| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cosmetic, quasi-medicine, medicine and food having an excellent bleaching action by including a specific substance having an inhibitory action of tyrosinase. SOLUTION: This cosmetic contains a substance of formula I (n is 1-20; R1 to R8 are each H or OH) (e.g. prodelphinidin, proapigeninidin, etc.). The compound of formula I is obtained, for example, by dissolving a compound of formula II (e.g. naringenin, ampeloptin, etc.), in a solvent such as ethanol, etc., adding sodium borohydride of 2-5 times mol numbers of the compound of formula II, degassing the solution, stirring for two hours, adding water, adjusting the solution to pH about 7, adding a compound of formula III (e.g. catechin, etc.), (equimolar amount to 1/20 mol based on the compound of formula II) dissolved in a solvent, adjusting the solution to pH 3-4 with an acid and stirring for 24-50 hours. A raw material for a cosmetic, quasi-medicine, medicine or food is formulated with the substance to give a product effective for bleaching.
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