PubAg

Main content area

Identifying an isoflavone from the root of Pueraria lobata as a potent tyrosinase inhibitor

Author:
Wagle, Aditi, Seong, Su Hui, Jung, Hyun Ah, Choi, Jae Sue
Source:
Food chemistry 2019 v.276 pp. 383-389
ISSN:
0308-8146
Subject:
L-dopa, Pueraria montana var. lobata, active sites, computer simulation, daidzein, dose response, enzyme inhibitors, enzymes, ethanol, formononetin, functional foods, inhibitory concentration 50, moieties, mushrooms, tyrosine
Abstract:
Traditionally, the root of Pueraria lobata are widely used as a functional food. It was observed that a 70% ethanol extract showed a dose-dependent inhibition towards mushroom tyrosinase. Among the different isolated compounds, calycosin demonstrated potent inhibitory activity against substrates l-tyrosine and l-DOPA, with IC50 of 1.45 ± 0.03 and 7.02 ± 0.46 µM, respectively. Conversely, formononetin and daidzein exhibit weak inhibition. Moreover, kinetic studies revealed calycosin to be a competitive inhibitor for both substrates. Additionally, molecular docking simulation showed that the hydroxyl groups at C-3′ and C-7 positions interacted with the catalytic site and peripheral residues, demonstrating a higher affinity toward mushroom tyrosinase. Accordingly, our results suggest that, rather than a mono-substituted hydroxyl or methoxyl group, the presence of a hydroxyl group at C-3′ and a methoxyl group at C-4′ position of the isoflavone skeleton plays an essential role in the manifestation of anti-browning activity in food products.