Biting deterrency of undecanoic acid and dodecanoic acid ester analogs against Aedes aegypti

BACKGROUND Mosquitoes remain one of the most significant threats to the health of humans throughout the world. This study was designed to evaluate the biting deterrent effects of a series of ester analogs of undecanoic acid (C:11:0) and dodecanoic acid (C:12:0) against Aedes aegypti (L), (Diptera: Culicidae), the yellow fever mosquito, using Klun and Debboun (K&D) and Ali and Khan (A&K) bioassay systems. RESULTS In the K&D bioassays, C:11:0 esters methyl undecanoate, propyl undecanoate, butyl undecanoate, and pentyl undecanoate, and the C:12:0 esters methyl dodecanoate, ethyl dodecanoate, propyl dodecanoate, octyl dodecanoate, and dodecyl dodecanoate were most active. All of these esters were as effective as N , N ‐diethyl‐ m ‐toluamide (DEET) and as effective as the parent acids undecanoic acid and dodecanoic acid with biting deterrence index values ranging from 0.80 to 0.99. In the in vitro A&K bioassay undecanoic acid with a minimum effective dose (MED) of 3.125 μg cm −2 was the most active compound and showed higher activity than DEET (MED of 25 μg cm −2 ). The most active synthetic analog was butyl undecanoate with a MED of 12.5 μg cm −2 . The next most active analogs are the methyl ester analogs methyl undecanoate and methyl dodecanoate, both with MED values of 25 μg cm −2 . CONCLUSION Fatty acid synthetic esters and structural analogs are a promising source of new mosquito repelling compounds and should be investigated further. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.