Biological Activity of Optically Active Salithion and Salioxon

Abstract

Salioxon enantiomers were obtained from salithion enantiomers by MCPBA oxidation. The larvicidal and adulticidal activities of salithion enantiomers, and the anti-cholinesterase activity of salioxon enantiomers were determined on house flies. On larvae, the potency of (S)(-)-salithion (LC₅₀=1.1 ppm) was about two-fold higher than the (R)(+)-enantiomer (LC₅₀ = 2.1 ppm). A similar ratio was obtained when these compounds were applied topically to female adults. The relative potency of these enantiomers correlated well with the anti-cholinesterase activity of their respective oxidative enantiomers, (R)(+)-and (S)(-)-salioxon, which are assumed to have been formed after their application to the insects.