Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Three new triterpene saponins, leonticins I (1), J (2) and L (3) were isolated from the tubers of Leontice smirnowii. On the basis of spectroscopic methods, including 2D NMR experiments (DEPT, gs-COSY, gs-HMQC, gs-HMBC and gs-HSQC-TOCSY), mass spectrometry (HR-ESI-MS) and chemical degradation, the structures of the new compounds were elucidated as 3-O-β-D-glucopyranosyl- (1 → 3)-[β-D-xylopyranosyl-1 → 2)]-α-L-arabinopyranosyl-28- O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]-3β-hydroxy-30-norolean-12,20(29)-dien-28-oic acid (1), 3-O-[β-D-xylopyranosyl-(1 → 3)-β-D-galactopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranosyl]-28-O- [α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]-3β-hydroxy-30-norolean-12,20(29)-dien-28-oic acid (2) and 3-O-[β-D-xylopyranosyl-(1 → 3)-β-D-galactopyranosyl- (1 → 4)-β-D-glucopyranosyl-(1 → 3)]-[β-D-xylopyranosyl-(1 → 2)]-α-L-arabinopyranosyl]-28-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]-3β- hydroxy-30-norolean-12,20(29)-dien-28-oic acid (3), respectively. The aglycone 3β-hydroxy-30-norolean-12,20(29)-dien-28-oic acid was observed for the first time in Leontice species.