Pentacyclic Triterpenoid Saponin from Cyclamen coum

A new triterpenoid saponin, coumoside B, has been isolated from the whole plant of Cyclamen coum. The structure of the compound 3 (C 58 H 92 O 27 ) has been deduced by NMR (400 MHz) methods based on the 1 H, 13 C, DEPT, 1 H- 1 H COSY, HETCOR, NOESY-NMR experiments, and FAB-mass spectrum. Compound 3 was shown to have the structure 16α-hydroxy-3β-{{([β-xylopyranosyl-(1→2)]-[β-glucopyranosyl-(1→4)]-[β-glucopyranosyl-(1→2)]-α-arabinopyranosyl]-oxy]olean-12-eno-30,28-lactone and is named coumoside B.