Lignans from the Stem Barks of Kalopanax septemlobus

As a part of an ongoing collaborative program to discover novel bioactive components of plant origin, the stem barks of Kalopanax septemlobus were extracted with MeOH, and successively partitioned with CH$_2$Cl$_2$, EtOAc, BuOH and water. Repeated column chromatographic separation of the CH$_2$Cl$_2$ fraction resulted in the isolation of four compounds. Their structures were identified as vladinol E (1), (-)-simulanol｛4-［3-hydroxymethyl-5-((E)-3-hydroxypropenyl)-7-methoxy-2,3-dihydrobenzofuran-2-yl］-2,6-dimethoxy-phenol｝ (2), vladinol F (3), and (${\pm}$)-secoisolariciresinol (4). This is the first report on the isolation of these compounds from Kalopanax species.