Allelopathy and Identification of Five Allelochemicals in the Leaves of the Aromatic Medicinal Tree (L.) Correa.

(L.) Correa is an economically and therapeutically valuable tree. It is cultivated as a fruit plant in southeast Asian countries. In this research, we investigated the allelopathy and possible allelochemicals in the leaves of . Aqueous methanol extracts of exhibited significant inhibitory effects against the growth of , , , , , and . Bioassay-directed chromatographic purification of the extracts resulted in identifying five active compounds: umbelliferone (), -ferulic acid (), ()-4-hydroxycinnamic acid methyl ester (), -cinnamic acid (), and methyl ()-3'-hydroxyl-4'-methoxycinnamate (). The hypocotyl and root growth of were considerably suppressed by these compounds. Methyl ()-3'-hydroxyl-4'-methoxycinnamate also suppressed the coleoptile and root growth of . The concentrations of these compounds, causing 50% growth reduction () of , were in the range of 74.19-785.4 μM. The findings suggest that these isolated compounds might function in the allelopathy of .