Patent ID: 7754864

Claim:
An arbutin ester compound represented by formula (1): wherein Ra is selected from the group consisting of: R 1 —CH═CH 2 , wherein R 1 is a single bond, an unsubstituted alkyl group or an arylene group; wherein R 1 is a single bond, an alkyl group or an arylene group; R 1 —COOCH═CH 2 , wherein R 1 is a single bond, an alkyl group or an arylene group; R 1 —COOH, wherein R 1 is a single bond, an alkyl group or an arylene group; R 1 —COO—R 2 , wherein R 1 is a single bond, an alkyl group or an arylene group; and R 2 is an alkyl group or an aryl group; and R 1 —C(CH 3 ) 3 , wherein R 1 is a single bond, an alkyl group or an arylene group.