A new ellagic acid derivative, 3,3'-dimethylellagic acid-4'-O-(6″-galloyl)-β-D-glucoside, named runcinatside (5), together with four known compounds 3,3'-dimethylellagic acid (1), 3,3',4'-trimethylellagic acid (2), 3,3'-dimethylellagic acid-4'-O-β-D-glucoside (3) and 3-methylellagic acid-4'-O-α-L-rhamno-pyranoside (4), was isolated from the roots of Polygonum runcinatum Buch.-Ham. ex D.Don Var. sinense Hemsl and the structures of these compounds were established by spectroscopic methods and comparison with previously reported data. All compounds showed antioxidant activities in vitro and compound 5 possessed the highest activity.
Keywords: Polygonum runcinatum; antioxidant activity; chemical constituents; ellagic acid derivative.