A Chrysanthemum Extract and Its Application in Cosmetics

Abstract

This invention discloses a *Chrysanthemum indicum* extract and its application in cosmetics, belonging to the field of cosmetic technology. The extract is a *Chrysanthemum indicum* polysaccharide that has undergone acetylation-fucosylation dual modification, prepared through water extraction and alcohol precipitation, enzymatic acetylation, and carbodiimide-mediated grafting of fucose. This targeted modified extract is then compounded with fructooligosaccharides, β-glucan, dipotassium glycyrrhizate derivatives, and asiaticoside to prepare a chitosan-algin bilayer structure for layered release microcapsule gel. The extract of this invention can target and regulate the skin's microecology, and the composition possesses anti-inflammatory, soothing, barrier-repairing, and slow-release effects, is gentle and non-irritating, and suitable for sensitive skin care. This invention solves the problems of weak targeting, single efficacy, and poor stability in traditional prebiotic cosmetics, with controllable process and promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of cosmetic raw materials and preparation technology, specifically to a Shennong chrysanthemum extract and its application in cosmetics. Background Technology

[0002] The core problem of acne-prone skin stems from a vicious cycle of imbalanced skin microecology and damaged skin barrier. Excessive proliferation of harmful bacteria triggers recurring inflammation, while a weakened barrier exacerbates sensitivity and redness. Conventional skincare products struggle to simultaneously address inflammation and acne while providing gentle repair. Existing acne treatments often contain prohibited ingredients such as antibiotics and hormones, which, while providing short-term relief, can easily lead to bacterial imbalances and drug resistance. Natural plant extracts, due to their limited targeting and singular efficacy, fail to achieve precise regulation. Shennong chrysanthemum, a characteristic medicinal plant of Shennongjia, possesses extracts with excellent anti-inflammatory and soothing activities, making it a valuable resource for cosmeceutical development. However, traditional extraction methods utilize only the essential oil from the flowers, resulting in significant waste of stem and leaf resources. Furthermore, unmodified polysaccharides have poor targeting and low skin absorption efficiency, failing to fully leverage their microecological regulatory effects. Therefore, developing a highly effective and gentle cosmetic ingredient based on the entire Shennong chrysanthemum plant, precisely modified, and capable of synergistically regulating the skin microecology has become a key need for solving the challenges of acne-prone skin care. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a Shennong chrysanthemum extract and its application in cosmetics. After dual modification, the extract exhibits significantly enhanced targeting, effectively regulating the skin's microecology and repairing the barrier of sensitive skin, thus meeting the application needs of people with acne-prone skin for safe and effective skincare products.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing Shennong Xiangju extract includes the following steps: S1. Grind the whole plant of Shennong Xiangju to 20-40 mesh, add deionized water at a material-to-liquid ratio of 1:15-1:25 (g / mL), and reflux extract at 80-90℃ for 2-3 hours. After filtering the extract, concentrate it to 1 / 3-1 / 2 of the original volume, add 3-5 times the volume of 70-80% ethanol, let it stand at 4℃ for 12-18 hours, and collect the precipitate by centrifugation. After deproteinizing the precipitate by Sevag method and decolorizing it with 3-5% H2O2 solution, freeze-dry it to obtain Shennong Xiangju polysaccharide with a purity ≥85%. S2. Take Shennong Xiangju polysaccharide, add deionized water to prepare a polysaccharide solution with a mass concentration of 5-10 mg / mL, add acetyltransferase at 0.5-1.2% of the polysaccharide mass, adjust the pH of the system to 4.5-5.5, react at 40-45℃ for 2-3 hours, boil for 10-15 minutes to inactivate the enzyme after the reaction, centrifuge to collect the supernatant, dialyze with a dialysis bag with a molecular weight cutoff of 8000-10000 Da for 24-36 hours, and freeze dry to obtain acetylated modified polysaccharide; S3. Take the acetylated polysaccharide and prepare a solution with a mass concentration of 8-12 mg / mL by adding phosphate buffer at pH 6.0-7.0. Add EDC·HCl and NHS sequentially at a molar ratio of 1:1-1:1.2 and activate at room temperature for 30-60 min. Then add fucose at a molar ratio of 1:3-1:5 to acetylated polysaccharide and react at 35-40℃ in the dark for 1.5-2 h. Dialyze the reaction solution with a dialysis bag with a molecular weight cutoff of 8000-10000 Da for 24-36 h and freeze-dry to obtain the targeted modified Shennong Xiangju extract.

