Acylsugar diversity in the resin glycosides from Ipomoea tricolor seeds as chemosensitizers in breast cancer cells

Abstract Mexican morning glory, Ipomoea tricolor Cav., is native to America and widely cultivated as an ornamental plant. High performance liquid chromatography profiling coupled with off-line electrospray mass spectrometry detection was applied to identify novel acylsugar from the CHCl 3 -soluble resin glycoside from seeds. Dereplication of known tricolorins A-J included the recording of mass values for ions [M + Na] + and [M – H] − , in addition to comparison of retention times. Recycling HPLC was used for the purification of novel tricolorins K-M. NMR analysis revealed acylation at the C-2 and C-4 positions on the third pyranose unit of the tetrasaccharides by short chain aliphatic acyl groups. Acylsugar diversity results from variations in the esterification of sugar cores. Tricolorin A at a concentration of 25 μ g/ml exerted a strong potentiation of vinblastine susceptibility in multidrug-resistant human breast carcinoma cells with a reversal factor of 2164-fold.