Coreopsis tinctoria extract, preparation method, external skin preparation and liquid skin care product

Abstract

The invention discloses a coreopsis tinctoria extract, a preparation method, an external skin preparation and a liquid skin care product. The coreopsis tinctoria extract has the effects of moisturizing, resisting aging and whitening skin. The preparation method comprises the following steps: obtaining a water extracting solution of coreopsis tinctoria powder; selecting at least one of microfiltration, ultrafiltration and nanofiltration to filter the water extract; and concentrating and drying the filtered water extract to obtain the coreopsis tinctoria extract.

Description

Technical Field

[0001] The present application relates to the technical field of skin care, and in particular to a snow chrysanthemum extract, a preparation method, an external skin preparation and a liquid skin care product. Background Art

[0002] Cosmetics refer to chemical industrial products or fine chemical products that are spread on any part of the human body by smearing, spraying or other similar methods for the purpose of cleaning, maintenance, beautification, modification and change of appearance, or correction of body odor and maintenance of good condition.

[0003] In the early development stage of cosmetics, the function of a single cosmetic may be relatively simple, such as anti-aging, whitening, moisturizing, etc. Even today, the development route of single-function cosmetics still maintains a very important position in society; cosmetics set products seem to illustrate this point well. For example, in common skin care set products, some products are responsible for moisturizing, others may be responsible for whitening, and some may be responsible for anti-aging, etc. Although the above phenomenon in the field of cosmetics is still relatively obvious. But on the other hand, people have also realized the disadvantages of single-functional products, so more and more cosmetics are developing in the direction of multi-function. In this development direction, a single cosmetic may need to have multiple functions such as anti-aging and moisturizing at the same time.

[0004] Snow chrysanthemum, also known as two-color coreopsis (Coreopsis tinctoria. Nutt.), is an annual herb. Snow chrysanthemum has been widely used in the history of Uyghur medicine. It has the effects of clearing away heat and detoxifying, promoting blood circulation and removing blood stasis, and harmonizing the stomach and spleen. People often use snow chrysanthemum flowers to make tea and drink it to treat diseases such as thirst, high blood pressure, palpitations, gastrointestinal discomfort, loss of appetite, dysentery, and sores, boils, and swellings. Due to its effect of scavenging oxygen free radicals, snow chrysanthemum has gradually stepped out of the field of medicine and entered the field of cosmetics. Snow chrysanthemum extract is also one of the many raw materials for cosmetics and is increasingly used in skin care products.

[0005] In order to ensure the content of flavonoids in snow chrysanthemum extracts to enhance their anti-aging effects in cosmetics, the existing snow chrysanthemum extracts used in cosmetics are mostly obtained by extracting snow chrysanthemum raw materials with ethanol. For details, please refer to the Chinese patent document with publication number CN108703912A, entitled "A snow chrysanthemum total flavonoid extract, preparation method thereof, and application in cosmetics". One of the drawbacks caused by this is that many substances that can be used for moisturizing in snow chrysanthemum extracts are screened out. As for how to overcome the aforementioned drawbacks, no relevant solutions have been found in the field of cosmetics.

[0006] In summary, the snow chrysanthemum extract provided by the prior art is difficult to be used in cosmetics that need to ensure moisturizing effect, or in other words, it is difficult to take into account both the anti-aging and moisturizing functions of cosmetics. Summary of the invention

[0007] One purpose of the embodiments of the present application is to solve the above-mentioned problems and provide corresponding beneficial effects.

[0008] Another purpose of the embodiments of the present application is to provide a snow chrysanthemum extract, a preparation method, an external skin preparation and a liquid skin care product that can take into account the moisturizing, anti-aging and whitening effects on the skin.

[0009] To achieve the above objectives, the embodiments of the present application provide the following technical solutions.

[0010] In a first aspect, the present invention provides a method for preparing a snow chrysanthemum extract, comprising:

[0011] Obtain a water extract of snow chrysanthemum powder;

[0012] filtering the water extract to obtain a filtrate; centrifuging the filtrate to obtain a supernatant;

[0013] Performing microfiltration treatment on the supernatant using a microfiltration membrane to obtain a permeate;

[0014] Using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate;

[0015] Performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate;

[0016] The nanofiltrate is concentrated and dried to obtain the snow chrysanthemum extract.

[0017] In a second aspect, the present invention provides a method for preparing a snow chrysanthemum extract, comprising:

[0018] Obtain a water extract of snow chrysanthemum powder;

[0019] Performing microfiltration treatment on the water extract using a microfiltration membrane to obtain a permeate;

[0020] Using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate;

[0021] Performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate;

[0022] The nanofiltrate is concentrated and dried to obtain the snow chrysanthemum extract.

[0023] The third aspect of the embodiment of the present application provides a method for preparing a snow chrysanthemum extract, comprising the following steps:

[0024] Obtain a water extract of snow chrysanthemum powder;

[0025] Select at least one of microfiltration, ultrafiltration and nanofiltration to filter the water extract;

[0026] The filtered water extract is concentrated and dried to obtain a snow chrysanthemum extract.

[0027] In a fourth aspect, the present application also provides a method for preparing a snow chrysanthemum extract, comprising:

[0028] Obtain a water extract of snow chrysanthemum powder;

[0029] Filtering the water extract to remove macromolecular substances with a molecular weight greater than or equal to a predetermined threshold;

[0030] The filtered water extract is concentrated and dried to obtain a snow chrysanthemum extract.

[0031] In a fifth aspect, an embodiment of the present application further provides a snow chrysanthemum extract, which is prepared according to the preparation method of the snow chrysanthemum extract described in any embodiment of the first to fourth aspects.

[0032] In a sixth aspect, the embodiments of the present application also provide an external skin preparation comprising the snow chrysanthemum extract described in the fifth aspect.

[0033] In a seventh aspect, the present application also provides a liquid skin care product, comprising:

[0034] Solvents; and

[0035] The snow chrysanthemum extract according to the fifth aspect;

[0036] Wherein, the concentration of the snow chrysanthemum extract in the liquid skin care product is 0.05% to 0.15%.

[0037] Compared with the prior art, the beneficial effects of the embodiments of the present application include:

[0038] In some embodiments, the preparation method of the snow chrysanthemum extract provided in the embodiments of the present application, due to the coordinated use of water extraction and membrane filtration and other means, the prepared snow chrysanthemum extract is not only rich in anti-aging, moisturizing and other effective ingredients, effectively retains the whitening effective ingredients, but also can effectively remove pigment molecules, dilute the color of the snow chrysanthemum extract, and is suitable for preparing whitening cosmetics; therefore, the aforementioned snow chrysanthemum extract can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, (1) the aforementioned snow chrysanthemum extract can take into account the content of effective ingredients such as total flavonoids and total sugars, thereby ensuring anti-aging and moisturizing functions; (2) it contains more whitening effective ingredients, can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect; (3) due to the effective removal of pigment molecules, the color of the solution is lighter, which can further ensure the whitening effect.

[0039] In some embodiments, water extraction may also effectively retain amino acid compounds, terpenoid compounds and other active ingredients with moisturizing effects, so that the snow chrysanthemum extract is rich in these active ingredients, which can further enhance the moisturizing effect.

[0040] In some embodiments, membrane filtration can also effectively remove unstable components such as protein and starch in the snow chrysanthemum extract, thereby improving the stability of the aqueous solution of the snow chrysanthemum extract.

[0041] In some embodiments, the preparation method of the embodiment of the present application comprehensively uses three filter membranes, namely, microfiltration membrane, ultrafiltration membrane and nanofiltration membrane, to treat the water extract, which can further effectively screen out the macromolecular pigments and unstable components in the snow chrysanthemum extract.

[0042] In some embodiments, the preparation method of the present application embodiment filters the water extract layer by layer in a graded filtration manner through a microfiltration membrane, an ultrafiltration membrane, and a nanofiltration membrane in a certain order, respectively achieving the effects of impurity removal and concentration, which is beneficial to retaining the content of the effective ingredients in the snow chrysanthemum extract. In addition to the above, the water extract is also filtered and centrifuged before membrane filtration, which is also beneficial to remove impurities and increase the content of the effective ingredients in the snow chrysanthemum extract.

[0043] In some embodiments, the present application embodiment is based on water extraction and multiple membrane filtration technology means, and through corresponding experimental verification, a method for preparing a snow chrysanthemum extract is organically constructed. In this method, by rationally configuring the specific technical parameters of the steps such as water extraction and multiple filtration, such as the temperature of heating reflux extraction, the transmembrane pressure, feed liquid temperature and pore size of microfiltration treatment, the transmembrane pressure, feed liquid temperature and pore size of ultrafiltration treatment, the transmembrane pressure, feed liquid temperature and pore size of nanofiltration treatment, etc., these steps are synergistically screened out the ineffective ingredients in the snow chrysanthemum extract, retain the required anti-aging substances and moisturizing substances, and coordinate the proportion of the two effective ingredients in the snow chrysanthemum extract, while increasing the total flavonoid content to more than 36% and the total sugar content to more than 41%, so that the moisture absorption rate reaches more than 9.6%, and the snow chrysanthemum extract can significantly increase the transcription levels of filament protein and caspase 14 of each group of hacat cells in the concentration range of 0.05% to 0.15%, so it has good anti-aging and moisturizing properties! On this basis, the snow chrysanthemum extract also retains a large number of effective whitening ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect; in addition, it also effectively removes pigment molecules and reduces the color of the snow chrysanthemum extract in the solution, making it suitable for the preparation of cosmetics.

