Four New Dibenzocyclooctadiene Lignans from Schisandra rubriflora

AimTo study the chemical constituents of the stems of Schisandra rubriflora (Franch.) Rehd. et Wils collected from Enshi, Hubei Province, China.MethodsCompounds were isolated by column chromatography with silica gel, RP-18 gel, and semi-preparative and preparative HPLC. Their structures were elucidated by extensive spectroscopic methods, including 2D-NMR, HR-ESI-MS and CD techniques.ResultsFour new dibenzocyclooctadiene lignans, schirubrisins A-D (1–4), together with fourteen known ones (5–18) were isolated from the stems of S. rubriflora.ConclusionCompounds 1–4 are new dibenzocyclooctadiene lignans.