ANTINEOPLASTIC AGENTS .1. 3 SPIROSTANOL GLYCOSIDES FROM RHIZOMES OF DIOSCOREA-COLLETTII VAR HYPOGLAUCA

By activity-guided fractionation, three known steroidal saponins, pros apogenin A of dioscin, dioscin and gracillin, were isolated from the t otal saponin fraction of Dioscorea collettii var. hypoglauca as active compounds causing morphological abnormality of Pyricularia oryzae myc elia. The compounds also exhibited cytotoxic activity against the canc er cell line K562 in vitro. The structures of the compounds were eluci dated on the basis of chemical evidence and IR, FAB-MS, H-1-NMR, C-13- NMR, and two-dimensional NMR (2D-NMR) analysis.