Location: Mosquito and Fly ResearchTitle: Biting deterrence and insecticidal activity of hydrazide–hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles against Aedes aegypti ) Author
|Bernier, Ulrich - Uli|
Submitted to: Pest Management Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/30/2012
Publication Date: 9/11/2012
Publication URL: DOI 10.1002/ps.3424
Citation: Tabanca, N., Ali, A., Bernier, U.R., Khan, I.A., Kocyigit-Kaymakciogl, B., Oruc-Emre, E.E., Unsalan, S., Rollas, S. 2012. Biting deterrence and insecticidal activity of hydrazide–hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles against Aedes aegypti. Pest Management Science. 69:703-708. Interpretive Summary: Mosquito-borne diseases are major health problems worldwide. The yellow fever mosquito, Aedes aegypti is found throughout the world and in many areas of high human population. In recent years, an emphasis has been placed upon the development of natural repellents to replace synthetic repellents as a means to protect people and animals from mosquito bites. Scientists at the University of Mississippi and the Center for Medical, Agricultural, and Veterinary Entomology, USDA, ARS, Gainesville, Florida evaluated the mosquito repellency of compounds used for controlling agricultural and horticultural pests. Various aryl substituted hydrazones of 4-fluorobenzoic acid hydrazides and 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles were tested for their ability to stop mosquito biting and kill larvae of Ae. aegypti mosquitoes. Two compounds were good at preventing bites in screening assays; however these two compounds were not repellent when tested on cloth worn by human volunteers. In the larvicidal assays, two oxadiazole derivatives were superior at killing Ae. aegypt larvae. The use of natural repellents and natural larvicides may reduce our dependence upon synthetic compounds.
Technical Abstract: BACKGROUND: Hydrazones are important compounds for drug design and they have also good insecticidal activity. In this study, A series of hydrazide–hydrazones (1-10) and 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles (11-20) were investigated for their biting deterrent and insecticidal activities against Aedes aegypti. RESULTS: The compound 3-acetyl-5-(4-fluorophenyl)-2-(4-(dimethylamino)phenyl)-2,3-dihydro-1,3,4-oxadiazole (17) produced the highest biting deterrent activity (BDI=1.025) followed by 4-fluorobenzoic acid [(phenyl)methylene] hydrazide (1). This activity results were similar to DEET which showed proportion not biting values ranging between 0.8 to 0.92. When the compounds 1 and 17 were tested on cloth worn on human volunteers, compound 1 was not repellent for some volunteers until present in excess of 500 nmol/cm2, while compound 17 was not repellent at the highest concentration tested (1685 nmol/cm2). In the larvicidal screening bioassays, only compounds 10, 11, 12 and 17 showed 100% mortality at the highest screening dose of 100 ppm. Two oxadiazole derivatives, 3-acetyl-5-(4-fluorophenyl)-2-phenyl-2,3-dihydro-1,3,4-oxadiazole (11) and 3-acetyl-5-(4-fluorophenyl)-2-(4-bromophenyl)-2,3-dihydro-1,3,4-oxadiazole (12) showed good larvicidal activity with LD50 values of 24.1 and 30.9 ppm, respectively at 24-h post-treatment while the LD50 values of 4-fluorobenzoic acid [(2-furanyl)methylene]hydrazide (10) and 17 were 80.3 and 58.7 ppm respectively. CONCLUSION: Hydrazide and hydrazones derivatives can be useful information in the discovery of potent repellent and insecticides in the future.