Five cholestane glycosides (1 - 5) including three new ones (3 - 5) with potent cytostatic activity on leukemia HL-60 cells were isolated from Ornithogalum saundersiae bulbs. Compound 1, a main constituent in the bulbs, was revealed to be exceptionally cytostatic against various malignant tumor cells and effective to mouse P388 leukemia in in vivo evaluation. (C) 1997 Elsevier Science Ltd. All rights reserved.