Steroids of the spirostan and furostan series of plants of the Allium genus. XXIII. Structure of cepagenin and of alliospirosides C and D from Allium cepa

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-1,3,24-triol. Alliospirosides C and D are cepagenin 1-O-O--L-rhamnopyranosyl-(12)-L-arabinopyranoside] and 1-O-O--L-rhamnopyranosyl-(12)-O--D-galactopyranoside], respectively.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 843–849, November–December, 1987.