title: Enzymatic activation of hydrazine derivatives. A spin-trapping study.
abstract: The oxidative metabolism of hydralazine, isoniazid, iproniazid, and phenylhydrazine has been studied using spin-trapping techniques. The oxidation of these hydrazine derivatives, catalyzed by horseradish peroxidase and prostaglandin synthetase, produces reactive free radical intermediates. Enzymatic activation of hydralazine produce the nitrogen-centered hydralazyl radical (RNHNH); phenylhydrazine formed only the phenyl radical. Iproniazid, on the other hand, formed both the isopropyl radical and a hydroperoxy radical. The formation of the hydroperoxy radical was not inhibited by superoxide dismutase. The horseradish peroxidase-catalyzed oxidation of isoniazid produced two different carbon-centered radicals. The identity of these radicals is not clear; however, they may arise from an acyl (RCO) radical and an alkyl (R) radical.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D006830:Hydralazine / Q000378:metabolism*; D006834:Hydrazines / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007490:Iproniazid / Q000378:metabolism; D007538:Isoniazid / Q000378:metabolism; D010659:Phenylhydrazines / Q000378:metabolism
chemical_list: D006834:Hydrazines; D010659:Phenylhydrazines; C030299:phenylhydrazine; D006830:Hydralazine; D007490:Iproniazid; D007538:Isoniazid