Effects of Tetrahydropterines on the Generation of Quinones Catalyzed by Tyrosinase

Abstract

Tetrahydrobiopterine (6BH₄) can diminish the oxidative stress undergone by keratinocytes and melanocytes by reducing the o-quinones generated by the oxidation of the corresponding o-diphenols. We found that 6BH₄ and their analogs reduced all the o-quinones studied. The formal potentials of different quinone/diphenol pairs indicate that the o-quinones with withdrawing groups are more potent oxidants than those with donating groups.