A New Benzophenone -Glucoside and Other Constituents of and Their α-Glucosidase Inhibitory Activity.

Phytochemical investigations of the leaves and stems of led to the isolation of a new benzophenone -glucoside named pseuduvarioside (), together with six known compounds including (-)-guaiol (), (+)-isocorydine (), cyathocaline (), isoursoline (), --coumaroyltyramine (), and --feruloyltyramine (). Their structures were characterized by NMR spectroscopy and mass spectrometry. All of the isolates were evaluated for inhibitory activity against the enzyme α-glucosidase. --coumaroyltyramine and --feruloyltyramine showed higher activity than the drug acarbose. Kinetic studies revealed that both tyramine-derived amides were uncompetitive inhibitors of the enzyme.