Cytotoxic steroidal glycosides from Paris rugosa rhizomes.

Two previously undescribed steroidal saponins, rugosarosides A (1) and B (2), as well as 16 known compounds (3–18), were isolated from the rhizomes of Paris rugosa H. Li & S. Kurita (Melanthiaceae). Their chemical structures were elucidated based on extensive analyses of NMR and MS data and acidic hydrolyses. These isolates were evaluated for their cytotoxicity to five human cancer cell lines (HL-60, SW480, MDA-MB-231, A549, and A549/Taxol) and the normal human bronchial epithelial cell line BEAS-2B using the MTS test. Spirostanol saponins 6 – 12 and furostanol saponin 16 showed cytotoxic activity, with IC 50 values ranging from 0.13 to 3.88 μ M. The furostanol saponins 14 , 15 , and 17 selectively inhibited HL-60, A549, and A549/Taxol cells (IC 50 : 3.45–9.51 μ M), with no cytotoxicity to SW480 and MDA-MB-231 cells (IC 50 > 40 μ M). [Display omitted] • Two previously undescribed steroidal saponins were isolated from Paris rugosa rhizomes. • Seven spirostanol saponins showed inhibitory activity against five human cancer cell lines. • Three furostanol saponins selectively inhibited HL-60, A549, and A549/Taxol cells. [ABSTRACT FROM AUTHOR]