New minor spirostanol glycosides from Helleborus thibetanus.

ABSTRACT

Phytochemical reinvestigation of the dried roots and rhizomes of Helleborus thibetanus afforded four new minor spirostanol glycosides (1-4) and four known spirostanol glycosides (5-8). Their structures were determined on the basis of spectroscopic analyses, including 1D and 2D NMR experiments, together with HR-ESI-MS and IR measurements and the results of acid hydrolysis.