[0044] In some embodiments, the snow chrysanthemum extract provided in the embodiments of the present application can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, the aforementioned snow chrysanthemum extract not only takes into account the content of effective ingredients such as total flavonoids and total sugars, which can ensure anti-aging and moisturizing functions, but is also rich in more whitening effective ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect. In addition, since the color of the snow chrysanthemum extract in the solution is lighter, the whitening effect can be further ensured.

[0045] In some embodiments, the snow chrysanthemum extract may also effectively retain the active ingredients with moisturizing effects such as amino acid compounds and terpenoid compounds, further enhancing the moisturizing effect.

[0046] In some embodiments, unstable components such as protein and starch in the snow chrysanthemum extract are effectively removed from the snow chrysanthemum extract, thereby improving the stability of the aqueous solution prepared with the snow chrysanthemum extract.

[0047] In some embodiments, the snow chrysanthemum extract can significantly increase the transcription levels of filaggrin and caspase 14 in each group of hacat cells within a concentration range of 0.05% to 0.15%, and has an excellent moisturizing effect.

[0048] In some embodiments, the topical skin preparation provided by the embodiments of the present application comprises the aforementioned snow chrysanthemum extract. Compared with the cosmetics using snow chrysanthemum extract in the prior art, the topical skin preparation has better moisturizing effect, anti-aging effect and whitening effect on the skin.

[0049] In some embodiments, the liquid skin care product provided by the embodiments of the present application comprises a solvent and the snow chrysanthemum extract; the concentration of the snow chrysanthemum extract is 0.05% to 0.15%. When the concentration of the snow chrysanthemum extract is 0.05% to 0.15%, the transcription levels of filaggrin and caspase 14 in hacat cells can be significantly increased, thereby further improving the moisturizing effect of the liquid skin care product on the skin.

[0050] Additional aspects and advantages of the present application will be given in part in the following description, and in part will become apparent from the following description, or will be understood through the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic flow chart of the preparation method of the snow chrysanthemum extract according to the embodiment of the present application is shown;

[0052] Figure 2 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Example 1 in the examples of the present application is shown;

[0053] Figure 3 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Example 2 in the present application is shown;

[0054] Figure 4 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Example 3 in the examples of the present application is shown;

[0055] Figure 5 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Comparative Example 1 is shown;

[0056] Figure 6 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Comparative Example 2 is shown;

[0057] Figure 7 A schematic diagram of an aqueous solution of the snow chrysanthemum extract of Comparative Example 3 is shown;

[0058] Figure 8 A schematic diagram showing the transcriptional effects of the snow chrysanthemum extract of the present application example on filaggrin, aquaporin 3 and hyaluronan synthase 1 of hacat cells;

[0059] Fig. 9 A schematic diagram showing the transcriptional effect of the snow chrysanthemum extract of the present application example on caspase 14 in hacat cells;

[0060] Fig.10 A line graph showing the tyrosinase inhibition rate of the snow chrysanthemum extract of the embodiment of the present application is shown;

[0061] Fig.11 A line graph showing the ABTS free radical scavenging rate of the snow chrysanthemum extract of the embodiment of the present application is shown;

[0062] Fig.12 A line graph of DPPH radical scavenging rate of the snow chrysanthemum extract of the example of the present application is shown. DETAILED DESCRIPTION

[0063] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Several embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0065] The term "comprising" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0066] In addition to the above, it is still necessary to emphasize that the reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0067] In this document, unless otherwise specified, the term "%" means "mass %"; the term "Mpa" means: megapascal; the term "℃" means: degrees Celsius; the term "KD" means: kilodalton; the term "D" means: dalton; the term "μm" means: micrometer. In this document, unless otherwise specified, the term "%" herein refers to the total weight of the composition of the present application.

[0068] In this article, unless otherwise specified, all defined ranges are meant to include each specific range within a given range and a combination of sub-ranges between given ranges. For example, a range of 1 to 5 specifically includes 1, 2, 3, 4 and 5, and also includes sub-ranges such as 2 to 5, 3 to 5, 2 to 3, 2 to 4, 1 to 4, etc.

[0069] In the embodiments of the present application, the term "water extract" refers to the extract obtained by treating the object to be extracted by water extraction. Among them, water extraction is different from alcohol extraction using organic solvents such as ethanol. Both have a certain degree of, or even very obvious, influence on the composition of the extract. For example, for snow chrysanthemum plants, water extraction is more likely to retain substances with moisturizing effects.

[0070] In the embodiments of the present application, the term "membrane filtration" refers to membrane separation technology, also known as membrane filtration technology. Common membrane filtration includes microfiltration, ultrafiltration and nanofiltration. Microfiltration (MF) can be used to separate particulate substances, such as intercepting particles, bacteria, pollutants, etc. from gas and liquid phases. Ultrafiltration usually uses pressure difference as the driving force and utilizes the interception ability of a porous membrane to separate particles of different sizes in a solution by physical interception, thereby achieving the purpose of purifying, concentrating and screening different components in the solution. Nanofiltration (NF) is usually used to separate substances with a relatively small molecular mass, such as inorganic salts or small molecular organic substances such as glucose and sucrose, from solvents.

[0071] As described in the previous background technology, the snow chrysanthemum extract provided by the prior art is difficult to take into account the anti-aging and moisturizing functions of skin care products, especially the content of total flavonoids (which can play an anti-aging role) and total sugars (which can play a moisturizing role). To solve this problem, the present application found that moisturizing substances such as sugars can be effectively retained by water extraction means based on a large amount of experimental data. However, if snow chrysanthemum powder is treated with water extraction means alone, the color of the obtained snow chrysanthemum extract in the solution is very dark, which is not conducive to its application in skin care products. The specific reason is that skin care products, as a kind of cosmetics, usually work by applying on the skin, and many requirements should not show a darker color after applying on the skin, so as to avoid residual pigment molecules on the skin, affecting the skin's perception or whitening. The embodiment of the present application combines water extraction and membrane filtration technology to comprehensively treat snow chrysanthemum powder to obtain a water extract, and then obtains snow chrysanthemum extract according to the water extract, which can not only effectively avoid the loss of sugar compounds on the basis of taking into account the total flavonoid content in the snow chrysanthemum extract, but also make the snow chrysanthemum extract rich in moisturizing substances and anti-aging substances, and can also retain whitening substances and effectively remove pigment molecules.

[0072] In summary, in order to make the obtained snow chrysanthemum extract contain more effective ingredients such as anti-aging, moisturizing and whitening, so as to take into account the anti-aging function, moisturizing function and whitening effect of skin care products, the embodiments of the present application provide the snow chrysanthemum extract for whitening and its preparation method, external skin preparation and liquid skin care products described in the following aspects.

[0073] <First aspect>

[0074] like Figure 1 As shown, the first aspect of the embodiment of the present application provides a method for preparing a snow chrysanthemum extract, comprising the following steps S101-S106:

[0075] S101, obtaining a water extract of snow chrysanthemum powder.

[0076] Water extraction can effectively retain the anti-aging and moisturizing active ingredients of snow chrysanthemum extract. First, water extraction is conducive to retaining the moisturizing substance of total sugar in snow chrysanthemum extract, thereby improving the moisturizing effect. Second, water extraction can also take into account flavonoid compounds, making the snow chrysanthemum extract rich in total flavonoids. Total flavonoids can not only enhance the anti-aging and antioxidant effects of snow chrysanthemum extract, but also have a certain degree of moisturizing effect. Third, water extraction may also effectively retain amino acid compounds and terpenoid compounds, thereby further improving the moisturizing effect.

[0077] S102, filtering the water extract to obtain a filtrate; and centrifuging the filtrate to obtain a supernatant.

[0078] Filtration can separate the solid and liquid of the drug residue and the water extract, and remove some large particles of the drug residue, which is beneficial to retain the content of effective ingredients such as moisturizing substances and anti-aging substances in the snow chrysanthemum extract.

[0079] S103, performing microfiltration treatment on the supernatant using a microfiltration membrane to obtain a permeate.

[0080] Microfiltration can remove colloids, microorganisms and other substances, which is beneficial to retaining the content of effective ingredients in the snow chrysanthemum extract. In addition, since there are many colloids and microorganisms, this step can also reduce the colloids and microorganisms in the solution, thereby improving the stability of the snow chrysanthemum extract.

[0081] S104, using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate.

[0082] Ultrafiltration can not only remove some macromolecular compounds such as proteins and starches, but also effectively screen out some macromolecular pigment molecules, which is beneficial to increase the content of effective ingredients in snow chrysanthemum extract, and can also improve the whitening performance of snow chrysanthemum extract and reduce the color of the extract.

[0083] S105, performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate.

[0084] Nanofiltration can remove water molecules and some ineffective ingredients, play a concentrating role, reduce the water content and ineffective ingredients in the nanofiltrate, and help increase the content of effective ingredients in snow chrysanthemum extract.

[0085] S106, concentrating and drying the nanofiltrate to obtain the snow chrysanthemum extract.

