Kojic acid ester tyrosinase inhibitor as well as synthesis method and application thereof
By synthesizing new kojimate compounds, the toxicity, water solubility and cost problems of existing tyrosinase inhibitors have been solved, and the stronger tyrosinase inhibition effect has been achieved, which has promoted the development of whitening products.
Patent Information
- Application Number
- CN202510306155.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-07-04
AI Technical Summary
The existing tyrosinase inhibitors have problems such as cytotoxicity, poor water solubility, low photothermal stability and high cost, which limits their application in whitening products.
The new kojimate compounds (5-hydroxy-4-oxypyran-2-yl)methyl-2-furancarboxylate and (5-hydroxy-4-oxypyran-2-yl)methyl-3-(4-hydroxyphenyl)propionate were synthesized to prepare tyrosinase inhibitors through specific synthetic methods for whitening products and the treatment of melanin-producing skin diseases.
The new compounds have stronger inhibitory effects on tyrosinase, simple synthesis method and low cost, providing a theoretical basis for the development of whitening products.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of biomedicine, and specifically to kojic acid esters as tyrosinase inhibitors, their synthesis methods and applications. Background Art
[0002] As the key enzyme in melanin biosynthesis, the inhibition of tyrosinase activity is the core strategy of whitening technology. Tyrosinase inhibitors mainly include hydroquinone derivatives (such as arbutin), resorcinol derivatives (such as SymWhite 377), natural plant extracts (such as glabridin), kojic acid and its derivatives, etc. Hydroquinones are restricted for use in the European Union due to cytotoxicity and the risk of leukoderma; although arbutin reduces toxicity through glycosylation, it may still slowly release hydroquinone, causing irritation disputes; although resorcinol derivatives have strong inhibitory activity, such as the inhibition rate of 4-butylresorcinol being 25 times that of kojic acid, they have problems such as poor water solubility and low photo-thermal stability, and rely on micro-liposome encapsulation technology to improve transdermal efficiency; natural components such as glabridin have a significant inhibitory effect, up to 15 times that of kojic acid, but the extraction cost is high, and complex processes are required to improve its water solubility and stability. In addition, most kojic acid esters are formed by the reaction of kojic acid with benzoic acid and its derivatives, and the raw material prices and synthesis costs are relatively high. Studying the synthesis of new compounds as tyrosinase inhibitors and their application in the whitening field has important research significance and application value. Summary of the Invention
[0003] The content of the present invention is to synthesize kojic acid esters as tyrosinase inhibitors to inhibit melanin production.
[0004] In order to achieve the above-mentioned invention purpose, the present technology adopts the following technical solutions:
[0005] The present invention provides kojic acid ester compounds, with the structural formula:
[0006]
[0007] In the above technical solution, further, the preparation method is as follows:
[0008]
[0009] Reaction conditions: a. Thionyl chloride, DMF, room temperature; b. Carboxylate, DMF, 110°C - 120°C;
[0010] The carboxylate is sodium 2-furancarboxylate or sodium 4-hydroxyphenylpropionate.
[0011] In the above technical solution, further, the preparation method of chlorokojic acid: Dissolve kojic acid in thionyl chloride, stir into a paste at room temperature, and air-dry to obtain a pale yellow powder;
[0012] The preparation method of sodium 2-furanate: 2-furoic acid and sodium bicarbonate are added with water to generate a large amount of bubbles. Stir until no bubbles are generated and the substrate is completely dissolved, then heat at 60°C to 100°C and dry to obtain a white solid.
[0013] The preparation method of sodium 4-hydroxyphenylpropionate: 4-hydroxyphenylpropionic acid and sodium bicarbonate are added with water to generate a large amount of bubbles. Stir until no bubbles are generated and the substrate is completely dissolved, then heat at 60°C to 100°C and dry to obtain a brown solid.
[0014] The present invention provides the application of the aforementioned kojic acid esters in the preparation of tyrosinase inhibitors.
[0015] In the above technical solution, further, the tyrosinase is mushroom tyrosinase.
[0016] The present invention also provides the application of the aforementioned kojic acid esters as tyrosinase inhibitors in the preparation of whitening cosmetics.
[0017] The present invention also provides the application of the aforementioned kojic acid esters as tyrosinase inhibitors in the preparation of drugs for treating skin diseases with excessive melanin production.
[0018] In the above technical solution, further, the drug is an external preparation.
[0019] In the above technical solution, further, the IC 50 of 3a against tyrosinase is 451 μM; the IC 50
[0020] of 3b against tyrosinase is 27.9 μM.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] The present invention first synthesizes (5-hydroxy-4-oxopyran-2-yl)methyl 2-furoate and (5-hydroxy-4-oxopyran-2-yl)methyl 3-(4-hydroxyphenyl)propionate, which have inhibitory effects on tyrosinase. Compared with the kojic acid with whitening effect molecules on the market, the synthesized new molecules have stronger activity, and the preparation method is simple and the synthesis cost is low. The present invention provides a theoretical basis for the development of whitening products. Description of the Drawings
[0023] Figure 1 Effects of kojic acid at different concentrations on tyrosinase activity:
[0024] Figure 2 Effects of 3a at different concentrations on tyrosinase activity;
[0025] Figure 3 Effects of 3b at different concentrations on tyrosinase activity. Detailed implementation mode
[0026] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any way.
