Allelochemicals isolated from the leaves of Virola michelli Heckel
Abstract
Two compounds, the flavone tithonine (1) and the lignan eudesmin (2), were isolated from the leaves of Virola michelli. Phytotoxic effects of these compounds and of the crude extracts (hexane, ethyl acetate and methanolic) of the leaves of V. michelli were examined in a Petri dish bioassay. The ethyl acetate and methanolic crude extracts drastically inhibited the seed germination of Mimosa pudica weed (at 1% w/v) by 88 and 100%, respectively. The two isolated compounds inhibited the radicle elongation, seed germination and hypocotyl length of Mimosa pudica. Substance 1 caused 45% inhibition in radicle elongation and 39% inhibition in hypocotyls elongetion at the highest dose tested (4.0 mg.L−1) and 35% inhibition in seed germinaton. The flavone 1 had greater herbicidal activity against the Mimosa pudica weed as compared to the lignan 2.
Keywords
Allelochemicals, allelopathy, eudesmin, flavone, lignan, Mimosa pudica, Myristicaceae, tithonine, Virola michelli.