Insecticidal Activity of Pyrethroids Containing a Heterocycle against Musca domestica and Their Structure-Activity Relationship

Abstract

Various kinds of pyrethroids containing a heterocycle in their alcohol moiety were synthesized and their insecticidal activity against Musca domestica, the housefly was determined by the filter paper contact method. The activity was greatly influenced by the kinds of heterocycles introduced in the alcohol moiety. The stable conformations of these pyrethroids were calculated by the MNDO molecular orbital method and their steric resemblance was studied in the stable conformations. The hydrophobicity of these pyrethroids was also measured by reversed phase HPLC and expressed in terms of logk′[=log(t_R-t₀)/t₀, t_R: retention time of the trans isomer of the test compound, t₀: retention time of formamide]. The analysis of the structure-activity relationship by the use of physicochemical parameters and regression analysis showed the importance of molecular shape and hydrophobicity to the insecticidal activity.