Triterpene saponins from the roots of Clematis chinensis

A saponin-enriched fraction prepared from the MeOH extract of the roots of Clematis chinensis showed cytotoxic activity against HL-60 promyelocytic leukemia cells, from which five new triterpene saponins (1-5) based on oleanolic acid, along with three known saponins (6-8), were isolated. The structures of the new saponins were determined on the basis of spectroscopic analysis, including extensive 1D and 2D NMR data and hydrolysis followed by chromatographic and spectroscopic analysis. Among the isolated saponins, monodesmosidic saponins exhibited cytotoxic activities against cultured tumor cells.