Three acylated glycosidic acid methyl esters and two acylated methyl glycosides generated from the convolvulin fraction of seeds of Quamoclit pennata by treatment with indium(III) chloride in methanol.

Treatment of the ether-insoluble resin glycoside (convolvulin) fraction from seeds of Quamoclit pennata (Convolvulaceae) with indium(III) chloride in methanol provided three oligoglycosides of hydroxy fatty acid (glycosidic acid) methyl esters and two methyl glycosides, which were partially acylated by a glycosidic acid, 7S-hydroxydecanoic acid 7-O-β-D-quinovopyranoside (quamoclinic acid B) and/or two organic acids, (E)-2-methylbut-2-enoic (tiglic) acid and/or 3R-hydroxy-2R-methylbutyric (nilic) acid. Their structures were elucidated on the basis of spectroscopic data and chemical conversions.