Megastigmane Glycosides with α-Glucosidase Inhibitory Activity from Viburnum urceolatum Fruits

Abstract

A new megastigmane glycoside (1), viburcoside A, and four known analogs (2–5) were isolated from the methanol extract of Viburnum urceolatum fruits. The structure, including the absolute configuration of compound 1, was elucidated by extensive spectroscopic analysis (NMR and HR-ESI-MS), DP4+ NMR and ECD calculations, and enzyme hydrolysis. In the in vitro assay, viburcoside A (1) exhibited the potential inhibition of α-glucosidase with the IC₅₀ value of 16.03 μM, compared with the positive control acarbose (IC₅₀ = 18.84 μM).