| abstract |
PROBLEM TO BE SOLVED: To provide an effective depigmenting drug which is stable in a composition, is non-toxic to the skin, and has no unpleasant odor, especially as far as the drug applied to the skin is concerned. I do. SOLUTION: The following formula (I): [In the above formula (I), X is COOH or the following ring: (In the upper ring, Z 1 , Z 2 and Z 3 are each independently Represents H, OR or R, wherein R is an optionally substituted, saturated or unsaturated, linear or branched C 1- Corresponding to C 8 represents an alkyl represents a group)], to produce at least one derivative or an ester of said derivative, or a metal complex or salt. |