exosome part.

[0045] In one embodiment, the conditions for chromatography and analysis are:

[0046] The sample loading volume is 0.2-0.7 times the filling volume of the dextran chromatography column; the volume of the eluent during analysis is 1.8-3.8 times the filling volume of the dextran chromatography column, and the eluent is collected to obtain the analysis solution.

[0047] Preferably, the sample volume is 0.3-0.5 times the filling volume of the dextran chromatography column; the volume of the eluent during analysis is 2.5-3.8 times the filling volume of the dextran chromatography column, and the eluent is collected to obtain the analysis solution. Further preferably, the sample volume is 0.35-0.44 times the filling volume of the dextran chromatography column; the volume of the eluent during analysis is 3.0-3.6 times the filling volume of the dextran chromatography column, and the eluent is collected to obtain the analysis solution.

[0048] By limiting the volume ratio of the sample to the filling column and the volume ratio of the eluent to the filling column, the extract can be separated more effectively, and a stable and highly active peony whitening extract can be efficiently prepared.

[0049] In one embodiment, the filling volume of the dextran chromatography column is 8000-10000 mL, and the loading volume is 2000-5000 mL; the eluent volume during analysis is 15000-36000 mL; 2000-3000 mL is taken as one volume, and every three volumes are collected.

[0050] More preferably, the peony whitening extract is collected in three volumes with 2500 mL as one volume, and the activity of the peony whitening extract in the 7th to 9th volumes of the analytical solution is optimal.

[0051] In one embodiment, the eluent is Tris-buffered saline. Preferably, the composition of the Tris-buffered saline is 100 mM Tris, 100 mM NaCl, 10 mM EDTA, and the pH is 7.2.

[0052] In one embodiment, after the peony plant is extracted with Tris buffered saline, it is filtered before chromatography. The solid and liquid are separated by filtration, and the filtrate is then chromatographed, which can reduce the chromatography pressure, enhance the chromatography separation ability, and more accurately collect the peony whitening extract.

[0053] In one embodiment, the filtration uses one or more of gauze, filter paper, and 0.22-0.45 μm filter membrane as the medium.

[0054] In one embodiment, the analyte after chromatography is filtered using one or more of gauze, filter paper, and 0.22-0.45 μm filter membrane as a medium.

[0055] Filtration of the analytical solution can be used to remove the filler and other substances under the chromatographic flow to avoid the introduction of impurities in the subsequent aggregation and precipitation process.

[0056] In one embodiment, the hydrophilic polymer is polyacrylamide.

[0057] Polymer precipitation is a commonly used method for isolating exosomes. Highly hydrophilic polymers interact with water molecules around exosomes to form a hydrophobic microenvironment, which leads to exosome precipitation. Among various hydrophilic polymers, polyacrylamide is a non-toxic polymer that has the ability to reshape the water solubility of surrounding materials. Therefore, it is used to precipitate active plant extracts by polymer precipitation. The polymer precipitation method will not denature or affect the active plant extracts, and the activity of the active plant extracts will be retained to a large extent.

[0058] In one embodiment, the mass ratio of the polyacrylamide to the analytical solution is 1:(5-20). Preferably, the mass ratio of the polyacrylamide to the filtrate is 1:12.

[0059] In one embodiment, the precipitate is obtained by centrifugation at 10,000-15,000 rpm for 30-60 min. Preferably, the centrifugation is at 12,500 rpm for 40 min.

[0060] The rotation speed of the centrifuge affects the precipitation of the active ingredients. Under the above centrifugal conditions of the present application, the polymerized active plant extracts can be precipitated, while other small molecule components are retained in the liquid to achieve separation.

[0061] In one embodiment, the resuspending reagent is Tris buffered saline.

[0062] In one embodiment, the supernatant is obtained by resuspension followed by centrifugation; the centrifugation condition is: 8000-12000 rpm for 10-25 min. Preferably, the centrifugation condition is 10000 rpm for 15 min.

