Resorcinol conjugate as well as preparation method and application thereof

Abstract

The invention discloses a resorcinol conjugate as well as a preparation method and application thereof, and belongs to the technical field of cosmetics. The structural formula of the resorcinol conjugate is as follows: # imgabs0 #, R1 and R2 independently comprise alpha glucoside, beta glucoside or phenolic hydroxyl groups, and R1 and R2 are not phenolic hydroxyl groups at the same time. The resorcinol conjugate is not prone to self-oxidation reaction, high in stability, long in shelf life and long in efficacy durability. The resorcinol conjugate can whiten skin, fade spots, reduce skin irritation and sensitivity and promote proliferation of beneficial bacteria on epidermis.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and more particularly, to a resorcinol conjugate, a preparation method thereof, and an application thereof. Background Art

[0002] Existing 4-phenethylresorcinol has good whitening effects in cosmetics. However, this compound is prone to autoxidation reactions, resulting in a short product shelf life, easy color change, and poor efficacy persistence.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a resorcinol conjugate, a preparation method thereof, and an application thereof to solve or improve the above technical problems.

[0005] The present invention can be implemented as follows:

[0006] The present invention provides a resorcinol conjugate, and the structural formula of the resorcinol conjugate is as follows: Wherein, R1 and R2 independently include α-glucoside, β-glucoside or phenolic hydroxyl, and R1 and R2 are not phenolic hydroxyl at the same time.

[0007] In an alternative embodiment, the resorcinol conjugate includes at least one of 4-phenethylresorcinol-1-o-α-glucoside, 4-phenethylresorcinol-1-o-β-glucoside, 4-phenethylresorcinol-1,3-bis-o-α-glucoside, and 4-phenethylresorcinol-1,3-bis-o-β-glucoside.

[0008] The present invention also provides a preparation method of the resorcinol conjugate as described in the foregoing embodiment, including the following steps: according to the preset structural formula of the resorcinol conjugate, by chemical synthesis, modify the glycoside corresponding to R1 to the phenolic hydroxyl position para to the phenethyl group in 4-phenethylresorcinol; or, according to the preset structural formula of the resorcinol conjugate, by chemical synthesis, modify the glycoside corresponding to R1 to the phenolic hydroxyl position para to the phenethyl group in 4-phenethylresorcinol, and modify the glycoside corresponding to R2 to the phenolic hydroxyl position ortho to the phenethyl group in 4-phenethylresorcinol.

[0009] In an alternative embodiment, when the resorcinol conjugate is 4-phenethylresorcinol-1-o-α-glucoside or 4-phenethylresorcinol-1,3-bis-o-α-glucoside, the preparation of the resorcinol conjugate includes the following steps: prepare a glycosylation donor using fully acetylated glucose; react the activated 4-phenethylresorcinol with the glycosylation donor.

[0010] In an alternative embodiment, when the resorcinol conjugate is 4-phenethylresorcinol-1-O-β-glucoside or 4-phenethylresorcinol-1,3-bis-O-β-glucoside, the preparation of the resorcinol conjugate comprises the following steps: preparing a halosugarylated donor using fully acetylated glucose; reacting the activated 4-phenethylresorcinol with the halosugarylated donor.

[0011] The present invention also provides an application of the resorcinol conjugate as described in the foregoing embodiments in at least one of the following aspects:

[0012] Aspect 1: Promoting the proliferation of beneficial epidermal bacteria;

[0013] Aspect 2: Improving or enhancing skin whitening effect;

[0014] Aspect 3: Fading spots;

[0015] Aspect 4: Reducing or improving skin irritation.

[0016] In an alternative embodiment, the beneficial epidermal bacteria include Staphylococcus epidermidis.

[0017] In an alternative embodiment, the resorcinol conjugate is used to relieve or improve skin pigmentation.

[0018] In an alternative embodiment, the resorcinol conjugate is used to reduce the content of hydroxyl radicals.

[0019] The present invention also provides a cosmetic product containing the resorcinol conjugate as described in the foregoing embodiments.

