Cyclic peptide, and composition and use thereof

Abstract

The present disclosure relates to the technical field of polypeptides. Disclosed are a cyclic peptide, and a composition and the use thereof. The cyclic peptide of the present disclosure has a structure as shown in formula (I): Cyclo-[Gly-His-Lys-Lys] (I). The present disclosure specifically relates to the cyclic peptide or a salt thereof, or a composition thereof, and the use thereof in the preparation of a composition for caring or treating skin or mucosa.

Description

Cyclic peptides and their compositions and uses

[0001] This application is based on the application with CN application number 202410266907.6 and application date March 8, 2024, and claims its priority. The disclosed content of the CN application is hereby introduced as a whole into this application. Technical Field

[0002] The present disclosure relates to the field of polypeptide technology, in particular to a cyclic peptide and a composition thereof, and uses thereof. Background Art

[0003] Collagen, a major component of the extracellular matrix (ECM), is produced by fibroblasts and provides the skin with strength and structural support against stretch. With aging, collagen production decreases, and existing collagen degrades, leading to sagging and wrinkling. Elastin, another important ECM component, contributes to the skin's elasticity and resilience. In normal physiology, elastase participates in ECM remodeling, helping to remove damaged elastin and promote new elastin production. However, overactive elastase can lead to excessive elastin degradation, impairing the skin's elasticity and overall structure. Hyaluronic acid, an acidic mucopolysaccharide, has a strong water-retention capacity in the skin, helping to maintain hydration and volume. Hyaluronidase is an enzyme that degrades hyaluronic acid. By regulating its degradation, it affects the skin's water balance and texture. Increased hyaluronidase activity leads to a significant decrease in hyaluronic acid, disrupting the skin's barrier function and accelerating water loss. Tyrosinase is a key enzyme involved in melanin synthesis, catalyzing the conversion of tyrosine to dopaquinone, which is then formed into melanin. Melanin protects the skin from UV damage, preventing DNA damage and skin cancer. However, excessive tyrosinase activity can lead to excessive pigmentation, resulting in pigmentary skin diseases such as freckles and melasma. Therefore, tyrosinase activity affects the evenness of skin color.

[0004] In summary, collagen, elastase, hyaluronidase and tyrosinase all play important roles in maintaining skin structure and function. Summary of the Invention

[0005] The present disclosure relates to cyclic peptides, and these cyclic peptides and compositions containing these cyclic peptides have the effects of caring for or treating skin or mucous membranes.

[0006] In one aspect, the present disclosure provides a cyclic peptide represented by formula (I), or a stereoisomer thereof, or a mixture of stereoisomers thereof, or a salt thereof, Cyclo-[Gly-His-Lys-Lys] (I).

[0007] The cyclic peptide shown in formula (I) of the present disclosure can exist as a mixture of stereoisomers or stereoisomers; for example, the amino acids it contains can have L-, D- configurations, or be racemic independently of each other. Therefore, it is possible to obtain isomeric mixtures as well as racemic mixtures or diastereomeric mixtures, or pure diastereomers or enantiomers, depending on the number of asymmetric carbons and what isomers or isomeric mixtures are present. In some embodiments, the structure of the cyclic peptide shown in formula (I) of the present disclosure is a pure isomer, that is, an enantiomer or a diastereomer. In some embodiments, the structure of the cyclic peptide shown in formula (I) of the present disclosure is an L-isomer.

[0008] The present disclosure also includes all suitable isotopic variants of the cyclic peptides represented by formula (I). Isotopic variants of these cyclic peptides disclosed herein are understood herein to refer to compounds in which at least one atom in the cyclic peptides disclosed herein is replaced by another atom of the same atomic number, but the atomic mass of the other atom is different from the atomic mass usually or predominantly present in nature. Examples of isotopes that can be incorporated into the cyclic peptides disclosed herein are those of hydrogen, carbon, nitrogen or oxygen, e.g. 2 H (deuterium), 3 H (tritium), 13 C. 14 C. 15 N. 17 O or 18 O. Certain isotopic variants of the cyclic peptides disclosed herein (particularly those into which one or more radioactive isotopes have been incorporated) may be useful, for example, for examining the mechanism of action or distribution of the active compound in vivo; due to their relative ease of preparation and detectability, particularly with 3 H or 14 Compounds labeled with a C isotope are suitable for this purpose. In addition, due to the greater metabolic stability of the compound, the incorporation of an isotope (e.g., deuterium) can produce specific therapeutic benefits, such as an extension of the half-life in vivo or a reduction in the required active dose. Isotopic variants of the cyclic peptides of the present disclosure can be prepared by methods known to those skilled in the art, such as by the methods further described below and in the examples, by using the respective reagents and / or corresponding isotopic modifications of the starting materials.

[0009] The term "salt" refers to a salt approved for use in animals, and more specifically, humans, including metal salts of the cyclic peptide represented by formula (I), wherein the metal includes, but is not limited to, lithium, sodium, potassium, calcium, magnesium, manganese, copper, zinc or aluminum; including salts formed between the cyclic peptide represented by formula (I) and an organic base, wherein the organic base includes, but is not limited to, ethylamine, diethylamine, ethylenediamine, ethanolamine, diethanolamine, arginine, lysine, histidine or piperazine; including salts formed between the cyclic peptide represented by formula (I) and an inorganic acid or an organic acid, wherein the organic acid includes, but is not limited to, acetic acid, citric acid, lactic acid, malonic acid, maleic acid, tartaric acid, fumaric acid, benzoic acid, aspartic acid, glutamic acid, succinic acid, oleic acid, trifluoroacetic acid, oxalic acid, pamoate or gluconic acid; and the inorganic acid includes, but is not limited to, hydrochloric acid, sulfuric acid, boric acid or carbonic acid.

[0010] The synthesis of the cyclic peptide represented by formula (I) or a salt thereof can be carried out according to conventional methods known in the art, such as solid phase synthesis, liquid phase synthesis or a combination of solid phase and liquid phase methods, and can also be prepared by biotechnology methods aimed at producing the desired sequence, or by controlled hydrolysis of proteins of animal, fungal or plant origin.

