Insecticidal compounds against mosquito larvae from Oscillatoria agardhii strain 27

It was found that Oscillatoria agardhii strain 27 produced compounds toxic against mosquito larvae (Aedes albopictus), therefore, these compounds were extracted and separated for insecticide development. Structural characteri zation of the toxic fraction by H-1-NMR and GC-MS showed that these compoun ds are not the neurotoxins or hepatotoxins conventionally produced by Oscil latoria, but it contained a mixture of unsaturated fatty acids, oleic, lino leic, and gamma-linolenic acids, as well as saturated fatty acids, myristic , palmitic, and stearic acids, in a bioassay developed for these hydrophobi c compounds using mosquito larvae, authentic unsaturated fatty acids were s hown to be toxic, whereas saturated ones were not active. The results sugge sted that it might be possible to use unsaturated fatty acids as environmen tally safe and effective insecticides without the side effects of the chemi cally synthesized insecticides. (C) 2000 by John Wiley & Sons, Inc.