STEROIDAL SAPONINS FROM NOLINA-RECURVATA STEMS AND THEIR INHIBITORY ACTIVITY ON CYCLIC-AMP PHOSPHODIESTERASE

Seven steroidal saponins were isolated from the stems of Nolina recurv ata, five of which appeared to be new compounds and were assigned as s pirosta-5,25(27)-diene-1 beta,3 beta-diol (neoruscogenin) xylopyranosy l-(1-->3)]-alpha-L-arabinopyranoside}, (25S)-spirost-5-ene-1 beta,3 be ta-diol [(25S)-ruscogenin] xylopyranosyl-(1-->3)]-alpha-l-arabinopyran oside}, neoruscogenin rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl- (1 -->3)]-beta-D-fucopyranoside}, glucopyranosyl-22-O-methylfurosta-5, 25(27)-diene-1 beta,3 beta,22 xi,26-tetrol -xylopyranosyl-(1-->3)]-alp ha-L-arabinopyranoside} and a-D-glucopyranosylfurosta-5,20(22),25(27)- triene-1 beta,3 beta,26-triol hamnopyranosyl-(1-->2)-alpha-L-arabinopy ranoside}. The isolated saponins were evaluated for their inhibitory a ctivity on cyclic AMP phosphodiesterase to identify new compounds with medicinal potential.