Polypeptide compound and use thereof in field of cosmetics

Abstract

The present invention relates to the field of polymer application, in particular to a polypeptide compound and the use thereof in the field of cosmetics. Disclosed in the present invention is a low-molecular-weight polypeptide compound with a structural formula of [γ-glu]n-Aa, wherein n is 1-10, glu is glutamic acid, and Aa is selected from any one of glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, methionine, serine, threonine, cysteine, proline, histidine or arginine. In the structural formula, n is preferably 1-8. The polypeptide derivative has a molecular weight of 250-1500 Da. Tests show that the above-described polypeptide compound has an excellent moisturizing performance and a low molecular weight, which is beneficial for absorption and utilization by the skin, thereby reducing the risk of clogging pores and sweat gland openings.

Description

A polypeptide compound and its application in the field of cosmetics Technical Field

[0001] The present invention relates to the field of polymer applications, and in particular to a polypeptide compound and its application in the field of cosmetics. Background Art

[0002] Polyglutamic acid is a straight-chain linear polymer of homopolyglutamic acid connected by γ-amide bonds. It can be obtained by fermentation with Bacillus subtilis. The large number of peptide bonds on the polyglutamic acid backbone are easily affected by light, heat and hydrolases in the environment, and degrade into non-toxic short peptides or glutamic acid monomers. Therefore, polyglutamic acid can be naturally degraded and is safe and environmentally friendly to use.

[0003] The structural formula of polyglutamic acid currently on the market is: [γ-glu] n , where n>200 and the molecular weight is around 1000000Da; due to its large molecular weight, when it is actually used as a skin care product, when it is applied to cosmetics and stays on the skin surface, especially in a humid environment or when sweating profusely, the polyglutamic acid will absorb moisture and expand, and may clog the skin sweat gland openings and pores, thereby causing local redness, swelling, pustules and other skin discomforts.

[0004] Therefore, polyglutamic acid needs to be properly degraded to prevent the occurrence of the above-mentioned skin discomfort. The existing technology for the degradation of polyglutamic acid is either complicated or the performance of the product obtained by degradation is poor.

[0005] γ-Glutamyl peptides are a class of substances containing γ-glutamyl residues, which are formed by the dehydration condensation of the γ-carboxyl group of γ-glutamic acid and the amino group of amino acids or peptides. They are widely distributed in animals, plants and microorganisms in nature (Yao Yujing, Cui Chun, Huang Junwei. Research progress on the flavor characteristics, identification and preparation methods of γ-glutamyl peptides [J]. Chinese Condiments, 2016, 41(3): 146-152.). The study of γ-glutamyl peptides began in the 1950s. Some scholars isolated and identified a γ-glutamyl peptide (γ-L-glutamyl-S-methyl-L-cysteine) by isolating and identifying bean seed extracts (Thompson J, Morris CJ, Zacharius R. Isolation of (−) S-methyl-L-cysteine ​​from beans (Phaseolus vulgaris) [J]. Nature, 1956, 178(4533): 593-593.). Later, naturally occurring γ-glutamyl peptides were found in legumes, mushrooms, alliums, tea, algae, and fermented condiments such as cheese, fish sauce, and soy sauce. γ-Glutamyl peptides are highly soluble in water and have health benefits such as anti-inflammatory, mood regulation, antioxidant, anti-epileptic, anti-cancer, memory improvement, and lowering blood sugar levels. The most representative of these is glutathione, a powerful antioxidant that protects the skin from oxidative damage and is a raw material for anti-aging skin care products (Puurunen J, Tiira K, Vapalahti K, et al. Fearful dogs have increased plasma glutamine and γ-glutamyl glutamine[J]. Scientific Reports, 2018, 8(1): 1-12.). There are many types of γ-glutamyl peptides, but few have been developed as cosmetic raw materials. This study aims to develop γ-glutamyl peptides into cosmetic raw materials with various functions.

