Antioxidant and Anti-α-glucosidase Compounds from the Rhizome of Peltiphyllum peltatum (Torr.) Engl

The antioxidant, anti-alpha-glucosidase and anticholinesterase effects of the alcohol extract of fresh underground rhizomes of Peltiphyllum peltatum were studied. A potent antioxidant activity accompanied by a selective alpha-glucosidase effect was observed for the crude extract. Further activity-guided fractionation (petroleum ether, chloroform, ethyl acetate, n-butanol and water) resulted in the identification of the ethyl acetate fraction with the highest antioxidant effect. Gallic acid, methyl-3-O-methyl gallate, catechin, gallocatechin, bergenin and 11-O-galloylbergenin were isolated from the ethyl acetate fraction. While all the isolated compounds did show a variable degree of radical scavenging effect, 11-O-galloylbergenin was identified as the selective alpha-glucosidase inhibitor. The isolation, structural elucidation and biological effects of these compounds are discussed. Copyright (c) 2012 John Wiley & Sons, Ltd.