Abstract: Provided are a very safe skin whitening agent, melanin production inhibitor, and dopa oxidase activity inhibitor. Use of kitsunenomago or an organic solvent extract thereof to inhibit the dopa oxidase activity.

Abstract: The invention provides a method for inhibiting dopa oxidase activity, for inhibiting melanin production, or for whitening skin using haguro-so or an organic solvent extract thereof, or a compound of formula (I):

Abstract: Provided are a very safe skin whitening agent, melanin production inhibitor, and dopa oxidase activity inhibitor. Use of kitsunenomago or an organic solvent extract thereof to inhibit the dopa oxidase activity.

Abstract: Use of haguro-so or an organic solvent extract thereof, or a compound represented by the following formula (I) or a salt thereof, for inhibiting a dopa oxidase activity, for inhibiting melanin production, or for whitening the skin; in the formula (I), R1 and R2, being the same or different, each represent a hydroxyl group, or a C1-4 linear or branched alkoxy group, or R1 and R2 together form a methylenedioxy group; R3 and R4, being the same or different, each represent a hydroxyl group, or a C1-4 linear or branched alkoxy group, or R3 and R4 together form a methylenedioxy group; R5 represents a hydrogen atom, a hydroxyl group, a C1-5 linear or branched alkoxy group, a C1-4 acyl group, or a sugar residue selected from the group consisting of (D-apio-?-D-furanosyl)oxy, (?-D-glucopyranosyl)oxy, (3-O,4-O-dimethyl-D-xylopyranosyl)oxy, (2-O,3-O,4-O-trimethyl-?-D-xylopyranosyl)oxy, and (3-O-methyl-?-D-glucopyranosyl)oxy; R6 and R7 are each a hydrogen atom and R8 and R9 together represent an oxygen atom, or R8 and R9