Identification of four allelopathic compounds including a novel compound from Elaeocarpus floribundus Blume and determination of their allelopathic activity.

Allelopathic compounds can play a vital role in protecting the environment from pollution by synthetic herbicides. Compounds isolated from plant species with allelopathic potential can be used as natural herbicides to control weeds and help reduce environmental pollution. Elaeocarpus floribundus has been reported to contain allelopathic compounds. Aqueous methanolic extracts of the leaves of this plant showed strong growth inhibitory potential against two test species (monocotyledonous Italian ryegrass and dicotyledonous alfalfa) in plants- and dose-dependent technique. Several extensive chromatographic separations of the E. floribundus leaf extracts yielded four active compounds 1, 2, 3, and 4 (novel compound). All the identified compounds showed strong growth inhibitory potential against cress. The concentrations caused for 50% growth limitation (I values) of the cress seedlings were in the range 500.4-1913.1 μM. The findings indicate that the identified compounds might play a pivotal function in the allelopathic potential of E. floribundus tree. This report is the first on elaeocarpunone and its allelopathic potential.