Metabolism of ( S)-bioallethrin and related compounds in humans

Abstract

Chrysanthemate insecticides like ( S)-bioallethrin, natural pyrethins, and related pyrethroids are subjected to extensive hydrolytic and oxidative degeneration by the mammalian metabolism, leading to a complex series of metabolites partially conjugated and finally eliminated in the urine. The major oxidation products of chrysanthemic acid, cis-(E)- and trans-(E)-chrysanthemumdicarboxcylic acid ( cis-(E) and trans-(E)-CDCA), were synthesized and their structures were established by nuclear magnetic resonance spectrometry (H 1-NMR) and mass spectrometry (MS). Diastereoselective separation was by high performance liquid chromatography (HPLC) and capillary gas chromatography (GC). An analytical method for extraction and identification of CDCA from human urine was developed. Quantitation was by gas chromatography and electron-impact mass spectrometry (GC/MS). The limit of detection was 20 μg/l for cis-(E)-CDCA and 10 μg/l for trans-(E)-CDCA. To test the applicability of the presented method, urine samples of humans exposed to ( S)-bioallethrin were investigated. Urinary peak excretion of trans-(E)-CDCA occurred within 24 h after exposure.