Two new monosaccharide steroidal saponins, named ypsilandroside S (1) and ypsilandroside T (2), have been isolated from the whole plants of Ypsilandra thibetica. Their structures were elucidated as heloniogenin 3-O-β-D-apiofuranoside (1) and pregna 5,16-dien-3β,12α-diol-20-one-3-O-β-D-apiofuranoside (2) by spectroscopic techniques (1D and 2D NMR, MS). Compounds 1 and 2 were tested for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells.
Keywords: Liliaceae; Ypsilandra thibetica; Ypsilandroside S; Ypsilandroside T.