[0011] For example, a method for obtaining the cyclic peptide represented by formula (I) comprises the following steps:

[0012] - coupling an amino acid having a protected N-terminus and a free C-terminus with an amino acid having a free N-terminus and a protected or solid support-bound C-terminus;

[0013] - Elimination of the group protecting the N-terminus;

[0014] - repeating this coupling sequence and eliminating the group protecting the N-terminus until the desired peptide sequence is obtained;

[0015] - elimination of the group protecting the C-terminus or cleavage from the solid support;

[0016] - The free amino group at the N-terminus of the peptide sequence and the free carboxyl group at the C-terminus undergo condensation reaction to form a head-to-tail cyclization;

[0017] - Elimination of groups protecting side chains.

[0018] In some embodiments, the C-terminus is bound to a solid support and the method is performed on a solid phase, comprising coupling an amino acid having a protected N-terminus and a free C-terminus to an amino acid having a free N-terminus and a C-terminus bound to a polymer support; eliminating the group protecting the N-terminus; and repeating this sequence as many times as required to thereby obtain a peptide of the desired length, followed by cleavage of the synthesized peptide from the initial polymer support.

[0019] The functional groups of the side chains of these amino acids remain adequately protected with temporary or permanent protecting groups throughout the synthesis.

[0020] In some embodiments, solid phase synthesis can be performed by a convergent strategy of coupling a dipeptide or tripeptide to a polymer support or to a dipeptide or amino acid previously bound to a polymer support.

[0021] Another aspect of the present disclosure provides a composition comprising an effective amount of the cyclic peptide represented by the above formula (I), or a stereoisomer thereof, or a mixture of stereoisomers thereof, or a salt thereof, and at least one excipient and an optional adjuvant.

[0022] In some embodiments, the adjuvant is selected from the group consisting of analgesics, agents that inhibit PAR-2 ​​activity, collagen synthesis stimulators, agents that regulate PGC-1α synthesis, agents that regulate PPARγ activity, agents that increase or decrease the triglyceride content of adipocytes, agents that stimulate or delay adipocyte differentiation, lipolytic agents or agents that stimulate lipolysis, lipogenic agents, inhibitors of acetylcholine receptor aggregation, agents that inhibit muscle contraction, anticholinergic agents, elastase inhibitors, matrix metalloproteinase inhibitors, melanin synthesis stimulators or inhibitors, whitening agents or depigmenting agents, pro-pigmentation agents, self-tanning agents, anti-aging agents, NO-synthase inhibitors, 5α-reductase inhibitors, inhibitors of lysyl hydroxylase and / or prolyl hydroxylase, Antioxidants, free radical scavengers and / or anti-air pollution agents, active carbonyl scavengers, anti-glycation agents, antihistamines, antivirals, antiparasitic agents, emulsifiers, emollients, organic solvents, liquid propellants, moisture-retaining substances, alpha hydroxy acids, beta hydroxy acids, moisturizers, epidermal hydrolases, vitamins, amino acids, proteins, pigments, dyes, biopolymers, gelling polymers, thickeners, surfactants, softeners, adhesives, preservatives, anti-wrinkle agents, agents capable of reducing or treating under-eye bags, keratolytic agents, antimicrobial agents, agents that stimulate the synthesis of dermal or epidermal macromolecules and / or can inhibit or prevent their degradation, agents that stimulate elastin synthesis, agents that stimulate decorin synthesis, agents that stimulate laminin synthesis agents that stimulate defensin synthesis, agents that stimulate chaperone protein synthesis, agents that stimulate cAMP synthesis, agents that stimulate hyaluronic acid synthesis, agents that stimulate fibronectin synthesis, agents that stimulate deacetylase synthesis, agents that stimulate the synthesis of lipids and stratum corneum components, ceramides, fatty acids, agents that inhibit collagen degradation, agents that inhibit elastin degradation, agents that inhibit serine proteases, agents that stimulate fibroblast proliferation, agents that stimulate keratinocyte proliferation, agents that stimulate adipocyte proliferation, agents that stimulate melanocyte proliferation, agents that stimulate keratinocyte differentiation, agents that inhibit acetylcholinesterase, skin relaxants, agents that stimulate glycosaminoglycan synthesis, anti-hyperkeratosis agents, comedolytic agents, anti-psoriasis agents, anti-eczema agents, DNA repair agents, DNA protective agents, stabilizers, antipruritic agents, agents for treating and / or caring for sensitive skin, firming agents, firming agents, restructuring agents, agents against stretch marks, agents regulating sebum production, antiperspirants, agents that stimulate healing, agents that assist healing, agents that stimulate re-epithelialization, agents that assist re-epithelialization, cytokines, sedatives, anti-inflammatory agents, anesthetics, agents acting on capillary circulation and / or microcirculation, agents stimulating angiogenesis, agents inhibiting vascular permeability, venous tension agents, agents acting on cellular metabolism, agents for improving dermal-epidermal junction, agents inducing hair growth, agents that inhibit or delay hair growth, fragrances, chelating agents, plant extracts, essential oils, marine extracts, agents obtained from biological fermentation processes, inorganic salts, cell extracts, sunscreens,and organic or inorganic light protection agents or mixtures thereof that are effective against ultraviolet A and / or ultraviolet B rays.

[0023] The effective amount of the cyclic peptides of the present disclosure to be administered, as well as their dosage, will depend on a number of factors, including the age, condition of the user, severity of the condition, route and frequency of administration, and the specific nature of the cyclic peptide to be used.

[0024] "Effective amount" means an amount of one or more cyclic peptides of the present disclosure that is non-toxic but sufficient to provide the desired effect. The cyclic peptides of the present disclosure are used in the compositions of the present disclosure at concentrations effective to achieve the desired effect. In some embodiments, the concentration is between 0.00000001% (by weight) and 20% (by weight) relative to the total weight of the composition; in some embodiments, the concentration is between 0.000001% (by weight) and 15% (by weight) relative to the total weight of the composition; in some embodiments, the concentration is between 0.0001% (by weight) and 10% (by weight) relative to the total weight of the composition; in some embodiments, the concentration is between 0.0001% (by weight) and 5% (by weight) relative to the total weight of the composition.

[0025] Another aspect of the present disclosure provides a delivery system or sustained-release system to achieve better penetration of the active ingredient, which comprises an effective amount of the cyclic peptide represented by the above formula (I), or its stereoisomer, or a mixture of its stereoisomers, or a salt thereof, or the above composition.

