Abstract: | Kojic acid inhibits effectively the rate of L-tyrosine and tyramine hydroxylation by mushroom tyrosinase. It also affects the spectrum of product (s) formed, this being due to the ability of dopaquinone and dopamine-o-quinone to oxidize kojic acid to a yellow product(s). Kojic acid prevents the conversion of these o-quinones to their corresponding melanins. An insoluble yellow product(s) is formed when tyramine, but not L-tyrosine, is incubated with tyrosinase for 20 h in the presence of excess kojic acid. |