Nobiletin as a tyrosinase inhibitor from the peel of Citrus fruit.

A tyrosinase inhibitor was isolated from the peel of Citrus fruit by activity-guided fractionation, and identified as 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) by comparison with reported spectral data. Nobiletin (IC50 of; 46.2 microM) exhibited more potency than Kojic acid (IC50; 77.4 microM) used as a positive control, and it was found to be potentially an effective inhibitor of the production of melanin.