[0026] The term "delivery system" refers to a diluent, adjuvant, excipient or carrier administered with the cyclic peptides of the present invention, selected from the group consisting of water, oils or surfactants, including those of petroleum origin, animal origin, plant origin, or synthetic origin, such as and not limited to peanut oil, soybean oil, mineral oil, sesame oil, castor oil, polysorbates, sorbitan esters, ether sulfates, sulfates, betaines, glucosides, maltosides, fatty alcohols, nonoxynol ethers, poloxamers, polyoxyethylene, polyethylene glycol, dextrose, glycerol, digitonin and the like. Those skilled in the art are aware of the diluents that can be used in the different delivery systems in which the cyclic peptides of the present invention can be administered.

[0027] The term "sustained release" is used in its conventional sense to refer to a delivery system that provides for the gradual release of a compound over a period of time. In some embodiments, a sustained release system has a relatively constant level of compound release over a period of time.

[0028] Examples of delivery systems or sustained-release systems include, but are not limited to, liposomes, oleosomes, ethosomes, millicapsules, microcapsules, nanocapsules, nanostructured lipid carriers, sponges, inclusion compounds, lipid vesicles, micelles, millispheres, microspheres, nanospheres, lipid spheres, microemulsions, nanoemulsions, milliparticles, microparticles, or nanoparticles.

[0029] Another aspect of the present disclosure provides a cosmetic comprising an effective amount of the cyclic peptide represented by formula (I) above, or its stereoisomers, or a mixture of its stereoisomers, or a salt thereof, or the above composition, or the above delivery system or sustained-release system.

[0030] In some embodiments, the dosage form of the cosmetic comprises ointment, cream, emulsion, aqueous solution, oil, gel, powder, tablet, mud, patch, film, aerosol, spray, freeze-dried preparation or nano preparation.

[0031] Another aspect of the present disclosure provides a use of the cyclic peptide represented by the above formula (I), or its stereoisomer, or a mixture of its stereoisomers, or a salt thereof, or the above composition, or the above delivery system or sustained-release system in the preparation of a composition for caring for or treating skin or mucous membranes.

[0032] Another aspect of the present disclosure provides a use of the cyclic peptide represented by the above formula (I), or its stereoisomers, or a mixture of its stereoisomers, or a salt thereof, or the above composition, or the above delivery system or sustained-release system in the preparation of a composition for anti-aging, repairing, moisturizing or soothing.

[0033] Another aspect of the present disclosure provides a use of the cyclic peptide represented by the above formula (I), or its stereoisomer, or a mixture of its stereoisomers, or a salt thereof, or the above composition, or the above delivery system or sustained-release system in the preparation of a composition for whitening, brightening skin color, removing spots and / or eliminating uneven skin color.

[0034] Another aspect of the present disclosure provides a use of the cyclic peptide represented by the above formula (I), or its stereoisomer, or a mixture of its stereoisomers, or a salt thereof, or the above composition, or the above delivery system or sustained-release system in preparing a composition for inhibiting elastase activity, or in preparing a composition for promoting collagen production, or in preparing a composition for increasing skin elasticity and / or improving skin firmness, or in preparing a composition for promoting regeneration or healing of skin or mucous membranes, or in preparing a composition for repairing the skin barrier, or in preparing a composition for inhibiting hyaluronidase activity, or in preparing a composition for inhibiting tyrosinase activity, or in preparing a composition for inhibiting melanin production.

[0035] Another aspect of the present disclosure provides a use of the cyclic peptide represented by formula (I), or its stereoisomer, or its mixture of stereoisomers, or its salt, or the above composition, or the above delivery system or sustained-release system in the preparation of a sunscreen.

[0036] Another aspect of the present disclosure provides a use of the cyclic peptide represented by formula (I), or its stereoisomers, or a mixture of its stereoisomers, or a salt thereof, or the above-mentioned composition, or the above-mentioned delivery system or sustained-release system in the preparation of cosmetics.

[0037] In the present disclosure, the term "skin" is understood to include the multiple layers comprising it, from the uppermost layer or stratum corneum to the lowermost layer or subcutaneous tissue, both ends inclusive. These layers are composed of different types of cells, such as keratinocytes, fibroblasts, melanocytes, and / or adipocytes. In the present disclosure, the term "skin" includes the scalp.

[0038] The term "skin care" refers to the maintenance and care of the skin, improving the condition of the skin, making the skin delicate, smooth, tender and healthy.

[0039] The present disclosure has the following advantages and effects:

[0040] 1. The cyclic peptide disclosed herein can inhibit elastase activity, promote collagen production, increase skin elasticity, improve skin firmness, promote regeneration or healing of skin or mucous membranes, inhibit hyaluronidase activity, and repair the skin barrier. It can also inhibit tyrosinase activity, inhibit melanin production, brighten skin color, fade spots, and eliminate uneven skin tone. It has multiple effects such as anti-aging, repair, moisturizing, soothing, and whitening.

[0041] 2. The cyclic peptide disclosed in the present invention is obtained by condensing the free amino group at the N-terminus and the free carboxyl group at the C-terminus of the linear peptide GHKK to form a head-to-tail cyclization. However, compared with the linear peptide GHKK, the cyclic peptide disclosed in the present invention has achieved unexpected technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solution of the present disclosure, the following briefly introduces the drawings required for use in the description of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 is a mass spectrum of cyclic peptide A Cyclo-[Gly-His-Lys-Lys].

[0044] FIG2 is a graph showing the effect of the test samples on the collagen I content.

[0045] FIG3 is a graph showing the effect of the test samples on the collagen III content. DETAILED DESCRIPTION

[0046] To make the objectives, features, and advantages of the present disclosure more readily apparent, the present disclosure is further described below in detail with reference to the accompanying drawings and examples. It should be understood that the described embodiments are only a portion of the embodiments of the present disclosure, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without inventive effort are intended to fall within the scope of protection of the claims appended to the present disclosure.

[0047] In the present disclosure, the abbreviations used for amino acids follow the rules specified by the IUPAC-IUB Commission of Biochemical Nomenclature in Eur. J. Biochem. 1984, 138: 9-37.