[0006] The moisturizing or barrier repair function of the skin system is mainly affected by the following proteins:

[0007] Aquaporins, also known as water porins, are proteins located on cell membranes that facilitate water transport across them. Without the assistance of aquaporins, water molecules diffuse slowly across the membrane. However, aquaporins allow water molecules to flow rapidly out of or into the cell membrane, helping cells regulate internal osmotic pressure. The integumentary system includes skin, hair, nails, as well as nerves, fat, and certain glands. AQP1, AQP3, AQP7, AQP9, and AQP10 are primarily expressed in the integumentary system.

[0008] AQP3 is primarily expressed in keratinocytes and skin fibroblasts. Its role in the skin is primarily twofold (Luo Ying. Research Progress on Aquaporin 3 and Skin. Medical Information. 2015). First, moisturizing. Since glycerol content in the stratum corneum directly or indirectly influences skin moisturizing, its supply is crucial. AQP3 not only transports endogenous glycerol from the circulation and triglycerides from the sebaceous glands into the epidermis but also participates in glycerol metabolism in epidermal cells. Second, it supports barrier repair. When the skin barrier is damaged by artificial forces or chemical agents, AQP3 expression increases. However, filaggrin (which, upon hydrolysis, provides the natural moisturizing factor (NMF)) shows a transient but significant decrease in expression three hours after barrier disruption and returns to normal within 24 hours, at which point AQP3 expression peaks. This suggests that when filaggrin decreases, AQP3 expression increases, replacing the role played by filaggrin. Therefore, AQP3's role in barrier repair may be achieved through interaction with filaggrin.

[0009] Claudin-1, also known as senescence-associated epithelial membrane protein-1, is located on human chromosome 3q28, has a molecular weight of 22.7 kDa, and is composed of 211 amino acid residues. Claudin-1 contains four transmembrane domains, two extracellular loops, ECL1 and ECL2, a cytoplasmic loop, and NH2- and COOH-termini located in the cytoplasm. The extracellular loops seal adjacent cells in a "zipper"-like structure. ECL1 is composed of approximately 50 amino acids, including a highly conserved set of residues, W-GLWC-C. This amino acid composition influences paracellular charge selectivity and determines the properties of the paracellular pore. ECL1 contains two cysteines at positions 54 and 64, respectively. These two cysteines form an intramolecular disulfide bridge, which is highly conserved and determines the binding behavior of ECL1 as a whole, making it crucial for the sealing function of claudin-1. ECL2, on the other hand, is relatively small, containing 16–33 amino acid residues. It mediates claudin-claudin interactions within and between adjacent cells and acts as a barrier to the flow of extracellular water and solutes and the translocation of other cells by regulating the charge and size selectivity of the paracellular space. Claudin-1 has a COOH-terminus ending in valine, 21–63 amino acid residues in length, and contains a PDZ domain-binding motif. This motif binds to zonula occludens-1 and multi-PDZ domain protein 1, forming tight junctions and ultimately contributing to epithelial barrier function (Ji Rong et al., Progress in Research on the Function of Claudin-1, Chinese Journal of Cell Biology, 2020).

[0010] Filaggrin (FLG) is a crucial protein for maintaining the integrity of the epidermal barrier function. Encoded by the FLG gene at human locus 1q21, it is a key protein for normal epidermal terminal differentiation and maintaining skin hydration. Its precursor, profilaggrin (proFLG), is synthesized within cells of the epidermal stratum granulosum and participates in the formation of keratin granules. Under elevated calcium ion concentrations, proFLG is dephosphorylated to FLG, which is further hydrolyzed by serine proteases (SPs) to ultimately generate large amounts of NMF under the action of caspase 14. NMF is a key molecule influencing skin hydration. Its reduction or deficiency can weaken the skin barrier function and lead to the development of various skin diseases.

[0011] In view of the problems existing in the existing technology, targeted exploration is needed to determine suitable low molecular weight polypeptide compounds that meet the moisturizing and skin repair requirements of cosmetics. Summary of the Invention

[0012] The first aspect of the present invention discloses a low molecular weight polypeptide compound, the structural formula of which is: [γ-glu] n -Aa, where glu is glutamic acid;

[0013] Aa is selected from any one of glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, methionine, serine, threonine, cysteine, proline, histidine or arginine; n is 1-10.

