Molecular design of antibrowning agents: antioxidative tyrosinase inhibitors

Dodecyl (C12) gallate (3,4,5-trihydroxybenzoate) was found to inhibit the oxidation of l-3,4-dihydroxyphenylalanine (l-DOPA) catalyzed by tyrosinase. This inhibition is a slow and reversible reaction with residual enzyme activity. The inhibition kinetics analyzed by Lineweaver–Burk plots revealed that dodecyl (lauryl) gallate is an uncompetitive inhibitor (KIS=0.636 mM). Gallic acid, the parent compound of dodecyl gallate, acts as a reducing agent for o-quinone produced by the enzymic oxidation.