Discovery and mechanistic elucidation of 2,4-resorcinol-based potent human tyrosinase inhibitors through integrated experimental and computational approaches

Tyrosinase is a copper-dependent enzyme essential for melanin biosynthesis and a validated target for managing hyperpigmentation. To discover potent inhibitors, we synthesized and screened 120 resorcinol-based analogues using mushroom tyrosinase (abTYR) assays and B16 melanoma cell models. This experimental workflow identified five promising candidates for further evaluation. Compound 3 consistently emerged as the lead inhibitor, demonstrating submicromolar potency against abTYR (IC₅₀ = 0.2 μM), strong cellular efficacy in suppressing melanogenesis (IC₅₀ = 1.6 μM) in B16 cells, and the broadest safety margin (LD₅₀ = 345.9 μM; TI ≈ 216). To elucidate its mechanism, a homology model of human tyrosinase (hsTYR) was constructed and analyzed through molecular docking, molecular dynamics simulations, and MM-PBSA free energy calculations, which confirmed stable interactions with the conserved binuclear copper center. These results highlight the value of combining experiment-driven prioritization with structure-guided modeling and identify compound 3 as a promising and selective inhibitor of hsTYR for therapeutic and cosmetic applications.