[0020] The beneficial effects of the present invention include:

[0021] The resorcinol conjugate provided by the present invention grafts a glycoside at the position of at least one phenolic hydroxyl group in 4-phenethylresorcinol. After grafting, the compound molecule is not prone to autoxidation reaction, has strong stability, and can have a long shelf life and efficacy persistence. The resorcinol conjugate can whiten the skin, fade spots, reduce skin irritation and sensitivity, and in addition, can promote the proliferation of beneficial epidermal bacteria. Detailed implementation manners

[0022] 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. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0023] The resorcinol conjugate provided by the present invention, its preparation method and application will be specifically described below.

[0024] The present invention provides a class of resorcinol conjugates, and their structural formula is as follows: Wherein, R1 and R2 independently include α-glucoside, β-glucoside or phenolic hydroxyl group, and R1 and R2 are not phenolic hydroxyl groups at the same time.

[0025] In some alternative embodiments, the resorcinol conjugate may include at least one of 4-phenethylresorcinol-1-o-α-glucoside, 4-phenethylresorcinol-1-o-β-glucoside, 4-phenethylresorcinol-1,3-bis-o-α-glucoside and 4-phenethylresorcinol-1,3-bis-o-β-glucoside.

[0026] Among them, the structural formula of 4-phenethylresorcinol-1-o-α-glucoside is: The structural formula of 4-phenethylresorcinol-1-o-β-glucoside is The structural formula of 4-phenethylresorcinol-1,3-bis-o-α-glucoside is The structural formula of 4-phenethylresorcinol-1,3-bis-o-β-glucoside is

[0027] The resorcinol conjugate provided by the present invention grafts glycosides at the position of at least one phenolic hydroxyl group in 4-phenethylresorcinol. After grafting, the compound molecule is not prone to autoxidation reaction, has strong stability, and can have a long shelf life and efficacy persistence. The resorcinol conjugate can whiten the skin, fade spots, reduce skin irritation and sensitivity, and in addition, can promote the proliferation of beneficial bacteria on the epidermis.

[0028] Among them, after grafting glycosides, not only the hydrophilicity of the compound is improved, but also the direct exposure of phenolic hydroxyl groups is avoided, so that the irritation and sensitivity of the compound to the skin can be reduced, and adverse reactions such as skin redness, stinging, and dryness can be reduced. Secondly, the glycoside group can protect the hydroxyl group through steric hindrance effect, reduce the generation of free radicals and the possibility of reaction with oxygen, so that the resorcinol conjugate has a long shelf life and efficacy persistence. In addition, the resorcinol conjugate after grafting glycosides can be degraded through skin microecology, and effectively exert the whitening effect of 4-phenethylresorcinol.

[0029] Accordingly, the present invention provides a method for preparing the above-mentioned resorcinol conjugate, comprising the following steps: According to the preset resorcinol conjugate structural formula, by means of chemical synthesis, glycosides corresponding to R1 are modified to the phenolic hydroxyl position para to the phenethyl group in 4-phenethylresorcinol. Or, according to the preset resorcinol conjugate structural formula, by means of chemical synthesis, glycosides corresponding to R1 are modified to the phenolic hydroxyl position para to the phenethyl group in 4-phenethylresorcinol, and glycosides corresponding to R2 are modified to the phenolic hydroxyl position ortho to the phenethyl group in 4-phenethylresorcinol.

[0030] In some optional embodiments, when the resorcinol conjugate is 4-phenethylresorcinol-1-o-α-glucoside or 4-phenethylresorcinol-1,3-bis-o-α-glucoside, the preparation of the resorcinol conjugate comprises the following steps: preparing a glycosylation donor using fully acetylated glucose; reacting the activated 4-phenethylresorcinol with the glycosylation donor. Subsequently, 4-phenethylresorcinol-1-o-α-glucoside and 4-phenethylresorcinol-1,3-bis-o-α-glucoside can be separated by conventional silica gel column chromatography and reverse-phase preparative column for separation and purification.

