Three steroids with unique structural feature of 5β-Spirostan-1β,3β,17α-trihydroxyl from Reineckia carnea.

A new spirostanol sapogenin and two spirostanol saponins, tentatively named reineckiagenin A (1), reineckiagenoside A (2), and reineckiagenoside B (3), were isolated from the whole plant of Reineckia carnea. By detailed analysis of their 1D and 2D NMR spectra, chemical methods, and by comparison with spectra data of known compounds, the structures of the new steroids were determined to be 25(S)-5β-spirostan-1β,3β,17α-triol (1), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-β-D-xylopyranoside (2), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (3). Compounds 1, 2, and 3 are the first naturally occurring steroids with unique structural feature of 5β-spirostan-1β,3β,17α-trihydroxyl.