ACYLATED CHOLESTANE GLYCOSIDES FROM THE BULBS OF ORNITHOGALUM-SAUNDERSIAE

Phytochemical examination of the bulbs of Ornithogalum saundersiae led to the isolation of three new acylated cholestane glycosides. Their structures were elucidated, on the basis of the spectroscopic data and chemical evidences, and by comparing them with those of known compounds, as 3beta,16beta,17alpha-trihydroxycholest-5-en-22-one 16-O-beta-D-xylopyranosyl-(1-->3)-(2-O-acetyl-alpha-L-arabinopyranoside), 3beta,16beta,17alpha-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-beta-D-Xylopyranosyl)-(1-->3)-(2-O-acetyl-alpha-L-arabinopyranoside) and 3beta,16beta,17alpha-trihydroxy-cholest-5-en-22-one 16-O-(2-O-3,4-dimethoxybenzoyl-beta-D-xylopyranosyl)-(1-->3)-(2-O-acetyl-alpha-L-arabinopyranoside). Inhibitory activity on cyclic AMP phosphodiesterase of the cholestane glycosides was evaluated.