title: Bactericidal agents generated by the peroxidase-catalyzed oxidation of para-hydroquinones.
abstract: For the three Gram-negative bacteria, Pseudomonas fluorescens, Escherichia coli, and Erwinia amylovora, p-benzoquinone was the principal bactericidal agent formed in vitro during the oxidation of hydroquinone by horseradish peroxidase, whereas no toxicity could be associated with either phenolic or oxygen-free radicals. Even the continuous generation of p-benzosemiquinone during the simultaneous reduction of p-benzoquinone by xanthine oxidase and reoxidation of hydroquinone by peroxidase was no more toxic than p-benzoquinone alone. Anaerobiosis had no effect on the toxicity of either p-benzoquinone or the peroxidase reaction and the generation of superoxide and hydroxyl radicals catalyzed by xanthine oxidase was not bactericidal. Substitutions on the p-benzoquinone ring decreased quinone toxicity in rough proportion to the decrease in quinone redox potential, suggesting that strong oxidizing potentials are important for such quinone toxicity.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016227:Benzoquinones; D001711:Biotransformation; D004885:Erwinia / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D006873:Hydroquinones / Q000378:metabolism / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009994:Osmolar Concentration; D010544:Peroxidases / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000187:drug effects*; D011809:Quinones / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D000900:Anti-Bacterial Agents; D016227:Benzoquinones; D006873:Hydroquinones; D011809:Quinones; C004532:quinone; D010544:Peroxidases; C031927:hydroquinone