[0086] The preparation method of the first aspect of the embodiment of the present application adopts water extraction and membrane filtration in a coordinated manner, so that the prepared snow chrysanthemum extract is not only rich in anti-aging, moisturizing and other effective ingredients, effectively retains the whitening effective ingredients, but also can effectively remove pigment molecules and dilute the color of the snow chrysanthemum extract, which is suitable for preparing whitening cosmetics; therefore, the aforementioned snow chrysanthemum extract can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, (1) the aforementioned snow chrysanthemum extract can take into account the content of effective ingredients such as total flavonoids and total sugars, thereby ensuring anti-aging and moisturizing functions; (2) it contains more whitening effective ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect; (3) in addition, since the pigment molecules are effectively removed, the color of the solution is lighter, which can further ensure the whitening effect.

[0087] In addition, water extraction may also effectively retain amino acid compounds, terpenoid compounds and other active ingredients with moisturizing effects, making the snow chrysanthemum extract rich in these active ingredients, which can further enhance the moisturizing effect.

[0088] Furthermore, membrane filtration can effectively remove unstable components such as protein and starch in the snow chrysanthemum extract, thereby improving the stability of the aqueous solution of the snow chrysanthemum extract.

[0089] More importantly, in the first aspect, the embodiment adopts a combination of three kinds of filter membranes, namely, microfiltration membrane, ultrafiltration membrane and nanofiltration membrane, to treat the water extract, which can further effectively screen out the macromolecular pigments and unstable components in the snow chrysanthemum extract. In addition, in the first aspect, the embodiment uses a microfiltration membrane, an ultrafiltration membrane and a nanofiltration membrane in a certain order to filter the water extract layer by layer in a graded filtration manner, thereby achieving the effects of impurity removal and concentration, respectively, which is conducive to retaining the content of the effective components of the snow chrysanthemum extract.

[0090] In addition to the above, the first embodiment also filters and centrifuges the water extract before membrane filtration, which is also beneficial for removing impurities and increasing the content of active ingredients in the snow chrysanthemum extract.

[0091] In at least one embodiment, step S101 specifically includes S1011 - S1012.

[0092] S1011, obtaining the snow chrysanthemum powder.

[0093] S1012, mixing the snow chrysanthemum powder and purified water to obtain a mixed solution, performing heating reflux extraction treatment on the mixed solution at least once, collecting and combining the extracts obtained from each heating reflux extraction to obtain the water extract.

[0094] In some embodiments, step S1011, obtaining the snow chrysanthemum powder, comprises: taking dried snow chrysanthemum, crushing it, and passing it through a 20-mesh sieve to obtain the snow chrysanthemum powder.

[0095] In some embodiments, the mass ratio of the snow inulin powder to the purified water in step S1012 is 1:(2-40).

[0096] In some embodiments, in step S1012, the number of heating reflux extractions is 1-5 times. It is easy to understand that too many times of heating reflux extractions will increase the total preparation time, resulting in too long preparation time and consumption of manpower and material resources; in addition, when the number of extractions reaches a certain level, the help for the extraction of effective ingredients is no longer very obvious. The number of heating reflux extractions of 1-5 times proposed in the embodiment of the present application can basically extract the effective ingredients such as total flavonoids and total sugars in the snow chrysanthemum powder, and can take into account the extraction efficiency while ensuring the acquisition rate of the effective ingredients. Furthermore, the number of heating reflux extractions is 2 times.

[0097] In some embodiments, in step S1012, the temperature of the heating reflux extraction is 60-100° C. Exemplarily, the temperature of the heating reflux extraction can be 60° C., 80° C., 100° C., etc. The temperature of 60-100° C. is to ensure that sufficient effective ingredients, such as total flavonoids and total sugars, can be retained in the snow chrysanthemum extract.

[0098] In at least one embodiment, in step S1012, the time of each heating reflux extraction is 0.5 hours to 4 hours. This method is mainly to improve the acquisition rate of effective components such as total flavonoids and total sugars in the snow chrysanthemum extract.

[0099] In some embodiments, in step S102, the filtrate is centrifuged in a tubular centrifuge at a speed of 5000 rpm to 30000 rpm, mainly to increase the content of effective ingredients such as total flavonoids and total sugars in the snow chrysanthemum extract.

[0100] In some embodiments, in step S103, the pore size or molecular weight cut-off of the microfiltration membrane is 0.45 μm to 0.005 μm, mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0101] In some embodiments, in step S103, the transmembrane pressure of the microfiltration process is 0.01-0.3 MPa, mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0102] In some embodiments, in step S103, the temperature of the microfiltration solution is 10° C. to 50° C. This is mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0103] In some embodiments, in step S104, the pore size or molecular weight cutoff of the ultrafiltration membrane is between 10KD and 50KD. In a further example, the pore size of the ultrafiltration membrane is 20KD, which is convenient for retaining substances with a molecular weight cutoff of more than 20KD and separating them from the snow chrysanthemum extract. This is mainly to increase the content of active ingredients in the snow chrysanthemum extract.

[0104] In some embodiments, in step S104, the transmembrane pressure of the ultrafiltration treatment is 0.01-0.7 MPa, mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0105] In some embodiments, in step S104, the temperature of the ultrafiltration solution is 10° C. to 50° C. This is mainly to increase the content of effective ingredients in the snow chrysanthemum extract.

[0106] In some embodiments, in step S105, the pore size or molecular weight cutoff of the nanofiltration membrane is between 100D and 300D. This is mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0107] In some embodiments, in step S105, the transmembrane pressure of the nanofiltration treatment is 0.3-1.5 MPa, mainly to increase the content of the active ingredient in the snow chrysanthemum extract.

[0108] In some embodiments, in step S105, the temperature of the feed solution during nanofiltration treatment is 10° C. to 50° C. This is mainly to increase the content of effective ingredients in the snow chrysanthemum extract.

[0109] In some embodiments, in step S106, the temperature of concentration and drying is 40-80° C. This is mainly to increase the content of active ingredients in the snow chrysanthemum extract.

[0110] In some embodiments, in step S106, the vacuum degree of concentration and drying is 0.02-0.08 MPa, mainly to increase the content of active ingredients in the snow chrysanthemum extract.

[0111] In some embodiments, in step S106, the concentration is reduced pressure concentration, mainly to increase the content of active ingredients in the snow chrysanthemum extract.

[0112] In the field of cosmetics, there is a high pursuit for both anti-aging and moisturizing properties. However, the snow chrysanthemum extracts provided by the prior art either have too low anti-aging substance content (the main anti-aging substance, total flavonoids, is less than 25%), or too low moisturizing substances, resulting in low moisture absorption rate (the main moisturizing substance, total sugar, is less than 15%, and the moisture absorption rate is less than 1%), so it is difficult to provide cosmetics with good anti-aging and moisturizing properties at the same time. Accordingly, one of the core purposes of the present invention is to take into account the two effective ingredients of anti-aging substances and moisturizing substances in snow chrysanthemum extracts.

[0113] The reason why the existing technology is difficult to take into account both the anti-aging substances and moisturizing substances in snow chrysanthemum extracts may be that the total flavonoids, which mainly play an anti-aging role, also have a moisturizing effect, but their moisturizing effect may be inferior to the moisturizing substance such as total sugar; therefore, it is difficult to properly adjust the proportion of total flavonoids and total sugar. Specifically, when the total flavonoids are too low, if the total flavonoids content is excessively reduced in order to increase the total sugar content, it will not only greatly reduce the anti-aging properties, but may also have an adverse effect on the moisturizing performance, because the total flavonoids themselves have certain moisturizing properties. Similarly, if the total sugar content is excessively reduced in order to increase the total flavonoids content, although the anti-aging properties can be improved, it may also have an adverse effect on the moisturizing performance.

[0114] In addition, there are some other moisturizing substances in snow chrysanthemum extract besides total flavonoids and total sugars, such as amino acid compounds and terpenoid compounds. This further exacerbates the complexity of the moisturizing mechanism of snow chrysanthemum extract. Therefore, how to adjust the total flavonoids and total sugars in snow chrysanthemum extract to a reasonable level so that it can take into account both good moisturizing and anti-aging properties is a difficult point!

[0115] To achieve the above objectives, in some embodiments, the present application embodiment is based on water extraction and multiple membrane filtration technology means, and through corresponding experimental verification, a method for preparing a snow chrysanthemum extract is organically constructed. In this method, by rationally configuring the specific technical parameters of the steps of water extraction and multiple filtration, such as the temperature of heating reflux extraction, the transmembrane pressure, feed liquid temperature and pore size of microfiltration treatment, the transmembrane pressure, feed liquid temperature and pore size of ultrafiltration treatment, the transmembrane pressure, feed liquid temperature and pore size of nanofiltration treatment, etc., these steps are synergistically screened out the ineffective ingredients in the snow chrysanthemum extract, retain the required anti-aging substances and moisturizing substances, and coordinate the proportion of the two effective ingredients in the snow chrysanthemum extract, while increasing the total flavonoid content to more than 36% and the total sugar content to more than 41%, so that the moisture absorption rate reaches more than 9.6%, and the snow chrysanthemum extract can significantly increase the transcription levels of filament protein and caspase 14 of each group of hacat cells in the concentration range of 0.05% to 0.15%, so it has good anti-aging and moisturizing properties! On this basis, snow chrysanthemum extract also retains a large number of effective whitening ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect on the skin; in addition, it also effectively removes pigment molecules and reduces the color of snow chrysanthemum extract in the solution, making it suitable for the preparation of cosmetics.

[0116] <Second Aspect>

[0117] In a second aspect, the present invention provides a method for preparing a snow chrysanthemum extract, comprising steps S201-205:

[0118] S201, obtaining a water extract of snow chrysanthemum powder.