[0031] Exemplarily, fully acetylated glucose can be used to prepare a glycosylation donor by catalytically initiating the neighboring group participation effect under low temperature and a catalyst. Among them, the low temperature can be -10°C to -20°C, and the catalyst can be, for example, BF3·Et2O. After dissolving 4-phenethylresorcinol (the solvent can be, for example, anhydrous N,N-dimethylformamide), an activator (60% oil dispersion) is added for activation to generate a phenoxide anion, activating the phenolic hydroxyl group. Among them, the activator can be NaH (60% oil dispersion), and its dosage can be 1.2 equivalents of 4-phenethylresorcinol. The activation temperature can be 0°C to 5°C, and the activation time can be 20 min to 40 min. React the activated 4-phenethylresorcinol with the glycosyl donor in CH2Cl2, and stir for 16 h to 20 h under the protection of argon at -15°C to -25°C. After TLC monitoring shows that the raw material spot disappears, saturated NaHCO3 is added for quenching to obtain a crude product. The crude product is obtained as a white solid by silica gel column chromatography, and then further separated and purified by a reverse-phase preparative column. The elution solvent is an organic solvent containing water, and the eluate containing the target product is collected. The eluate is concentrated under reduced pressure and freeze-dried.

[0032] In some alternative embodiments, when the resorcinol conjugate is 4-phenethylresorcinol-1-O-β-glucoside or 4-phenethylresorcinol-1,3-bis-O-β-glucoside, the preparation of the resorcinol conjugate comprises the following steps: preparing a halogenated glycosylation donor using fully acetylated glucose; reacting the activated 4-phenethylresorcinol with the halogenated glycosylation donor. Subsequently, 4-phenethylresorcinol-1-O-β-glucoside and 4-phenethylresorcinol-1,3-bis-O-β-glucoside can be separated by conventional silica gel column chromatography and reverse-phase preparative column for separation and purification.

[0033] Exemplarily, the fully acetylated glucose can be reacted with a 30% - 35% HX / acetic acid solution for 2 h - 4 h to prepare the halogenated glycosylation donor. Herein, X in HX is a halogen, such as Cl, Br, I, etc. After dissolving 4-phenethylresorcinol (the solvent can be, for example, anhydrous N,N-dimethylformamide), an activator (60% oil dispersion) is added for activation to generate a phenoxide anion, activating the phenolic hydroxyl group. The activator can be NaH (60% oil dispersion), and its dosage can be 1.2 equivalents of 4-phenethylresorcinol. The activation temperature can be 0°C - 5°C, and the activation time can be 20 min - 40 min. The activated 4-phenethylresorcinol and the halogenated glycosylation donor are mixed in anhydrous acetonitrile, Ag2CO3 and a molecular sieve (such as molecular sieve) are added, and the mixture is stirred at 50°C - 60°C for 20 h - 28 h to obtain a crude product. Herein, Ag2CO3 can play the following roles: ①. Activating the halogenated sugar donor: Ag + (partial dissociation from Ag2CO3) combines with the halogen (such as Br - 、I - etc.) in the halogenated sugar to form insoluble silver halide (such as AgBr), promoting the dissociation of the halogen leaving group. This process generates an activated oxonium ion intermediate (glycosyl cation), making it more susceptible to attack by a nucleophile (phenoxide anion), thereby forming a glycosidic bond. ②. Neutralizing the reaction by-product acid (HX): The HX (such as HBr) generated in the reaction will acidify the system, which may cause the decomposition of the glycosyl donor or the product. As a weakly basic salt, Ag2CO3 reacts with HX to generate CO2, H2O and AgX precipitate, consuming the acidic by-product and maintaining the pH stability of the reaction system to prevent side reactions under acidic conditions. The white solid is obtained by silica gel column chromatography, and then further separation and purification are carried out using a reverse-phase preparative column. The elution solvent is an organic solvent containing water, the eluate containing the target product is collected, and the eluate is concentrated under reduced pressure and freeze-dried.

[0034] It should be noted that the above content only provides one feasible method among many preparation methods. During the actual production and preparation process, the above preparation parameters and conditions can be reasonably adjusted and replaced, and no excessive limitations are imposed here.

[0035] In addition, the present invention also provides the application of the above resorcinol conjugate.

[0036] Exemplarily, the above resorcinol conjugate can be used in at least one of the following aspects:

[0037] Aspect 1: Promote the proliferation of beneficial bacteria on the epidermis, such as promoting the proliferation of Staphylococcus epidermidis.

[0038] Aspect 2: Improve or enhance the skin whitening effect, such as alleviating or improving skin pigmentation, especially inhibiting the tyrosinase activity in B16F10 melanoma cells;

[0039] Aspect 3: Fade skin blemishes, such as alleviating or improving skin pigmentation, especially inhibiting the tyrosinase activity in B16F10 melanoma cells;

[0040] Aspect 4: Reduce or improve skin irritation, such as reducing the content of hydroxyl radicals.

