HELVETICA CHIMICA ACTA, vol.87, no.3, pp.611-619, 2004 (SCI-Expanded)
The isolation and structure elucidation of two new oleanane-type triterpene glycosides, 29-(beta-D-glucopyranosyloxy)-2alpha,3beta,23-trihydroxyolean-12-en-28-oic acid (=(2alpha,3beta,4alpha,29alpha)-29-(beta-D-glucopyranosyloxy)-2,3,23-trihydroxyolean-12-en-28-oic acid; 1) and its C(20)-epimer, 30-(beta-D-glucopyranosyloxy)-2alpha,3beta,23-trihydroxyolean-12-en-28-oic acid (=(2alpha,3beta,4alpha,29beta)-29-beta-D-glucopyranosyloxy)-2,3,23-trihydroxyolean-12-en-28-oic acid; 2), and a novel nortriterpene glycoside, (17S)-2alpha,18beta,23-trihydroxy-3,19-dioxo-19(18 --> 17)-abeo-28-norolean-12-en-25-oic acid beta-D-glucopyranosyl ester (=(IR,2S,4aS,4bR,6aR,7R,9R,10aS,10bS)-3,4,4a,4b,5,6,6a,7,8,9,10,10a,10b,11-tetradecahydro-1-hydroxy-7-(hydroxymethyl)-3',4',4a,4b,7-pentamethyl-2',8- dioxospiro[chrysene-2(1H),1'-cyclopentane]-10a-carboxylic acid beta-D-glucopyranosyl ester; 3) from Phlomis viscosa (Lamiaceae) are reported. The structures of the compounds were asigned by means of spectroscopic (IR, ID- and 2D-NMR, and LC-ESI-MS) and chemical (acetylation) methods.