Natural Antioxidants, Tyrosinase and Acetylcholinesterase Inhibitors from Cercis glabra Leaves.

is a plant belonging to the legume family, whose flowers and barks are commonly used as food and traditional Chinese medicines. However, its leaves are usually disposed of as wastes. This research comprehensively investigated the bioactive constituents of leaves, and two new phenolic, ceroffesters A-B (-) and thirteen known compounds (-) were isolated. Their structures were elucidated by spectroscopic methods such as nuclear magnetic resonance (1D NMR and 2D NMR), high-resolution electrospray ionization mass spectra (HR-ESI-MS), optical rotatory dispersion (ORD) and electronic circular dichroism (ECD). All of them were assessed for their antioxidant activities through ABTS, DPPH and PTIO methodologies, and evaluated for inhibitory activities against two enzymes (mushroom tyrosinase and acetylcholinesterase). As a result, compounds -, and exhibited evident antioxidant activities. Meanwhile, compounds , and showed the most potent tyrosinase inhibitory activities, with IC of 0.64, 0.65 and 0.59 mM, and compared with the positive control of 0.63 mM (kojic acid). In the initial concentration of 1 mg/mL, compounds , and demonstrated moderate inhibitory activities against acetylcholinesterase with 85.27 ± 0.06%, 83.65 ± 0.48% and 82.21 ± 0.09%, respectively, compared with the positive control of 91.17 ± 0.23% (donepezil). These bioactive components could be promising antioxidants, tyrosinase and acetylcholinesterase inhibitors.