[0119] It is basically the same as step S101 of the first aspect, and thus can be implemented with reference to step S101.

[0120] S202, using a microfiltration membrane to perform microfiltration treatment on the water extract to obtain a permeate.

[0121] S203, using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate.

[0122] S204, performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate.

[0123] S205, concentrating and drying the nanofiltrate to obtain the snow chrysanthemum extract.

[0124] The preparation method of the second aspect of the embodiment of the present application adopts the means of water extraction and membrane filtration in a coordinated manner, so that the prepared snow chrysanthemum extract is not only rich in anti-aging, moisturizing and whitening effective ingredients, but also can effectively remove the pigment molecules in the snow chrysanthemum extract, dilute the color of the snow chrysanthemum extract, and is suitable for preparing whitening cosmetics; therefore, the aforementioned snow chrysanthemum extract can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, the aforementioned snow chrysanthemum extract not only takes into account the content of effective ingredients such as total flavonoids and total sugars, which can ensure anti-aging and moisturizing functions, but is also rich in more whitening effective ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect. In addition, due to the lighter color, the whitening effect can be further guaranteed.

[0125] In addition, water extraction can effectively retain amino acid compounds, terpene compounds and other active ingredients with moisturizing effects, making the snow chrysanthemum extract rich in these active ingredients, which can further enhance the moisturizing effect.

[0126] Furthermore, membrane filtration can effectively remove unstable components such as protein and starch in the snow chrysanthemum extract, thereby improving the stability of the aqueous solution prepared with the snow chrysanthemum extract.

[0127] More importantly, in the second embodiment, three kinds of filter membranes, namely, microfiltration membrane, ultrafiltration membrane and nanofiltration membrane, are used to treat the water extract, which can further effectively screen out the macromolecular pigments and unstable components in the snow chrysanthemum extract. In addition, in the second embodiment, the water extract is filtered layer by layer in a graded filtration manner through a microfiltration membrane, an ultrafiltration membrane and a nanofiltration membrane in a certain order, thereby achieving the effects of impurity removal and concentration, respectively.

[0128] In some embodiments, step S202 includes steps S2021-S2022.

[0129] S2021, filtering the water extract to obtain a filtrate; centrifuging the filtrate to obtain a supernatant; it is basically the same as step S102 of the first aspect, and thus can be implemented with reference to step S102.

[0130] S2022, using a microfiltration membrane to perform microfiltration on the supernatant to obtain a permeate.

[0131] Step S203 is substantially the same as step S104 of the first aspect, and thus may be implemented with reference to step S104.

[0132] Step S204 is substantially the same as step S105 of the first aspect, and thus may be implemented with reference to step S105.

[0133] Step S205 is substantially the same as step S106 of the first aspect, and thus may be implemented with reference to step S106.

[0134] <Third Aspect>

[0135] In a third aspect, the present application provides a method for preparing a snow chrysanthemum extract, comprising steps S301-303:

[0136] S301, obtaining a water extract of snow chrysanthemum powder.

[0137] S302, selecting at least one of microfiltration, ultrafiltration and nanofiltration to filter the water extract.

[0138] S303, concentrating and drying the filtered water extract to obtain snow chrysanthemum extract.

[0139] Step S301 is substantially the same as step S101 of the first aspect, and thus may be implemented with reference to step S101.

[0140] Step S303 is substantially the same as step S106 of the first aspect, and thus may be implemented with reference to step S106.

[0141] The preparation method of the third aspect of the embodiment of the present application, due to the coordinated use of water extraction and membrane filtration means, not only makes the prepared snow chrysanthemum extract not only rich in anti-aging, moisturizing and whitening effective ingredients, but also can effectively remove the pigment molecules in the snow chrysanthemum extract, dilute the color of the snow chrysanthemum extract, and is suitable for preparing whitening cosmetics; therefore, the aforementioned snow chrysanthemum extract can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, the aforementioned snow chrysanthemum extract not only takes into account the content of effective ingredients such as total flavonoids and total sugars, can ensure anti-aging and moisturizing functions, but is also rich in more whitening effective ingredients, can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and enhance the whitening effect. In addition, due to the lighter color, the whitening effect can be further guaranteed.

[0142] In addition, water extraction can effectively retain amino acid compounds, terpene compounds and other active ingredients with moisturizing effects, making the snow chrysanthemum extract rich in these active ingredients, which can further enhance the moisturizing effect.

[0143] Furthermore, membrane filtration can effectively remove unstable components such as protein and starch in the snow chrysanthemum extract, thereby improving the stability of the aqueous solution prepared with the snow chrysanthemum extract.

[0144] In some embodiments, step S302 specifically includes steps S3021 - S3022 .

[0145] S3021, filtering the water extract to obtain a filtrate; and centrifuging the filtrate to obtain a supernatant.

[0146] S3022. Select at least one of microfiltration, ultrafiltration and nanofiltration to treat the supernatant to obtain the water extract filtrate.

[0147] Step S3021 is substantially the same as step S102 of the first aspect, and thus may be implemented with reference to step S102.

[0148] In some embodiments, in step S3022, the pore size or molecular weight cutoff of the microfiltration membrane is 0.45 μm to 0.005 μm.

[0149] In some embodiments, in step S3022, the transmembrane pressure of the microfiltration treatment is 0.01-0.3 MPa.

[0150] In some embodiments, in step S3022, the temperature of the slurry subjected to microfiltration treatment is 10°C to 50°C.

[0151] In some embodiments, in step S3022, the pore size or molecular weight cutoff of the ultrafiltration membrane is between 10KD and 50KD. In a further example, the pore size of the ultrafiltration membrane is 20KD, so as to cut off substances with a molecular weight above 20KD and separate them from the snow chrysanthemum extract.

[0152] In some embodiments, in step S3022, the transmembrane pressure of the ultrafiltration treatment is 0.01-0.7 MPa.

[0153] In some embodiments, in step S3022, the temperature of the feed solution in the ultrafiltration treatment is 10°C to 50°C.

[0154] In some embodiments, in step S3022, the pore size or molecular weight cutoff of the nanofiltration membrane is between 100D and 300D.

[0155] In some embodiments, in step S3022, the transmembrane pressure of the nanofiltration treatment is 0.3-1.5 MPa.

[0156] In some embodiments, in step S3022, the temperature of the feed solution for nanofiltration treatment is 10°C to 50°C.

[0157] <Fourth Aspect>

[0158] In a fourth aspect, the present application also provides a method for preparing a snow chrysanthemum extract, comprising steps S401-403:

[0159] S401, obtaining a water extract of snow chrysanthemum powder. This is basically the same as step S101 of the first aspect, and thus can be implemented with reference to step S101.

[0160] S402, filtering the water extract to remove macromolecular substances with a molecular weight greater than or equal to a predetermined threshold.

[0161] S403, concentrating and drying the filtered water extract to obtain snow chrysanthemum extract. This is basically the same as step S103 of the first aspect, and thus can be implemented with reference to step S103.

[0162] In some embodiments, the predetermined threshold is 0.005 μm. In some embodiments, the predetermined threshold is 10 KD. In some embodiments, the predetermined threshold is 100D.

[0163] In some embodiments, in step S402, the water extract is filtered through at least one of a microfiltration membrane, an ultrafiltration membrane, and a nanofiltration membrane.

[0164] <Fifth Aspect>

[0165] In a fifth aspect, an embodiment of the present application further provides a snow chrysanthemum extract, which is prepared according to the preparation method of the snow chrysanthemum extract described in any embodiment of the first to fourth aspects.

[0166] The snow chrysanthemum extract provided in the embodiment of the present application can take into account the anti-aging function, moisturizing function and whitening effect of skin care products, and is suitable for preparing multifunctional external skin preparations or skin care products. Specifically, the aforementioned snow chrysanthemum extract not only takes into account the content of effective ingredients such as total flavonoids and total sugars, which can ensure anti-aging and moisturizing functions, but is also rich in more whitening effective ingredients, which can effectively inhibit the activity of tyrosinase, remove ABTS free radicals and DPPH free radicals, and improve the whitening effect. In addition, since the color of the snow chrysanthemum extract in the solution is lighter, the whitening effect can be further guaranteed. In addition, the snow chrysanthemum extract may also effectively retain the effective ingredients with moisturizing effects such as amino acid compounds and terpenoid compounds, further improving the moisturizing effect. In addition, the unstable components such as protein and starch in the snow chrysanthemum extract are effectively removed from the snow chrysanthemum extract, thereby improving the stability of the aqueous solution configured with the snow chrysanthemum extract.

[0167] In summary, the snow chrysanthemum extract provided in the examples of the present application is particularly suitable for preparing a multifunctional external skin preparation having moisturizing, anti-aging and whitening effects.

[0168] <Sixth Aspect>

[0169] Therefore, in the sixth aspect, the embodiment of the present application further provides an external skin preparation, comprising the snow chrysanthemum extract described in the fifth aspect. Compared with the cosmetics using snow chrysanthemum extract in the prior art, the external skin preparation has better moisturizing effect, anti-aging effect and whitening effect.

[0170] Illustratively, the topical skin preparation described in the embodiments of the present application can be any one of a lotion, an essence, a spray, an emulsion, a cream, a mask, a gel, a sunscreen, and an isolation.

[0171] <Seventh Aspect>

[0172] In a seventh aspect, the present application also provides a liquid skin care product, comprising:

[0173] Solvents; and

[0174] The snow chrysanthemum extract according to the fifth aspect;

[0175] Wherein, the concentration of the snow chrysanthemum extract is 0.05% to 0.15%.

