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United States Department of Agriculture

Agricultural Research Service

Research Project: BITING ARTHROPODS: INTEGRATED PEST MANAGEMENT

Location: Mosquito and Fly Research Unit

Title: Mosquito repellency of novel Trifluoromethylphenyl amides

Authors
item Tsikolia, Maia
item Bernier, Ulrich
item Agramonte, Natasha
item Coy, Monique
item Estep, Alden -
item Becnel, James
item Clark, Gary
item Linthicum, Kenneth
item Guerin, Patrick -
item Krober, Thomas -

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 5, 2014
Publication Date: N/A

Technical Abstract: Human diseases caused by mosquito-transmitted pathogens include malaria, dengue and yellow fever and are responsible for several million human deaths every year, according to the World Health Organization (WHO). Our current research projects focus on the development of new insecticides and repellents to prevent mosquito bites and thereby reduce disease risk to humans. Based on visual inspection of the potent insecticide fipronil, a set of 34 trifluoromethylphenyl amide analogues were designed and synthesized. This set of compounds consisted of arrangements of the trifluoromethyl- groups in the ortho-, meta- or para- positions of a phenyl ring of N-phenyl amides with the various substituents attached to the carbonyl carbon, i.e., 2,6-dinitrophenyl, 2-methylphenyl, trifluoromethyl, pentafluoroethyl, 2-chloroethyl, 3-pentyl and n-alkyl (pentyl, hexyl, heptyl, nonyl and decyl) groups. The 34 compounds were evaluated as larvicides, adulticides, feeding deterrents, and repellents against Aedes aegypti, the primary vector of dengue and yellow fever. Some of the better repellents of Ae. aegypti were also evaluated for repellency against female Anopheles gambiae, a significant vector of malaria. Four compounds exhibited potent repellency, comparable to or up to two times better than that of the standard DEET, in repellency assays against Ae. aegypti. Two of these compounds had repellency comparable to DEET against An. gambiae. In the feeding bioassay with Ae. aegypti, within 1 h exposure at 1 'mol concentration, weak knockdown was observed for 6 compounds (1.1-3.3%), which was comparable to fipronil (2.2%). The same six compounds induced some mortality in larval or adult mosquitoes; however, they were not as potent as fipronil. This study has resulted in several structural leads that could facilitate further design to discover new compounds with insecticidal and repellent activity.

Last Modified: 12/20/2014
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