Studies on the Mode of Action of Fenvalerate Enantiomers : IV.Neural Effects of Fenvalerate Enantiomers on the American Cockroach, Periplaneta americana(L.)

Abstract

The R, S-S isomer of fenvalerate, (R, S) α-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)-isovalerate, and its optical R, S-R isomer, (R, S) α-cyano-3-phenoxybenzyl (R)-2-(4-chlorophenyl)-isovalerate, were compared for their effects on electrical activity of the American cockroach, Periplaneta americana (L.). The R, S-S isomer caused increase and then decrease in repetitive firing of the central and peripheral nervous systems. This effect appeared earlier as isomer concentration was increased. However, R, S-R isomer caused no effect in the central and peripheral nervous systems even at concentrations up to 1×10^-3M. It was concluded that the difference between the two isomers' effects on the nervous systems was responsible for the difference in insecticidal activity.