[0005] Optionally, in step S1, the centrifugation speed is 6000-8000 rpm and the centrifugation time is 10-15 min.

[0006] Optionally, in step S3, the concentration of the phosphate buffer solution is 0.05-0.1 mol / L.

[0007] Optionally, the prepared targeted modified Shennong Xiangju extract is a fucoidylated-acetylated dual-modified polysaccharide, whose surface has both hydrophilic acetyl groups and skin-targeting fucoidan groups.

[0008] Optionally, the cosmetic composition of Shennong Xiangju extract is prepared from the following raw materials in parts by weight: 2-4 parts of targeted modified Shennong Xiangju extract, 1-3 parts of fructooligosaccharide, 0.5-1.5 parts of β-glucan, 0.6-1.0 parts of dipotassium glycyrrhizate derivative, and 0.3-0.7 parts of asiaticoside.

[0009] Optionally, the fructooligosaccharides and β-glucan are exogenous prebiotics, and the dipotassium glycyrrhizate derivative and asiaticoside are anti-inflammatory components.

[0010] Optionally, the cosmetic composition is a layered release microcapsule gel, wherein the microcapsules have a chitosan-alginic acid bilayer structure with a particle size of 150-200 nm, the outer layer encapsulates anti-inflammatory ingredients, and the inner layer encapsulates modified extracts and exogenous prebiotics.

[0011] The beneficial effects of this invention are as follows: The targeted modified Shennong Xiangju extract prepared by this invention has a beneficial bacteria proliferation rate of 500%-650%, which can precisely regulate the microecology of acne-prone skin; after double modification, the targeting and skin absorption efficiency are significantly improved, and it works synergistically with exogenous prebiotics and anti-inflammatory components to achieve gentle anti-inflammatory acne treatment and barrier repair, effectively relieving sensitivity and redness. The extract is derived from the whole Shennong Xiangju plant, with high resource utilization and no harmful additives, and excellent safety; the corresponding microcapsule gel composition can precisely and sustainably release the active ingredients, enhancing the duration of efficacy, forming a synergistic advantage in gentleness, effectiveness and safety, meeting the core needs of acne-prone skin care. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Example 1: An extract of Shennong Xiangju (a type of chrysanthemum) from Example 1 includes the following steps: S1. Grind the whole plant of Shennong Xiangju into 20-40 mesh, pass it through a 40 mesh sieve, add 2000 mL of deionized water at a material-to-liquid ratio of 1:20 (g / mL), reflux at 85℃ for 2.5 h, and filter to obtain the extract; S2. Place the extract in a rotary evaporator and concentrate it to 1 / 3 of the original volume at 60℃ and -0.08MPa. After cooling to room temperature, slowly add 3 times the volume of 75% ethanol solution while stirring at 300rpm. Let it stand in a refrigerator at 4℃ for 16h. S3. Place the settled mixture in a high-speed centrifuge, centrifuge at 7000 rpm for 12 min to collect the precipitate, reconstitute with 500 mL of deionized water, and deproteinize 3 times according to the Sevag method (chloroform: n-butanol = 4:1, v / v). Then add 4% H2O2 solution to decolorize in the dark for 2 h, and dialyze with an 8000 Da dialysis bag for 24 h (changing the water every 6 h). S4. Place the dialyzed solution in a freeze dryer and freeze dry at -50℃ and 0.01MPa for 24h to obtain Shennong Xiangju polysaccharide powder with a purity of 88.6%. S5. Weigh 10g of Shennong Xiangju polysaccharide, add deionized water to prepare a polysaccharide solution of 8mg / mL, add 0.08g of acetyltransferase (enzyme activity ≥1000U / g) at 0.8% of the polysaccharide mass, adjust the pH to 5.0 with 0.1mol / L HCl, react in a constant temperature water bath at 42℃ and 150rpm for 2.5h with shaking, boil for 12min to inactivate the enzyme, centrifuge at 8000rpm for 10min to collect the supernatant, dialyze with an 8000Da dialysis bag for 30h and freeze dry to obtain acetylated modified polysaccharide; S6. Weigh 5g of acetylated polysaccharide, add 0.08mol / L phosphate buffer (pH 6.5) to prepare a 10mg / mL solution, add 0.3g EDC·HCl and 0.18g NHS, activate at room temperature by magnetic stirring at 200rpm for 45min, add 2.3g fucose (purity ≥98%) at a fucose to acetylated polysaccharide molar ratio of 1:4 (calculated by moles based on the molecular weight of the polysaccharide repeating unit), and react at 38℃ in the dark for 1.8h. S7. The reaction solution was dialyzed with a 10000Da dialysis bag for 30 hours (the water was changed every 8 hours), and then freeze-dried to obtain the targeted modified Shennong Xiangju extract powder.

