Kojyl thioether derivatives having both tyrosinase inhibitory and anti-inflammatory properties

This study was conducted to examine the tyrosinase inhibitory and anti-inflammatory activities of kojic acid derivatives. A series of kojic acid derivatives containing thioether, sulfoxide, and sulfone linkages were synthesized. In the tyrosinase assay, kojyl thioether derivatives containing appropriate lipophilic alkyl chains (pentane, hexane, and cyclohexane) showed potent inhibitory activity. However, sulfoxides and sulfones exhibited decreased activity. Similar experimental results were obtained with inhibitory activities of NO production being induced by LPS. The presence of thioether linkage and appropriated lipophilic acid moiety was critical for the tyrosinase inhibitory and anti-inflammatory activities. (C) 2010 Elsevier Ltd. All rights reserved.