Bioassay-oriented isolation of an insecticide from Ailanthus altissima

The tree-of-heaven, Ailanthus altissima Swingle(Simaroubaceae), was studied for its potential insecticide activity against the pea aphid, Acyrtosiphon pisum (Harris). First instar aphids were dipped in water solutions of root extract and of leaf extract of A. altissima, and this was followed by bioassay-oriented fractioning of leaf extract (more active in bioassays) with petroleum ether, chloroform, chloroform-methanol, methanol and water, and of chromatographic fractions. The putative active constituent ailanthone, isolated from the plant resulting in the highest aphid mortality, has been assayed as a pure compound in different concentrations, proving to be responsible, for the insecticidal activity reported.