Ronald K. Mitchum

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Cunninghamella elegans oxidized naphthalene to ethyl acetate-soluble and water-soluble metabolites. Experiments with [14C]-naphthalene indicated that 21% of the substrate was converted into metabolites. The ratio of organic-soluble metabolites to water-soluble metabolites was 76:24. The major ethyl acetate-soluble naphthalene metabolites were(More)
The mechanism of naphthalene oxidation by the filamentous fungus, Cunninghamella elegans is described. C. elegans oxidized naphthalene predominately to trans-1,2-dihydroxy-1,2-dihydroxy-1,2-dihydronaphthalene. A trans configuration was assigned for the dihydrodiol by nuclear magnetic resonance (NMR) spectroscopy at 500 MHz which showed a large coupling(More)
1. The hepatic microsomal metabolism of N-phenyl-2-naphthylamine (P2NA), an industrial antioxidant and suspected carcinogen, was studied in seven mammalian species to determine if N-dephenylation, reported to occur in vivo, could be demonstrated in vitro and if macromolecular binding occurs without an obligatory N-dephenylation. 2. The rate of hepatic(More)
The hepatic metabolism of arylamine bladder carcinogens to N-hydroxy arylamine N-glucuronides, their excretion in the urine, and their subsequent acidic hydrolysis to highly carcinogenic and reactive N-hydroxy arylamines have been proposed as essential steps in arylamine-induced urinary bladder carcinogenesis. In this study, alteration of urinary pH,(More)
Analysis of doxylamine N-oxide and pyrilamine N-oxide as synthetic standards and biologically derived metabolites by thermospray mass spectrometry (TSP/MS) provided [M + H]+ ions for each metabolite. TSP/tandem mass spectrometry (TSP/MS/MS) of the [M + H]+ ions provided fragment ions characteristic of these metabolites. In addition, TSP mass spectrometry(More)
This study demonstrated the utility of negative ion atmospheric pressure ionization mass spectrometry for the routine quantitation of 2,4,5-trichlorophenoxyacetic acid and its glycine and taurine amide metabolites in mouse blood, urine and feces samples. The quantitation of 2,4,5-trichlorophenoxyacetic acid in blood follows a short cleanup procedure and(More)
The mechanism of microsomal hydroxylation of benzene to phenol has been studied by examining the microsomal metabolism of the specifically deuterated derivative 1,3,5-[2H3]benzene. Evidence for the formation of the following four products was obtained: 2,3,5-[2H3]phenol, 3,5-[2H2]phenol, 2,4,6-[2H3]phenol, and 2,4-[2H2]phenol. The presence of(More)
Major concern over the chemical group of chlorodioxins has arisen since 2,3,7,8-tetrachlorodibenzo-p-dioxin with its extremely toxic and teratogenic properties has been found in widely distributed pesticides such as the herbicide 2,4,5-trichlorophenoxy acetic acid. Because of its chemical stability and lipophilic nature, 2,3,7,8-tetrachlorodibenzo-p-dioxin(More)
A fly ash sample found to contain polychlorinated dioxins and dibenzofurans was analyzed for brominated analytes. Bromochloro-polynuclear aromatic hydrocarbons, dioxins and dibenzofurans, as well as bromo PAH were found in ppt to ppb concentrations. Analytical results were confirmed by high-resolution mass spectrometric accurate mass determinations and by(More)