[0176] When the concentration (mass ratio) of the snow chrysanthemum extract is 0.05% to 0.15%, the transcription levels of filaggrin and caspase 14 in hacat cells can be significantly increased, thereby further improving the moisturizing effect of liquid skin care products on the skin.

[0177] Liquid skin care products can be understood as liquid external skin preparations. For example, the liquid skin care products described in the embodiments of the present application can be any one of lotion, essence, spray, emulsion, mask water, sunscreen water, and isolation water.

[0178] In some embodiments, the solvent is water.

[0179] In certain embodiments, the concentration of the snow chrysanthemum extract is 0.15%, which can further increase the transcription levels of filaggrin and caspase 14 in hacat cells, thereby further improving the moisturizing effect of the liquid skin care product on the skin.

[0180] Preparation Example of Snow Chrysanthemum Extract

[0181] Example 1

[0182] Take dried snow chrysanthemum and grind it, pass it through a 20-mesh sieve, take 8 kg of snow chrysanthemum powder, add 10 times the amount of purified water, heat and reflux extract twice, the time of each heating and reflux extraction is 2 hours, the temperature of the heating and reflux extraction is 90° C., combine the two extracts to obtain a water extract of snow chrysanthemum powder;

[0183] The water treatment liquid is filtered to obtain a filtrate. The filtrate is centrifuged using a tubular centrifuge to obtain a supernatant, wherein the centrifugal speed is 15000 revolutions per minute;

[0184] The supernatant was treated by microfiltration using a microfiltration membrane with a pore size of 0.005 μm to obtain a permeate, wherein the transmembrane pressure of the microfiltration treatment was 0.2 MPa and the feed liquid temperature was 25°C;

[0185] The permeate was treated by ultrafiltration using an ultrafiltration membrane with a pore size of 30KD to obtain an ultrafiltrate, wherein the transmembrane pressure of the ultrafiltration treatment was 0.5Mpa and the feed liquid temperature was 25°C;

[0186] The ultrafiltrate was treated by nanofiltration using a hollow fiber nanofiltration membrane with a pore size of 200D to obtain a nanofiltrate, wherein the transmembrane pressure of the nanofiltration treatment was 1.0 MPa and the feed liquid temperature was 25°C;

[0187] The nanofiltrate is concentrated and dried under reduced pressure, and then dried to obtain a solid snow chrysanthemum extract, wherein the vacuum degree of the reduced pressure concentration and drying is 0.05 MPa, and the temperature of the reduced pressure concentration and drying is 60°C.

[0188] Embodiment 2-6

[0189] Examples 2-6 are basically the same as Example 1, except that the control variable method is used to adjust the preparation conditions such as the microfiltration membrane pore size, the transmembrane pressure of the microfiltration membrane, the ultrafiltration membrane pore size, the transmembrane pressure of the ultrafiltration membrane, the nanofiltration membrane pore size, and the transmembrane pressure of the nanofiltration membrane. Please refer to Tables 1 and 2 below for details.

[0190] Table 1

[0191]

[0192]

[0193] Table 2

[0194]

[0195] Comparative Example 1

[0196] Take dried snow chrysanthemum and crush it, pass it through a 20-mesh sieve, take 8 kg of snow chrysanthemum powder, add 10 times the amount of 60% ethanol solution, heat and reflux for 1 hour, extract twice, combine the extracts, and obtain an ethanol extract;

[0197] Filtering the obtained ethanol extract to obtain a filtrate; recovering ethanol, and concentrating the obtained filtrate to a relative density of 1.10-1.20 measured at a temperature of 50° C. to obtain a concentrated solution;

[0198] The concentrate was diluted with water to a solution with a ratio of medicinal material to medicinal liquid of 1:1 (i.e., for 100 g of medicinal material, the concentrate was diluted to 100 ml), allowed to stand, filtered, and the filtrate was centrifuged at 15,000 rpm to obtain the supernatant obtained after centrifugation;

[0199] The supernatant obtained by microfiltration is treated with a microfiltration membrane with a pore size of 0.02 μm to obtain a permeate; wherein the transmembrane pressure of the microfiltration treatment is 0.5 MPa and the feed liquid temperature is 25°C;

[0200] The permeate obtained by ultrafiltration is treated with an ultrafiltration membrane with a pore size of 2000D to obtain an ultrafiltrate; wherein the transmembrane pressure is 0.5Mpa and the feed liquid temperature is 25°C;

[0201] The ultrafiltrate obtained is treated by ultrafiltration using a hollow fiber nanofiltration membrane with a pore size of 200D to obtain a nanofiltrate; wherein the transmembrane pressure is 1.0Mpa and the feed liquid temperature is 25°C;

[0202] The obtained nanofiltrate was concentrated under reduced pressure and dried to obtain a solid snow chrysanthemum extract.

[0203] Comparative Example 2

[0204] The preparation method disclosed in patent CN108703912A was used to prepare snow chrysanthemum extract, as follows:

[0205] The dried snow chrysanthemum is crushed and passed through a 20-mesh sieve, 8 kg of snow chrysanthemum powder is taken, 10 times the amount of purified water is added, the mixture is heated and refluxed for 2 hours, extracted twice, and the extracts are combined; the mixture is filtered, the filtrate is loaded onto a pretreated D101 macroporous resin column (column volume 1.0 L / BV), eluted with 3 BV of water and 3 BV of 50% ethanol in sequence, the flow rate is 1.5-2.5 BV / h, the 50% ethanol elution portion is collected, concentrated, and dried to obtain a snow chrysanthemum extract.

[0206] Comparative Example 3

[0207] Take dried snow chrysanthemum, grind it, pass it through a 20-mesh sieve, take 8 kg of snow chrysanthemum powder, add 10 times the amount of purified water, heat and reflux for 2 hours, extract twice, combine the extracts, filter, concentrate under reduced pressure, and dry to obtain snow chrysanthemum extract.

[0208] Determination of the content of components in snow chrysanthemum extract

[0209] The weight of the snow chrysanthemum extracts, the total flavonoids (expressed as rutin) and the total sugar content in the snow chrysanthemum extracts in Examples 1-6 and Comparative Examples 1-3 were measured respectively, and the results were recorded, as shown in Table 3.

[0210] Among them, in comparative example 1, the total flavonoids of snow chrysanthemum can be obtained according to the following method: the solid snow chrysanthemum extract is extracted by two-phase aqueous extraction, and the two-phase aqueous extraction system is mixed evenly according to the ratio of 5mL ethanol + 5mL water + 2g ammonium sulfate + 0.15g solid, centrifuged at room temperature and 2000 rpm, and the two-phase aqueous system is divided into upper and lower phases, and the upper phase is concentrated under reduced pressure and dried to obtain 160g of total flavonoids of snow chrysanthemum. After measurement, the content of total flavonoids (in terms of rutin) is 93.5%.

[0211] Table 3

[0212]

[0213] <Experiment 1: Hygroscopicity test>

[0214] The hygroscopicity of the snow chrysanthemum extracts prepared in Examples 1-6 and Comparative Examples 1-3 was tested, and the results were recorded as shown in Table 3.

[0215] <Experiment 2: Color detection of aqueous solution of snow chrysanthemum extract>

[0216] The snow chrysanthemum extracts prepared in Examples 1-6 and Comparative Examples 1-3 were respectively prepared into aqueous solutions with a mass ratio or concentration of 0.1% of the snow chrysanthemum extract, and their colors were visually detected. The results were recorded as shown in Table 3. Among them, the aqueous solutions corresponding to Examples 1-3 and Comparative Examples 1-3 can also be found in Figure 2-7 .

[0217] Note: In order to comply with the patent law regulations for the submission of drawings, Figure 2-7 A grayscale image of an actual picture is used, so it cannot fully reflect the difference between the comparative example and the embodiment of the present application. In fact, the color difference between the two is more obvious.

[0218] Analysis of the results of Experiments 1 and 2

[0219] Combining the results of the above experiments 1 and 2, we can determine the following conclusions:

[0220] First, the snow chrysanthemum extracts of Examples 1-6 of the present application have good moisture absorption rates. Combined with Table 3, it can be found from the results of Experiment 1 that the content of total sugar in the snow chrysanthemum extracts of Examples 1-6 of the present application is at least 40.3%, which is much higher than that of Comparative Examples 1 and 2, which has a very good effect on improving the moisture absorption function; it can also be seen from the data in the table that this is indeed the case, and the moisture absorption rates of Examples 1-6 of the present application are all above 9.6%, which is also much higher than 0.5% of the Comparative Example and 1% of Comparative Example 2.

[0221] Second, the solution color of the snow chrysanthemum extract of Examples 1-6 of the present application is lighter. Figure 2-7It can be seen that Examples 1-3 of the present application are light yellow, which is much lighter than the dark brown in Comparative Example 3. Therefore, it has a good application prospect in the development of moisturizing skin care products, and the prepared extract solution is light in color, which is convenient for the development and application of subsequent skin care products.

[0222] Third, the total flavonoid content of the snow chrysanthemum extracts of Examples 1-6 of the present application is above 36.7%. That is, Examples 1-6 of the present application not only take into account the moisturizing effect and the color of the solution, but also ensure the content of total flavonoids.