[0063] The resuspension not only separates the polyacrylamide in the polymer precipitation from the active plant extract, but also washes the active plant extract again. The supernatant is collected again, and the active plant extract is retained in the supernatant, achieving the final extraction and separation.

[0064] In one embodiment, the supernatant is freeze-dried to obtain the peony whitening extract.

[0065] In one embodiment, freeze drying uses a lyoprotectant, which includes one or a combination of two or more of mannitol, polyethylene glycol, sucrose or dextran 30000.

[0066] The supernatant is freeze-dried to facilitate the storage and subsequent use of the peony whitening extract. Mannitol, polyethylene glycol, sucrose or dextran 30000 are commonly used freeze-drying protective agents in the art and can be used in whitening products at the same time, so no additional processing process is added when the whitening product is used in the subsequent application.

[0067] The embodiment of the present application provides a peony whitening extract, which is prepared by any of the above-mentioned methods for preparing a peony whitening extract.

[0068] The embodiments of the present application provide the application of the peony whitening extract in whitening products.

[0069] The following is a further description with reference to specific embodiments.

[0070] Example 1

[0071] The raw material powder of peony plant was mixed with Tris buffered saline in a solid-liquid ratio of 1:8, stirred at room temperature for 2 hours, and filtered using filter paper; the composition of Tris buffered saline was 100mM Tris, 100mM NaCl, 10mM EDTA; the pH was 7.2; the filtrate was chromatographed on a dextran column; the dextran column was chromatographed with Sephadex G25 is used as filler, the filler volume is 9000mL, and the filtrate loading volume is 3500mL; after loading, 30000mL Tris buffered saline is used for elution, and the analytical solution is collected, and the analytical solution is collected every 3 volumes with a volume of 2500mL; the first analytical solution A1 (volumes 1-3), the second analytical solution A2 (volumes 4-6), the third analytical solution A3 (volumes 7-9), and the fourth analytical solution A4 (volumes 10-12) are obtained; each part of the analytical solution is filtered, and polyacrylamide is added for polymerization precipitation, and the mass ratio of polyacrylamide to filtrate is 1:12; after the polymerization precipitation is completed, it is centrifuged at 12500rpm for 40min to harvest the precipitate; the precipitate is resuspended in Tris buffered saline, centrifuged at 10000rpm for 15min, and the supernatant is taken; the supernatant is freeze-dried to obtain freeze-dried powder, which is peony whitening extract, namely peony whitening extract A1, peony whitening extract A2, peony whitening extract A3, and peony whitening extract A4.

[0072] Example 2

[0073] The raw material powder of peony plant was mixed with Tris buffered saline in a solid-liquid ratio of 1:1, stirred at 30°C for 1 hour, and filtered using filter paper; the composition of Tris buffered saline was 100mMTris, 100mMNaCl, 10mMEDTA; the pH was 7.2; the filtrate was chromatographed on a dextran column; the dextran column was filled with Sephadex G25; the filler volume was 8000mL, and the filtrate loading volume was 3500mL; after loading, 24000mL was used The solution was eluted with Tris buffered saline and the analytical solution was collected, with 2000 mL as one volume and every 3 volumes collected; the first analytical solution B1 (volumes 1-3), the second analytical solution B2 (volumes 4-6), the third analytical solution B3 (volumes 7-9) and the fourth analytical solution B4 (volumes 10-12) were obtained; each part of the analytical solution was filtered, and polyacrylamide was added for polymerization precipitation, and the mass ratio of polyacrylamide to filtrate was 1:20; after the polymerization precipitation was completed, the solution was centrifuged at 10000 rpm for 60 minutes to harvest the precipitate; the precipitate was resuspended with Tris buffered saline, centrifuged at 12000 rpm for 10 minutes, and the supernatant was taken; the supernatant was freeze-dried to obtain freeze-dried powder, which was peony whitening extract, namely peony whitening extract B1, peony whitening extract B2, peony whitening extract B3 and peony whitening extract B4.