[0014] Among them, Aa is preferably glutamine Gln.

[0015] In the structural formula, n is preferably 1-8, and n is selected from any number of 1, 2, 3, 4, 5, 6, 7 or 8.

[0016] The molecular weight of the polypeptide compound is 250-1500 Da.

[0017] The polypeptide compound is prepared by a fermentation method.

[0018] The second aspect of the present invention discloses the use of the above-mentioned polypeptide compounds in moisturizing and skin barrier repair, including use in the preparation of moisturizing products.

[0019] Preferably, the above polypeptide compounds are used in the preparation of moisturizing cosmetics, such as moisturizing masks, creams, lotions, etc.

[0020] The polypeptide compound can also be used in the preparation of products for repairing skin barrier function, which have firming and anti-wrinkle effects.

[0021] The third aspect of the present invention discloses the use of a polypeptide compound moisturizing product and one or a combination of the following substances:

[0022] I), an auxiliary agent that promotes the moisturizing effect of polypeptide compounds;

[0023] II) Contains moisturizing agents that have a synergistic moisturizing effect.

[0024] The above-mentioned adjuvants include antioxidants, preservatives, surfactants, pH adjusting buffers and other additives used in moisturizing products.

[0025] The above-mentioned moisturizers can respectively play the role of moisture absorption, water locking, biological regulation or film-forming moisturizing, such as glycerin, propylene glycol, butylene glycol, mineral oil, vegetable oil, animal oil, ceramide, free fatty acids, triglycerides, squalene, sodium hyaluronate, pullulan, tremella polysaccharide, etc.

[0026] After testing, the above-mentioned polypeptide compounds have excellent moisturizing properties and low molecular weight, which is conducive to being absorbed and utilized by the skin, reducing the risk of clogging pores and sweat gland openings.

[0027] The polypeptide compound provided by the present invention has a molecular weight of 250-1500Da and can be used as a moisturizer in cosmetics to effectively moisturize, promote absorption, and increase skin elasticity. It can also be used as a drug carrier in the medical field. Its low molecular weight can reduce the side effects caused by drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a secondary mass spectrum of the structure γ-Glu-Gln.

[0029] FIG2 is a secondary mass spectrum of the structure γ-Glu-Glu-Gln.

[0030] FIG3 is a secondary mass spectrum of the structure γ-Glu-Glu-Glu-Gln.

[0031] FIG4 is a secondary mass spectrum of the structure γ-Glu-Glu-Glu-Glu-Gln.

[0032] Figure 5 is a secondary mass spectrum of the structure γ-Glu-Glu-Glu-Glu-Glu-Glu-Gln.

[0033] FIG6 is a diagram showing the moisturizing effect of the polypeptide compound disclosed in Example 2.

[0034] Figure 7. Histogram of the effects of peptides on HaCaT cell proliferation.

[0035] FIG8 is a bar graph showing the effect of oligomeric hyaluronic acid on HaCaT cell proliferation.

[0036] Fig. 9 Changes in AQP1 expression in HaCaT cells.

[0037] Fig. 10 Changes in AQP3 expression in HaCaT cells.

[0038] Fig. 11 Changes in FLG expression in HaCaT cells.

[0039] Fig. 12 Changes in Claudin-1 expression in HaCaT cells.

[0040] FIG. 13 is a diagram showing the measurement results of the transepidermal water loss experiment in Example 4.

[0041] FIG. 14 is a diagram showing the measurement results of the skin elasticity experiment in Example 4.

[0042] FIG. 15 is a diagram showing the measurement results of the skin density experiment in Example 4.

[0043] FIG. 16 is a diagram showing the measurement results of the skin stratum corneum thickness experiment in Example 4.

[0044] FIG17 is a diagram showing the measurement results of the skin stratum corneum moisture experiment in Example 4.

[0045] FIG18 is a graph showing the measurement results of the cell activity experiment in Example 5.

[0046] FIG19 is a graph showing the expression of AQP1, AQP3, Claudin-1 and FLG genes after treatment with different polypeptide compounds in Example 6.

