Cytotoxic triterpenoid glycosides from the roots of Camellia oleifera

Eight new triterpenoid saponins, oleiferosides A-H (1-8), were isolated from the EtOH extract of the roots of Camellia oleifera. Their structures were elucidated by a combination of 1D and 2D NMR techniques, mass spectrometry, and chemical methods. All were characterized to be oleanane-type saponins with sugar moieties linked to C-3 of the aglycone. Cytotoxic activities of these saponins were evaluated against four human tumor cell lines (A549, B16, BEL-7402, and MCF-7) by using the MTT in vitro assay. Compound 3 exhibited potent cytotoxic activitiy against all the tested cell lines with IC50 values < 10 µM. Compounds 1, 2, 4, and 5 showed moderate cytotoxic activities toward the tested cell lines.