Three new triterpenoid saponins from the seeds of Vaccaria segetalis

Three new triterpenoid saponins, named segetoside G (1), H (2) and I (3), have been isolated from the seeds of Vaccaria sgetalis. On the basis of chemical reaction and spectral data, their structures have been established as: 28-O-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-arabinofuranosyl (1 --> 3)]-beta-D-(4-O-acetyl)-fucopyranosyl-gypsogenin-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-(6-O-butyl ester)-glucuronopyranoside (1), 28-O-beta-D-xylopyranosyl- (1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-(5-O-acetyl)-arabinofuranosyl-(1 --> 3)]-beta-D-(4-O-acetyl)-fucopyranosyl-gypsogenin-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-glucuronopyranoside (2) and 28-O-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-(5-O-acetyl)-arabinofuranosyl-(1 --> 3)]-beta-D-(4-O-acetyl)-fucopyranosyl-quillaic acid-3-O-beta-D-galactopyranosyl-(1 --> 2)-alpha-D-glucuronopyranoside (3).