A new lignan, chicanine, isolated from the fruit of Schisandra sp., is shown to possess structure 1, 2S-(3-methoxy-4-hydroxyphenyl)-3R,4S-dimethyl-5S-(3,4-methylenedioxyphenyl)tetrahydrofuran, from spectra analysis and chemical conversions. The tetrahydrofuran ring exists in a "twist envelope" conformation.