Three new spirostanol glycosides from Helleborus thibetanus.

An ongoing chemical investigation on n-BuOH extract of roots and rhizomes of Helleborus thibetanus afforded three new spirostanol glycosides (1-3). Their structures were elucidated by extensive analysis of 1 D, 2 D NMR spectra, together with IR and MS methods and acid hydrolysis. This is the first report of the isolation of spirostanol glycoside with xylose at C-24 of the aglycone in Helleborus.