Triterpene saponins from Pleurospermum kamtschaticum and their biological activity

Eleven new triterpene saponins (1-11), together with fourteen known triterpene and triterpene saponins (12-25) were isolated from a MeOH extract of Pleurospermum kamtschaticum HOFFMANN (Umbelliferae). The chemical structures of the new compounds (1-11) were determined by means of MS, (1)H-NMR, (13)C-NMR, correlated spectroscopy (COSY), heteronuclear multiple bond correlation (HMBC), total correlated spectroscopy (TOCSY) and nuclear Overhauser effect spectroscopy (NOESY) to be pleurosaponin A (1)-K (11). The isolated compounds were tested for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, HCT15) in vitro using the sulforhodamine B bioassay (SRB) assay. All compounds showed little cytotoxicity against tested cell lines (IC(50) >30 µM).