[0047] Wherein HA refers to oligomeric hyaluronic acid, and polypeptide refers to the polypeptide compound prepared in Example 1

[0048] The symbol * represents a statistically significant difference compared with the blank control group (control), * represents P < 0.05, ** represents P < 0.01, and *** represents P < 0.001; the symbol # represents a statistically significant difference between the two treatment groups, # represents P < 0.05, ## represents P < 0.01, and ### represents P < 0.001. DETAILED DESCRIPTION

[0049] The present invention is further illustrated by way of examples below, but the invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications. The raw materials and equipment used in the examples are well known to those skilled in the art and are all commercially available, easily obtained, or prepared.

[0050] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0051] Example 1: Mass spectrometry identification of samples

[0052] The present invention uses amino acids as raw materials to synthesize polypeptide compounds through a fermentation method, and its structure is determined by HPLC-MS / MS. The structure is shown in Figures 1-5.

[0053] Example 2: Zebrafish Moisturizing Efficacy Test

[0054] 1. System and sample size

[0055] Test system: zebrafish (Albino) with melanin allele mutations, sample solution: a mixed system containing the polypeptide compound disclosed in Structural Example 1.

[0056] Zebrafish age: 2 days post fertilization (2 dpf).

[0057] The experimental sample size for each group was 15 (N=10). Normal control group: zebrafish were not dehydrated; model control group: zebrafish were dehydrated; sample group: zebrafish were immersed in sample solution for dehydration.

[0058] Adult fish rearing and breeding methods: Follow our laboratory standard rearing and breeding methods, in line with the requirements of the international AAALAC certification (certification number: 001458)

[0059] 2. Principle and method: When zebrafish are treated with sodium chloride, the skin surface will lose water and shrink due to osmotic pressure, and the tail area will become smaller due to shrinkage. The moisturizing effect of cosmetics can be evaluated by the impact on the tail area.

[0060] 3. Experimental steps:

[0061] 1) Randomly select zebrafish and place them in a 6-well plate, with 15 zebrafish per well.

[0062] 2) Water-soluble samples were administered, and a normal control group and a model control group were set up at the same time. The volume of each well was 3 mL.

[0063] 3) Sodium chloride was simultaneously administered in water to establish a zebrafish skin dehydration model.

[0064] 4) Incubate at 28°C in the dark for 22 hours.

[0065] 5) Ten zebrafish were randomly selected from each experimental group and photographed under a dissecting microscope. Advanced image processing software was used to analyze and collect data. The tail area (S) of the zebrafish was analyzed, and the moisturizing efficacy of the sample was calculated using a formula to determine whether it possessed moisturizing efficacy. (Statistical analysis indicated a significant difference when p < 0.05.)

[0066]

[0067] 4. Test results

[0068]

[0069] The results are shown in FIG6 , which shows that the tail area of ​​the sample disclosed in Example 2 is significantly increased compared with the model control group, indicating that the sample has a moisturizing effect.

[0070] Example 3: Cell activity experiment

[0071] 1. Effects of peptides on the proliferation of the immortalized human skin keratinocyte cell line HaCaT

[0072] Experimental method: HaCaT cells were revived within 1 minute at 37°C in DMEM medium containing 10% fetal bovine serum and 1% triple antibody. They were cultured in a 37°C, 5% CO2 incubator and passaged every 48-72 hours at a passage ratio of 1:3. Cells in the exponential growth phase were collected, counted, and counted as 1×10 4 HaCaT cells were plated in a 96-well plate at 1:1 ratio, with 200 μL of complete DMEM medium per well. After 24 hours of culture, the cells were divided into a control group and an experimental group. The control group was treated with oligohyaluronic acid at concentrations of 0.05%, 0.1%, 0.2%, 0.5%, and 1%, while the experimental group was treated with the peptide mixture of Example 1 at concentrations of 0.05%, 0.1%, 0.2%, 0.5%, and 1%. 24 hours after addition, 10 μL of CCK8 reagent was added to each well to assess cell proliferation.

