Chemical constituents from Schisandra sphenanthera and their cytotoxic activity

Extensive phytochemical investigation of Schisandra sphenanthera leaves resulted in the isolation of six highly oxygenated nortriterpenoids (1–6) and five lignans (7–11) including a new pre-schisanartane-type, schisandrathera A (1), a new dibenzocyclooctadiene glycoside, schisandrathera B (7) and two new lignans, schisandrathera C (8) and schisandrathera D (9). Their chemical structures including absolute configurations were determined extensively by means of HR-ESI-MS, NMR, and ECD spectra. In addition, all isolated compounds were tested for cytotoxic activity against PC3 (prostate cancer) and MCF7 (breast cancer) cell lines. Among these compounds, schirubrisin B (3) showed strong cytotoxic effect on both PC3 and MCF7 cell lines with IC50 values of 3.21 ± 0.68, 13.30 ± 0.68 μM, respectively, whereas ten remaining compounds were found to be less effective in the investigated models.