Constituents from Aerial Parts of Bidens ceruna L. and Their DPPH Radical Scavenging Activity

A new chalcone glycoside, butein-4-methoxyl-4'-O-(6"-O-acetyl)-beta-D-glucopyranoside(2), along with seven known compounds, namely, quercitrin(1), lutcolin-7-O-beta-D-glucopyranoside(3), butein-4'-O-beta-D-glucopyranoside(4), butein-4-methoxyl-4'-O-beta-D-glucopyranoside(5), butin-7-O-beta-D-glucopyranoside(6), isoquercitrin(7), and sulfurein(8) was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activity.