Dibenzocyclooctadiene lignans from the fruits of Schisandra chinensis and their cytotoxicity on human cancer cell lines

Repeated chromatographic separations of the EtOAc fraction of Schisandra chinensis fruits on silica gel, octadecyl silica gel, and Sephadex LH-20 led to the isolation and identification of seven dibenzocyclooctadiene lignans (1–7). The NMR data reported in the literature for angeloyl gomisin H (5) were shown to be incorrect. We unambiguously identified the compounds based on detailed analysis of the 1D and 2D NMR data, especially from HMBC and NOESY experiments. In addition, MTT assays and cell viability experiments verified the cytotoxicity of the isolated dibenzocyclooctadiene lignans against the human cancer cell lines AGS, HeLa, and HT-29.