[0014] The preparation method of the cosmetic composition (microcapsule gel) of Shennong Xiangju extract is as follows: S1. Weigh out the following ingredients by weight: 3 parts of targeted modified Shennong Xiangju extract, 2 parts of fructooligosaccharide, 1 part of β-glucan, 0.8 parts of dipotassium glycyrrhizate derivative, 0.5 parts of asiaticoside, 92.7 parts of deionized water, 5 parts of caprylic / capric triglyceride, 3 parts of polydimethylsiloxane, and 0.2 parts of ethylparaben. S2. Aqueous phase preparation: Add deionized water to a beaker, heat to 70°C, add fructooligosaccharides and β-glucan, and stir at 300 rpm for 30 min until completely dissolved; Oil phase preparation: In another beaker, add caprylic / capric triglyceride and polydimethylsiloxane, heat and stir at 75°C until mixed and dissolved, and keep warm for later use; Slowly add the oil phase to the aqueous phase, emulsify by high-speed stirring at 800 rpm for 15 min, and cool to 45°C to obtain the basic emulsion; S3. Add targeted modified Shennong Xiangju extract powder to the base emulsion, stir and disperse evenly at 200 rpm, then add 2% chitosan solution at 5% (v / v) of the base emulsion volume, adjust the pH of the system to 5.5 with 0.1 mol / L citric acid solution, and continue stirring for 30 min to form the core (encapsulating the extract and prebiotics); then add 1.5% sodium alginate solution at 3% (v / v) of the base emulsion volume at a rate of 1 mL / min, and continue stirring for 60 min after the addition is complete to form a chitosan-alginic acid bilayer microcapsule wall; then add dipotassium glycyrrhizate derivative and asiaticoside, and stir for 30 min to load them onto the outer layer of the microcapsules; S4. Cool the system to room temperature, add ethylparaben and stir for 10 min. Homogenize twice at 20 MPa pressure to obtain a layered release microcapsule gel composition with a particle size of 150-200 nm, an outer layer encapsulating anti-inflammatory components, and an inner layer encapsulating extracts and prebiotics.

[0015] Example 2: The preparation method of the Shennong Xiangju extract in Example 2 is the same as that in Example 1, except that the material-liquid ratio is modified to 1:15 (g / mL). The preparation method of the cosmetic composition (microcapsule gel) of Shennong Xiangju extract is the same as that in Example 1.

[0016] Example 3: The preparation method of the Shennong Xiangju extract in Example 3 is the same as that in Example 1, except that the material-liquid ratio is modified to 1:25 (g / mL). The preparation method of the cosmetic composition (microcapsule gel) of Shennong Xiangju extract is the same as that in Example 1.

[0017] Comparative Example 1: The preparation method of the Shennong Xiangju extract in Comparative Example 1 is the same as that in Example 1, except that the fucoidylation step in S6 is removed. The preparation method of the cosmetic composition (microcapsule gel) of Shennong Xiangju extract is the same as that in Example 1.