[0027] Synthesize (5-hydroxy-4-oxopyran-2-yl)methyl 2-furancarboxylate, (5-hydroxy-4-oxopyran-2-yl)methyl 3-(4-hydroxyphenyl)propionate, and detect tyrosinase activity in vitro.
[0028]
[0029] Reaction conditions: (a) Thionyl chloride, DMF, room temperature; (b) Carboxylate, DMF, 110°C - 120°C.
[0030] The carboxylate is sodium 2-furancarboxylate or sodium 3-(4-hydroxyphenyl)propionate.
[0031] Preparation method of intermediate sodium 2-furancarboxylate:
[0032] Weigh 2-furancarboxylic acid (1 g, 0.0089 mol) and sodium bicarbonate (0.75 g, 0.0089 mol), add 4 mL of water, a large amount of bubbles are generated, stir, and wait until no bubbles are generated and the substrate is completely dissolved. Then heat at 100°C and dry to obtain 1.1833 g of white solid, and the yield is 99.2%.
[0033] Preparation method of intermediate sodium 3-(4-hydroxyphenyl)propionate:
[0034] Weigh 3-(4-hydroxyphenyl)propionic acid (1 g, 0.006 mol) and sodium bicarbonate (0.5 g, 0.006 mol), add 4 mL of water, a large amount of bubbles are generated, stir, and wait until no bubbles are generated and the substrate is completely dissolved. Then heat at 100°C and dry to obtain 1.1223 g of brown solid, and the yield is 99.4%.
[0035] Preparation method of intermediate chlorotrioneic acid:
[0036] Weigh kojic acid (1 g, 0.007 moL) and dissolve it in thionyl chloride (3 mL, 0.041 moL), stir at room temperature until it becomes a paste, and air-dry to obtain 1.1 g of light yellow powder, and the yield is 97.9%.
[0037] Example 1
[0038] Preparation method of target compound 3a (5-hydroxy-4-oxopyran-2-yl)methyl 2-furancarboxylate:
[0039] Sodium 2 - furanecarboxylate (0.5 g, 3.74 mmol) and chloranilic acid (0.602 g, 3.74 mmol) were mixed in 40 mL of DMF solution, heated and stirred at 110 °C for 2 hours, distilled under reduced pressure, extracted with ethyl acetate, washed with saturated sodium chloride solution, the organic layer was dried over anhydrous magnesium sulfate, and rotary evaporated to obtain 0.51 g of light brown powder with a yield of 57.7%.
[0040] 1 H NMR (500 MHz, DMSO) δ 9.29 (s, 1H), 8.12 (s, 1H), 8.03 (d, J = 1.5 Hz, 1H), 7.45 (d, J = 3.5 Hz, 1H), 6.74 (m, J = 3.5 Hz, 1H), 6.54 (s, 1H), 5.18 (s, 2H).
[0041] 13 C NMR (126 MHz, DMSO) δ 173.80, 161.32, 157.21, 148.53, 146.28, 143.04, 140.20, 119.79, 113.03, 112.77, 61.81.
[0042] FABMS, m / e 235.2 [M - H] + 。
[0043] Example 2
[0044] Preparation method of the target compound 3b ((5 - hydroxy - 4 - oxopyran - 2 - yl)methyl 3 - (4 - hydroxyphenyl)propionate):
[0045] Sodium 4 - hydroxyphenylpropionate (1.8817 g, 10 mmol) and chloranilic acid (1.6056 g, 10 mmol) were mixed in 80 mL of DMF solution, heated and stirred at 110 °C for 2 hours, distilled under reduced pressure, extracted with ethyl acetate, washed with saturated sodium chloride solution, the organic layer was dried over anhydrous magnesium sulfate, and rotary evaporated to obtain a red - brown liquid. Water was added, and a solid insoluble in water was precipitated. After filtration and vacuum freeze - drying, a crude product was obtained. The eluent was dichloromethane:methanol (2:1). After column chromatography, 1.29 g of milky white solid was obtained with a yield of 44.4%.
[0046] 1 H NMR (500 MHz, DMSO) δ 9.27 (s, 1H), 9.22 (s, 1H), 8.05 (s, 1H), 6.99 (d, J = 8.4 Hz, 2H), 6.66 (d, J = 8.4 Hz, 2H), 6.45 (s, 1H), 4.92 (s, 2H), 2.75 (t, J = 7.5 Hz, 2H), 2.65 (t, J = 7.5 Hz, 2H).
[0047] 13 13C NMR(126 MHz, DMSO) δ 173.98, 172.07, 161.80, 155.80, 146.32, 140.15, 130.58, 129.60, 115.41, 112.86, 61.51, 35.45, 29.64.
