Whitening compound as well as preparation method and application thereof

Abstract

The invention discloses a whitening compound as well as a preparation method and application thereof, and belongs to the technical field of cosmetics. The structural formula of the whitening compound 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 whitening compound has higher stability, is not easy to generate self-oxidation reaction, and is beneficial to prolonging the shelf life of the product and prolonging the durability of the whitening effect; moreover, the whitening compound is suitable for sensitive skin, and can reduce skin irritation and reduce adverse reactions such as red and swollen, stabbing pain, dryness and the like; in addition, the whitening compound can promote proliferation of beneficial bacteria on epidermis, and can improve or improve the skin whitening effect to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and in particular, to a whitening compound, a preparation method thereof, and an application thereof. Background Art

[0002] Existing compounds containing resorcinol structures, such as 4-butylresorcinol, have good whitening effects in cosmetics. However, this compound is prone to auto-oxidation, and there are the following problems during storage and use: (1) irritation; (2) reduction of whitening activity; (3) easy discoloration; (4) affecting the overall stability of the formulation.

[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 whitening compound, 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] In a first aspect, the present invention provides a whitening compound, and the structural formula of the whitening compound 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 whitening compound includes at least one of 4-butylresorcinol-1-o-α-glucoside, 4-butylresorcinol-1-o-β-glucoside, 4-butylresorcinol-1,3-bis-α-glucoside, and 4-butylresorcinol-1,3-bis-β-glucoside.

[0008] In a second aspect, the present invention provides a preparation method of a whitening compound as described in the foregoing embodiment, including the following steps: according to the preset structural formula of the whitening compound, by chemical synthesis, modify the glycoside corresponding to R1 to the phenolic hydroxyl position para to the butyl group in 4-butylresorcinol;

[0009] Or, according to the preset structural formula of the whitening compound, by chemical synthesis, modify the glycoside corresponding to R1 to the phenolic hydroxyl position para to the butyl group in 4-butylresorcinol, and modify the glycoside corresponding to R2 to the phenolic hydroxyl position ortho to the butyl group in 4-butylresorcinol.

[0010] In a third aspect, the present invention provides an application of a whitening compound as described in the foregoing embodiment in reducing or improving skin irritation.

[0011] In an alternative embodiment, the whitening compound is used to reduce the content of hydroxyl radicals.

[0012] Fourthly, the present invention provides an application of a whitening compound as described in the foregoing embodiments in promoting the proliferation of beneficial bacteria on the epidermis.

[0013] In an alternative embodiment, the beneficial bacteria on the epidermis include Staphylococcus epidermidis.

[0014] Fifthly, the present invention provides an application of a whitening compound as described in the foregoing embodiments in enhancing or improving skin whitening.

[0015] In an alternative embodiment, the whitening compound is used to alleviate or improve skin pigmentation.

[0016] In an alternative embodiment, the whitening compound is used to inhibit the tyrosinase activity in B16F10 melanoma cells.

[0017] Sixthly, the present invention provides a cosmetic product, which contains the whitening compound as described in the foregoing embodiments.

[0018] The beneficial effects of the present invention include:

[0019] The whitening compound provided by the present invention grafts a glycoside at the position of at least one phenolic hydroxyl group in 4-butylresorcinol. After grafting, the compound molecule is more stable in structure and is not prone to autoxidation reactions. The glycoside group can protect the hydroxyl group through a steric hindrance effect, reducing the generation of free radicals and the possibility of reacting with oxygen, thereby prolonging the shelf life of the product and the persistence of the whitening effect. In addition, glycoside grafting not only increases the hydrophilicity of the compound but also avoids the exposure of phenolic hydroxyl groups, thereby reducing the irritation caused by its degradation. Moreover, the glycoside itself has a mild nature, which can reduce skin irritation and allergic reactions. The compound grafted with glycoside can reduce adverse reactions such as skin redness, stinging, and dryness, and is also suitable for sensitive skin. Furthermore, the whitening compound grafted with glycoside can be degraded into glycoside and resorcinol compounds through skin microecology, and can maintain good whitening activity. Specific Embodiments

[0020] 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. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.

