Abstract
An epoxy intermediate, 2-(4-nitrophenoxy)oxirane (NPO), previously proposed to be a shortlived intermediate in the microsomal metabolism of 4-nitrophenyl vinyl ether (NPVE), was isolated by high-performance liquid chromatography and identified by mass spectrometric comparison with an authentic specimen. NPO decomposed to glycolaldehyde and 4-nitrophenol with a half life of 4.6min in 0.1M phosphate buffer, pH7.4, at 37°C. The hydrolytic decomposition was accelerated by the addition of rat hepatic microsomes, but the accelerating effect was reduced by the addition of 3, 3, 3-trichloropropene oxide, a microsomal epoxide hydrolase inhibitor.These results indicate that NPO is an obligatory intermediate in the microsomal conversion of NPVE to glycolaldehyde and 4-nitrophenol.