[0048] FABMS, m / e 289.3 [M-H] + 。
[0049] Example 3 Detection of Tyrosinase Activity in Vitro
[0050] Method: The tyrosinase used was mushroom tyrosinase purchased from Hunan Wokai Biotechnology Co., Ltd. Tyrosinase can convert L-DOPA into L-DOPA quinone. By detecting the absorbance of the generated L-DOPA quinone at a wavelength of 475 nm, the inhibitory effect of the sample solution on tyrosinase can be detected.
[0051] 1×PBS (containing 4.5% dimethyl sulfoxide) was used to prepare a 6 mL solution of 15000 U tyrosinase, with an enzyme concentration of 2500 U / mL. L-DOPA was prepared into a 4 mM stock solution. Kojic acid, 3a, and 3b were prepared into sample solutions with 1×PBS (containing 4.5% dimethyl sulfoxide). The concentration gradients of kojic acid and 3a in the 96-well microplate were 1.6, 0.8, 0.4, 0.2, 0.1 mM. The concentration gradient of 3b in the 96-well microplate was 50, 25, 12.5, 6.25, 3.125 μM. Group Ta was 10 μL of tyrosinase + 90 μL of 1×PBS, Group Tb was 10 μL of tyrosinase + 40 μL of L-DOPA + 50 μL of 1×PBS, Group Tc was 10 μL of tyrosinase + 40 μL of sample solution + 50 μL of 1×PBS, and Group Td was 10 μL of tyrosinase + 40 μL of L-DOPA + 40 μL of sample solution + 10 μL of 1×PBS. Each of the four groups Ta, Tb, Tc, and Td was set with 3 replicate wells, and kojic acid was used as a positive control. 20 minutes after adding the samples, the absorbance was measured with a microplate reader at a temperature of 37°C and a wavelength of 475 nm. Using the concentration gradient of the samples as the abscissa and A Td -A Tc as the ordinate to make a curve graph. The pH of different concentration gradients of kojic acid, 3a, and 3b in the 96-well microplate was detected with a pH meter.
[0052] Results: At 1.6, 0.8, 0.4, 0.2 and 0.1 mM, and 25 °C, the corresponding pH values of kojic acid were 7.26, 7.232, 7.33, 7.35 and 7.37. The corresponding pH values of 3a were 7.16, 7.21, 7.26, 7.30 and 7.32. At 50, 25, 12.5, 6.25 and 3.125 μM, and 25 °C, the corresponding pH values of 3b were 7.35, 7.37, 7.39, 7.39 and 7.39. When detecting the tyrosinase activity at different concentrations of kojic acid, 3a and 3b, the corresponding pH values were all neutral. Therefore, the influence of pH on the enzyme activity can be ignored, and the enzyme inhibition is caused by 3a and 3b.
[0053] A without kojic acid, 3a and 3b Tb -A Ta was 0.645. The rate of tyrosinase-catalyzed L-DOPA production of L-DOPA quinone slowed down with the increase of the concentrations of the inhibitors kojic acid, 3a and 3b, and the absorbance decreased. The IC 50 of kojic acid on tyrosinase was 556 μM, the IC 50 of 3a on tyrosinase was 451 μM, and the IC 50 of 3b on tyrosinase was 27.9 μM.
Claims
1. A kojic acid ester compound, characterized in that, The structural formula is as follows:
2. The kojic acid ester compound according to claim 1, wherein The preparation method is as follows: Reaction conditions: a. Thionyl chloride, DMF, room temperature; b. Carboxylate, DMF, 110°C - 120°C; The carboxylate is sodium 2-furancarboxylate or sodium 4-hydroxybenzenepropionate.
3. The kojic acid ester compound according to claim 2, characterized in that The preparation method of chlorokojic acid: Dissolve kojic acid in thionyl chloride, stir into a paste at room temperature, and air-dry to obtain a pale yellow powder; The preparation method of sodium 2-furancarboxylate: 2-Furancarboxylic acid and sodium bicarbonate, add water to generate a large amount of bubbles, stir, wait until no bubbles are generated, and after the substrate is completely dissolved, heat at 60°C - 100°C, and dry to obtain a white solid; The preparation method of sodium 4-hydroxybenzenepropionate: 4-Hydroxybenzenepropionic acid and sodium bicarbonate, add water to generate a large amount of bubbles, stir, wait until no bubbles are generated, and after the substrate is completely dissolved, heat at 60°C - 100°C, and dry to obtain a brown solid.
4. Use of the kojic acid ester compound according to claims 1 to 3 in the preparation of a tyrosinase inhibitor.
5. The application according to claim 4, characterized in that, The tyrosinase is mushroom tyrosinase.
6. Use of the kojic acid ester compound according to claims 1 to 3 as a tyrosinase inhibitor in the preparation of a whitening cosmetic.
7. Use of the kojic acid ester compound according to claims 1 to 3 as a tyrosinase inhibitor in the preparation of a drug for treating skin diseases with excessive melanin production.
8. The application according to claim 4 or 6, characterized in that, IC of 3a against tyrosinase 50 = 451 μM; IC of 3b against tyrosinase 50 = 27.9 μM.