3 NEW FUROSTANOL SAPONINS FROM THE BULBS OF IPHEION UNIFLORUM

Phytochemical screening of the bulbs of Ipheion uniflorum (Liliaceae) has led to the isolation of three new furostanol saponins (2-4) along with a known phytoecdysteroid, ecdysterone (1). The structures of the new compounds were determined by two-dimensional NMR techniques, H-1-H -1 correlation spectroscopy (COSY), homonuclear Hartmann-Hahn (HOHAHA) , phase-sensitive nuclear Overhauser effect spectroscopy (NOESY), hete ronuclear multiple quantum coherence (HMQC) and heteronuclear multiple -bond correlation (HMBC) spectra, and hydrolysis to be 3 beta-hydroxy- 22 alpha-methoxy-26-O-beta-D-glucopyranosyloxy-5 alpha-furost-25(27)-e n-2-one eta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl -(1-->4)]-b eta-D-galactopyranoside (2) and its 25(27)-dihydro derivatives (3: 25S ; 4: 25R). The inhibitory activity exhibited by compounds 1-4 and the corresponding spirostanol saponins (2a and 3a) of 2 and 3 on cAMP phos phodiesterase was assayed as a primary screening test to identify new compounds with medicinal potential.