[0021] The following specifically describes the whitening compound provided by the present invention, its preparation method, and its application.

[0022] The inventors have proposed through research that the reasons for the irritation of resorcinol compounds include: during the oxidation reaction process, resorcinol compounds will generate free radicals and quinone derivatives. These generated compounds usually have high reactivity and can not only react with the cellular proteins on the skin surface but also trigger a series of inflammatory reactions, causing skin irritation.

[0023] The reasons for the reduction of the whitening activity of resorcinol compounds include: resorcinol compounds provide whitening effects mainly by inhibiting the activity of tyrosinase. However, when these compounds undergo auto-oxidation during storage or use, the generated quinone substances cannot effectively inhibit tyrosinase, resulting in a reduction in their overall whitening activity.

[0024] The reasons for the easy discoloration of resorcinol compounds include: the auto-oxidation process of resorcinol not only changes the chemical structure of the compound but also causes a significant change in the color of the product. Usually, the quinone compounds generated by auto-oxidation are yellow or brown, so the originally colorless or light-colored cosmetics will change color due to the oxidation process. This phenomenon not only affects the appearance of the product but also makes consumers question the quality and stability of the product.

[0025] The reasons for the resorcinol compounds affecting the overall stability of the formulation include: the free radicals and quinone substances generated by the auto-oxidation of resorcinol may react with other components in the formulation, thus affecting the overall stability of the product. For example, free radicals may trigger lipid oxidation, causing the oil components in the formulation to become rancid and produce an unpleasant smell. In addition, the generated quinone compounds may also react unfavorably with other functional components such as antioxidants and moisturizers, reducing the overall performance and acceptance of the product.

[0026] The present invention creatively proposes a new class of compounds that can avoid or improve the above problems. The structural formula of this class of whitening compounds 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.

[0027] In other words, R1 and R2 independently may include Wherein, "*" represents the grafting position.

[0028] In some alternative embodiments, the whitening compounds may exemplarily include at least one of 4-butylresorcinol-1-o-α-glucoside, 4-butylresorcinol-1-o-β-glucoside, 4-butylresorcinol-1,3-bis-α-glucoside, and 4-butylresorcinol-1,3-bis-β-glucoside.

[0029] The above-mentioned whitening compound provided by the present invention is grafted with a glycoside at at least one phenolic hydroxyl position of 4-butylresorcinol. After grafting, the molecular structure of the compound is more stable and less prone to auto-oxidation reactions. The glycoside group can protect the hydroxyl group through steric hindrance effects, reducing the generation of free radicals and the possibility of reacting with oxygen, thereby extending the shelf life of the product and the persistence of the whitening effect. In addition, glycoside grafting not only increases the hydrophilicity of the compound but also avoids the exposure of phenolic hydroxyl groups, thereby reducing the irritation caused by its degradation. Moreover, the glycoside itself has mild properties and can alleviate skin irritation and allergic reactions. The compound grafted with glycoside can reduce adverse reactions such as skin redness, stinging, and dryness, and is also suitable for sensitive skin. Furthermore, the whitening compound after grafting with glycoside can be degraded into glycoside and resorcinol compounds through the skin microecosystem, maintaining good whitening activity.

[0030] Correspondingly, the present invention provides a preparation method of the above-mentioned whitening compound, including the following steps: According to the preset structural formula of the whitening compound, through chemical synthesis, the glycoside corresponding to R1 is modified to the phenolic hydroxyl position para to the butyl group in 4-butylresorcinol;

[0031] Or, according to the preset structural formula of the whitening compound, through chemical synthesis, the glycoside corresponding to R1 is modified to the phenolic hydroxyl position para to the butyl group in 4-butylresorcinol, and the glycoside corresponding to R2 is modified to the phenolic hydroxyl position ortho to the butyl group in 4-butylresorcinol.

