ALLELOPATHIC POTENTIAL OF COMPOUNDS ISOLATED FROM IPOMOEA-TRICOLOR CAV (CONVOLVULACEAE)

The allelopathic potential of I. tricolor, used in traditional agriculture as a weed controller, has been demonstrated by measuring the inhibitory activity of aqueous lixiviates and organic extracts of the plant material on seedling growth of Amaranthus leucocarpus and Echinochloa crusgalli. Bioactivity-guided fractionation of the most active organic extract led to the isolation of the allelopathic principles, which turned out to be a mixture of glycosides, having jalapinolic acid as the aglycone portion glycosidically linked in the 11 position to an oligosaccharide composed of glucose, rhamnose, and fucose, which also combines with the carboxyl group of the aglycone to form a macrocyclic ester. © 1990 Plenum Publishing Corporation.