[0041] Furthermore, the present invention also provides a cosmetic, which contains the above resorcinol conjugate. It should be noted that the specific types of cosmetics to which the resorcinol conjugate of the present invention can be applied are not limited, and existing cosmetic types can all be used.

[0042] The features and properties of the present invention are further described in detail below in conjunction with the examples.

[0043] Example 1

[0044] This example provides two resorcinol conjugates. Among them, the structural formula of 4-phenethylresorcinol-1-o-α-glucoside is: The structural formula of 4-phenethylresorcinol-1,3-bis-o-α-glucoside is:

[0045] The synthesis methods of the above two resorcinol conjugates (both with a purity > 95%) are as follows: Using fully acetylated glucose, under the conditions of low temperature (-10°C) and a catalyst (BF3·Et2O), the neighboring group participation effect is catalytically initiated to obtain a glycosylated donor. After dissolving 4-phenethylresorcinol (the solvent is anhydrous N,N-dimethylformamide), an activator is added for activation to generate a phenoxide anion, thereby activating the phenolic hydroxyl group. Among them, the activator is NaH (60% oil dispersion), and its dosage is 1.2 equivalents of 4-phenethylresorcinol. The activation temperature is 0°C, and the activation time is 40 min. The activated 4-phenethylresorcinol is reacted with the glycosylated donor in CH2Cl2, and stirring is carried out at -15°C under argon protection for 20 h. After TLC monitoring shows that the raw material spots disappear, saturated NaHCO3 is added for quenching to obtain a crude product. The crude product is obtained as a white solid through silica gel column chromatography, and then further separation and purification are carried out using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. The eluate containing the target product is collected, and the eluate is concentrated under reduced pressure and freeze-dried.

[0046] That is, the crude product contains both 4-phenethylresorcinol-1-o-α-glucoside and 4-phenethylresorcinol-1,3-bis-o-α-glucoside. The above two resorcinol conjugates can be separated through subsequent silica gel column chromatography and reverse-phase preparative column separation and purification.

[0047] Among them, the conditions for silica gel column chromatography are as follows:

[0048] Stationary phase: silica gel (200 mesh - 300 mesh, diameter 2 cm, height 30 cm);

[0049] Flow rate: 5 mL / min;

[0050] Mobile phase: In the form of gradient elution, starting with petroleum ether (PE) / ethyl acetate (EA) = 8:2 (v / v), and gradually increasing to PE / EA = 6:4 (1 h) after 1 h to obtain a crude product of diglycoside, and then to PE / EA = 5:5 (1 h) to obtain a crude product of monoglycoside;

[0051] The conditions for reverse-phase preparative liquid chromatography are as follows:

[0052] Stationary phase: reverse-phase C18 preparative column (5 μm, 21.2×50 mm);

[0053] Flow rate: 10 mL / min;

[0054] Mobile phase: acetonitrile:H2O = 40:60 (v / v).

[0055] Example 2

[0056] This example provides a synthesis method for two resorcinol conjugates, 4-phenethylresorcinol-1-O-α-glucoside and 4-phenethylresorcinol-1,3-bis-O-α-glucoside (both with a purity > 95%). The differences from Example 1 are as follows: Using fully acetylated glucose, the neighboring group participation effect is catalytically initiated under low temperature (-20 °C) and in the presence of a catalyst (BF3·Et2O) to obtain a glycosylated donor. After dissolving 4-phenethylresorcinol (the solvent is anhydrous N,N-dimethylformamide), an activator is added for activation to generate a phenoxide anion, activating the phenolic hydroxyl group. Among them, the activator is NaH (60% oil dispersion), and its dosage is 1.2 equivalents of 4-phenethylresorcinol. The activation temperature is 5 °C, and the activation time is 20 min. The activated 4-phenethylresorcinol is reacted with the glycosylated donor in CH2Cl2, and stirring is carried out at -25 °C under argon protection for 16 h. After TLC monitoring shows that the raw material spots disappear, saturated NaHCO3 is added for quenching to obtain a crude product. The crude product is obtained as a white solid by silica gel column chromatography, and then further separated and purified using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. The eluate containing the target product is collected, and the eluate is concentrated under reduced pressure and freeze-dried.

