20(22)Z and 20(22)E Dammarane Saponins From the Roots of Panax pseudoginseng Wall.

Abstract

Panax pseudoginseng Wall. is famous as a traditional Vietnamese medicinal plant used to promote health and aid in cancer treatment. From the roots of this plant, 1 new (1) and 4 known (2-5) Δ20(22)-dammarane-type triterpenoid glycosides were isolated by various chromatographic methods. Their chemical structures were determined as 3β,6α,12β-trihydroxydammarane-( Z)-20(22),24-diene 6 -O-β-D-glucopyranoside (1), 3β,6α,12β-trihydroxy-dammar-( E)-20(22),25-diene 6 -O-β-D-glucopyranoside (2, ginsenoside Rh4), ginsenoside Rg5 (3), 3β,12β-dihydroxydammarane-( E)-20(22),24-diene 6 -O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside (4), and 3β,12β-dihydroxydammarane-( E)-20(22),24-diene 6 -O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (5). The E/ Z-Δ20(22) configurations in the dammarane compounds were further evidenced by 1D and 2D NMR data.