Development of hydroxylated naphthylchalcones as polyphenol oxidase inhibitors: Synthesis, biochemistry and molecular docking studies
摘要:
Polyphenol oxidase (Tyrosinase) has received great attention, since it is the key enzyme in melanin biosynthesis. In this study, novel hydroxy naphthylchalcone compounds were synthesized, and their inhibitory effects on mushroom tyrosinase activity were evaluated. The structures of the compounds synthesized were confirmed by H-1 NMR, C-13 NMR, FTIR and HRMS. Two of the compounds synthesized inhibited the diphenolase activity of tyrosinase in a dose dependent manner and exhibited much higher tyrosinase inhibitory activities (IC50 values of 10.4 mu M and 14.4 mu M, respectively) than the positive control, kojic acid (IC50: 27.5 mu M). Kinetic analysis showed that their inhibition was reversible. Both the novel compounds displayed competitive inhibition with their K-i values of 3.8 mu M and 4.5 mu M, respectively. Docking results confirmed that the active inhibitors strongly interacted with the mushroom tyrosinase residues. This study suggests hydroxy naphthylchalcone compounds to serve as promising candidates for use as depigmentation agents. (C) 2015 Elsevier Inc. All rights reserved.
Integrated kinetic studies and computational analysis on naphthyl chalcones as mushroom tyrosinase inhibitors
摘要:
Melanin helps to protect skin from the damaging ultraviolet radiation of the sun. Tyrosinase, the key enzyme in melanogenesis is responsible for coloration of skin, hair and eyes. This enzyme is considered to have a critical role in governing the quality and economics of fruits and vegetables, as tyrosinase activity can lead to spoilage through browning. Development of tyrosinase inhibitors is a promising approach to combat hyperpigmentation conditions like ephelides, lentigo, freckles and post-inflammatory hyperpigmentation. In the present study, we have used a docking algorithm to simulate binding between tyrosinase and hydroxy-substituted naphthyl chalcone oxime compounds and studied the inhibition of tyrosinase. The results of virtual screening studies indicated that the estimated free energy of binding of all the docked ligands ranged between -19.29 and -9.12 kcal/mol. Two of the oximes synthesized were identified as competitive tyrosinase inhibitors and were found to be twice as potent as the control kojic acid with their IC50 values of 12.22 mu M and 19.45 mu M, respectively. This strategy of integrating experimental and virtual screening methods could give better insights to explore potent depigmentation agents. (C) 2015 Elsevier Ltd. All rights reserved.