Novel Steroidal Glycosides from the Whole Plants of Helleborus foetidus

抄録

Phytochemical analysis of the whole Helleborus foetidus plants identified 28 steroidal glycosides (1–28), including 20 novel spirostanol glycosides (1–20) and a novel furostanol glycoside (21). The structures of the newly identified compounds were elucidated by two-dimensional NMR spectroscopy and hydrolytic cleavage. Compounds 12, 13, and 15 were determined to be spirostanol trisdesmosides bearing sugar moieties at the C-1, -21, and -24 hydroxy groups of the aglycone unit. The isolated compounds were subsequently evaluated for cytotoxic activity against HL-60 human promyelocytic leukemia cells and A549 human lung carcinoma cells. In particular, 7 showed cytotoxic activity against the HL-60 and A549 cells, with IC₅₀ values of 5.9 and 6.6 µM, respectively, whereas 19 was selectively cytotoxic to A549 cells with an IC₅₀ value of 5.5 µM.