New polyhydroxylated cholestane glycosides from the Bulbs of Ornithogalum saundersiae

Article abstract of DOI:10.1248/cpb.40.2469

Fresh bulbs of Ornithogalum saundersiae were found to contain five new polyhydroxylated cholestane glycosides. Their structures were determined to be (22S)-cholest-5-ene-3β,11β,16β,22-tetrol 16-O-α-L-rhamnopyranoside (1) and its acetyl derivatives (2 and 3), and (22S)-cholesta-5,24-diene-3β,11β,16β,22-tetrol 16-O-α-L-rhamnopyranoside (4) and its acetyl derivative (5) using spectroscopic analysis and chemical correlations. Determination of the absolute configuration at the C-22 hydroxyl position of 1 was achieved by the application of the advanced Mosher's method to the aglycon (1a) of 1, and those of 2-5 by correlating them to 1. The cholestane glycosides with an acetyl group at the C-3 hydroxyl position of the rhamnose showed potent inhibitory activity on cyclic adenosine monophosphate (AMP) phosphodiesterase.

Full text of DOI:10.1248/cpb.40.2469

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