Tyrosinase inhibition by isoflavones that are contained in soy
was demonstrated by Chang et al. (2007). These authors found
that daidzein, glycitein, daidzin, and genistin act as competitive
inhibitors that reversibly inhibit the monophenolase activity of
mushroom tyrosinase. In addition, there is evidence that the position
and number of the hydroxyl group in the A-ring of the isoflavone
structure could affect both the strength and mode of inhibition of
isoflavones on mushroom tyrosinase (Chang et al., 2007)