[0073] The experimental results, as shown in Figures 7 and 8, show that compared with the control group, oligomeric hyaluronic acid had no significant effect on the proliferation of HaCaT cells at different concentrations, and the polypeptide compound mixture of Example 1 had no significant effect on the proliferation of HaCaT cells at a concentration range of 0-1.0%.

[0074] 2 peptides for the effects of AQP1, AQP3, Claudin-1 and FLG genes

[0075] Experimental methods: (1) HaCaT cells were collected in the exponential growth phase and plated in 12-well plates. HaCaT cells were cultured for 24 h using culture medium containing 0.05% and 0.5% oligomeric hyaluronic acid and 0.05% and 0.5% of the mixture of polypeptide compounds of Example 1, respectively. The expression levels of aquaporins AQP1 and AQP3, tight junction protein Claudin-1, and filaggrin FLG genes were detected. (2) Cells were cultured at 37°C for 24 h, and cellular RNA was extracted using the TRIzol method. (3) RNA was reverse transcribed using a kit to obtain cDNA. (4) The expression of aquaporins (AQP1, AQP3), tight junction protein (Claudin-1), and FLG genes in each group was detected by qPCR. qPCR reaction conditions: 95°C for 4 min, 95°C for 15 sec, 60°C for 30 sec, 40 repeats, 95°C for 15 sec, 60°C for 1 min, and 37°C for 1 min.

[0076] As shown in Figures 9, 10, 11, and 12, the expression levels of AQP1, AQP3, Claudin-1, and FLG did not significantly change after treatment with 0.05% oligomeric hyaluronic acid. However, treatment with 0.5% oligomeric hyaluronic acid significantly increased the expression of AQP3, Claudin-1, and FLG. Treatment with the peptide mixture of Example 1 increased the expression of AQP1, AQP3, Claudin-1, and FLG, with the 0.5% peptide increasing more significantly than the 0.05% peptide. These results demonstrate that, at equivalent detection levels, this peptide exhibits superior moisturizing and barrier-repairing properties compared to oligomeric hyaluronic acid.

[0077] Example 4

[0078] [γ-glu] n -Gln human skin repair effect

[0079] Experimental methods:

[0080] Recruit 10 volunteers (aged 20-27 years old) and give them a 9cm injection on the inner side of their forearms. 2 , sample concentration 1%, control 1: ceramide (Chongqing Zhihe); control 2: ceramide (Evonik); sample: [γ-glu] n -Gln.

[0081] Test method:

[0082] 1. Transepidermal water loss

[0083] The subjects were tested with the instrument four times, namely before use, 30 minutes after use, 7 days after use, and 14 days after use, and the inner forearm area was selected for testing.

[0084] Each time the Tewameter is used for testing, three values ​​are read and the average is taken.

[0085] Parameter explanation: The higher the test value, the higher the transepidermal water loss and the worse the skin barrier function. The lower the test value, the lower the transepidermal water loss and the better the skin barrier function.

[0086] Result determination: If after using the product, the transepidermal water loss in the test area is significantly reduced compared with the initial value before use, it means that the test sample has the effect of improving the skin barrier function.

[0087] 2. Skin elasticity

[0088] The subjects were tested with the instrument four times before use, 24 hours after use, 7 days after use, and 14 days after use. The inner area of ​​the right forearm was selected for testing.

[0089] Each time you use the Cutometer test, read three values ​​and take the average.

[0090] Parameter explanation: The R2 value is the total elasticity of the skin. A value closer to 1 indicates higher elasticity.

[0091] Result determination: If the skin elasticity and collagen values ​​in the test area after use of the product are significantly increased compared to the initial values ​​before use, it means that the test sample has the effect of increasing skin elasticity and improving skin firmness.

[0092] 3. Skin density

[0093] The subjects were tested with the instrument four times, namely before use, 30 minutes after use, 7 days after use, and 14 days after use. The inner area of ​​the right forearm was selected for testing.

[0094] Each time, use Ultrascan UC22 skin ultrasound instrument to read three values ​​and take the average.

[0095] Parameter explanation: The higher the test value, the higher the skin density; the lower the test value, the lower the skin density.

