Triterpene saponins from Cyclamen coum var. coum.

From the tubers of Cyclamen coum (Primulaceae) three new saponins, cyclaminorin (1), cyclacoumin (3) and mirabilin lactone (4) were isolated together with a known saponin, deglucocyclamin (2). The structures of the new compounds were established as 13 beta,28-epoxy-3 beta-(([beta-D-glucopyranosyl-(1-->2)]- [beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl) oxy) 16 alpha-hydroxy-olean-30-al (1), 13 beta,28-epoxy-3 beta-((([beta-D-xylopyranosyl-(1-->2) -beta-D-glucopyranosyl-(1-->4)]-[beta-D-glucopyranosyl-(1-->2)]- alpha-L-arabinopyranosyl)oxy)-16 alpha,23-dihydroxy-olean-30-al (3) and 16 alpha-hydroxy-3 beta-((([beta-D-xylopyranosyl-(1-->2)]- [beta-D-glucopyranosyl-1-->6)]-beta D-glucopyranosyl-(1-->4))- [beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)-oxy) olean-12-eno-30,28-lactone (4). Structure elucidattions were accomplished using both spectral (NMR, MS, IR) and chemical methods.