Skip to main content
ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Mosquito and Fly Research » Research » Publications at this Location » Publication #393629
Research Project: Integrated Pest Management of Mosquitoes and Biting Flies

Location: Mosquito and Fly Research

Title: Ester moiety structural modification of repellent and insecticidal pyrethroids

Author
item RICHOUX, GARY - University Of Florida
item YANG, LIU - University Of Florida
item Linthicum, Kenneth - Ken
item Norris, Edmund
item BLOOMQUIST, JEFFREY - University Of Florida

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/12/2021
Publication Date: 2/25/2021
Citation: Richoux, G.M., Yang, L., Linthicum, K., Norris, E.J., Bloomquist, J. 2021. Ester moiety structural modification of repellent and insecticidal pyrethroids. Emerging Pathogens Institute Research Day. p.57-58.

Interpretive Summary:

Technical Abstract: One of the most effective ways of reducing the propagation of mosquito vectored diseases is through the prevention of biting and subsequent transmission of pathogens. A highly utilized means of accomplishing this is through the development and deployment of spatially-acting mosquito repellents and insecticides. Significant market and field success has been realized through the implementation of pyrethroid-class compounds such as transfluthrin, metofluthrin, and resmethrin. Unfortunately, heavy use of these repellents and insecticides has led to the emergence of field dominant strains of pyrethroid-resistant mosquitoes. This resistance necessitates further research into the development of new repellents and insecticides in the pursuit of resistance breaking activities. Because the efficacy of pyrethroid actives is practically unparalleled in modern-day mosquito control, we endeavored to explore the modification of existing pyrethroids to identify structural motifs which might not be affected by the active site mutations eliciting pyrethroid-resistance. Since it’s understood that most synthetic pyrethroids contain activity-specific and - dependent chiral centers, we chose instead to focus our efforts on exploring the alkoxy moiety of the ester obtained from the esterification of trans-permethrinic and trans-chrysanthemic acid. To this end, we synthesized and screened 26 compounds for spatially-acting repellency and insecticidal activity against the pyrethroid-susceptible, Orlando (OR), 58 and pyrethroid-resistant, Puerto Rico (PR), strains of Aedes aegypti mosquito. Screening was completed utilizing the high-throughput benchtop glass tube assay developed within our laboratories. If sufficient repellency or toxicity was observed at our screening concentration of 100 µg/cm2, EC50 or LC50 values were obtained. So far, we have screened a mixture of branched, unbranched, aliphatic, halogenated, cyclic, non cyclic, and heteroatom-containing esters. Early trends indicate that n propyl, n-butyl, n-pentyl, cyclobutyl- and cyclopental-substituents exhibit promising repellent and insecticidal activity with minimal resistance. While this activity is not near as potent as observed with transfluthrin, further derivatization of these functional groups offer a promising route to future synthesis. Additionally, a handful of derivatives, such as GMR082 and GMR146 exhibit excellent activity. While we have not yet completed screening of these compounds against the PR mosquito strain, this information will be obtained in the near future.