PURPOSE: To provide a novel melamine production-inhibiting agent containing a specific yakuchinone derivative as an active ingredient, having an excellent tyrosinase-inhibiting activity, high in safety, and giving a cosmetic having an excellent whitening effect and a good using touch.
CONSTITUTION: The melamine production-inhibiting agent contains a yakuchinone derivative represented by the formula (one or two of R1-R3 are OH, methoxy, and the remaining is H; the dotted line is a single bond or double bond) and comprising pale yellow needle-like crystals as an active ingredient. The yakuchinone derivative of the formula is produced as follows: adding a 10% potassium hydroxide aqueous solution to the ethanol solution of 1-phenyl-5- hexanone, stirring the mixture at room temperature for 30min, gradually adding the ethanol solution of 2-hydroxy-3-methoxybenzaldehyde solution, reacting the solution for 24hr, filtering the deposited crystals, dissolving the crystals in methylene chloride, washing the solution with water, distilling out the solvent, and subsequently recrystallizing the product from n-hexane/ethyl acetate.
MIYAZAKI KOJI
AIYAMA RITSUO
ICHIOKA MINORU
YOKOKURA TERUO