[0223] Fourth, although the snow chrysanthemum extract prepared in Comparative Example 3 also has a good moisture absorption rate, the color of the snow chrysanthemum extract solution is very dark and the total flavonoid content is low; in contrast, although Comparative Examples 1 and 2 have lighter colors, their moisture absorption rates are far lower than those of the snow chrysanthemum extract prepared in Examples 1 to 6 of the present invention. In other words, Comparative Examples 1 to 3 cannot take into account both the moisture retention rate and the solution color at the same time, not to mention further ensuring the total flavonoid content on this basis.

[0224] It can be seen that the snow chrysanthemum extracts prepared according to Comparative Examples 1-3 cannot take into account good total flavonoid content, moisturizing rate and lighter solution color, which are exactly what are required by skin care products of external skin preparations. In other words, the snow chrysanthemum extracts provided in Comparative Examples 1-3 have insurmountable defects in the application of skin care products, especially whitening skin care products. That is, the snow chrysanthemum extracts prepared according to the embodiments of the present application can not only provide a higher total flavonoid content and moisturizing effect, but also present a lighter solution color, and are particularly suitable for whitening skin care products.

[0225] <Experiment 3: Effects of snow chrysanthemum extract on transcriptional levels of human immortal keratinocytes (HACAT)>

[0226] Experiment 3 includes the following steps A1-A8:

[0227] Step A1: Set up the experimental group and the control group.

[0228] Five experimental groups, one blank control group and one positive control group were set up. The experimental groups were numbered 1-5 in sequence, and three parallel experiments were set up in each group.

[0229] A 6-well plate for pre-culturing hacat cells was prepared for each of the experimental groups 1-5, the blank control group and a positive control group. 100uL of hacat cells was inoculated into the 6-well plate of each group, and then pre-cultured for 24 hours; wherein, about 200,000 hacat cells were placed in each well of the 6-well plate, i.e., 20w cells / well.

[0230] Step A2: prepare culture medium for culturing hacat cells for the experimental group and the positive control group.

[0231] The snow chrysanthemum extract prepared in Example 1 of the present application was taken and dissolved in PBS buffer to prepare a mother solution. The mother solution was then filtered using a filter membrane, and the filtered mother solution was diluted with a complete culture medium into 5 concentrations of culture solutions, the concentrations of the snow chrysanthemum extract in the 5 culture solutions were 0.15%, 0.1%, 0.05%, 0.025% and 0.0125%, respectively, and were recorded as culture solutions 1-5. Culture solutions 1-5 were used to culture the pre-cultured hacat cells in experimental groups 1-5, respectively.

[0232] The culture medium 6 was prepared with macromolecular hyaluronic acid and used to culture the pre-cultured hacat cells in the positive control. The concentration of macromolecular hyaluronic acid in the culture medium 6 was 0.025%.

[0233] Step A3, continue to culture each group of pre-cultured hacat cells in a cell culture incubator.

[0234] Take the 6-well plates of experimental groups 1-5, positive control group and blank control group that have been pre-cultured in step A1.

[0235] The culture solutions 1-6 prepared in step A2 were added to the pre-cultured 6-well plates in the experimental groups 1-5 and the positive control group, respectively, and no culture solution was added to the 6-well plates in the blank control group. See Table 4 for details.

[0236] Then, the 6-well plates of experimental groups 1-5, positive control group, and blank control group without culture medium were moved to a cell culture incubator and cultured for 24 h. The carbon dioxide (CO 2 ) concentration is 5% and the temperature is 37°C.

[0237] Table 4

[0238] Culture medium Culture medium concentration Experimental Group 1 Culture medium 1 0.15％ Experimental Group 2 Culture medium 2 0.1％ Experimental Group 3 Culture medium 3 0.05％ Experimental Group 4 Culture medium 4 0.025％ Experimental Group 5 Culture medium 5 0.0125％ Positive control group Culture medium 6 0.025％ Blank control group none

[0239] Step A4: washing each group of hacat cells after being cultured in a cell culture incubator.

[0240] The 6-well plates of each group cultured in the cell culture incubator in step A3 were taken out, and the 6-well plates of each group were washed twice with PBS buffer to remove colored substances on the Hacat cells cultured in the 6-well plates.

[0241] Step A5: extract RNA from hacat cells of each group.

[0242] The hacat cells in the 6-well plates of each group that have been washed in step A4 were taken, and the corresponding RNA was extracted from the hacat cells of each group.

[0243] Step A6: reverse transcription treatment of RNA of hacat cells in each group.

[0244] The RNA concentration of the hacat cells of each group obtained in step A5 was measured.

[0245] The RNA of each group of hacat cells in step A5 with a predetermined volume is selected as each group of RNA samples to be tested; wherein, the predetermined volume of each group of RNA samples to be tested is calculated based on the concentration of each group of RNA and the mass of 2 ug.

[0246] Corresponding volumes of nuclease-free water (RNase Free water) and reverse transcriptase mix (mix is ​​the name of the reagent, meaning mixture) were added to the RNA samples of each group to form the RT-PCR (Reverse Transcription-Polymerase Chain Reaction) reaction system of each group (see Table 5), and the total volume of the system was 20 μL.

[0247] Table 5 RT-PCR reaction system

[0248] name volume RNA 2ug Nuclease-free water Up to 20μL 5X Reverse Transcriptase Mix 4μL

[0249] Note: (1) Up to 20 μL means that the total volume of the RT-PCR reaction system will not exceed 20 μL. In other words, except for RNA and reverse transcriptase mix, the rest of the RT-PCR reaction system is nuclease-free water. (2) 5X means the dilution factor of the reverse transcriptase mix. In the example shown in Table 5, the amount of reverse transcriptase mix added is 4 μL, and the total volume of the RT-PCR reaction system is 20 μL, so it is diluted five times.

[0250] After obtaining the RT-PCR reaction system of each group, the RT-PCR reaction program was started for each group. Please refer to Table 6 below. First, react at 37°C for 40 minutes, then react at 85°C for 5 seconds, and finally react at 12°C for 1 hour to obtain 20 μL of reverse transcription samples for each group.

[0251] Table 6 RT-PCR reaction procedure

[0252] temperature time 37℃ 40 minutes 85℃ 5 seconds 12℃ 1h

[0253] Step A7, dilute the reverse transcription sample.

[0254] After the reverse transcription process was completed, 20 μL of the reverse transcription sample in each group was diluted to 400 μL to obtain a cDNA (complementary DNA) sample with a final concentration of 5 ng / μL (nanograms per microliter).

[0255] Step A8: Analyze the cDNA samples by using the real-time fluorescence quantitative PCR (Quantitative Real-time PCR, QPCR) technology.

[0256] Each group took 4 μL (microliter) of the cDNA sample in step A7 as a cDNA template.

[0257] Then, 5 μL of premixed solution (QPCR SYBR Green Master Mix) and double distilled water (ddH 2 O) 0.4 μL and primers (including forward primer and reverse primer) 10 uM (micromolar) to form a QPCR reaction system, see Table 7.

[0258] Table 7 QPCR reaction system

[0259] name volume cDNA template 4μL 2X QPCR SYBR Green Master Mix 5μL <![CDATA[ddH 2 The]]> 0.4μL 10uM primer (forward + reverse) 0.6μL

[0260] Note: 2X is the dilution multiple of the premixed solution.

[0261] After obtaining the QPCR reaction system of each group, the QPCR program was carried out on the machine.

[0262] Record the QPCR results of each group, as follows Figure 8-9 shown.

[0263] Analysis of the results of Experiment 3

[0264] from Figure 8-9 It can be seen from the mRNA expression levels in the data that the snow chrysanthemum extract provided in the examples of the present application affects the transcription levels of filaggrin (FLG), aquaporin 3 (Aquaporin3, AQP3), caspase 14 (CASP14) and hyaluronic acid synthase 1 (HAS1) in each group of hacat cells.

[0265] Filaggrin is an important molecule that connects keratin fibers in the stratum corneum of human skin. With the help of FLG monomers, keratin fibers are regularly aggregated to form a solid physical barrier in the outermost layer of the epidermis, which can prevent the loss of epidermal moisture and the invasion of external allergic substances. Filaggrin is essential for regulating epidermal homeostasis. In the stratum corneum, filaggrin monomers can be bound to the lipid envelope responsible for the skin barrier function; or, they can interact with keratin intermediate filaments. That is, filaggrin is further processed in the upper stratum corneum and can release free amino acids that help retain water.

[0266] The expression and processing of caspase 14 may be involved in keratinocyte terminal differentiation, which is important for the formation of the skin barrier.

[0267] It can be seen that the snow chrysanthemum extract (experimental groups 1-5) provided in the examples of the present application can significantly increase the transcription levels of filaggrin and caspase 14 in each group of hacat cells within a concentration range of 0.05% to 0.15%. When experimental group 1 was treated at a working solution concentration of 0.15% for 24 hours, compared with the mean value of the blank control group, filaggrin was increased by 6 times and caspase 14 was increased by 25.9 times.

[0268] In summary, the snow chrysanthemum extract prepared by the present application can enhance the moisturizing effect of liquid external skin preparations on the skin.

[0269] <Experiment 4: Experiment on the effect of snow chrysanthemum extract on the inhibitory activity of tyrosinase>

[0270] Experiment 4 includes the following steps B1-B2:

[0271] Step B1: Prepare PBS buffer solution, L-dopa solution and tyrosinase test solution

[0272] PBS buffer solution: Accurately weigh 2.3720 g of disodium hydrogen phosphate and 2.0090 g of sodium dihydrogen phosphate, dissolve them in appropriate amount of ultrapure water, transfer to a 1000 mL volumetric flask, make up to volume, shake well, and obtain a PBS buffer solution with a concentration of 0.067 mol / L and pH = 6.8.

