Abstract
Inhibition by Aloe extracts of L-dopa oxidation by mushroom-tyrosinase was examined. 2″-O-Feruloylaloesin and aloesin at concentrations of 0.4 µM showed inhibition of 27 and 30%, respectively. Lineweaver-Burk plots of the concentration of L-dopa in the absence and presence of 2″-O-feruloylaloesin, 0.4 and 0.8 µM, showed that this compound inhibits mushroom-tyrosinase noncompetitively. The Ki value obtained was 8.5 × 10-5 M. 2″-O-Feruloylaloesin and aloesin contents were analyzed by a reversed-phase HPLC, and their seasonal variations were observed.
