A novel C6-sulfonated celastrol analog as a tyrosinase and melanin inhibitor: Design, synthesis, biological evaluation and molecular simulation

To improve the application prospects of celastrol (CE), a novel C 6 -sulfonated CE analog (called CENFN in this study) was designed via quantum chemical calculations. On this basis, CENFN was synthesized and clarified by spectroscopic methods (IR, 1 H NMR, UV–Vis and fluorescence spectra). Subsequently, the tyrosinase and melanin inhibitory effects of CE and CENFN were comparably explored in silico and in vitro . The calculation and spectroscopy results confirmed the rationality of the synthetic reactions of CENFN. The molecular simulation results showed that CENFN possessed a higher level of tyrosinase and melanin inhibition than CE, which was consistent with the experimental results. All these findings can help to design and synthesize CE analogs as tyrosinase and melanin inhibitors.