Stilbene derivatives from Gnetum montanum Markgr. with their xanthine oxidase inhibition activity

Abstract

Phytochemical study on the methanol extract of the trunks of Gnetum montanum Markgr. led to the isolation of one new stilbene derivative, (E)-2′-methoxy-3,5,5′-trihydroxystilbene (1) and six known compounds, lehmbachol (2), gnetulin (3), trans-shegansu B (4), cis-shegansu B (5), (+)-hannokinol (6), and gnetol (7). Their chemical structures were determined by spectroscopic analyses including HR-ESI-MS, 1D and 2D NMR, and circular dichroism methods in comparison with the reported data. In addition, compounds 1-5 showed xanthine oxidase inhibitory activity with IC50 values of 13.6, 35.2, 38.7, 43.4, and 47.7 µm, respectively, compared to the positive control, allopurinol, which showed IC₅₀ value of 2.9 µm.