[0032] In some optional embodiments, the preparation method of 4-butylresorcinol-1-o-α-glucoside may include: Using fully acetylated glucose, through low-temperature (-15°C) BF3·Et2O catalysis to initiate the neighboring group participation effect, a glycosylation donor is prepared. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate at 0°C for 30 minutes to generate a phenoxide anion and activate the phenolic hydroxyl group. React the activated 4-butylresorcinol with the glycosyl donor in CH2Cl2, stir at -20°C under argon protection for 18 hours. After TLC monitoring shows that the raw material spot has disappeared, add saturated NaHCO3 to quench and prepare the crude product. Obtain a white solid through silica gel column chromatography, and then further separate and purify it using a reverse-phase preparative column. The elution solvent is an organic solvent containing water, collect the eluate containing the target product, and concentrate the eluate under reduced pressure and freeze-dry to obtain a target product with a purity of over 95%.

[0033] In some alternative embodiments, the preparation method of 4-butylresorcinol-1-o-β-glucoside may include: reacting fully acetylated glucose with 33% HBr / acetic acid solution for 3 hours to prepare a brominated glycosyl donor. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate at 0 °C for 30 minutes to generate a phenoxide anion and activate the phenolic hydroxyl group. The activated phenol is mixed with the brominated glycosyl donor in anhydrous acetonitrile, and Ag2CO3 and molecular sieve are added, and stirred at 55 °C for 24 hours to prepare 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 preparative reverse-phase 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 to obtain a target product with a purity of over 95%.

[0034] In some alternative embodiments, the preparation method of 4-butylresorcinol-1,3-bis-o-α-glucoside may include: using fully acetylated glucose, and catalyzing the neighboring group participation effect through BF3·Et2O at low temperature (-15 °C) to prepare a glycosylation donor. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate at 0 °C for 30 minutes to generate a phenoxide anion and activate the phenolic hydroxyl group. React the activated 4-butylresorcinol with the glycosyl donor in CH2Cl2, and stir at -20 °C under argon protection for 18 hours. After TLC monitoring shows that the starting material spot disappears, add saturated NaHCO3 to quench and prepare 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 preparative reverse-phase 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 to obtain a target product with a purity of over 95%.

[0035] In some alternative embodiments, the preparation method of 4-butylresorcinol-1,3-bis-o-β-glucoside may include: reacting fully acetylated glucose with 33% HBr / acetic acid solution for 3 hours to prepare a brominated glycosyl donor. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate at 0 °C for 30 minutes to generate a phenoxide anion and activate the phenolic hydroxyl group. The activated phenol is mixed with the brominated glycosyl donor in anhydrous acetonitrile, and Ag2CO3 and molecular sieve are added, and stirred at 55 °C for 24 hours to prepare 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 preparative reverse-phase 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 to obtain a target product with a purity of over 95%.

[0036] It should be noted that the above content only provides one feasible method among many preparation methods. In the actual production and preparation process, the above preparation parameters and conditions can be reasonably adjusted and replaced, and no excessive restrictions are made here.

[0037] In addition, the present invention also provides the application of the whitening compound.

[0038] In some optional embodiments, the whitening compound can be used to reduce or improve skin irritation. For example, the whitening compound can be used to reduce the hydroxyl radical content.

[0039] In some optional embodiments, the whitening compound can be used to promote the proliferation of beneficial bacteria on the skin, wherein the beneficial bacteria on the skin can exemplarily include Staphylococcus epidermidis.

[0040] In some optional embodiments, the whitening compound can be used to enhance or improve the skin whitening effect. For example, the whitening compound can be used to alleviate or improve skin pigmentation. For example, the whitening compound can be used to inhibit tyrosinase activity in B16F10 melanoma cells.

[0041] Furthermore, the present invention also provides a cosmetic containing the whitening compound. It should be noted that the whitening compound in the present invention can be applied to any type of cosmetics, and any existing type of cosmetics can be used.

