A new acetylated spirostanol saponin and other constituents from the rhizomes of Dioscorea althaeoides R. Knuth (Dioscoreaceae)

A new acetylated spirostanol saponin (7), dioscin-6′-O-acetate, was isolated from the rhizomes of Dioscorea althaeoides R. Knuth (Dioscoreaceae), together with fourteen known compounds, including three spirostanol saponins (1-2, 6), three furostanol saponins (10-12), one diarylheptanoid (3), three sterols (4-5, 9), three aliphatic acids (8, 13-14) and one aliphatic alkane (15). Their structures were established by extensive 1D- and 2D- NMR (DEPT, 1H-1H COSY, HSQC, HMBC and NOESY) experiments in conjunction with IR and HRESI/TOF-MS data, as well as the results of acid hydrolysis. The compounds (3-8, 10-15) were isolated from this species for the first time. The chemotaxonomic significance of these compounds was also discussed