Insecticidal activity of the pyrethrins and related compounds IV.—Essential features for insecticidal activity in chrysanthemates and related cyclopropane esters

Abstract

A range of 5‐benzyl‐3‐furylmethyl cyclopropane carboxylates and other esters are evaluated against house‐flies, mustard beetles and two mosquito species. The results show the importance for activity of a gem‐dimethyl group on the cyclopropane ring and that substitutions at C3 give wide variations in insecticidal activity and marked species specificity. Some of the compounds had considerable knockdown activity against houseflies, but the structural requirements for this type of action differ markedly from those for kill.

Configurational Relationship between Substituents on Cyclopropane Ring of Pyrethroids and Their Insecticidal Toxicity

“…If only one cis-methyl was introduced, the toxicity was greatly enhanced and the additional introduction of methyl group also resulted in the promotion of toxicity. Therefore, the relationship between the methyl configuration on cyclopropane ring and the insecticidal activity which was obtained in our previous work 11 can be extended to the series of the methyl substituted cyclopropanecarboxylates, that is, the cis-methyl group is most important for the appearance of the insecticidal acti vi ty .…”

Resmethrin, the first modern pyrethroid insecticide

“…2). Evaluation of the four individual resmethrin isomers 6,9 revealed that only two possessed significant insecticidal activity: bioresmethrin, the ester of 1R,trans-chrysanthemic acid (the acid moiety of pyrethrin I), and cismethrin, the ester of 1R,cis-chrysanthemic acid. These two isomers have identical absolute configuration at cyclopropane C-1 (bearing the carbonyl group) but opposite configurations at C-3 (bearing the isobutenyl moiety).…”

Toxicity Of Fenvalerate On Larvae Of The Susceptible And Resistant Strains Of <i>Tribolium Castaneum</i> (Herbst)

“…The resistance and contamination problems have, therefore, brought about interest in the use of a safer insecticide, like the synthetic pyrethriods due to their significant insecticidal properties (Elliott and Janes 1973;Elliott et al 1978). The use of pyrethroids became worldwide because of their good knock down and lethal activity to insects, low mammalian toxicity, photostability, high degradability and effective at minimum dose (Barlow et al 1971;Hadaway 1972). Because of insecticidal and lethal activity, many researchers have done a plenty of works on synthetic pyrethroids for determination of lethal dose and enzymatic activities against a number of insects (Tabassum et al 1998;Mujeeb and Shakoori 2007;Yousuf et al 2008).…”