[0057] Example 3

[0058] This example provides two resorcinol conjugates. Among them, the structural formula of 4-phenethylresorcinol-1-O-β-glucoside is: The structural formula of 4-phenethylresorcinol-1,3-bis-O-β-glucoside is:

[0059] The synthesis method of the above two resorcinol conjugates (both with a purity > 95%) is as follows: React fully acetylated glucose with 30% HBr / acetic acid solution for 2 h to obtain a brominated glycosylated donor. After dissolving 4-phenethylresorcinol (the solvent is anhydrous N,N-dimethylformamide), an activator is added for activation to generate a phenoxide anion, activating the phenolic hydroxyl group. Among them, the activator is NaH (60% oil dispersion), and its dosage is 1.2 equivalents of 4-phenethylresorcinol. The activation temperature is 0 °C, and the activation time is 40 min. The activated 4-phenethylresorcinol is mixed with the brominated glycosylated donor in anhydrous acetonitrile, Ag2CO3 and molecular sieve ( molecular sieve) are added, and stirring is carried out at 50 °C for 28 h to obtain a crude product. The crude product is obtained as a white solid by silica gel column chromatography, and then further separated and purified using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. The eluate containing the target product is collected, and the eluate is concentrated under reduced pressure and freeze-dried.

[0060] That is, the crude product contains both 4-phenethylresorcinol-1-O-β-glucoside and 4-phenethylresorcinol-1,3-bis-O-β-glucoside. The above two resorcinol conjugates can be separated by subsequent silica gel column chromatography and reverse-phase preparative column separation and purification.

[0061] Among them, the conditions for silica gel column chromatography are as follows:

[0062] Stationary phase: silica gel (200 mesh - 300 mesh, diameter 2 cm, height 30 cm);

[0063] Flow rate: 5 mL / min;

[0064] Mobile phase: in the form of gradient elution. Initially, petroleum ether (PE) / ethyl acetate (EA) = 8:2 (v / v), and it is gradually increased to PE / EA = 6:4 (1 h) after 1 h to obtain the crude product of diglycoside, and then to PE / EA = 5:5 (1 h) to obtain the crude product of monoglycoside.

[0065] The conditions for reverse-phase preparative liquid chromatography are as follows:

[0066] Stationary phase: reverse-phase C18 preparative column (5 μm, 21.2×50 mm);

[0067] Flow rate: 10 mL / min;

[0068] Mobile phase: acetonitrile:H2O = 40:60 (v / v).

[0069] Example 4

[0070] This example provides a synthesis method for two resorcinol conjugates, 4-phenethylresorcinol-1-O-β-glucoside and 4-phenethylresorcinol-1,3-bis-O-β-glucoside (both with a purity > 95%). The differences from Example 3 are as follows: Peracetylated glucose is reacted with 35% HCl / acetic acid solution for 4 h to obtain a chloroglycosylated donor. After dissolving 4-phenethylresorcinol (the solvent is anhydrous N,N-dimethylformamide), an activator is added for activation to generate a phenoxide anion and activate the phenolic hydroxyl group. Among them, the activator is NaH (60% oil dispersion), and its dosage is 1.2 equivalents of 4-phenethylresorcinol. The activation temperature is 5 °C, and the activation time is 20 min. The activated 4-phenethylresorcinol is mixed with the chloroglycosylated donor in anhydrous acetonitrile, Ag2CO3 and molecular sieve ( molecular sieve) are added, and the mixture is stirred at 60 °C for 20 h to obtain a crude product. A white solid is obtained through silica gel column chromatography, and then further separation and purification are carried out using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. The eluate containing the target product is collected, and the eluate is concentrated under reduced pressure and freeze-dried.

[0071] Example 5

[0072] Investigation on the stability of resorcinol conjugates.

[0073] Taking the resorcinol conjugates provided in Example 1 and Example 3 as examples, and using 4-phenethylresorcinol without glycosylation modification as a comparison.

[0074] The above-mentioned resorcinol conjugates and 4-phenethylresorcinol were respectively prepared into DMSO solutions with a concentration of 0.3 wt% with water and dispensed into sterile experimental bottles. The dispensed samples were placed in a thermostatic and humidified chamber at a temperature of 55 °C and a humidity of 50% for stability investigation. After 1 month, each sample was taken out and the change of its main components (calculated by retention rate) was detected by HPLC. The test results are shown in Table 1.

