title: N-hydroxy-N-arylacetamides--IV. Differences in the mechanism of haemoglobin oxidation in vitro between N-hydroxy-N-arylacetamides and arylhydroxylamines.
abstract: In solutions of purified human haemoglobin N-hydroxy-4-chloroacetanilide (N-hydroxy-4ClAA] was one of the most active compounds and N-hydroxy-acetanilide (N-hydroxy-AA) was the least active compound among the six N-hydroxy-N-arylacetamides tested for ferrihaemoglobin (HbFe3+)-forming activity. Co-oxidation of haemoglobin by N-hydroxy-4-chloroacetanilide was compared with that of N-hydroxy-4-chloroaniline(N-hydroxy-4ClA) and found to differ in the kinetics of HbFe2+-oxidation, in the catalytic activity of the two compounds, in the activation energy, and in the product pattern, indicating that the mechanism by which N-hydroxy-N-arylacetamides oxidize oxyhaemoglobin in vitro is different from that of arylhydroxylamines. Attempts have failed to detect by EPR spectroscopy acetyl 4-chlorophenyl nitroxide radical, the postulated catalytically-active oxidation product of N-hydroxy-4-chloroacetanilide.
mesh_terms: D000083:Acetanilides / Q000378:metabolism*; D002374:Catalase / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D006898:Hydroxylamines / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D010100:Oxygen / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D000083:Acetanilides; D006454:Hemoglobins; D006898:Hydroxylamines; C052916:N-hydroxy-4-chloroacetanilide; C018485:4-chlorophenylhydroxylamine; D002374:Catalase; D013482:Superoxide Dismutase; D010100:Oxygen