Abstract: | Two new steroid glycosides of the spirostan series have been isolated from the fruit ofAllium cepa L. (family Liliaceae): alliospirosides C and D. On the basis of chemical transformations and spectral characteristics it has been established that the aglycon of both glycosides is a new steroid sapogenin — cepagenin — having the structure of (24S,25R)-spirost-5-ene-1β,3β,24-triol. Alliospirosides C and D are cepagenin 1-O-[O-α-L-rhamnopyranosyl-(1→2)α-L-arabinopyranoside] and 1-O-[O-α-L-rhamnopyranosyl-(1→2)-O-β-D-galactopyranoside], respectively. |