[0273] L-DOPA solution: Accurately weigh 0.03947 g of L-DOPA, dissolve it in the prepared PBS buffer, transfer it to a 100 mL volumetric flask, make up to volume, and shake well to obtain an L-DOPA solution with a concentration of 2 mmol / L.

[0274] Tyrosinase test solution: Take a stock solution containing 25 kU of tyrosinase (may be mushroom tyrosinase), dilute the tyrosinase stock solution to 125 U / mL with PBS buffer, and obtain a 125 U / mL tyrosinase test solution.

[0275] Step B2, determining the anti-tyrosinase diphenolase activity of the snow chrysanthemum extract.

[0276] Step B2 further includes the following steps B21-B22.

[0277] Step B21, weigh the snow chrysanthemum extract prepared in Example 1 of the present application as a sample, first dissolve it with purified water into a preparatory solution with a concentration of 800 μg / mL, and then dilute the preparatory solution with PBS buffer solution in sequence into sample solutions with concentrations of 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL, and 800 μg / mL.

[0278] Step B22, measuring the absorbance values ​​corresponding to sample solutions of different concentrations, and calculating the tyrosinase inhibition rate corresponding to the absorbance values. The tyrosinase inhibition rate can characterize the anti-tyrosinase activity of the snow chrysanthemum extract.

[0279] Step B22 can be specifically implemented as follows:

[0280] Prepare a corresponding 96-well plate for each concentration of sample solution in step B21.

[0281] On the 96-well plate corresponding to each concentration of sample solution, four groups S1, S2, S3 and S4 are set, and three duplicate wells are set in each group. In the S1 group of each 96-well plate, 80 μL of PBS buffer solution, 80 μL of tyrosinase test solution, and 80 μL of L-DOPA solution are added to each well. In the S2 group of each 96-well plate, 160 μL of PBS buffer solution and 80 μL of L-DOPA solution are added to each well. In the S3 group of each 96-well plate, 80 μL of tyrosinase test solution, 80 μL of sample solution, and 80 μL of L-DOPA solution are added to each well; it should be noted that the S3 group of the well plate corresponding to each concentration of sample solution is added with the sample solution of the corresponding concentration, for example, the S3 group of the well plate corresponding to the sample solution of 50 μg / mL concentration is added with the sample solution of 50 μg / mL concentration. In the S4 group of each 96-well plate, 80 μL of PBS buffer solution, 80 μL of sample solution, and 80 μL of L-DOPA solution were added to each well; it should be noted that the sample solution of each concentration was added to the S4 group of the well plate corresponding to the well plate, for example, the sample solution of 50 μg / mL concentration was added to the S3 group of the well plate corresponding to the sample solution of 50 μg / mL concentration.

[0282] In each well of each group of the above 96-well plates, first add other solutions except tyrosinase test solution, shake the 96-well plate at 37°C for 10 minutes, then add 125U / mL tyrosinase test solution, react for 20 minutes, and use a microplate reader to detect the absorbance value of each group at 475nm. Calculate the tyrosinase inhibition rate corresponding to each sample solution based on the absorbance value. The tyrosinase inhibition rate calculation formula is as follows:

[0283] Tyrosinase inhibition rate (%) = [((S1 inhalation - S2 inhalation) - (S3 inhalation - S4 inhalation)) / (S1 inhalation - S2 inhalation)] × 100%;

[0284] Among them, S1 absorbance refers to the absorbance value of S1 group, S2 absorbance refers to the absorbance value of S2 group, S3 absorbance refers to the absorbance value of S3 group, and S4 absorbance refers to the absorbance value of S4 group.

[0285] The tyrosinase inhibition rate of the sample solution at each concentration was calculated according to the above formula, and the calculation results are shown in Table 8.

[0286] Table 8 Tyrosinase inhibition rate of different concentrations of snow chrysanthemum extract aqueous solution

[0287] Serial number Sample solution concentration (μg / mL) Tyrosinase inhibition rate (%) 1 50 22.69 2 100 40.9 3 200 51.73 4 400 65.27 5 800 80.78

[0288] After obtaining the tyrosinase inhibition rates of the sample solutions at five concentrations of 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL, and 800 μg / mL, the IC of the sample (i.e., the snow chrysanthemum extract prepared in Example 1 of the present application) was calculated based on the five tyrosinase inhibition rates. 50 (half inhibition rate, also known as half inhibition concentration) value. Specifically, Graphpad Prism 8.0 software can be used to draw a graph to obtain Fig.10 The tyrosinase inhibition rate line graph shown in FIG. 1 is used to calculate the IC value of the tyrosinase inhibition rate of the snow chrysanthemum extract provided in the embodiment of the present application. 50 0.1887 mg·mL -1 .

[0289] Analysis of the results of Experiment 4

[0290] The melanin content and distribution of melanin particles in the skin play a key role in skin color. The synthesis and transport of melanin are mainly completed by melanocytes and keratinocytes, among which tyrosinase is the key enzyme in melanin synthesis.

[0291] According to the results of the above experiment 4, the aqueous solution of the snow chrysanthemum extract provided in the present embodiment has a very good inhibitory effect on the activity of tyrosinase at the in vitro enzyme level at different concentrations. And as the concentration increases, the inhibitory effect increases (see Fig.10 ). Therefore, the snow chrysanthemum extract provided in the embodiment of the present application can effectively inhibit the synthesis of melanin and enhance the whitening effect on human skin.

[0292] <Experiment 5: Experiment on the scavenging ability of snow chrysanthemum extract on ABTS free radicals>

[0293] ABTS (2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate in English and 2,2-azobis-(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt in Chinese) free radical is an activating factor that can induce melanin production. The snow chrysanthemum extract of the present embodiment can effectively remove this activating factor, which is verified by Experiment 5 below.

[0294] Experiment 5 includes the following steps C1-C3:

[0295] Step C1, preparing ABTS free radical test solution.

[0296] A volume of 5 mL, a molar mass of 7 mM ABTS deionized water solution and a mass of 3.31142 mg (molar mass of 2.45 mM) K 2 S 2 O 8 (potassium persulfate) and react at room temperature in the dark for 12 to 16 hours, overnight to obtain ABTS free radical stock solution. The concentration of 2,2-azino-bis(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt in ABTS deionized water solution is 19.2 mg / 5 mL.

[0297] Water (H 2 O) Dilute the ABTS free radical stock solution to an absorbance value (OD value) of 0.7±0.02 at 734 nm to obtain the ABTS free radical test solution.

[0298] Step C2: prepare sample solution.

[0299] The snow chrysanthemum extract prepared in Example 1 of the present application was weighed, dissolved in purified water, and then prepared into 6 sample solutions of different concentrations, namely, 0.8004 mg·mL-1, 0.2668 mg·mL-1, 0.08893 mg·mL-1, 0.02964 mg·mL-1, 0.009881 mg·mL-1, and 0.003294 mg·mL-1.

[0300] Step C3, prepare PBS buffer solution.

[0301] PBS buffer solution: Accurately weigh 2.3720 g of disodium hydrogen phosphate and 2.0090 g of sodium dihydrogen phosphate, then dissolve them in an appropriate amount of ultrapure water, transfer to a 1000 mL volumetric flask, make up to volume, and shake well to obtain a PBS buffer solution with a concentration of 0.067 mol / L and pH = 6.8.

[0302] Step C4, measuring the light absorption values ​​corresponding to each group of sample solutions with different concentrations, and calculating the ABTS free radical scavenging rate corresponding to the light absorption value.

[0303] Step C4 can be specifically implemented as follows:

[0304] Prepare a corresponding 96-well plate for each concentration of sample solution in step C21.

[0305] On the 96-well plate corresponding to each concentration of sample solution, three groups of P1, P2 and P3 were set up, and three duplicate wells were set up in each group. In the P1 group of each 96-well plate, 16 μL of sample solution and 184 μL of ABTS free radical test solution were added to each well. In the P2 group of each 96-well plate, 16 μL of PBS buffer solution and 184 μL of purified water were added to each well. In the P3 group of each 96-well plate, 16 μL of ABTS free radical test solution and 184 μL of purified water were added to each well.

[0306] The total volume of the reaction system of each group in the above 96-well plate is 200 μL. After each group of each 96-well plate reacts in the dark for 5 minutes, the light absorption value of each group at 734 nm is measured by an ELISA reader at a temperature of 20°C. The ABTS free radical scavenging rate of sample solutions of different concentrations is calculated based on the light absorption value of each group. The calculation formula of the ABTS free radical scavenging rate is as follows:

[0307] ABTS free radical scavenging rate (%) = [1-(P1 absorption-P2 absorption) / (P3 absorption)] × 100%);

[0308] Among them, P1 absorption refers to the light absorption value of the P1 group, P2 absorption refers to the light absorption value of the P1 group, and P1 absorption refers to the light absorption value of the P3 group.

[0309] The ABTS free radical scavenging rate of sample solutions at various concentrations was calculated according to the above formula. The calculation results are shown in Table 9.

