A new ellagic acid derivative from Polygonum runcinatum

A new ellagic acid derivative, 3,3 '-dimethylellagic acid-4 '-O-(6 ''-galloyl)-beta-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-beta-d-glucoside (3) and 3-methylellagic acid-4 '-O-alpha-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.