Triterpene saponins and lignans from the roots of Pulsatilla chinensis and their cytotoxic activity against HL-60 cells

Two new triterpene saponins (8 and 9) and seven previously reported triterpene saponins (1-7) based upon oleanolic acid or hederagenin, along with two known Lignans, (+)-pinoresinol (10) and beta-peltatin (11), were isolated from a saponin fraction prepared from the MeOH extract of the roots of Pulsatilla chinensis. The structures of the new saponins were determined by spectroscopic analysis, including 2D NMR spectroscopic techniques, and the results of hydrolytic cleavage. The isolated compounds and some derivatives were evaluated for their cytotoxic activity against HL-60 human leukemia cells.