TERMITE ANTIFEEDANT ACTIVITY IN TROPICAL PLANTS .2. TERMITE ANTIFEEDANT ACTIVITY IN AFRAMOMUM-MELEGUETA

n-Hexane and methanolic seed extracts of Aframomum melegueta were stud ied for termite antifeedant activity against workers of Reticulitermes speratus. Strong antifeedant activity was observed when the termite w orkers were tested in a choice filter paper disk bioassay containing 1 % crude extracts. Bioassay-directed fractionation led to the isolation of gingerdione, 5-oxo-1-(4-hydroxy-3-methoxyphenyl)decan-3-one, [6]-p aradol, 1-(4-hydroxy-3-methoxyphenyl)decan-3-one, [6]-gingerol, 5-hydr oxy-1-(4-hydroxy-3-methoxyphenyl)decan-3-one and [6]-shogaol, 1-(4-hyd roxy-3-methoxyphenyl)dec-5-en-3-one, as the antifeedant compounds. [6] -Gingerol and [6]-shogaol exhibited the strongest antifeedant activity at 1000 ppm, corresponding to 8 mu g cm(-2).