Triterpene saponins from Nigella sativa L

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-[$\beta$-D-xylopyranosyl-$(1\rightarrow 3)$-$\alpha$- L-rhamnopyranosyl-($1\rightarrow 2$)-$\alpha$-L-arabinopyranosyl]-28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl- (1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (1), 3-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl]- 28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl-(1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (2), and 3-O-[$\beta$-D-xylopyranosyl-(1\rightarrow 3)-$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl] -hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella.