New Dammarane Monodesmosides from the Acidic Deglycosylation of Notoginseng-Leaf Saponins

Three new dammarane monodesmosides, named notoginsenosides Ft1 (1), Ft2 (2), and Ft3 (3), together with three known ginsenosides, were obtained from a mild acidic hydrolysis of the saponins from notoginseng (Panax notoginseng (Burk.) F. H. Chen) leaves. Their structures were elucidated to be (3β,12β,20R)-12,20-dihydroxydammar-24-en-3-yl O-β-D-xylopyranosyl-(1 → 2)-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (1), (3β,12β)-12,20,25-trihydroxydammaran-3-yl O-β-D-xylopyranosyl-(1 → 2)-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (2), and (3β,12β,24ξ)-12,20,24-trihydroxydammar-25-en-3-yl O-β-D-xylopyranosyl-(1 → 2)-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (3), by means of spectroscopic evidences. The known ginsenosides Rh2 and Rg3 4–6 were obtained as the major products from this acidic deglycosylation.