[0042] The whitening compound provided by the present invention improves the stability of the current resorcinol compounds in cosmetics through the stabilizing effect of glycosides and avoids discoloration. At the same time, the whitening compound provided by the present invention can be separated from glycosides under the action of skin microecology and restored to the resorcinol structure, thereby achieving its whitening function.

[0043] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0044] Example 1

[0045] This embodiment provides a whitening compound, which is 4-butylresorcinol-1-o-α-glucoside, and has the structural formula:

[0046] The synthesis method of the whitening compound is as follows: Using fully acetylated glucose, the glycosyl donor is prepared by initiating the neighboring group participation effect through BF3·Et2O catalysis at low temperature (-15°C). Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate it at 0°C for 30 minutes to generate phenoxide anion and activate the phenolic hydroxyl group. React the activated 4-butylresorcinol with the glycosyl donor in CH2Cl2, stir at -20°C under argon protection for 18 hours. After monitoring by TLC shows that the raw material spot disappears, quench with saturated NaHCO3 to obtain the crude product. Obtain a white solid through silica gel column chromatography, and then further separate and purify it using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. Collect the eluate containing the target product, concentrate the eluate under reduced pressure, and freeze-dry to obtain the target product with a purity of over 95%.

[0047] Example 2

[0048] This example provides a whitening compound, which is 4-butylresorcinol-1-o-β-glucoside, and its structural formula is:

[0049] The synthesis method of the whitening compound is as follows: React fully acetylated glucose with 33% HBr / acetic acid solution for 3 hours to prepare the brominated glycosyl donor. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate it at 0°C for 30 minutes to generate phenoxide anion and activate the phenolic hydroxyl group. Mix the activated phenol with the brominated glycosyl donor in anhydrous acetonitrile, add Ag2CO3 and molecular sieve, stir at 55°C for 24 hours to obtain the crude product. Obtain a white solid through silica gel column chromatography, and then further separate and purify it using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. Collect the eluate containing the target product, concentrate the eluate under reduced pressure, and freeze-dry to obtain the target product with a purity of over 95%.

[0050] Example 3

[0051] This example provides a whitening compound, which is 4-butylresorcinol-1,3-bis-o-α-glucoside, and its structural formula is:

[0052] The synthesis method of the whitening compound is as follows: Using fully acetylated glucose, the glycosyl donor is prepared by initiating the neighboring group participation effect through BF3·Et2O catalysis at low temperature (-15°C). Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate it at 0°C for 30 minutes to generate phenoxide anion and activate the phenolic hydroxyl group. React the activated 4-butylresorcinol with the glycosyl donor in CH2Cl2, stir at -20°C under argon protection for 18 hours. After monitoring by TLC shows that the raw material spots disappear, quench with saturated NaHCO3 to obtain the crude product. Obtain a white solid through silica gel column chromatography, and then further separate and purify it using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. Collect the eluate containing the target product, concentrate the eluate under reduced pressure, and freeze-dry to obtain the target product with a purity of over 95%.

[0053] Example 4

[0054] This example provides a whitening compound, which is 4-butylresorcinol-1,3-bis-o-β-glucoside, and its structural formula is:

[0055] The synthesis method of the whitening compound is as follows: React fully acetylated glucose with 33% HBr / acetic acid solution for 3 hours to prepare a brominated glycosyl donor. Dissolve 4-butylresorcinol in anhydrous DMF, add 1.2 equivalents of NaH (60% oil dispersion) and activate it at 0°C for 30 minutes to generate phenoxide anion and activate the phenolic hydroxyl group. Mix the activated phenol with the brominated glycosyl donor in anhydrous acetonitrile, add Ag2CO3 and molecular sieve, stir at 55°C for 24 hours to obtain the crude product. Obtain a white solid through silica gel column chromatography, and then further separate and purify it using a reverse-phase preparative column. The elution solvent is an organic solvent containing water. Collect the eluate containing the target product, concentrate the eluate under reduced pressure, and freeze-dry to obtain the target product with a purity of over 95%.

[0056] Example 5

[0057] Investigation on the stability of the whitening compound.