[0018] Comparative Example 2: The preparation method of the Shennong Xiangju extract in Comparative Example 2 is the same as that in Example 1, except that the acetylation step in S5 is removed. The preparation method of the cosmetic composition (microcapsule gel) of Shennong Xiangju extract is the same as that in Example 1.

[0019] Comparative Example 3: The preparation method of the Shennong Xiangju extract in Comparative Example 3 is the same as that in Example 1; The preparation method of the cosmetic composition of Shennong Xiangju extract (without microcapsule structure) is the same as that in Example 1, except that step S3 is modified as follows: add targeted modified Shennong Xiangju extract powder, dipotassium glycyrrhizate derivative and asiaticoside to the base emulsion and stir to disperse evenly; do not add chitosan solution, do not add sodium alginate solution, and do not perform any microcapsule encapsulation operation.

[0020] Performance testing 1. Polysaccharide purity determination The purity of the polysaccharide samples obtained from the examples and comparative examples was determined using the phenol-sulfuric acid method. 20.0 mg of polysaccharide sample was accurately weighed and diluted to 100 mL with deionized water to prepare the test solution. 1.0 mL of the test solution was placed in a stoppered test tube, and 1.0 mL of 5% phenol solution was added. 5.0 mL of concentrated sulfuric acid was quickly added dropwise and the mixture was shaken to mix. After standing at room temperature for 20 min, the mixture was heated in a boiling water bath for 15 min. After cooling to room temperature, the absorbance was measured at 490 nm using a UV-Vis spectrophotometer. A standard curve was plotted using glucose as a standard, and the polysaccharide content in the sample was calculated based on the standard curve, which is the polysaccharide purity.

[0021] Table 1. Data on the determination of polysaccharide purity in different samples

[0022] The purity of Shennong Xiangju polysaccharide in each embodiment and comparative example of the present invention was determined by the phenol-sulfuric acid method to be above 86%, with the highest purity of polysaccharide in Example 3 reaching 90.1%, indicating that the extraction and purification process of the present invention can obtain high-purity Shennong Xiangju polysaccharide. The purity of polysaccharide in each comparative example was similar to that in the examples, indicating that the single modification process and the microencapsulation-free formulation had no significant impact on the purity of the polysaccharide itself, providing a stable material basis for the subsequent efficacy.

[0023] 2. Particle size and potential determination Take 0.1 g of each of the microcapsule gel compositions of Examples 1-3 and Comparative Examples 1-3, add 10 mL of deionized water, and prepare a uniform dispersion by magnetic stirring at 200 rpm for 10 min at 25 °C. Filter the mixture through a 0.45 μm filter membrane to remove impurities. Use a nanoparticle size analyzer, set the test temperature to 25 °C and the scattering angle to 90 °C, to determine the particle size (Z-average particle size) and particle size distribution (PDI) of the samples. Each sample was tested in parallel three times and the average value was taken. At the same time, under the same temperature conditions, the Zeta potential was directly measured with the dispersion. Each sample was tested in parallel five times and the average value was taken. Record the average particle size, PDI value and Zeta potential data of each group of samples.

[0024] Table 2. Data on particle size and potential of different samples

[0025] The microcapsule gels prepared in Examples 1-3 of this invention have an average particle size distribution in the range of 172-186 nm, a PDI of less than 0.2, good dispersion uniformity, and an absolute value of Zeta potential higher than 27 mV, indicating excellent system stability. Comparative Examples 1-2 have slightly larger particle sizes, higher PDI, and lower absolute values ​​of potential, indicating that single chemical modification will affect the regularity of the microcapsule structure. Comparative Example 3 has no microcapsule structure, no obvious particle size characteristics, and poor potential stability, further proving that the synergy between dual modification and microcapsule structure is beneficial to improving the dispersibility and stability of the system.

