Triterpenoid saponins and sapogenins from Vaccaria segetalis

Article abstract of DOI:10.1016/S0031-9422(97)01128-X

Four new triterpenoid saponins, vaccarosides E, F, G and H were isolated from the seeds of Vaccaria segetalis and were respectively defined to be 3- O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl] quillaic acid 28- O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-[α-L- arabinofuranosyl-(1 → 3)]-β-D-4-O-acetylfucopyranoside; 3-O-[β-D- galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl] 3β,4α,16α-trihydroxy- 23-norolean-12-en-28-oic acid 28-O-β-D-xylopyranosyl-(1 → 4)-α-L- rhamnopyranosyl-(1 → 2)-[α-L-arabinofuranosyl-(1 → 3)]-β-D-4-O- acetylfucopyranoside; 3-O-[β-D-galactopyranosyl-(1 → 2)-β-D- glucuronopyranosyl] gypsogenin 28-O-β-D-xylopyranosyl-(1 → 4)-α-L- rhamnopyranosyl-(1 → 2)-[α-L-arabinofuranosyl-(1 → 3)]-β-D-4-O- acetylfucopyranoside; and 3-O-[β-D-galactopyranosyl-(1 → 2)-β-D- glucuronopyranosyl] 3β,4α-dihydroxy-23-norolean-12-en-28-oic acid 28-O-β- D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-[α-L- arabinofuranosyl-(1 → 3)]-β-D-4-O-acetylfucopyranoside. Their structures were established on the basis of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC AND NOESY), FAB-MS and ESI-MS studies as well as chemical strategies and enzymatic degradation. The new aglycones of two of the saponins have been designated as segetalic acid and vaccaric acid, respectively.