Synthesis and Biological Evaluation of Novel Methyl 2-Hydroxy-5-Substituted Benzoate Derivatives as Mushroom Tyrosinase Inhibitors

Novel methyl 2-hydroxy-5-substituted benzoate derivatives (2a–2i) were synthesized by esterification of methyl gentisate and long-chain fatty acids. The compounds were structurally confirmed by MS, IR, 1H NMR, and HR-MS spectroscopy. A preliminary bioassay test demonstrated that compounds 2b, 2c, 2f, 2g, 2h showed stronger inhibition of tyrosinase activity. Further pharmacological experiments showed that after substitution modification of compounds 2b, 2f, 2g, and 2h, they have no potential toxicity and phototoxicity.