Steroidal saponins from Nolina recurvata stems and their inhibitory activity on cyclic AMP phosphodiesterase

Seven steroidal saponins were isolated from the stems of Nolina recurvata, five of which appeared to be new compounds and were assigned as spirosta-5,25(27)-diene-1 beta,3 beta-diol (neoruscogenin) 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside}, (25S)-spirost-5-ene-1 beta,3 beta-diol [(25S)-ruscogenin] 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-l-arabinopyranoside}, neoruscogenin 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1 -->3)]-beta-D-fucopyranoside}, 26-O-beta-D-glucopyranosyl-22-O-methylfurosta-5,25(27)-diene-1 beta,3 beta,22 xi,26-tetrol 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside} and 26-O-beta-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1 beta,3 beta,26-triol 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside}. The isolated saponins were evaluated for their inhibitory activity on cyclic AMP phosphodiesterase to identify new compounds with medicinal potential.