Lignans from the roots of Saururus chinensis

Four new lignans, saucerneol F (1), saucerneol G (2), saucerneol H (3), and saucerneol I (4), were isolated from the EtOAc extract of the roots of Saururus chinensis, together with one known compound, saucerneol D (5). The structures of compounds 1-4 were elucidated by spectroscopic analysis. These compounds showed cytotoxic activities against HT-29, MCF-7, and HepG-2 cell lines.