Triterpene Saponins from Nigella sativa L.

Abstract

Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[b-D-xylopyranosyl- (1 \\to 3)-a-L-rhamnopyranosyl-(1 \\to 2)-a -L-arabinopyranosyl]- 28-O-[a-L-rhamnopyranosyl-(1 \\to 4)-b-D-glucopyranosyl-(1 \\to 6)- b-D-glucopyranosyl]-hederagenin (1), 3-O-[a -L-rhamnopyranosyl- (1 \\to 2)-a-L-arabinopyranosyl]-28-O-[a -L-rhamnopyranosyl-(1 \\to 4)- b-D-glucopyranosyl-(1\\to 6)-b-D-glucopyranosyl]-hederagenin (2), and 3-O-[b-D-xylopyranosyl- (1\\to 3)-a-L-rhamnopyranosyl-(1\\to 2)-a- L-arabinopyranosyl]-hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella.