Tyrosine-like condensed derivatives as tyrosinase inhibitors

Matos M. J;Santana L;Uriarte E;SERRA, SILVIA;Corda M;Fadda M. B;ERA, BENEDETTA;FAIS, ANTONELLA

2012-01-01

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Abstract

Objectives We report the pharmacological evaluation of a new series of 3-aminocoumarins differently substituted with hydroxyl groups, which have been synthesized because they include in their structures the tyrosine fragment (tyrosine-like compounds), with the aim of discovering structural features necessary for tyrosinase inhibitory activity. Methods The synthesized compounds 4 and 7-9 were evaluated in vitro as mushroom tyrosinase inhibitors. Key findings Two of the described compounds showed lower IC50 (concentration giving 50% inhibition of tyrosinase activity) than umbelliferone, used as a reference compound. Conclusions Compound 7 (IC50 = 53 μm) was the best tyrosinase inhibitor of this small series, having an IC50 value 10-fold lower than umbelliferone. Compound 7 (3-amino-7-hydroxycoumarin) had amino and hydroxyl groups precisely mimicking the same positions that both groups occupy on the tyrosine molecule.