[0026] 3. In vitro anti-inflammatory activity test An inflammation model was established using LPS-induced RAW264.7 macrophages. Logarithmically growing RAW264.7 cells were seeded at 5 × 10⁴ cells / well in 96-well plates and cultured at 37°C in a 5% CO₂ incubator for 24 h. The old culture medium was discarded, and culture medium containing samples from Examples 1-3 and Comparative Examples 1-3 (final sample concentration 100 μg / mL) was added. The medium without the samples served as a blank control, and the medium with only LPS served as the model control. After incubation for 2 h, LPS (final concentration 1 μg / mL) was added, and the cells were cultured for another 24 h. The NO content in the cell supernatant was detected using the Griess reagent method, and the secretion of TNF-α and IL-6 was detected using enzyme-linked immunosorbent assay (ELISA). The NO inhibition rate and the relative expression levels of TNF-α and IL-6 were calculated for each group. Six parallel wells were set up for each group, and the experiment was repeated three times, with the average value taken.

[0027] Table 3. In vitro anti-inflammatory activity test data of different samples

[0028] Compared with the model control group, Examples 1-3 of this invention significantly inhibited the production of NO by LPS-induced inflammatory cells, and significantly downregulated the relative expression levels of inflammatory factors such as TNF-α and IL-6, demonstrating excellent in vitro anti-inflammatory activity. Comparative Examples 1-2 showed significantly weaker anti-inflammatory effects than the Examples, indicating that single modification such as acetylation or fucoidylation cannot fully enhance the anti-inflammatory efficacy of Shennong Xiangju polysaccharide. Although Comparative Example 3 had a certain anti-inflammatory effect, the effect was slightly lower than that of the Examples, reflecting the enhancement effect of the microencapsulated sustained-release system on anti-inflammatory efficacy.

[0029] 4. Skin barrier repair ability test A 3D skin barrier damage model was constructed in vitro using sodium dodecyl sulfate (SDS) induction. Samples from each group (Examples 1-3 and Comparative Examples 1-3) were prepared to a final concentration of 50 μg / mL, with PBS buffer (without samples) serving as a blank control. The damaged 3D skin models were randomly divided into three replicates per group, each with its corresponding sample solution added, and incubated at 37°C with 5% CO2 for 48 h. Transdermal water loss (TEWL) measurements were taken before and after incubation using a transdermal water loss (TEWL) analyzer, and the barrier repair rate was calculated (repair rate = (TEWL value of damaged group - TEWL value of sample group) / (TEWL value of damaged group - TEWL value of normal group) × 100%). Simultaneously, the expression levels of barrier-related proteins in the model tissue were measured using a keratin 1 (K1) and filaggrin (FLG) ELISA kit. The experiment was repeated three times, and the average value was used to evaluate the skin barrier repair effect of each group.

[0030] Table 4. Test data on skin barrier repair capacity of different samples

[0031] Examples 1-3 of this invention can significantly reduce the TEWL value of the SDS-damaged skin model, with a barrier repair rate of over 78%. They can also significantly upregulate the relative expression levels of filaggrin (FLG) and keratin (K1), promote the synthesis of skin barrier structural proteins, and demonstrate excellent skin barrier repair function. Comparative Examples 1-2 show significantly lower repair rates and insufficient expression levels of related proteins, indicating that single modification is insufficient to achieve efficient barrier repair. Comparative Example 3 shows a repair effect close to that of the examples but still slightly different, indicating that the microcapsule structure can further enhance the barrier repair effect through stable controlled release.

[0032] 5. Beneficial bacteria proliferation activity test Skin probiotics (Bifidobacterium and Lactobacillus) were selected as test strains. After thawing the frozen strains, they were inoculated into MRS liquid medium and anaerobically cultured at 37°C for 24 h until the logarithmic growth phase. The samples from Examples 1-3 and Comparative Examples 1-3 were prepared into sample solutions (containing prebiotic components) with sterile PBS buffer to a final concentration of 50 μg / mL. MRS medium without samples was used as a blank control, and medium containing only prebiotics (fructooligosaccharides + β-glucan) was used as a positive control. 100 μL of bacterial culture was added to a 96-well plate, and 900 μL of the corresponding sample solution was added to each well. The plates were anaerobically cultured at 37°C for 24 h. The colony forming units (CFU / mL) before and after culture were determined by plate counting (dilution plating). The proliferation rate of beneficial bacteria was calculated (proliferation rate = (sample group CFU / mL - blank control group CFU / mL) / blank control group CFU / mL × 100%). Three parallel wells were set for each group, and the experiment was repeated three times and the average value was taken.

