Reactive intermediates in pesticide metabolism: peracid oxidations as possible biomimetic models.

Reactive intermediates generated by metabolic epoxidation, N-oxidation and S-oxidation are often identical to those obtained on peracid oxidation as illustrated by studies with a variety of pesticides. Epoxidation reactions carried out metabolically or with peracids lead to transitory or unstable epoxychrysanthemic acid, epoxycyclopentenolone and epoxyfuran derivatives from pyrethroids, and geranyl-derived diepoxides and epoxydiols from juvenoids. N-Oxidation with microsomal oxidases or peracids activates hydroxylamine ether proinsecticides and dimethylphosphoramide and aminodiphenyl ether promutagens, but the peracid system is not always a suitable biomimetic model. Sulphoxidations with peracids appear to give the same reactive intermediates as those involved in metabolism of S-alkyl thiocarbamate and S-methyl-triazinone herbicides, S-chloroallyl promutagens, and S-propyl phosphorothiolate and phosphinyliminodithiolane proinsecticides.