Phenolic Constituents with their α-Glucosidase Inhibitory Activities from the Leaves of Viburnum melanocarpum

A new compound 1, together with two known compounds (2, 3), has been isolated from the ethanolic extract of Viburnum melanocarpum leaves. Their structures were elucidated by extensive spectroscopic evidence and chemical method. In the in vitro assay, compounds 1 and 3 displayed potent inhibitory activity against α-glucosidase with IC50 values of 6.28 μM and 12.73 μM, respectively.