Pregnane glycosides from Solanum nigrum

Two new pregnane saponins, solanigroside A (1) and solanigroside B (2), along with two known compounds (3 and 4), were isolated from 60% ethanolic extract of the dried herb of Solanum nigrum L. The structures of 1 and 2 were elucidated as 5 alpha-pregn-16-en-3 beta-ol-20-one 3-O-beta-D-xylopyranosyl(1 -> 3)-O-[alpha-L-arabinopyranosyl-(1 -> 2)]-O-beta-D-glucopyranosyl-(1 -> 4)-O-[alpha-L-rhamnopyranosyl(1 -> 2)]-O-beta-D-galactopyranoside (1) and 5 alpha-pregn-16-en-3 beta-ol-20-one 3-O-beta-D-glucopyranosyl(1 -> 2)-O-[beta-D-glucopyranosyl-(1 -> 3)]-O-beta-D-glucopyranosyl-(1 -> 4)-O-beta-D-galactopyranoside (2), respectively, on the basis of extensive spectroscopic analysis as well as comparison with reported spectroscopic data of related compounds. This paper deals with the isolation and structural characterisation of pregnane glycosides from S. nigrum L.