[0048] Unless otherwise specified, the experimental reagents and materials used in this disclosure can be obtained commercially. The following are the abbreviations of some reagents and materials:

[0049] 2-CTC Resin: A starting resin for peptide synthesis (2-chlorotrityl chloride resin); DMF: N,N-dimethylformamide; DCM: dichloromethane; DIPEA: diisopropylethylamine; MeOH: methanol; piperidine: piperidine; HOBt: 1-hydroxybenzotriazole; DIC: diisopropylcarbodiimide; TFA: trifluoroacetic acid; HBTU: benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate; TIS: triisopropylsilane; Gly: glycine; His: histidine; Lys: lysine; Fmoc: 9-fluorenylmethoxycarbonyl; Trt: trityl; Boc: tert-butoxycarbonyl.

[0050] Example 1 Preparation of Cyclo-[Gly-His-Lys-Lys]

[0051] 1.1 Resin swelling

[0052] 10 g of 2-CTC Resin was weighed and placed in a solid phase synthesis reaction column, swollen with DCM, the resin was washed, and the solvent was removed.

[0053] 1.2 Feeding reaction

[0054] 11 g of Fmoc-Lys(Boc)-OH and 11.2 mL of DIPEA were added to the swollen resin and reacted for 3 hours. The reaction solution was aspirated, the resin was washed, and the solvent was aspirated. Endcapping was continued by adding DCM, MeOH, and DIPEA for 30 minutes. The resin was washed and the solvent was aspirated. This yielded Fmoc-Lys(Boc)-2-CTC resin.

[0055] Fmoc-Lys(Boc)-2-CTC Resin was depolymerized twice with 20% piperidine / DMF for 10 min each time. Samples were taken for K-test and dark blue color was observed. The resin was washed with DMF 7 times and the solvent was removed.

[0056] Weigh 11g of Fmoc-Lys(Boc)-OH and 3.5g of HOBt into a dry Erlenmeyer flask. Dissolve in DMF, seal, and freeze at -18°C for 30 minutes. Activate with 4.3mL of DIC for 7 minutes, avoiding moisture. Add the activated amino acid to the deprotected resin and react for 3 hours. Aspirate the reaction solution. A colorless, transparent resin on K-test indicates a complete reaction.

[0057] The N-terminal Fmoc group was deprotected, and 14.5 g of activated Fmoc-His(Trt)-OH was coupled to the peptidyl resin in the presence of 3.5 g of HOBt and 4.3 mL of DIC using DMF as solvent. The reaction was continued for 4 hours. The resin was then washed and the Fmoc group deprotection process was repeated to couple the next amino acid. In the presence of 3.5 g of HOBt and 4.3 mL of DIC, 7 g of Fmoc-Gly-OH was coupled using DMF as solvent. After the reaction was complete, the resin was washed and the solvent was removed.

[0058] The N-terminal Fmoc group of the peptidyl resin was deprotected using 20% ​​piperidine / DMF for two 10-min cycles. Samples were taken for K-analysis, revealing a dark blue color. The resin was washed six times with DMF, and the solvent was removed by evacuation. After shrinkage and drying, 5 g of H-Gly-His(Trt)-Lys(Boc)-Lys(Boc)-2-CTC Resin was obtained.

[0059] 1.3 Deresinization

[0060] 1 mL of TFA and 99 mL of DCM were measured and mixed and stirred to obtain a cleavage solution.

[0061] Weigh 5 g of H-Gly-His(Trt)-Lys(Boc)-Lys(Boc)-2-CTC Resin into a round-bottom flask. Add the lysate and stir for 0.5 h. Filter, collect the filtrate, and spin dry to obtain 3.2 g of H-Gly-His(Trt)-Lys(Boc)-Lys(Boc)-OH.

[0062] 1.4 ring closure

[0063] 3.2 g of H-Gly-His(Trt)-Lys(Boc)-Lys(Boc)-OH was dissolved in 200 mL of DCM, followed by the addition of 1.6 g of HBTU and 0.6 g of DIPEA. The reaction was allowed to react for 12 h. HPLC monitoring was performed until the reaction was complete. The reaction solution was extracted three times with purified water, and the aqueous phase was spin-dried to yield 5 g of oily Cyclo-[Gly-His(Trt)-Lys(Boc)-Lys(Boc)].

[0064] 1.5 Cleavage (deprotection group)

[0065] Measure 23 mL of TFA, 0.62 mL of TIS, and 0.62 mL of water and mix thoroughly. Add the above-mentioned Cyclo-[Gly-His(Trt)-Lys(Boc)-Lys(Boc)] and stir thoroughly for 2 h. Then filter the precipitated solid and wash it four times with isopropyl ether to obtain 1 g of crude Cyclo-[Gly-His-Lys-Lys] cyclic peptide.

[0066] 1.6 Purification

[0067] Weigh 1 g of crude Cyclo-[Gly-His-Lys-Lys] cyclic peptide and dissolve it in pure water. Filter it through a 0.45 μm microporous filter membrane to obtain a clear and transparent solution. Purify it by reverse-phase HPLC. The purification gradient is as shown in the following table:

[0068] The filtered sample was injected for purification, and the fractions were collected, concentrated, and lyophilized to obtain Cyclo-[Gly-His-Lys-Lys] with a purity of 95.22%, which was recorded as cyclic peptide A.

[0069] The molecular weight of cyclic peptide A was determined by ESI-MS. The test results are shown in Figure 1. The results show that [M+H] + The mass-to-charge ratio (m / z) of the ion peak was 451.84, and the molecular weight determined by mass spectrometry was 450.84.

[0070] The linear peptide H-Gly-His-Lys-Lys-OH can be obtained by a similar preparation method.

[0071] Example 2 Collagen I content test

[0072] 2.1 Reagents and Materials

[0073] Fetal bovine serum, DMEM medium, phosphate buffered saline (PBS), trypsin, RIPA lysis buffer, collagen I ELISA kit, BCA protein kit.

[0074] 2.2 Instruments

[0075] Microplate reader, CO2 incubator, and clean bench.

[0076] 2.3 Cell lines

[0077] Human dermal fibroblasts (HSF).

