Experimental and computational profiling of novel bis-Schiff base derivatives bearing α-naphthalene moiety as potential tyrosinase inhibitors

A library of novel bis-Schiff base derivatives (2a-u) of α-naphthalene moiety was successfully synthesized by four step reactions. Following structural elucidation, these products were evaluated for their in vitro tyrosinase inhibitory potential. In the series, nine derivatives (2e, 2r, 2t, 2 g, 2 u, 2p, 2a, 2d, and 2 h) attributed excellent inhibitory activity in the range of IC₅₀ values from 2.3 ± 1.7 to 17.6 ± 0.9 µM superior to the standard drug kojic acid. Similarly, four compounds showed significant activities near to the standard while the remaining eight compounds displayed good to moderate inhibition with IC₅₀ values from 29.3 ± 2.9 to 63.2 ± 1.1 µM. The molecular docking investigations for most active compounds (2e, 2r, 2t, 2 g, 2 u, 2p, 2a, 2d, and 2 h) form high stability in binding site of the tyrosinase active site, than standard kojic acid. Frontier molecular orbitals, such as HOMO and LUMO to show the charge transfer from molecule to biological medium and MEP map to show the chemically reactive zone appropriate for drug action, are calculated using TD-DFT. Besides, the drug-likeness prediction showed that these compounds showed a desirable property, such as high intestinal absorption, large volume of distribution, good BBB penetration, and low toxicity. These bis-Schiff bases have a high oral bioavailability, which can categorized as a unique drug candidate in future.