Three New Acylated Glycosidic Acid Methyl Esters from the Crude Resin Glycoside Fraction of <i>Ipomoea lacunosa</i> Seeds by Treatment with Indium(III) Chloride in Methanol

Three new acylated glycosidic acid methyl esters and one known compound were isolated by treating the crude resin glycoside fraction derived from the seeds of Ipomoea lacunosa with indium(III) chloride in methanol, and their structures were elucidated using spectroscopic methods. The new compounds contained methyl 3S,11S-dihydroxytetradecanoate as the aglycone. Two were hexaglycosides and one was a nonaglycoside, with saccharide cores partially acylated by a glycosidic acid, 7S-hydroxydecanoic acid 7-O-β-d-quinovopyranoside (quamoclinic acid B), and/or organic acids, including isobutyric and 2S-methylbutyric acids. Furthermore, the cytotoxic activities of the isolated compounds against HL-60 human promyelocytic leukemia cells were evaluated, and they exhibited moderate activities.