Antioxidant Flavonoid Glycosides from Daphniphyllum calycinum

Abstract

A novel flavonoid diglycoside, 5,6,7,4‘-tetrahydroxyflavonol 3-O-rutinoside (1), and a previously known compound, kaempferol 3-O-neohesperidoside (2), were isolated from an ethyl acetate extract of Daphniphyllum calycinum leaves that showed significant activity in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay. The structure of 1 was elucidated by a combination of spectroscopic methods, and compounds 1 and 2 were found to be moderately active as antioxidants in the DPPH assay.