Steroidal oligoglycosides from Solanum nigrum

Two new steroidal saponins, named nigrumnins I and II, together with two kn own saponins were obtained from the whole plant of Solanum nigrum L. On the basis of spectroscopic analysis (H-1-NMR, C-13-NMR, H-1-H-1 COSY, TOCSY, H MQC, HMBC and FAB-MS), nigrumnin I was established as (25R)-5 alpha-spirost an-3 beta-ol 3-O-beta-D-xylopyranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1- ->2)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl(1-->2)]-beta-D -galactopyranoside (1), and nigrumnin II was elucidated as (25R)-3 beta,17 alpha-dihydroxy-5 alpha-spirostan-12-one 3-O-beta-D-xylopyranosyl-(1-->3)-[ alpha-L-arabinopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rh amnopyranosyl-(1-->2)]-beta-D-galactopyranoside (2).