[0058] Taking the whitening compounds provided in Examples 1 to 4 as examples, and using 4-butylresorcinol (whitening agent) without glycosylation modification as a comparison.

[0059] Prepare solutions of the above-mentioned whitening compounds and whitening agents with a concentration of 0.3 wt% respectively using water and dispense them into sterile experimental bottles. Place each dispensed sample in a constant temperature and humidity chamber at 55°C and a humidity of 50% for stability investigation. After 1 month, take out each sample and use HPLC to detect the change of its main components (calculated by retention rate), and the test results are shown in Table 1.

[0060] The conditions for the above HPLC detection are as follows: C18 column (5μm, 150mm×4.6mm); the mobile phase is water (A) and acetonitrile (B), A:B = 70:30 (volume ratio); the flow rate is 1.0 mL / min; the injection volume is 10 μl; the detection wavelength is 280 nm.

[0061] Table 1 Results of stability test

[0062] Sample Name Retention Rate 4-Butylresorcinol 43.65％ 4-Butylresorcinol-1-o-α-glucoside 97.16％ 4-Butylresorcinol-1-o-β-glucoside 96.54％ 4-Butylresorcinol-1,3-bis-o-α-glucoside 98.77％ 4-Butylresorcinol-1,3-bis-o-β-glucoside 97.32％

[0063] It can be seen from Table 1 that: compared with 4-butylresorcinol without glycosylation modification, after the whitening compound provided by the present invention is formulated into a 0.3% aqueous solution, it remains stable after being examined at 55°C and 50% humidity for 1 month, and its stability is significantly better than that of the whitening agent as a comparison.

[0064] Example 6

[0065] Effect of the whitening compound on the content of hydroxyl radicals.

[0066] Taking the whitening compounds provided in Examples 1 to 4 as examples, and using 4-butylresorcinol (whitening agent) without glycosylation modification as a comparison.

[0067] The above-mentioned whitening compound and whitening agent were respectively formulated into solutions with a concentration of 0.3 wt% with water and dispensed into sterile experimental bottles, and the samples were placed in a constant temperature and humidity chamber at 55°C and 50% humidity for 1 month.

[0068] Add 10 μL of the above samples, 10 μL of HPF, and 80 μL of phosphate buffer (pH 7.2) to each well in a 96-well plate, with a total of 100 μL. After 60 min, measure the fluorescence intensity. The amount of hydroxyl radicals is measured by the fluorescence intensity after adding HPF, and the results are shown in Table 2.

[0069] Table 2 Relative generation amount of hydroxyl radicals (in terms of fluorescence intensity)

[0070] Sample Name Relative Generation Amount of Hydroxyl Radical 4-Butylresorcinol 16543 4-Butylresorcinol-1-o-α-glucoside 659 4-Butylresorcinol-1-o-β-glucoside 1009 4-Butylresorcinol-1,3-bis-o-α-glucoside 534 4-Butylresorcinol-1,3-bis-o-β-glucoside 487

[0071] It can be seen from Table 2 that: compared with 4-butylresorcinol without glycosylation modification, after the whitening compound provided by the present invention is formulated into a 0.3% aqueous solution, the amount of hydroxyl radicals generated after being examined at 55°C and 50% humidity for 1 month is significantly lower than that of the whitening agent as a comparison, that is, the irritation of the whitening compound provided by the present invention is lower.

[0072] Example 7

[0073] Effect of the whitening compound on the proliferation effect of epidermal beneficial bacteria.

[0074] Taking the whitening compounds provided in Examples 1 to 4 as examples, and using 4-butylresorcinol (whitening agent) without glycosylation modification as a comparison.

[0075] Staphylococcus epidermidis preserved at -80 °C (preservation number: CMCC26069, purchased from the China Center for Medical Bacterial Culture Collection) 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. After washing twice with sterile water, the medium was removed. 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 with a whitening compound, a whitening agent or a 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 every hour using an enzyme-linked immunosorbent assay (ELISA) reader, and a growth curve was plotted. The proliferation rate results of Staphylococcus epidermidis after 8 h are shown in Table 3.

[0076] 4-Butylresorcinol-1-o-α-glucoside was respectively formulated into aqueous solutions with concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm and 10000 ppm in the above manner, and the proliferation rates of Staphylococcus epidermidis corresponding to different concentrations after 8 h were tested by the above method. The results are shown in Table 4.

[0077] Table 3 Proliferation rate of Staphylococcus epidermidis

[0078] Sample Name Proliferation Rate of Staphylococcus epidermidis (%) 4-Butylresorcinol -9.94 4-Butylresorcinol-1-o-α-glucoside 67.57 4-Butylresorcinol-1-o-β-glucoside 42.98 4-Butylresorcinol-1,3-bis-o-α-glucoside 112.02 4-Butylresorcinol-1,3-bis-o-β-glucoside 103.31

[0079] Table 4 Effects of whitening agents with different concentrations on the proliferation rate of Staphylococcus epidermidis

[0080] Concentration of 4-Butylresorcinol-1-o-α-glucoside (ppm) Proliferation Rate of Staphylococcus epidermidis (%) 1 12.26 10 32.84 100 67.57 1000 95.37 10000 180.35

[0081] It can be seen from Table 3 that: compared with 4-butylresorcinol without glycosylation modification, the whitening compound provided by the present invention has the effect of promoting the proliferation of beneficial bacteria on the epidermis, which helps to establish a healthy skin microecological barrier.

[0082] It can be seen from Table 4 that: 4-Butylresorcinol-1-o-α-glucoside provided by the present invention has the effect of promoting the proliferation of beneficial bacteria on the epidermis within the concentration range of 1 ppm to 10000 ppm.

[0083] Example 8

[0084] Inhibitory effect of the metabolites of Staphylococcus epidermidis of the whitening compound on tyrosinase activity in B16F10 melanoma cells.

[0085] ① Preparation of the metabolites of Staphylococcus epidermidis of the whitening compound

[0086] Taking the whitening compounds provided in Examples 1 to 4 as examples, and using 4-butylresorcinol without glycosylation modification as a comparison.

[0087] Staphylococcus epidermidis stored at -80°C (preservation number: CMCC26069, purchased from the China Center for Medical Bacteria Culture Collection) was resuscitated in LB liquid medium at 37°C and 200 rpm for about 24 h. 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 bacterial suspension was aspirated and added to each sample group (whitening agent, whitening compound) 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 and sterilized twice through a 0.22-μm filter membrane, 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 (whitening agent, whitening compound) or blank control samples with final concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10000 ppm for subsequent experiments.

[0088] ②. Test of inhibitory effect

[0089] B16 melanoma cells in good growth state were inoculated on a 24-well plate at a concentration of 60000 cells / well (using high-glucose DMEM medium from Gibco). After 24 h, the metabolites of Staphylococcus epidermidis of the test samples (whitening agent, whitening compound) or blank control samples prepared in ① were added, and the final concentrations of the sample groups were 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10000 ppm. Then it was cultured at 37°C for 48 h. After washing 3 times with PBS, 500 μL of PBS solution containing L-DOPA at a concentration of 0.1 mmol / L and Triton-X at a concentration of 0.1% was added to each well. After incubation at 37°C for 30 min, the OD value at 475 nm was measured, and the inhibitory effect of the whitening agent or whitening compound on tyrosinase activity was calculated according to the following formula. The results are shown in Table 5.

[0090] Tyrosinase activity inhibition rate = [1 - (OD of sample group 475nm ) / (OD of blank group 475nm )] × 100%.

[0091] 4-Butylresorcinol-1-O-α-glucoside was respectively formulated into aqueous solutions with concentrations of 1 ppm, 10 ppm, 100 ppm, 1000 ppm, and 10000 ppm in the above manner, and the tyrosinase activity inhibition rates corresponding to different concentrations were tested by the above method. The results are shown in Table 6.