[0033] Table 5. Data on the Proliferation Activity of Beneficial Bacteria in Different Samples

[0034] Examples 1-3 of this invention showed significant proliferative effects on both Bifidobacterium and Lactobacillus, with the total beneficial bacteria proliferation rate being much higher than that of the blank control and the positive control containing only prebiotics. This indicates that the dual-modified polysaccharide product of Shennong Xiangju has a synergistic probiotic effect with fructooligosaccharides and β-glucan. The proliferation effect of comparative examples 1-2 was significantly weaker, revealing that the dual-modification structure plays a key role in enhancing the probiotic activity of polysaccharides. The proliferation rate of comparative example 3 was slightly lower than that of the examples, indicating that the microencapsulation system can protect the prebiotic components and maintain their effect, further optimizing the skin microecological regulation effect.

[0035] 6. In vitro sustained-release performance test In vitro sustained-release tests were conducted using the dialysis bag method. 0.5 g of samples from Examples 1-3 and Comparative Examples 1-3 were placed in dialysis bags with a molecular weight cutoff of 8000-14000 Da, sealed, and then placed in Erlenmeyer flasks containing 50 mL of PBS buffer (pH=7.4, simulating the physiological environment of skin). The Erlenmeyer flasks were placed in a constant-temperature water bath shaker at 37℃ and 100 rpm. At 1 h, 4 h, 8 h, 12 h, and 24 h of shaking incubation, 5 mL of the dialysis fluid was taken out, and 5 mL of fresh PBS buffer was added simultaneously to maintain a constant system volume. The concentration of Shennong Xiangju polysaccharide (the core component of the extract) in the dialysis fluid at each time point was determined by high-performance liquid chromatography (HPLC), and the cumulative release rate was calculated (cumulative release rate = total release at each time point / total content of effective components in the sample × 100%). Three parallel samples were set up for each group, and the experiment was repeated three times, with the average value taken.

[0036] Table 6. In vitro sustained-release performance test data of different samples

[0037] In Examples 1-3 of this invention, the cumulative release rate of Shennong Xiangju polysaccharide was controlled between 65% and 71% within 24 hours, with a flat release curve and obvious slow release characteristics. In Comparative Examples 1-2, the release rate was faster and the final release rate was higher, with a weaker sustained-release effect. In Comparative Example 3, which had no microcapsule structure, it released a large amount of polysaccharide rapidly in a short time, with a cumulative release rate of over 95% in 24 hours, but no obvious sustained-release effect. This demonstrates that dual modification combined with microcapsule encapsulation technology can achieve stable controlled release of active ingredients, prolong the duration of action, and improve bioavailability.

[0038] 7. Skin irritation test The irritancy of samples was assessed using the Heteroalanine Erythrocyte Carbohydrate-Complex (HET-CAM) test. Fertilized chicken embryos incubated for 10-12 days with well-developed allantoic membranes were selected. The blunt end of the eggshell was gently tapped to remove the shell membrane and expose the chorioalanine membrane. 0.3 mL of samples from Examples 1-3 and Comparative Examples 1-3 were evenly added to the surface of the allantoic membrane. Physiological saline was used as a negative control, and 0.1 mol / L NaOH solution as a positive control. After 5 minutes of treatment, the membrane was rinsed clean with physiological saline. The congestion, hemorrhage, and dissolution of the allantoic membrane were observed under a stereomicroscope. The samples were scored according to the HET-CAM irritancy rating scale (0-8 points, where 0 indicates no irritation, 1-4 indicates mild irritation, and 5-8 indicates severe irritation). Three parallel chicken embryos were used in each group, and the experiment was repeated three times. The average score was used to determine the irritancy level of the sample.

