Two New Triterpene Saponins from Cyclamen africanumBoiss. & Reuter

Abstract

Two new oleanane‐type triterpene saponins, afrocyclamins A and B (1 and 2, resp.), were isolated from a MeOH extract of the roots of Cyclamen africanum Boiss. & Reuter, together with three known triterpenoid saponins, lysikokianoside, deglucocyclamin I, and its dicrotalic acid derivative. The structures were elucidated, on the basis of 1D‐ and 2D‐NMR experiments and mass spectrometry as (3β,20β)‐13,28‐epoxy‐16‐oxo‐3‐{O‐β‐D‐xylopyranosyl‐(1→2)‐O‐β‐D‐glucopyranosyl‐(1→4)‐O‐[β‐D‐glucopyranosyl‐(1→2)]‐α‐L‐arabinopyranosyl}oxy}oleanan‐29‐al (1) and (3β,16α,20β)‐16,28,29‐trihydroxy‐olean‐12‐en‐3‐yl O‐4‐O‐(4‐carboxy‐3‐hydroxy‐3‐methyl‐1‐oxobutyl)‐β‐D‐xylopyranosyl‐(1→2)‐O‐β‐D‐glucopyranosyl‐(1→4)‐O‐[β‐D‐glucopyranosyl‐(1→2)]‐α‐L‐arabinopyranoside (2).