[0078] 2.4 Samples to be tested

[0079] Sample group: cyclic peptide A, linear peptide (GHKK), the test concentration was 25ppm;

[0080] Blank control group: PBS;

[0081] UV group: UV radiation, plus PBS.

[0082] 2.5 Experimental methods

[0083] Take HSF fibroblasts in good exponential growth phase, add 0.25% trypsin digestion solution, digest to make the adherent cells fall off, and count (1-4)×10 5 cells / mL to prepare a cell suspension.

[0084] The diluted cell suspension was inoculated into a 12-well plate and cultured for 24 hours until the cells were about 80% full. The UV photoaging model was established. The blank control group was added with 200 μL PBS and the culture medium was replenished to 800 μL without UV irradiation. The UV group and the sample group were repeatedly washed with appropriate amount of PBS until colorless, and then 200 μL PBS was added and placed in 80 mJ / cm 2 Irradiate under UV light, with the lamp source 15 cm away from the culture flask. After irradiation, discard the PBS solution, add PBS solution and culture medium to 800 μL in the UV group, and add culture medium and sample of the relevant concentration to 800 μL in the sample group. Incubate the blank control group, UV group, and sample group in a 37°C, 5% CO2 incubator for 48 hours.

[0085] After the culture was completed, the cells were collected and centrifuged to discard the supernatant. RIPA lysis buffer was added and the cells were shaken three times with a vortexer (30 s / time, 3 min interval). The cells were centrifuged at 12000 rpm for 10 min. The supernatant was aspirated and tested according to the collagen I ELISA operating instructions.

[0086] 2.6 Experimental Results

[0087] Type I collagen is the most abundant collagen in the human body. It has a thick, tightly packed bundle structure and strong tensile strength. It provides a strong support structure and support for the skin, giving the skin elasticity and toughness. Therefore, increasing the content of type I collagen is important for preventing aging and increasing skin elasticity and firmness. In this experiment, the test sample was used to treat cells after ultraviolet radiation, and the type I collagen content in the corresponding cells was detected to determine whether the cyclic peptide disclosed herein can promote the production of type I collagen.

[0088] The results of the effects of the test samples on the content of collagen I are shown in Figure 2. The results show that compared with the blank control group, the collagen I content of the UV group was significantly reduced, indicating that the modeling was successful (## indicates P < 0.01, with significant statistical difference); compared with the UV group, cyclic peptide A can significantly increase the content of collagen I and promote the production of type I collagen (** indicates P < 0.01, with significant statistical difference); while the linear peptide failed to increase the content of collagen I, indicating that the cyclic peptide A obtained by head-to-tail cyclization of the present disclosure has a new effect compared to the linear peptide before cyclization, and can significantly promote the production of type I collagen, achieving unexpected technical effects.

[0089] It can be seen from this that the cyclic peptide disclosed in the present invention can increase the collagen content in cells, promote collagen production, thereby increasing skin elasticity, improving skin firmness, and delaying skin aging.

[0090] Example 3 Collagen III content test

[0091] 3.1 Reagents and Materials

[0092] Fetal bovine serum, DMEM medium, phosphate buffered saline (PBS), trypsin, RIPA lysis buffer, collagen III ELISA kit, BCA protein kit.

[0093] 3.2 Instruments

[0094] Microplate reader, CO2 incubator, and clean bench.

[0095] 3.3 Cell lines

[0096] Human dermal fibroblasts (HSF).

[0097] 3.4 Samples to be tested

[0098] Sample group: cyclic peptide A, linear peptide (GHKK), test concentrations of 25ppm and 50ppm;

[0099] Blank control group: PBS;

[0100] UV group: UV radiation, plus PBS.

[0101] 3.5 Experimental methods

[0102] Take HSF fibroblasts in good exponential growth phase, add 0.25% trypsin digestion solution, digest to make the adherent cells fall off, and count (1-4)×10 5 cells / mL to prepare a cell suspension.

[0103] The diluted cell suspension was inoculated into a 12-well plate and cultured for 24 hours until the cells were about 80% full. The UV photoaging model was established. The blank control group was added with 200 μL PBS and the culture medium was replenished to 800 μL without UV irradiation. The UV group and the sample group were repeatedly washed with appropriate amount of PBS until colorless, and then 200 μL PBS was added and placed in 80 mJ / cm 2 Irradiate under UV light, with the lamp source 15 cm away from the culture flask. After irradiation, discard the PBS solution, add PBS solution and culture medium to 800 μL in the UV group, and add culture medium and samples of varying concentrations to 800 μL in the sample group. Incubate the blank control group, UV group, and sample group in a 37°C, 5% CO2 incubator for 48 hours.

[0104] After the culture was completed, the cells were collected and centrifuged to discard the supernatant. RIPA lysis buffer was added and the cells were shaken three times with a vortexer (30 s / time, 3 min interval). The cells were centrifuged at 12000 rpm for 10 min. The supernatant was aspirated and tested according to the collagen III ELISA operating instructions.

[0105] 3.6 Experimental Results

[0106] Type III collagen is a type of collagen that forms fibers and is primarily found at the junction of the dermis and epidermis. It provides elasticity and stress resistance to the skin, while also repairing damaged type I collagen and stimulating its regeneration. This has a significant effect on promoting repair and healing. Therefore, increasing type III collagen content is crucial for firming and repairing damaged skin. This experiment used a test sample to treat cells irradiated with ultraviolet light and detected the type III collagen content in the corresponding cells to determine whether the cyclic peptide disclosed herein could promote the production of type III collagen.

[0107] The results of the effects of the test samples on the content of collagen III are shown in Figure 3. The results show that compared with the blank control group, the collagen III content of the UV group was significantly reduced, indicating that the modeling was successful (## indicates P < 0.01, with significant statistical difference); compared with the UV group, cyclic peptide A can significantly increase the content of collagen III and promote the production of type III collagen (* indicates P < 0.05, with statistical difference), while the linear peptide cannot increase the content of collagen III, indicating that the cyclic peptide A disclosed in the present invention has achieved unexpected technical effects compared with the linear peptide before cyclization.

[0108] It can be seen from this that the cyclic peptide disclosed in the present invention can increase the collagen content in cells, promote collagen production, thereby increasing skin elasticity and improving skin firmness. It can also repair the skin or mucous membranes, promote the regeneration or healing of the skin or mucous membranes, and has anti-aging and repair effects.