[0074] Example 3

[0075] The raw material powder of peony plant was mixed with Tris buffered saline at a solid-liquid ratio of 1:10, stirred at 20°C for 5 hours, and filtered using filter paper; the composition of Tris buffered saline was 100mMTris, 100mMNaCl, 10mM EDTA; the pH was 7.2; the filtrate was chromatographed on a dextran column; the dextran column was filled with Sephadex G25; the filler volume was 10000mL, and the filtrate loading volume was 3500mL; after loading, 36000mL was used The solution was eluted with Tris buffered saline and the analytical solution was collected. The analytical solution was collected every 3 volumes with a volume of 3000 mL. The first analytical solution C1 (volumes 1-3), the second analytical solution C2 (volumes 4-6), the third analytical solution C3 (volumes 7-9), and the fourth analytical solution C4 (volumes 10-12) were obtained. The analytical solutions of each part were filtered and polyacrylamide was added for polymerization precipitation. The mass ratio of polyacrylamide to filtrate was 1:5. After the polymerization precipitation was completed, the solution was centrifuged at 15000 rpm for 30 minutes to harvest the precipitate. The precipitate was resuspended with Tris buffered saline and centrifuged at 8000 rpm for 25 minutes to obtain the supernatant. The supernatant was freeze-dried to obtain freeze-dried powder, which was the peony whitening extract, namely, the peony whitening extract C1, the peony whitening extract C2, the peony whitening extract C3, and the peony whitening extract C4.

[0076] Comparative Example 1

[0077] Arbutin aqueous solution with a mass concentration of 200 mg / kg.

[0078] Performance testing:

[0079] Tyrosine activity was determined by L-DOPA oxidation assay of B16 melanoma cells. The peony whitening extract of Example 1 was prepared into a 200 mg / kg aqueous solution, and the arbutin aqueous solution of Comparative Example 1 was used to treat B16 melanoma cells, and the absorbance was measured by a spectrophotometer at a wavelength of 490 nm. The tyrosinase activity and inhibition rate of the cells of the Example and the Comparative Example were calculated, and the test results are shown in Table 1.

[0080] Table 1

[0081]

[0082] According to the tyrosinase activity inhibition experiment, the peony whitening extract A3 and the peony whitening extract A4 of Example 1 were selected to measure the change of skin color using a Lab colorimetric system spectrophotometer (Minolta spectrophotometer CM-2600d). The test indicators are: Where: L, a, b are the coordinate values ​​of the three-dimensional rectangular coordinate system; X, Y, Z are the three stimulus values ​​of the XYZ color system; Xn, Yn, Zn are the three stimulus values ​​of the completely diffuse reflection surface. L: is the brightness. The larger the value, the more the color tends to be white, and vice versa, it tends to be black. a: is the red and green color, +a is the red direction, -a is the green direction. b: is the yellow and blue color, +b is the yellow direction, -b is the blue direction. c: is the saturation, which is used to indicate the color intensity of the object surface. h: is the hue angle, which indicates the characteristics of the separation of colors from each other.

[0083] In the Lab colorimetry system, the color difference ΔEab between two stimuli is represented by the difference ΔL, Δa, Δb between the coordinates L, a, and b, that is, the distance between two color points in the color space. In the formula: Since ΔEab is a comprehensive index of L, a, and b, it represents the three-dimensional change of chromaticity, so it is a more appropriate indicator for evaluating skin color changes.

[0084] The test subjects used the peony whitening extract A3 and peony whitening extract A4 of Example 1 continuously and applied the specified cosmetics on the face every morning and before going to bed at night after washing their faces. The amount of application was enough to slightly see the application layer. The neck was not applied as a self-control. The change of skin color was measured using a spectrophotometer 1 day before use of the example and on the 30th, 60th, and 90th days after use. The test was repeated 3 times and the average value was taken.

[0085] Test site: forehead (1.5cm above the eyebrows); left and right cheeks (1.5cm below the cheekbones); neck (1.5cm below the Adam's apple).

