A new furofuran lignan with antioxidant and antiseizure activities from the leaves of Petasites japonicus.

A new furofuran lignan (1) was isolated from the n-butanol fraction of the methanolic extract of the leaves of Petasites japonicus (Sieb. et Zucc.) Maxim. (Compositae). The structure of compound 1 was determined to be 2alpha-(4'-hydroxy-3'-methoxyphenyl)-6alpha-(4"-hydroxy-3"-methoxyphenyl)-8alpha-hydroxy-3,7-dioxabicyclo[3.3.0octane 4'-O-(beta-D-glucopyranoside) by spectroscopic methods including 2D-NMR. In further studies, it was found that the compound 1 expressed an antioxidant activity in DPPH radical scavenging assay, and moreover, ameliorated the seizure in kainic acid-treated mice.