Steroidal glycosides (1-21), including eight new spirostanol glycosides (1-8) and a new cholestane glycoside (9), were isolated from the bulbs of Lilium speciosum. The structures of the new compounds were determined based on spectroscopic data analysis and hydrolytic cleavage reactions. The isolated compounds and their aglycones (1a, 8a, and 9a) were evaluated for their cytotoxicity against HL-60 human
Steroidal glycosides (1-18), including 10 new compounds (1-10), were isolated from the bulbs of Fritillaria meleagris (Liliaceae). The structures of the new compounds were determined by two-dimensional (2D) NMR analysis, and by hydrolytic cleavage followed by spectroscopic and chromatographic analysis. The isolated compounds and their aglycones were evaluated for cytotoxic activity against HL-60 human promyelocytic leukemia cells and A549 human lung adenocarcinoma cells. Morphological observation and flow cytometry analysis showed that 5 beta-spirostanol glycoside (2) and a cholestane derivative (17a) induced apoptotic cell death in HL-60 cells through different mechanisms of action. Furthermore, the (22R)-spirosolanol glycoside (11) selectively induced apoptosis in A549 cells without affecting the caspase-3 activity level. (C) 2013 Elsevier Inc. All rights reserved.