[0086] Table 2 Comparison of color difference ΔE of a certain brand of whitening cosmetics used on different parts of the body at different times using the example

[0087]

[0088] Table 3 Comparison of cheek skin color values ​​at different times using the examples

[0089]

[0090]

[0091] After the experiment of this application, the cheek color difference increased after using different embodiments, and the cheek color difference changed significantly after 90d of use. Although the forehead color difference also showed an increasing trend after using different embodiments, it was not obvious compared with the cheek color difference, indicating that the cheek is the most sensitive part of the cheek. In this study, the neck was used as a self-control and the cheek was not applied. Therefore, the color difference change in this part reflected the natural changes in the skin color of the subjects. The results showed that the neck color difference showed a decreasing trend during the test. For this study, the a value of the neck decreased after using the cheek, the L value continued to increase, and the b value increased, indicating that the skin color changed in the yellow-white direction; the increase in the c value indicated that the yellow-white saturation of the skin color increased after continuous use of this brand of whitening cosmetics; the h value did not change much, indicating that the changes in skin color were more consistent. The comparison results show that Example 1 Peony Whitening Extract A3 has the best whitening effect.

[0092] In summary, the present invention uses Tris buffered saline to extract peony plants and uses dextran column chromatography and polymerization precipitation to separate peony whitening extracts with high whitening efficiency. The extraction process does not use organic reagents, and on the basis of focusing on natural safety and environmental protection, the active ingredients in the plant are retained as much as possible; the separation method is simple to operate and has low cost; making the production of peony whitening extracts more efficient and economical.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0095] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a peony whitening extract, characterized in that: The following steps are involved: Peony plants were extracted with Tris buffered saline, chromatographed on a dextran column, and analyzed to obtain an analytical solution; The analytical solution is precipitated by a hydrophilic polymer to obtain a precipitate; The precipitate is resuspended and the supernatant is collected to obtain the peony whitening extract.

2. The method for preparing the peony whitening extract according to claim 1, characterized in that: The peony plant is extracted by mixing with Tris buffered saline in the form of powder; The solid-liquid ratio of the peony plant to Tris buffered saline is 1:(1-10); The extraction temperature is 20-30°C and stirred for 1-5 hours.

3. The method for preparing the peony whitening extract according to claim 1, characterized in that: The dextran chromatography column filler is Sephadex G25; The conditions for chromatography and analysis are: The sample volume is 0.2-0.7 times the filling volume of the dextran chromatography column; the volume of the eluent during analysis is 1.8-3.8 times the filling volume of the dextran chromatography column; The eluent is Tris buffered saline.

4. The method for preparing the peony whitening extract according to claim 3, characterized in that: The filling volume of the dextran chromatography column is 8000-10000 mL, and the sample loading volume is 2000-5000 mL; the eluent volume during analysis is 15000-36000 mL; 2000-3000 mL is taken as one volume, and every three volumes are collected.

5. The method for preparing the peony whitening extract according to claim 1, characterized in that: The hydrophilic polymer is polyacrylamide; The mass ratio of the polyacrylamide to the analytical solution is 1:(5-20); The precipitate is obtained by centrifugation, and the centrifugation conditions are: 10000-15000 rpm for 30-60 min.

6. The method for preparing the peony whitening extract according to claim 1, characterized in that: The resuspension reagent was Tris-buffered saline; The supernatant is obtained by resuspension and centrifugation; the centrifugation conditions are: 8000-12000rpm for 10-25min.

7. The method for preparing the peony whitening extract according to claim 1, characterized in that: The supernatant is freeze-dried to obtain the peony whitening extract; preferably, freeze drying uses a lyoprotectant, and the lyoprotectant includes one or a combination of two or more of mannitol, polyethylene glycol, sucrose or dextran 30000.

8. The method for preparing the peony whitening extract according to any one of claims 1 to 7, characterized in that: The composition of the Tris buffered saline is 100 mM Tris, 100 mM NaCl, 10 mM EDTA; the pH is 7.

2.

9. A peony whitening extract, characterized in that: The peony whitening extract is prepared by the preparation method of the peony whitening extract according to any one of claims 1 to 8.

10. Use of the peony whitening extract according to claim 9 in whitening products.

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