[0075] The conditions for the above HPLC detection were: C18 column (5 μm, 150 mm × 4.6 mm); the mobile phase was water (A) and acetonitrile (B), A:B = 70:30 (volume ratio); the flow rate was 1.0 mL / min; the injection volume was 10 μl; the detection wavelength was 280 nm.

[0076] Table 1 Stability test results

[0077] Sample Name Retention Rate 4-Phenethylresorcinol 42.31％ 4-Phenethylresorcinol-1-o-α-glucoside 98.85％ 4-Phenethylresorcinol-1-o-β-glucoside 97.72％ 4-Phenethylresorcinol-1,3-bis-o-α-glucoside 98.74％ 4-Phenethylresorcinol-1,3-bis-o-β-glucoside 99.01％

[0078] It can be seen from Table 1 that after the resorcinol conjugate provided by the present invention was formulated into a 0.3% aqueous solution, compared with 4-phenethylresorcinol without glycosylation modification, it remained stable after being investigated at 55 °C and a humidity of 50% for 1 month, and its stability was significantly better than that of 4-phenethylresorcinol as a comparison.

[0079] Example 4

[0080] Effect of resorcinol conjugate on the content of hydroxyl radicals.

[0081] Taking the resorcinol conjugates provided in Example 1 and Example 3 as examples, and using 4-phenethylresorcinol without glycosylation modification as a comparison.

[0082] The above-mentioned resorcinol conjugates and 4-phenethylresorcinol were respectively prepared into solutions with a concentration of 0.3 wt% with water and dispensed into sterile experimental bottles. Each sample was placed in a thermostatic and humidified chamber at a temperature of 55 °C and a humidity of 50% for 1 month.

[0083] 10 μL of each of the above samples, 10 μL of HPF, and 80 μL of phosphate buffer (pH 7.2) were added to each well in a 96-well plate, with a total of 100 μL. The fluorescence intensity was measured after 60 min. The amount of hydroxyl radicals was measured by the fluorescence intensity after adding HPF, and the results are shown in Table 2.

[0084] Table 2 Relative generation amount of hydroxyl radicals (in terms of fluorescence intensity)

[0085] Sample Name Relative Generation Amount of Hydroxyl Radical 4-Phenethylresorcinol 18321 4-Phenethylresorcinol-1-o-α-glucoside 1804 4-Phenethylresorcinol-1-o-β-glucoside 3188 4-Phenethylresorcinol-1,3-bis-o-α-glucoside 973 4-Phenethylresorcinol-1,3-bis-o-β-glucoside 1209

[0086] As can be seen from Table 2: After the resorcinol conjugate provided by the present invention is formulated into a 0.3% aqueous solution, compared with 4-phenethylresorcinol without glycosylation modification, the amount of hydroxyl radicals generated after being examined at 55 °C and 50% humidity for 1 month is significantly lower than that of 4-phenethylresorcinol as a comparison, that is, the irritancy of the resorcinol conjugate provided by the present invention is lower.

[0087] Example 5

[0088] Effect of resorcinol conjugate on the proliferation of epidermal beneficial bacteria.

[0089] Taking the resorcinol conjugates provided in Example 1 and Example 3 as examples, and using 4-phenethylresorcinol without glycosylation modification as a comparison.

[0090] Staphylococcus epidermidis stored at -80 °C (preservation number: CMCC26069, purchased from the China Center for Medical Bacterial Preservation and Management) was resuscitated in LB liquid medium at 37 °C and 200 rpm for about 24 h, and the activated strain was collected by centrifugation at 4000 rpm for 2 min, and the medium was removed after washing twice with sterile water. The cells were suspended with sterile water to make the OD 600 value about 0.6. 600 μL of the cell suspension was taken and added with resorcinol conjugate, 4-phenethylresorcinol or blank control with a final concentration of 100 ppm into a 24-well plate, and continuously cultured at 37 °C and 100 rpm for 8 h. During this period, the OD 600 value was detected using a microplate reader every hour, and the growth curve was plotted. The proliferation rate results of Staphylococcus epidermidis after 8 h are shown in Table 3.