[0109] Example 4 Elastase inhibition experiment

[0110] 4.1 Reagents and Materials

[0111] PBS, elastase solution, AAAPAN (N-succinyl-alanine-alanine-alanine-p-nitroaniline) solution.

[0112] 4.2 Instruments

[0113] Microplate reader, electronic balance.

[0114] 4.3 Samples to be tested and grouping

[0115] 4.3.1 Samples to be tested

[0116] The test concentration of cyclic peptide A and linear peptide (GHKK) was 10 ppm.

[0117] 4.3.2 Grouping

[0118] Sample group: test sample, PBS, elastase, AAAPAN;

[0119] Sample zeroing group: test sample, PBS, AAAPAN;

[0120] Blank control group: PBS, elastase, AAAPAN;

[0121] Blank zero adjustment group: PBS, AAAPAN.

[0122] 4.4 Experimental methods

[0123] In a 96-well plate, add 85 μL PBS, 15 μL of the sample to be tested, and 25 μL of elastase solution (2 mg / mL) to the sample group; add 110 μL PBS and 15 μL of the sample to be tested to the sample zero adjustment group; add 100 μL PBS and 25 μL of elastase solution (2 mg / mL) to the blank control group; and add 125 μL PBS to the blank zero adjustment group. After incubation at 25°C for 15 minutes, add 25 μL of AAAPAN solution (1.015 mmol / L) to each well and incubate at 25°C for 15 minutes. Measure the OD at 410 nm. 410 value.

[0124] Where: A1 is the OD of the sample zeroing group 410 value, A2 is the OD of the sample group 410 A3 is the OD of the blank zero adjustment group. 410 A4 is the OD of the blank control group. 410 value.

[0125] 4.5 Experimental Results

[0126] Elastase has the ability to degrade various proteins such as collagen and elastin. The elastin in the skin is closely related to skin aging. Therefore, inhibiting the activity of elastase and reducing its degradation to elastin are of great significance for restoring skin elasticity and delaying skin aging. AAAPAN is a substrate of elastase and will be decomposed under the catalytic action of elastase. The decomposition product can absorb visible light of 410nm wavelength. This experiment adopts test sample to process elastase, by detecting the reaction amount of AAAPAN, to determine whether cyclic peptide of the present disclosure can inhibit the activity of elastase. The results of test sample inhibition rate of elastase activity are shown in Table 1.

[0127] Table 1 Inhibition rate of test samples on elastase activity (n=3)

[0128] The results showed that at a low concentration of 10 ppm, the inhibition rate of the cyclic peptide A of the present disclosure on elastase activity was 30.4%, while the inhibition rate of the linear peptide on elastase activity was only 16.1%. At the same concentration, the elastase inhibition rate of the cyclic peptide A of the present disclosure was significantly higher than that of the linear peptide, indicating that the cyclic peptide A obtained by head-to-tail cyclization of the present disclosure has a better technical effect than the linear peptide before cyclization, and its ability to inhibit elastase activity has been significantly improved.

[0129] It can be seen from this that the cyclic peptide disclosed in the present invention has an excellent ability to inhibit the activity of elastase. By inhibiting the activity of elastase, it reduces the decomposition of elastin, increases skin elasticity and / or improves skin firmness, improves skin problems such as skin sagging and wrinkles, and achieves anti-aging, firming, and anti-wrinkle effects.

[0130] Example 5 Hyaluronidase inhibition experiment

[0131] 5.1 Reagents and Materials

[0132] Sodium acetate buffer (pH=5.6), hyaluronidase, calcium chloride, sodium hyaluronate, acetylacetone, anhydrous ethanol, sodium carbonate, P-DAB (prepared by uniformly mixing p-dimethylaminobenzaldehyde (0.8 g), concentrated hydrochloric acid (15 mL) and an equal amount of glacial acetic acid).

[0133] 5.2 Instruments

[0134] Microplate reader, electronic balance.

[0135] 5.3 Samples to be tested and grouping

[0136] 5.3.1 Samples to be tested

[0137] The test concentration of cyclic peptide A and linear peptide (GHKK) was 500 ppm.

[0138] 5.3.2 Grouping

[0139] Sample group: test sample, hyaluronidase, sodium hyaluronate;

[0140] Sample zero adjustment group: test sample, sodium acetate buffer;

[0141] Blank control group: distilled water, hyaluronidase, sodium hyaluronate;

[0142] Blank zero adjustment group: distilled water, sodium acetate buffer.

[0143] 5.4 Experimental methods

[0144] Hyaluronidase and sodium hyaluronate were dissolved in sodium acetate buffer.

[0145] In a 96-well plate, 25 μL of the test sample and 25 μL of hyaluronidase (1000 U / mL) were added to the sample group; 25 μL of the test sample and 25 μL of sodium acetate buffer were added to the sample zero adjustment group; 25 μL of distilled water and 25 μL of hyaluronidase (1000 U / mL) were added to the blank control group; and 25 μL of distilled water and 25 μL of sodium acetate buffer were added to the blank zero adjustment group. After shaking in a 37°C constant temperature air bath for 20 minutes, 5 μL of calcium chloride solution (2.5 mol / L) was added to each well and the plates were shaken in a 37°C constant temperature air bath for 20 minutes. 25 μL of sodium hyaluronate (1 mg / mL) was added to the sample and blank control groups. The sample and blank zero adjustment groups were shaken in a 37°C constant temperature air bath for 40 minutes and then allowed to stand at room temperature for 10 minutes. Add 25 μL of distilled water, 5 μL of sodium hydroxide solution (5 mol / L), and 25 μL of acetylacetone solution to each well and place in a 90°C oven for 15 minutes, then ice bath for 10 minutes, and finally place at room temperature for 10 minutes. Add 50 μL of P-DAB to each well, then add 100 μL of anhydrous ethanol, place at room temperature for 30 minutes, and measure the OD at 570 nm. 570 value.

[0146] Where: A1 is the OD of the sample zeroing group 570 value, A2 is the sample group OD 570 A3 is the OD of the blank zero adjustment group. 570 A4 is the OD of the blank control group. 570 value.

