Refinement of arylthiosemicarbazone pharmacophore in inhibition of mushroom tyrosinase

Melanin play a major role in human skin protection and their biosynthesis is vital. Due to their color, they contribute to the skin pigmentation. Tyrosinase is a key enzyme involved in the first stage of melanin biosynthesis, it catalyzes the transformation of tyrosine into l-dopaquinone. The aim of the present study was to study molecules able to inhibit tyrosinase to be used in treating depigmentation-related disorders. In this study, we targeted arylthiosemicarbazone analogs with the aim to contribute to the identification of the optimal aryl ring to be linked to the thiosemicarbazone moiety. The biological activity was evaluated on commercial mushroom tyrosinase which was purified prior use. The results demonstrated that several of our compounds (1a–h, 1j, 1r and 5) had more potent inhibitory activities than kojic acid which was used as the reference inhibitor.

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► Arylthiosemicarbazones were investigated as tyrosinase inhibitors.
► We examine the impact of the aryl moiety on the inhibitory activity.
► A phenyl, furanyl or pyrolidinyl rings were found as the most advantageous.
► The distance separating the aryl ring from the thiourea moeity was important.