[0091] 4-Phenethylresorcinol-1-o-α-glucoside was formulated into aqueous solutions with concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm and 10000 ppm respectively in the above manner, and the proliferation rates of Staphylococcus epidermidis corresponding to different concentrations after 8 h were tested by the above method, and the results are shown in Table 4.

[0092] Table 3 Proliferation rate of Staphylococcus epidermidis

[0093] Sample Name Proliferation Rate of Staphylococcus epidermidis (%) 4-Phenethylresorcinol -3.71 4-Phenethylresorcinol-1-o-α-glucoside 65.37 4-Phenethylresorcinol-1-o-β-glucoside 44.92 4-Phenethylresorcinol-1,3-bis-o-α-glucoside 92.51 4-Phenethylresorcinol-1,3-bis-o-β-glucoside 89.78

[0094] Table 4 Effect of 4-phenethylresorcinol-1-o-α-glucoside with different concentrations on the proliferation rate of Staphylococcus epidermidis

[0095] Concentration of 4-Phenethylresorcinol-1-o-α-glucoside (ppm) Proliferation Rate of Staphylococcus epidermidis (%) 1 14.36 10 55.19 100 65.37 1000 102.12 10000 161.35

[0096] As can be seen from Table 3, the resorcinol conjugate provided by the present invention has the effect of promoting the proliferation of beneficial epidermal bacteria compared with 4-phenethylresorcinol without glycosylation modification, which helps to establish a healthy skin microecological barrier.

[0097] As can be seen from Table 4, 4-phenethylresorcinol-1-o-α-glucoside provided by the present invention has the effect of promoting the proliferation of beneficial epidermal bacteria in the concentration range of 1 ppm to 10,000 ppm.

[0098] Example 6

[0099] Inhibitory effect of metabolites of Staphylococcus epidermidis of resorcinol conjugate on tyrosinase activity in B16F10 melanoma cells.

[0100] ① Preparation of metabolites of Staphylococcus epidermidis of resorcinol conjugate <C <C

[0101] Taking the resorcinol conjugates provided in Example 1 and Example 3 as examples, and using 4-phenethylresorcinol without glycosylation modification as a comparison. <C <C

[0102] Staphylococcus epidermidis (preservation number: CMCC26069, purchased from China Center for Medical Bacteria Culture Collection) preserved at -80 °C was resuscitated in LB liquid medium at 37 °C and 200 rpm for about 24 h. The activated strains were collected by centrifugation at 4000 rpm for 2 min, and the medium was removed after washing twice with sterile water. The cells were suspended with sterile water to make the OD 600 value about 0.6. 600 μl of the bacterial suspension was taken and added to each sample group (4-phenethylresorcinol, resorcinol conjugate) or blank control in a 24-well plate. The final concentrations of the sample groups were 1 ppm, 10 ppm, 100 ppm, and 1000 ppm. After continuous culture at 37 °C and 100 rpm for 8 h, the supernatant was taken, filtered twice through a 0.22 μm filter membrane to remove bacteria, and then freeze-dried. Subsequently, it was dispersed in 600 μL of high-glucose DMEM medium to obtain the metabolites of Staphylococcus epidermidis of the test samples (4-phenethylresorcinol, resorcinol conjugate) or blank control samples with final concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10,000 ppm for subsequent experiments. <C <C

[0103] ② Test of inhibitory effect <C <C

[0104] B16 melanoma cells in good growth state were seeded in 24-well plates at a concentration of 60,000 cells / well (using high-glucose DMEM medium from Gibco). After 24 hours, the prepared test samples (4-phenethylresorcinol, resorcinol conjugate) or the metabolite of Staphylococcus epidermidis as the blank control sample were added, and the final concentrations of the sample groups were 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10,000 ppm. Then they were cultured at 37 °C for 48 hours. After washing 3 times with PBS, 500 μL of PBS solution containing 0.1 mmol / L L-DOPA and 0.1% Triton-X was added to each well. After incubating at 37 °C for 30 minutes, the OD value at 475 nm was measured, and the inhibitory effect of 4-phenethylresorcinol or resorcinol conjugate on tyrosinase activity was calculated according to the following formula. The results are shown in Table 5.

[0105] Inhibitory rate of tyrosinase activity = [1 - (OD of sample group 475nm ) / (OD of blank group 475nm )] × 100%.