[0310] Table 9 ABTS free radical scavenging rate of different concentrations of snow chrysanthemum extract sample solutions

[0311] Serial number <![CDATA[Sample solution concentration (mg〃mL -1 )]]> ABTS free radical scavenging rate (%) 1 0.8004 88.27 2 0.2668 63.85 3 0.08893 45.90 4 0.02964 25.50 5 0.009881 16.47 6 0.003294 13.03

[0312] After obtaining the ABTS free radical scavenging rates of the sample solutions at six concentrations of 0.8004 mg·mL-1, 0.2668 mg·mL-1, 0.08893 mg·mL-1, 0.02964 mg·mL-1, 0.009881 mg·mL-1, and 0.003294 mg·mL-1, the IC of the sample (i.e., the snow chrysanthemum extract prepared in Example 1 of the present application) was calculated based on the six ABTS free radical scavenging rates. 50 (half inhibition rate, also known as half inhibition concentration) value. Specifically, Graphpad Prism 8.0 software can be used to draw a graph to obtain Fig.11The ABTS free radical scavenging rate line graph is shown, and the IC value of the ABTS free radical scavenging rate of the snow chrysanthemum extract provided in the embodiment of the present application is calculated based on it. 50 0.1032 mg·mL -1 .

[0313] Analysis of the results of Experiment 5

[0314] According to the results of the above experiment 5, the aqueous solution of the snow chrysanthemum extract provided in the embodiment of the present application has a very good scavenging effect on ABTS free radicals at different concentrations. And as the concentration increases, the scavenging effect increases (see Fig.11 ). Therefore, the snow chrysanthemum extract provided in the embodiment of the present application has a whitening active ingredient, which can effectively inhibit the synthesis of melanin and enhance the whitening effect on human skin.

[0315] <Experiment 6: Experiment on the scavenging ability of snow chrysanthemum extract on DPPH free radicals>

[0316] DPPH (Chinese name is 1,1-diphenyl-2-trinitrophenylhydrazine, English name is 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) free radical is an activating factor that can induce melanin production. The snow chrysanthemum extract of the embodiment of the present application can effectively remove this activating factor, which is verified by the following experiment six.

[0317] Experiment 6 includes the following steps D1-D3:

[0318] Step D1, prepare DPPH free radical test solution. Prepare a 10 mL DPPH solution (mother solution) with a molar mass of 2 mM with anhydrous ethanol, dilute the above DPPH mother solution until the solution has an absorbance of OD at 515 nm. 515nm =0.7, and DPPH test solution is obtained.

[0319] Step D2, preparing sample solution:

[0320] The snow chrysanthemum extract prepared in Example 1 of the present application was weighed as a sample, and sample solutions of different concentrations were prepared with purified water to obtain concentrations of 0.8004 mg·mL -1 , 0.2668mg·mL -1 , 0.08893mg·mL -1 , 0.02964mg·mL -1 , 0.009881mg·mL -1 , 0.003294mg·mL -1There are 6 sample solutions with different concentrations.

[0321] Step D3, measuring the absorbance values ​​corresponding to each group of sample solutions of different concentrations, and calculating the DPPH free radical scavenging rate corresponding to the light absorption value.

[0322] Step D3 can be specifically implemented as follows:

[0323] Prepare a corresponding 96-well plate for each concentration of sample solution in step D2.

[0324] On the 96-well plate corresponding to each concentration of sample solution, three groups, Q1, Q2 and Q3, are set up, and three duplicate wells are set up in each group. In the Q1 group of each 96-well plate, 100 μL of sample solution and 100 μL of DPPH test solution are added to each well. In the Q2 group of each 96-well plate, 100 μL of sample solution and 100 μL of anhydrous ethanol solution are added to each well. In the Q3 group of each 96-well plate, 100 μL of DPPH test solution and 100 μL of anhydrous ethanol solution are added to each well.

[0325] After each group of the above 96-well plates reacted at room temperature in the dark for 30 minutes, the light absorption value of each group was measured at 515 nm using an ELISA reader. The free radical scavenging rate of the sample solution of different concentrations was calculated based on the light absorption value of each group. The calculation formula is as follows:

[0326] DPPH free radical scavenging rate (%) = [1-(Q1 absorption-Q2 absorption) / Q3 absorption] × 100%;

[0327] Among them, Q1 absorption refers to the light absorption value of the Q1 group, Q2 absorption refers to the light absorption value of the Q2 group, and Q3 absorption refers to the light absorption value of the Q3 group.

[0328] The DPPH free radical scavenging rate of sample solutions at various concentrations was calculated according to the above formula. The calculation results are shown in Table 10.

[0329] Table 10 DPPH free radical scavenging rate of different concentrations of snow chrysanthemum extract aqueous solution

[0330] Serial number <![CDATA[Sample solution concentration / mg〃mL -1 > DPPH free radical scavenging rate / % 1 0.8004 85.83 2 0.2668 72.52 3 0.08893 55.68 4 0.02964 44.04 5 0.009881 37.88 6 0.003294 36.80

[0331] After obtaining 0.8004 mg·mL -1 , 0.2668mg·mL -1 , 0.08893mg·mL -1 , 0.02964mg·mL -1 , 0.009881mg·mL -1 , 0.003294mg·mL -1After calculating the ABTS free radical scavenging rates of the sample solutions of the six concentrations, the IC of the sample (i.e., the snow chrysanthemum extract prepared in Example 1 of the present application) was calculated based on the six DPPH free radical scavenging rates. 50 (Half inhibition rate, also known as half inhibition concentration) value.

[0332] Specifically, Graphpad Prism 8.0 software can be used to draw a graph to obtain Fig.12 The DPPH free radical scavenging rate line graph shown in FIG. 1 is used to calculate the IC value of the DPPH free radical scavenging rate of the snow chrysanthemum extract provided in the embodiment of the present application. 50 0.02957 mg·mL -1 .

[0333] Analysis of the results of Experiment 6

[0334] According to the results of Experiment 6 above, the aqueous solution of the snow chrysanthemum extract provided in the present embodiment has a very good scavenging effect on DPPH free radicals at different concentrations. And as the concentration increases, the scavenging effect increases (see Fig.12 ). Therefore, the snow chrysanthemum extract provided in the embodiment of the present application has a whitening active ingredient, which can effectively inhibit the synthesis of melanin and enhance the whitening effect on human skin.

[0335] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for preparing a snow chrysanthemum extract, characterized in that: include: Get a water extract of snow indigo powder. Select at least one of microfiltration, ultrafiltration and nanofiltration to filter the water extract; The filtered water extract is concentrated and dried to obtain a snow chrysanthemum extract.

2. A method for preparing a snow chrysanthemum extract, characterized in that: include: Obtain a water extract of snow chrysanthemum powder; Performing microfiltration treatment on the water extract using a microfiltration membrane to obtain a permeate; Using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate; Performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate; The nanofiltrate is concentrated and dried to obtain the snow chrysanthemum extract.

3. A method for preparing a snow chrysanthemum extract, characterized in that: include: Obtain a water extract of snow chrysanthemum powder; filtering the water extract to obtain a filtrate; Centrifuging the filtrate to obtain a supernatant; Performing microfiltration treatment on the supernatant using a microfiltration membrane to obtain a permeate; Using an ultrafiltration membrane to ultrafilter the permeate to obtain an ultrafiltrate; Performing nanofiltration treatment on the ultrafiltrate using a nanofiltration membrane to obtain a nanofiltrate; The nanofiltrate is concentrated and dried to obtain the snow chrysanthemum extract.

4. The method for preparing the snow chrysanthemum extract according to claim 3, characterized in that: The method of obtaining the water extract of snow chrysanthemum powder comprises: Obtaining the snow chrysanthemum powder; The snow indigo powder and purified water are mixed, and the mixed solution is subjected to at least one heating reflux extraction treatment, and the extracts obtained from each heating reflux extraction are collected and combined to obtain the water extract.

5. The method for preparing the snow chrysanthemum extract according to claim 4, characterized in that: The temperature of the heating reflux extraction is 60-100°C; The time of each heating reflux extraction is 0.5 hour to 4 hours.

6. The method for preparing the snow chrysanthemum extract according to claim 3, characterized in that: The pore size or molecular weight cut-off of the microfiltration membrane is 0.45 μm to 0.005 μm; The transmembrane pressure of the microfiltration treatment is 0.01-0.3Mpa; The temperature of the microfiltration liquid is 10°C to 50°C; The temperature of the ultrafiltration liquid is 10°C to 50°C; The pore size or molecular weight cut-off of the ultrafiltration membrane is between 10KD and 50KD; The transmembrane pressure of the ultrafiltration treatment is 0.01-0.7 MPa; The pore size or molecular weight cut-off of the nanofiltration membrane is between 100D and 300D; The transmembrane pressure of the nanofiltration treatment is 0.3 to 1.5 MPa; The feed liquid temperature of the nanofiltration treatment is 10°C to 50°C.

7. The method for preparing the snow chrysanthemum extract according to claim 3, characterized in that: The concentration and drying temperature is 40 to 80°C; The vacuum degree of the concentration and drying is 0.02-0.08Mpa; The concentration and drying are concentration under reduced pressure.

8. Snow chrysanthemum extract, characterized in that Obtained according to the preparation method according to any one of claims 1 to 7.

9. A skin preparation for external use, characterized in that The invention comprises the snow chrysanthemum extract according to claim 8.

10. A liquid skin care product, characterized in that: Include: Solvents; and The snow chrysanthemum extract according to claim 8; Wherein, the concentration of the snow chrysanthemum extract in the liquid skin care product is 0.05% to 0.15%.

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