TERMITE ANTIFEEDANT ACTIVITY FROM TROPICAL PLANTS .1. TERMITE ANTIFEEDANT ACTIVITY IN XYLOPIA-AETHIOPICA

A hexane extract of Xylopia aethiopica fruits and an aqueous methanol extract of the seeds were studied for termite antifeedant activity aga inst workers of the subterranean termite, Reticulitermes speratus. The crude extract, at 1%, exhibited strong antifeedant activity in a choi ce filter paper disk bioassay. Bioassay-directed fractionation led to the isolation and identification of six ent-kaurane diterpenes in the hexane extract. Feeding deterrent activity varied significantly with t he structures when the compounds were tested at concentrations ranging from 5000 ppm (40 mu g cm(-2)) to 100 ppm (0.824 mu g cm(-2)). ( -)-K aur-16-en-19-oic acid had the strongest termite antifeedants activity among the ent-kauranes isolated. Two phenolic amides and four lignanam ides were also isolated from the aqueous methanolic extract of seeds. oxyphenyl)-N-2-[4-Hydroxyphenylethyl]2-Propenamide was more active tha n xyphenyl)-N-2-[4-Hydroxyphenylethyl]2-propenamide, whilst grossamide and the new lignanamide, demethylgrossamide, as well as (-)-cannabisi ns B and D exhibited potent feeding deterrent activity at 5000 ppm. Th e identity of these compounds was established by spectroscopic analysi s and synthesis. Two synthetic amides, 4-methylenedioxyphenyl)-N-2-[4- Hydroxyphenylethyl] propenamide and ethylenedioxyphenyl)-N-2-[octadecy l]-2-propenamide were also tested for antifeedant activity.