[0147] 5.5 Experimental Results

[0148] Hyaluronidase can decompose the hyaluronic acid in the body, turning it into a low-molecular-weight acidic irritant, thereby causing histamine release and inducing the body to produce sensitive symptoms. In addition, the reduction of hyaluronic acid can destroy the barrier function of the skin, leading to water loss inside the skin. Therefore, inhibiting the activity of hyaluronidase can achieve the effects of soothing, moisturizing and repairing the skin barrier. This experiment uses test samples to treat hyaluronidase, and by detecting the reaction amount of sodium hyaluronate, to determine whether the cyclic peptide disclosed herein can inhibit the activity of hyaluronidase. The inhibition rate of hyaluronidase activity by the test samples is shown in Table 2.

[0149] Table 2 Inhibition rate of test samples on hyaluronidase activity (n=3)

[0150] The results showed that at a concentration of 500 ppm, the cyclic peptide A of the present disclosure had an inhibition rate of up to 74.4% on hyaluronidase activity, while the linear peptide had an inhibition rate of 42.5% on hyaluronidase activity. At the same concentration, the hyaluronidase inhibition rate of the cyclic peptide A of the present disclosure was significantly higher than that of the linear peptide, indicating that the cyclic peptide A obtained by head-to-tail cyclization of the present disclosure has a better technical effect than the linear peptide before cyclization, and its ability to inhibit hyaluronidase activity has been significantly improved.

[0151] It can be seen from this that the cyclic peptide disclosed in the present invention can inhibit the activity of hyaluronidase, and play the role of soothing, moisturizing and repairing the skin barrier.

[0152] Example 6 Mushroom tyrosinase inhibition experiment

[0153] 6.1 Reagents and Materials

[0154] PBS, mushroom tyrosinase, and levodopa (L-DOPA).

[0155] 6.2 Instruments

[0156] Constant temperature water bath, microplate reader.

[0157] 6.3 Samples to be tested and grouping

[0158] 6.3.1 Samples to be tested

[0159] The test concentrations of cyclic peptide A and linear peptide (GHKK) were 200ppm and 500ppm respectively.

[0160] 6.3.2 Grouping

[0161] Sample group: test sample, tyrosinase, PBS, L-DOPA;

[0162] Sample zeroing group: test sample, PBS, L-DOPA;

[0163] Blank control group: PBS, tyrosinase, L-DOPA;

[0164] Blank zero adjustment group: PBS, L-DOPA.

[0165] 6.4 Experimental methods

[0166] Take a 96-well plate, add 50μL of the sample to be tested and 50μL of tyrosinase (final concentration of 25U / mL) to the sample group; add 50μL of the sample to be tested and 50μL of PBS to the sample zero adjustment group; add 50μL of PBS and 50μL of tyrosinase (final concentration of 25U / mL) to the blank control group; add 100μL of PBS to the blank zero adjustment group. Incubate at 37℃ for 5min. Add 50μL of PBS and 50μL of L-DOPA (final concentration of 0.5mmol / L) to each well and incubate at 37℃ for 10min. Measure OD at 475nm 475 The tyrosinase inhibition rate was calculated.

[0167] Where: A1 is the OD of the sample zeroing group 475 value, A2 is the OD of the sample group 475 A3 is the OD of the blank zero adjustment group. 475 A4 is the OD of the blank control group. 475 value.

[0168] 6.5 Experimental Results

[0169] The inhibition rates of the test samples on tyrosinase activity are shown in Table 3.

[0170] Table 3 Inhibition rate of tyrosinase activity by test samples (n=3)

[0171] The results showed that the linear peptide had essentially no effect on tyrosinase activity, while cyclic peptide A significantly inhibited tyrosinase activity at the same concentration. Cyclic peptide A exhibited an inhibition rate of 11.7% at a concentration of 200 ppm, and this inhibition rate increased further to 16.0% at a concentration of 500 ppm. This demonstrates that, compared to the pre-cyclized linear peptide, the disclosed cyclic peptide A exhibits a novel effect, inhibiting tyrosinase activity and achieving unexpected technical benefits.

[0172] It can be seen from this that the cyclic peptide disclosed in the present invention can inhibit the activity of tyrosinase and reduce the production of melanin. It can be used to brighten skin color, fade spots or eliminate uneven skin color, achieve the effect of whitening and removing spots, and can be used in whitening and removing spots products, and can also be used to prepare sunscreens.

[0173] Example 7 A serum containing cyclic peptide A

[0174] Preparation method: Add the materials of phase A into a stirring pot according to the formula and heat to 80-85°C with stirring; mix the materials of phase B evenly until there are no powder particles, add them into a stirring pot, and continue stirring for 10-15 minutes; start cooling to 60-65°C and add the materials of phase C; cool to 35-40°C, add the materials of phase D and phase E, and stir for 10-15 minutes to obtain the product.

[0175] Example 8 A cream containing cyclic peptide A

[0176] Preparation method: According to the formula and dosage, heat the phase D material to 55-60°C in a suitable container, dissolve completely, and set aside; add phase A to a stirring pot, stir and heat to 80-85°C; add the phase B materials to the oil phase pot, stir and heat to 75-80°C, and dissolve completely and become transparent; add phase B into phase A, turn on the vacuum, homogenize for 5 minutes, maintain stirring, and keep warm for 20 minutes; start cooling, cool to 60-65°C, add phase C and pre-dissolved phase D materials, and homogenize for 2 minutes; cool to 35-40°C, add phase E materials, and stir for 10-15 minutes.

[0177] In this disclosure, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device comprising the element.

[0178] Although the specific embodiments of the present disclosure have been described for illustrative purposes, those skilled in the art may make various modifications or improvements without departing from the spirit and scope of the present disclosure. These modifications or improvements should fall within the scope of the appended claims of the present disclosure.

Claims

1. A cyclic peptide or a salt thereof, characterized in that The cyclic peptide has a structure represented by formula (I): Cyclo-[Gly-His-Lys-Lys](I).

