Insecticidal compounds against mosquito larvae fromOscillatoria agardhii strain 27

Abstract

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 characterization of the toxic fraction by 1H‐NMR and GC‐MS showed that these compounds are not the neurotoxins or hepatotoxins conventionally produced by Oscillatoria, but it contained a mixture of unsaturated fatty acids, oleic, linoleic, and γ‐linolenic acids, as well as saturated fatty acids, myristic, palmitic, and stearic acids. In a bioassay developed for these hydrophobic compounds using mosquito larvae, authentic unsaturated fatty acids were shown to be toxic, whereas saturated ones were not active. The results suggested that it might be possible to use unsaturated fatty acids as environmentally safe and effective insecticides without the side effects of the chemically synthesized insecticides. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 114–119, 2000

Production of Secondary Metabolites by Freshwater Cyanobacteria

“…Recently, the isolation of fatty acids and glycolipids has been reported 26) ; we also isolated unsaturated fatty acids as an insecticidal agent against mosquito. 27) However, we consider that these compounds are not secondary metabolites. 894 Vol.…”

Mosquito Larvicides from Cyanobacteria

“…They can replace phospholipids in order to conserve phosphate and may play a direct role in photosynthesis (Dörmann and Benning, 2012). Interestingly, through the results of bioassay guided fractionation, the most mosquito larvicidal activity resides within membrane bound constituents (Harada et al, 2000;Komansilan, 2012, Ahmed et al, 2014 Figure 8: Mass spectra of prospective SGL-2 using negative ionization. Inadequacies of adulticiding include the use of pyrethroids which affect all insects including beneficial insects such as bees (Toynton et al, 2009).…”

“…One of the more notable discoveries of mosquito larvicidal compounds derived from cyanobacteria was the appearance of unsaturated fatty acids derived from Oscillatoria agardhii strain 27, which were found to be toxic to the larvae of Aedes albopictus (Harada et al, 2000). Compounds were characterized, and the common structure is relatively safe for mammals and the environment.…”

“…These compounds potentially help outcompete other photosynthetic organisms and/or act as deterrents to grazing invertebrates (Kearns and Hunter, 2001;Lürling, 2003). Considering the sympatry of cyanobacteria with mosquito larvae (Pope et al, 2005), cyanobacteria are a potential source for compounds with mosquito larvicidal activity (Harada et al, 2000).…”

“…Adult mosquitoes can have a flying range of 3 km in diameter from breeding sites (Hobbs et al, 1974;Lowe et al, 1975). Another benefit of controlling populations in the aquatic larval stage is that it reduces exposure to humans and other animals who can inhale aeriallyapplied insecticides (Harada et al, 2000).…”