The Luteolinidin and Petunidin 3--Glucoside: A Competitive Inhibitor of Tyrosinase.

The enzyme tyrosinase plays a key role in the early stages of melanin biosynthesis. This study evaluated the inhibitory activity of anthocyanidin () and anthocyanins (-) on the catalytic reaction. Of the six derivatives examined, - showed inhibitory activity with IC values of 3.7 ± 0.1, 10.3 ± 1.0, and 41.3 ± 3.2 μM, respectively. Based on enzyme kinetics, - were confirmed to be competitive inhibitors with values of 2.8, 9.0, and 51.9 μM, respectively. Molecular docking analysis revealed the formation of a binary encounter complex between - and the tyrosinase catalytic site. Luteolinidin () and petunidin 3--glucoside () may serve as tyrosinase inhibitors to block melanin production.