2. The cyclic peptide represented by formula (I) or a salt thereof according to claim 1, characterized in that The salt includes a metal salt of the cyclic peptide represented by formula (I), and the metal includes: lithium, sodium, potassium, calcium, magnesium, manganese, copper, zinc or aluminum; Alternatively, the salt includes a salt formed by the cyclic peptide represented by formula (I) and an organic base, wherein the organic base includes: ethylamine, diethylamine, ethylenediamine, ethanolamine, diethanolamine, arginine, lysine, histidine or piperazine; Alternatively, the salt includes a salt formed by the cyclic peptide represented by formula (I) and an inorganic acid or an organic acid, wherein the organic acid includes: acetic acid, citric acid, lactic acid, malonic acid, maleic acid, tartaric acid, fumaric acid, benzoic acid, aspartic acid, glutamic acid, succinic acid, oleic acid, trifluoroacetic acid, oxalic acid, pamoic acid or gluconic acid; the inorganic acid includes: hydrochloric acid, sulfuric acid, boric acid or carbonic acid.

3. A composition, characterized in that The invention comprises an effective amount of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, and at least one excipient and an optional adjuvant.

4. The composition according to claim 3, characterized in that The adjuvant is selected from the group consisting of analgesics, agents that inhibit PAR-2 ​​activity, collagen synthesis stimulators, agents that regulate PGC-1α synthesis, agents that regulate PPARγ activity, agents that increase or decrease the triglyceride content of adipocytes, agents that stimulate or delay adipocyte differentiation, lipolytic agents or agents that stimulate fat decomposition, lipolytic agents, lipogenic agents, inhibitors of acetylcholine receptor aggregation, agents that inhibit muscle contraction, anticholinergic agents, elastase inhibitors, matrix metalloproteinase inhibitors, melanin synthesis stimulators or inhibitors, whitening agents or depigmenting agents, pigmentation promoting agents, self-tanning agents, anti-aging agents, NO-synthase inhibitors, 5α-reductase inhibitors, inhibitors of lysyl hydroxylase and / or prolyl hydroxylase, antioxidants, self- Agents comprising radical scavengers and / or anti-atmospheric pollution agents, active carbonyl scavengers, anti-glycation agents, antihistamines, antivirals, antiparasitic agents, emulsifiers, emollients, organic solvents, liquid propellants, moisture-retaining substances, alpha hydroxy acids, beta hydroxy acids, moisturizers, epidermal hydrolases, vitamins, amino acids, proteins, pigments, dyes, biopolymers, gelling polymers, thickeners, surfactants, softeners, adhesives, preservatives, anti-wrinkle agents, agents capable of reducing or treating under-eye bags, keratolytic agents, antimicrobial agents, agents that stimulate the synthesis of dermal or epidermal macromolecules and / or are capable of inhibiting or preventing their degradation, agents that stimulate elastin synthesis, agents that stimulate decorin synthesis, agents that stimulate laminin synthesis, Agents that stimulate defensin synthesis, agents that stimulate chaperone protein synthesis, agents that stimulate cAMP synthesis, agents that stimulate hyaluronic acid synthesis, agents that stimulate fibronectin synthesis, agents that stimulate deacetylase synthesis, agents that stimulate the synthesis of lipids and stratum corneum components, ceramides, fatty acids, agents that inhibit collagen degradation, agents that inhibit elastin degradation, agents that inhibit serine proteases, agents that stimulate fibroblast proliferation, agents that stimulate keratinocyte proliferation, agents that stimulate adipocyte proliferation, agents that stimulate melanocyte proliferation, agents that stimulate keratinocyte differentiation, agents that inhibit acetylcholinesterase, skin relaxants, agents that stimulate glycosaminoglycan synthesis, anti-hyperkeratosis agents, comedolytic agents, anti-psoriatic agents, anti-eczema agents, DNA repair agents, DN A protective agent, a stabilizer, an antipruritic agent, an agent for treating and / or caring for sensitive skin, a firming agent, a firming agent, a restructuring agent, an agent against stretch marks, an agent for regulating sebum production, an antiperspirant, an agent that stimulates healing, an agent that assists healing, an agent that stimulates re-epithelialization, an agent that assists re-epithelialization, a cytokine, a sedative, an anti-inflammatory agent, an anesthetic, an agent that acts on capillary circulation and / or microcirculation, an agent that stimulates angiogenesis, an agent that inhibits vascular permeability, a venous tension agent, an agent that acts on cellular metabolism, an agent for improving the dermal-epidermal junction, an agent that induces hair growth, an agent that inhibits or delays hair growth, a fragrance, a chelating agent, a plant extract, an essential oil, a marine extract, an agent obtained from a biofermentation process, an inorganic salt, a cell extract, a sunscreen,and organic or inorganic light protection agents or mixtures thereof that are effective against ultraviolet A and / or ultraviolet B rays.

5. A delivery system or sustained-release system, characterized in that Comprising an effective amount of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4; The delivery system or sustained-release system includes: liposomes, oleosomes, ethosomes, millicapsules, microcapsules, nanocapsules, nanostructured lipid carriers, sponges, inclusion compounds, lipid vesicles, micelles, millispheres, microspheres, nanospheres, lipid spheres, microemulsions, nanoemulsions, milliparticles, microparticles or nanoparticles.

6. A cosmetic, characterized in that: Comprising an effective amount of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5.

7. The cosmetic according to claim 6, characterized in that The dosage forms of the cosmetics include ointments, creams, emulsions, aqueous solutions, oils, gels, powders, tablets, muds, patches, films, aerosols, sprays, freeze-dried preparations or nano preparations.

8. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in the preparation of a composition for caring for or treating skin or mucous membranes.

9. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in the preparation of a composition for anti-aging, repairing, moisturizing or soothing.

10. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in the preparation of a composition for whitening, brightening skin color, removing spots and / or eliminating uneven skin color.

11. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in preparing a composition for inhibiting elastase activity, or in preparing a composition for promoting collagen production, or in preparing a composition for increasing skin elasticity and / or improving skin firmness, or in preparing a composition for promoting regeneration or healing of skin or mucous membranes, or in preparing a composition for repairing the skin barrier, or in preparing a composition for inhibiting hyaluronidase activity, or in preparing a composition for inhibiting tyrosinase activity, or in preparing a composition for inhibiting melanin production.

12. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in the preparation of a sunscreen.

13. Use of the cyclic peptide represented by formula (I) or a salt thereof according to claim 1 or 2, or the composition according to claim 3 or 4, or the delivery system or sustained-release system according to claim 5 in the preparation of cosmetics.

Images