[0096] Result determination: If after using the product, the skin density of the test area is significantly increased compared with the initial value before use, it means that the test sample has the effect of improving the skin barrier function.

[0097] 4. Skin epidermal thickness

[0098] The subjects were tested with the instrument four times, namely before use, 30 minutes after use, 7 days after use, and 14 days after use. The inner area of ​​the right forearm was selected for testing.

[0099] Each time, use Ultrascan UC22 skin ultrasound instrument to read three values ​​and take the average.

[0100] Parameter explanation: The higher the test value, the thicker the skin epidermis; the lower the test value, the thinner the skin epidermis.

[0101] Result determination: If after using the product, the epidermal thickness of the test area is significantly increased compared with the initial value before use, it means that the test sample has the effect of improving the skin barrier function.

[0102] 5. Water content of the skin's stratum corneum

[0103] The subjects were tested with the instrument four times, namely before use, 30 minutes after use, 7 days after use, and 14 days after use, and the inner forearm area was selected for testing.

[0104] Each time using the Corneometer test, read three values ​​and take the average.

[0105] Parameter explanation: The higher the test value, the higher the moisture content of the skin's stratum corneum.

[0106] Result determination: If the moisture content of the stratum corneum in the test area after use of the product is significantly increased compared with the initial value before use, it means that the test sample has the effect of hydrating and moisturizing.

[0107] Test conclusion:

[0108] Using the test product ([γ-glu] n After 30 minutes of application, the skin moisture content in the test area increased slightly compared to before use, with an improvement rate of 4.4%. The transepidermal water loss value decreased slightly compared to before use, with an improvement rate of 13.47%. The total elasticity of the skin in the test area also improved slightly, with an improvement rate of 2.05%. This indicates that the product has the effect of moisturizing, replenishing water, and elasticizing the skin after one use.

[0109] With the test product ([γ-glu] nAfter seven days of using the product (-Gln), the skin moisture content in the test area increased significantly compared to before use, with an improvement rate of 3.76%. Transepidermal water loss decreased significantly, with a significant improvement rate of 18.69%. Total skin elasticity in the test area also improved, with a significant improvement rate of 3.67%. Skin density and stratum corneum thickness also improved, with improvement rates of 6.90% and 7.39%, respectively. This indicates that the product has significant moisturizing and hydrating effects, enhancing skin elasticity, and has a certain barrier repair effect after seven days of use.

[0110] Using the test product ([γ-glu] n After 14 days of using the product (-Gln), the skin moisture content in the test area increased significantly compared to before use, with an improvement rate of 13.99%, a highly significant difference. Transepidermal water loss decreased significantly compared to before use, with an improvement rate of 16.42%, a highly significant difference. Total skin elasticity improved significantly, with an improvement rate of 5.01%, a highly significant difference. Skin gloss increased significantly, with an improvement rate of 9.5%, a significant difference. Skin density and stratum corneum thickness also improved significantly, with improvement rates of 19.54% and 10.13%, respectively, with significant differences. This indicates that after 14 days of use, the product has significant moisturizing, barrier repair, and skin elasticity benefits.

[0111] Example 5 [γ-glu] n -Aa cell activity assay

[0112] Experimental method: HaCaT cells were revived within 1 minute at 37°C in DMEM medium containing 10% fetal bovine serum and 1% triple antibody. They were cultured in a 37°C, 5% CO2 incubator and passaged every 48-72 hours at a passage ratio of 1:3. Cells in the exponential growth phase were collected, counted, and counted as 1×10 4 HaCaT cells were plated in 96-well plates with 200 μL complete DMEM medium per well. After culturing for 24 hours, the cells were divided into a control group and an experimental group. The control group did not receive γ-glu n -Aa, experimental group added 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1% and 2% of [γ-glu] n 24 h after sample addition, 10 μL of CCK8 reagent was added to each well to detect cell proliferation.

[0113] The experimental results are shown in the figure, [γ-glu] n -Aa ([γ-glu] n -Trp, [γ-glu]n -Leu, [γ-glu] n -Phe, [γ-glu] n -Cys, [γ-glu] n -Met, [γ-glu] n -Tyr) had no significant effect on HaCaT proliferation in the concentration range of 0.001%~2.0%.