[0106] 4-Phenethylresorcinol-1-o-α-glucoside was respectively prepared into aqueous solutions with concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10,000 ppm in the above manner, and the inhibitory rates of tyrosinase activity corresponding to different concentrations were tested according to the above method. The results are shown in Table 6.

[0107] Table 5 Effects of metabolites of Staphylococcus epidermidis on tyrosinase activity in B16F10 melanoma cells

[0108]

[0109]

[0110] Table 6 Effects of metabolites of Staphylococcus epidermidis with different concentrations of 4-phenethylresorcinol-1-o-α-glucoside on tyrosinase activity in B16F10 melanoma cells

[0111]

[0112] It can be seen from Table 5 that the resorcinol conjugate provided by the present invention has a better effect of inhibiting tyrosinase activity in B16F10 melanoma cells compared with 4-phenethylresorcinol without glycosylation modification, which helps to alleviate or improve skin pigmentation.

[0113] As can be seen from Table 6, 4-phenethylresorcinol-1-O-α-glucoside provided by the present invention has the effect of inhibiting the tyrosinase activity in B16F10 melanoma cells within the concentration range of 1 ppm to 10,000 ppm.

[0114] In summary, the resorcinol conjugate provided by the present invention is not prone to autoxidation reaction, has strong stability, and can have a long shelf life and efficacy persistence. The resorcinol conjugate can whiten the skin, fade spots, reduce skin irritation and sensitivity, and in addition, can promote the proliferation of beneficial bacteria on the epidermis.

[0115] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A resorcinol conjugate, characterized in that, The structural formula of the resorcinol conjugate is as follows: Wherein, R1 and R2 independently include α-glucoside, β-glucoside or phenolic hydroxyl, and R1 and R2 are not phenolic hydroxyl at the same time.

2. The resorcinol conjugate according to claim 1, wherein The resorcinol conjugate includes at least one of 4-phenethylresorcinol-1-O-α-glucoside, 4-phenethylresorcinol-1-O-β-glucoside, 4-phenethylresorcinol-1,3-bis-O-α-glucoside, and 4-phenethylresorcinol-1,3-bis-O-β-glucoside.

3. A method for preparing a resorcinol conjugate as claimed in claim 1 or 2, characterized in that, It includes the following steps: According to the preset resorcinol conjugate structural formula, by chemical synthesis, glycosides corresponding to R1 are modified to the phenolic hydroxyl group position para to the phenethyl group in 4-phenethylresorcinol; or, according to the preset resorcinol conjugate structural formula, by chemical synthesis, glycosides corresponding to R1 are modified to the phenolic hydroxyl group position para to the phenethyl group in 4-phenethylresorcinol, and glycosides corresponding to R2 are modified to the phenolic hydroxyl group position ortho to the phenethyl group in 4-phenethylresorcinol.

4. The preparation method according to claim 3, characterized in that, When the resorcinol conjugate is 4-phenethylresorcinol-1-O-α-glucoside or 4-phenethylresorcinol-1,3-bis-O-α-glucoside, the preparation of the resorcinol conjugate includes the following steps: preparing a glycosylation donor using fully acetylated glucose; reacting the activated 4-phenethylresorcinol with the glycosylation donor.

5. The preparation method according to claim 3, wherein When the resorcinol conjugate is 4-phenethylresorcinol-1-O-β-glucoside or 4-phenethylresorcinol-1,3-bis-O-β-glucoside, the preparation of the resorcinol conjugate includes the following steps: preparing a halogenated glycosylation donor using fully acetylated glucose; reacting the activated 4-phenethylresorcinol with the halogenated glycosylation donor.

6. Use of a resorcinol conjugate as claimed in claim 1 or 2 in at least one of the following aspects: Aspect one: promoting the proliferation of beneficial epidermal bacteria; Aspect two: enhancing or improving skin whitening effect; Aspect three: fading spots; Aspect four: reducing or improving skin irritation.

7. The application according to claim 6, wherein The beneficial epidermal bacteria include Staphylococcus epidermidis.

8. The application according to claim 6, characterized in that, The resorcinol conjugate is used for relieving or improving skin pigmentation.

9. The application according to claim 7, characterized in that, The resorcinol conjugate is used for reducing the content of hydroxyl radicals.

10. A cosmetic, characterized in that, The cosmetic contains the resorcinol conjugate as claimed in claim 1 or 2.

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