New furanoflavanoids, intestinal alpha-glucosidase inhibitory and free-radical (DPPH) scavenging, activity from antihyperglycemic root extract of Derris indica (Lam.)

A bioassay-guided fractionation and chemical examination of antihyperglycemic root extract of Derris indica resulted in isolation and characterization of two new furanoflavanoids (1, 2) along with thirteen known compounds (3-15). Their structures were determined on the basis of extensive spectroscopic (IR, MS, 1D and 2D NMR) data analysis and by comparison with the literature data. All the compounds were tested in vitro for intestinal alpha-glucosidase inhibitory and DPPH radical activity. New compounds (1, 2) displayed moderate intestinal alpha-glucosidase inhibitory as well as free radical scavenging activity. Other compounds also displayed varying degrees of moderate intestinal alpha-glucosidase inhibitory activity. Pongamol (6) displayed potent intestinal alpha-glucosidase inhibition.