[0114] Example 6 [γ-glu] n -Aa's effects on AQP1, AQP3, Claudin-1, and FLG genes

[0115] Experimental method: (1) cells in exponential growth phase were collected and HaCaT cells were plated in 12-well plates. A control without sample, a plate containing 0.05% and 0.2% [γ-glu] n -Trp, 0.05% and 1% [γ-glu] n -Leu, 1% and 2% [γ-glu] n -Phe, 0.01% and 0.05% [γ-glu] n -Cys, 0.01% and 0.2% [γ-glu] n -Met, 1% and 2% [γ-glu] n HaCaT cells were cultured in -Tyr medium for 24 h, and the expression of aquaporins AQP1 and AQP3, tight junction protein Claudin-1, and filaggrin FLG genes was measured. (2) Cells were cultured at 37°C for 24 h, and cellular RNA was extracted using the TRIzol method. (3) RNA was reverse transcribed using a kit to obtain cDNA. (4) qPCR was used to measure the expression of aquaporins (AQP1, AQP3), tight junction protein (Claudin-1), and FLG genes in each group. qPCR reaction conditions: 95°C for 4 min, 95°C for 15 sec, 60°C for 30 sec, 40 repeats, 95°C for 15 sec, 60°C for 1 min, and 37°C for 1 min.

[0116] The experimental results are shown in the figure (1 and 2 refer to low and high concentrations respectively), 0.05% and 0.2% [γ-glu] n -Trp, 0.05% and 1% [γ-glu] n -Leu, 1% and 2% [γ-glu] n -Phe, 0.01% and 0.05% [γ-glu] n -Cys, 0.01% and 0.2% [γ-glu]n -Met, 1% and 2% [γ-glu] n After the cells were treated with -Tyr, the expression levels of AQP1, AQP3, Claudin-1 and FLG changed to varying degrees. n -Trp can significantly increase the expression of AQP3, Claudin-1 and FLG. 0.05% [γ-glu] n -Leu can significantly increase the expression of AQP1 and AQP3. 1% and 2% [γ-glu] n -Phe can significantly increase the expression of AQP1, AQP3, Claudin-1 and FLG. 2%[γ-glu] n -Tyr treatment significantly increased the expression of FLG. These results indicate that [γ-glu] n -Aa has moisturizing and barrier repair functions and can be used in various cosmetics.

[0117] [γ-glu] n -Aa in vitro efficacy study, [γ-glu] n The Gln in -Gln can be replaced by other amino acids including but not limited to Trp, Leu, Phe, Cys, Met, Tyr and other 19 kinds of amino acids, through fermentation, enzymatic method or chemical synthesis [γ-glu] n -Aa, n is 1-9, Aa is an amino acid other than Gln. [γ-glu] n -Aa and [γ-glu] n -Gln, and can be used as a functional raw material in various cosmetics.

[0118] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A polypeptide compound, characterized in that: Its structural formula is: [γ-glu]n-Aa, wherein glu is glutamic acid; Aa is selected from any one of glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, methionine, serine, threonine, cysteine, proline, histidine or arginine; and n is 1-10.

2. The polypeptide compound according to claim 1, wherein In the structural formula, n is preferably 1-8.

3. The polypeptide compound according to claim 1, wherein The molecular weight of the polypeptide compound is 250-1500 Da.

4. The polypeptide compound according to any one of claims 1 to 3, wherein The polypeptide compound is prepared by a fermentation method.

5. Use of the polypeptide compound according to any one of claims 1 to 3 in the field of cosmetics.

6. The use according to claim 5, characterized in that Application of the polypeptide compound in the preparation of moisturizing products.

7. The use according to claim 5, characterized in that The application of the polypeptide compound in the preparation of a product for repairing skin barrier function.

8. The use according to claim 6, characterized in that The moisturizing product includes the use of one or a combination of the following substances: I), an auxiliary agent that promotes the moisturizing effect of polypeptide compounds; II) Contains moisturizing agents that have a synergistic moisturizing effect.

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