Three novel furospirostanol glycosides and a steroidal alkaloid glycoside from the bulbs of Fritillaria camtschatcensis (L.) Ker Gawl., and their cytotoxicity

Three novel steroidal glycosides (1-3) and a previously described steroidal alkaloid glycoside (4) have been isolated from the bulbs of Fritillaria camtschatcensis (L.) Ker Gawl. (Liliaceae). The structures of novel compounds 1-3 were characterized based on NMR spectroscopy and chemical transformations. Compounds 1-3 are furospirostanol glycosides bearing a (3S)-3-hydroxy-3-methylglutaryl moiety at C-26 in the aglycone. Compounds 1-4 were evaluated in terms of their cytotoxic activities toward HL-60 human promyelocytic leukemia cells, A549 human lung adenocarcinoma cells, and SBC-3 human lung small cell carcinoma cells. Only 4 showed moderate cytotoxicity against HL-60, A549, and SBC-3 cells with IC50 values of 22.9, 13.3, and 11.9 mu M, respectively. Compound 4 was found to cause necrotic-like cell death in HL-60 cells.