[0092] Table 5 Effects of metabolites of Staphylococcus epidermidis on tyrosinase activity in B16F10 melanoma cells

[0093]

[0094]

[0095] Table 6 Effects of metabolites of Staphylococcus epidermidis of whitening agents with different concentrations on tyrosinase activity in B16F10 melanoma cells

[0096] Concentration of 4-Butylresorcinol-1-o-α-glucoside (ppm) Inhibition Rate of Tyrosinase Activity (%) 1 37.28 10 45.62 100 59.97 1000 65.87 10000 69.34

[0097] As can be seen from Table 5: The whitening compound provided by the present invention has the effect of inhibiting tyrosinase activity in B16F10 melanoma cells, and its effect is better than that of 4-butylresorcinol without glycosylation modification, which helps to relieve or improve skin pigmentation.

[0098] As can be seen from Table 6: 4-Butylresorcinol-1-O-glucoside provided by the present invention has the effect of inhibiting tyrosinase activity in B16F10 melanoma cells within the concentration range of 1 ppm to 10000 ppm.

[0099] In summary, the whitening compound provided by the present invention grafts glycosides at at least one phenolic hydroxyl position of 4-butylresorcinol. After grafting, the compound molecule is more stable in structure and not prone to auto-oxidation reaction. The glycoside group can protect the hydroxyl group through steric hindrance effect, reduce the generation of free radicals and the possibility of reacting with oxygen, thereby prolonging the shelf life of the product and the persistence of the whitening effect. In addition, glycoside grafting not only increases the hydrophilicity of the compound, but also avoids the exposure of phenolic hydroxyl groups, thereby reducing its irritation caused by degradation. Moreover, the glycoside itself has a mild property, which can slow down the irritation and allergic reactions to the skin. The compound grafted with glycoside can reduce adverse reactions such as skin redness, stinging, and dryness, and is also suitable for sensitive skin. Furthermore, the whitening compound grafted with glycoside can be degraded into glycoside and resorcinol compounds through skin microecology, and can maintain good whitening activity.

[0100] 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 may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A whitening compound, characterized in that The structural formula of the whitening compound 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.

2. The whitening compound according to claim 1, characterized in that The whitening compound includes at least one of 4-butylresorcinol-1-o-α-glucoside, 4-butylresorcinol-1-o-β-glucoside, 4-butylresorcinol-1,3-di-α-glucoside and 4-butylresorcinol-1,3-di-β-glucoside.

3. A method for preparing the whitening compound according to claim 1 or 2, characterized in that: The following steps are involved: According to the preset whitening compound structure, the glycoside corresponding to R1 is modified to the phenolic hydroxyl position in the 4-butylresorcinol which is in the para position to the butyl group by chemical synthesis.

4. A method for preparing a whitening compound as claimed in claim 1 or 2, characterized in that: The following steps are involved: According to the preset whitening compound structure, the glycoside corresponding to R1 is modified to the phenolic hydroxyl position in the para position to the butyl group in 4-butylresorcinol by chemical synthesis, and the glycoside corresponding to R2 is modified to the phenolic hydroxyl position in the ortho position to the butyl group in 4-butylresorcinol.

5. Use of the whitening compound as claimed in claim 1 or 2 in reducing or improving skin irritation; Preferably, the whitening compound is used to reduce the hydroxyl radical content.

6. Use of the whitening compound as claimed in claim 1 or 2 in promoting the proliferation of beneficial bacteria on the epidermis; Preferably, the beneficial bacteria for the epidermis include Staphylococcus epidermidis.

7. Use of the whitening compound according to claim 1 or 2 in enhancing or improving skin whitening.

8. The use according to claim 7, characterized in that: The whitening compounds are used to alleviate or improve skin pigmentation.

9. The use according to claim 7, characterized in that: The whitening compound is used for inhibiting tyrosinase activity in B16F10 melanoma cells.

10. A cosmetic, characterized in that: The cosmetic contains the whitening compound according to claim 1 or 2.

Images