[0039] Table 7. Data on skin irritation of different samples

[0040] The HET-CAM chicken embryo chorioallantoic membrane irritation test results showed that the negative control showed no irritation, while the positive control showed severe irritation, indicating that the experimental system was reliable. The average irritation scores of the samples in Examples 1-3 and each comparative example of this invention were all below 0.5 points, indicating that they were non-irritating to the skin and mild and safe. The double modification, microcapsule structure and ordinary gel formulation did not introduce any irritating factors, indicating that the obtained composition has high safety and is suitable for sensitive skin and long-term topical skin use.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing Shennong Xiangju extract, characterized in that, Includes the following steps: S1. Grind the whole plant of Shennong Xiangju to 20-40 mesh, add deionized water at a material-to-liquid ratio of 1:15-1:25 (g / mL), and reflux extract at 80-90℃ for 2-3 hours. After filtering the extract, concentrate it to 1 / 3-1 / 2 of the original volume, add 3-5 times the volume of 70-80% ethanol, let it stand at 4℃ for 12-18 hours, and collect the precipitate by centrifugation. After deproteinizing the precipitate by Sevag method and decolorizing it with 3-5% H2O2 solution, freeze-dry it to obtain Shennong Xiangju polysaccharide with a purity ≥85%. S2. Take Shennong Xiangju polysaccharide, add deionized water to prepare a polysaccharide solution with a mass concentration of 5-10 mg / mL, add acetyltransferase at 0.5-1.2% of the polysaccharide mass, adjust the pH of the system to 4.5-5.5, react at 40-45℃ for 2-3 hours, boil for 10-15 minutes to inactivate the enzyme after the reaction, centrifuge to collect the supernatant, dialyze with a dialysis bag with a molecular weight cutoff of 8000-10000 Da for 24-36 hours, and freeze dry to obtain acetylated modified polysaccharide; S3. Take the acetylated polysaccharide and prepare a solution with a mass concentration of 8-12 mg / mL by adding phosphate buffer at pH 6.0-7.

0. Add EDC·HCl and NHS sequentially at a molar ratio of 1:1-1:1.2 and activate at room temperature for 30-60 min. Then add fucose at a molar ratio of 1:3-1:5 to acetylated polysaccharide and react at 35-40℃ in the dark for 1.5-2 h. Dialyze the reaction solution with a dialysis bag with a molecular weight cutoff of 8000-10000 Da for 24-36 h and freeze-dry to obtain the targeted modified Shennong Xiangju extract.

2. The method for preparing Shennong Xiangju extract according to claim 1, characterized in that, In step S1, the centrifugation speed is 6000-8000 rpm and the centrifugation time is 10-15 min.

3. The method for preparing Shennong Xiangju extract according to claim 1, characterized in that, In step S3, the concentration of the phosphate buffer solution is 0.05-0.1 mol / L.

4. The method for preparing Shennong Xiangju extract according to claim 1, characterized in that, The prepared targeted modified Shennong Xiangju extract is a fucosylated-acetylated dual-modified polysaccharide with both hydrophilic acetyl groups and skin-targeting fucosylated groups on its surface.

5. A cosmetic composition containing Shennong chrysanthemum extract, characterized in that, The cosmetic composition is prepared from the following raw materials in parts by weight: 2-4 parts of targeted modified Shennong Xiangju extract, 1-3 parts of fructooligosaccharide, 0.5-1.5 parts of β-glucan, 0.6-1.0 parts of dipotassium glycyrrhizate derivative, and 0.3-0.7 parts of asiaticoside.

6. The cosmetic composition of Shennong Xiangju extract according to claim 5, characterized in that, The fructooligosaccharides and β-glucan are exogenous prebiotics, and the dipotassium glycyrrhizate derivative and asiaticoside are anti-inflammatory components.

7. The cosmetic composition of Shennong Xiangju extract according to claim 5, characterized in that, The cosmetic composition is a layered release microcapsule gel. The microcapsules have a chitosan-algin bilayer structure with a particle size of 150-200nm. The outer layer encapsulates anti-inflammatory ingredients, and the inner layer encapsulates modified extracts and exogenous prebiotics.

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