Coumaroyl and feruloyl flavonoid glycosides from the male flowers of L. and their inhibitory activity against α-glucosidase.

Four flavonoid glycosides containing coumaroyl or feruloyl groups were isolated from the male flowers of L., and compounds and were identified as novel compounds. The inhibitory activities against α-glucosidase were investigated by docking studies, assays and kinetic studies. The docking results showed that all compounds mainly formed hydrogen-bond and π-π-stacking interactions with α-glucosidase. Compound had the lowest binding energy and maximum number of hydrogen bonds. Subsequently, the assays showed that compound exhibited the strongest inhibitory potency. Finally, the kinetic studies indicated the inhibitory mode of compounds - against α-glucosidase were mixed types of competitive and non-competitive. Together, these findings suggested that the isolated flavonoid glycosides in this study, especially compound , have potential as α-glucosidase inhibitors.