Chemical and enzymatic oxidation of alkylated benzo[a]pyrenes

Sullivan, Paul D.; Ellis, Larry E.; Calle, Luz M.; Ocasio, Ignacio

doi:10.1016/0009-2797(82)90100-4

Cited by 6 publications

(5 citation statements)

References 24 publications

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“…7-methyl-BaP does not, however, show a decrease in width, indicating that substituents peri to the 6 position can prevent reaction at this position. Similarly, substitution at the 6 position results in the production of the genuine cation radicals from 6-methyl-BaP, 6-ethyl-BaP and 6-methoxy-BaP (44 (13) However, the spectrum is not fully resolved, and the parameters given for the BaP cation radical are not in agreement with those proposed in Table 2. Poorly resolved EPR spectra of the BaP and 6-methyl-BaP cation radicals have also been recently obtained by dissolving the appropriate cation radical salts in TFA or acetonitrile (36).…”

Section: Other Epr Studies Of Bap Cation Radicalsmentioning

confidence: 88%

“…(7)- (8)], via an intermediate semiquinone radical, which would produce large amounts of reactive oxygen radicals. The production of hydroxyl radicals also indicates the possibility of a positive feedback mechanism, since hydroxy radicals, generated by Fenton's reagent, have been observed to react with BaP to generate 6-oxy-BaP radicals and BaP diones (12,44). It has been proposed that after a BaP molecule is committed to either the epoxidation or free-radical pathway there is no exchange of intermediates between the pathways (37).…”

Section: Oxygenated Bap Radicalsmentioning

confidence: 99%

“…Well resolved EPR spectra have been reported for the 6-oxy radicals of 10-methyl-, 7-methyl-and 7,10-dimethyl-BaP in TFA/ H202 (44), and unpublished spectra have also been obtained from 7-and 8-F-BaP None of these spectra have been analyzed in detail.…”

Section: Oxy Radicals From Substituted Bapsmentioning

confidence: 99%

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Free Radicals of Benzo(a)pyrene and Derivatives

Sullivan¹

1985

Environmental Health Perspectives

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Section: Other Epr Studies Of Bap Cation Radicalsmentioning

confidence: 88%

Section: Oxygenated Bap Radicalsmentioning

confidence: 99%

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Free Radicals of Benzo(a)pyrene and Derivatives

Sullivan¹

1985

Environmental Health Perspectives

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Section: Other Epr Studies Of Bap Cation Radicalsmentioning

confidence: 66%

Free radicals of benzo(a)pyrene and derivatives.

Sullivan¹

1985

Environ Health Perspect

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“…Of predominance, is the importance that (±)-anti-7,8-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene has been shown to play in the metabolic activation and subsequent carcinogenicity of the parent hydrocarbon ( Figure 3) (26)(27)(28)(29)(30)(31)(32). Other key pathways of metabolic activation of aromatic hydrocarbons have been shown to be mediated through one electron oxidation pathways as well as via substitution at reactive centers of the aromatic hydrocarbon, yielding alkyl substituted and related intermediates (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46).…”

Section: Introductionmentioning

confidence: 99%

KINETICS OF FORMATION OF (±)-Anti-7, 8-Dihydroxy-9α,10α -EPOXY-7, 8, 9, 10-Tetrahydrobenzo[a]pyrene ADDUCTS WITH MOUSE AND HUMAN HEMOGLOBIN

Myers

Hurst

Cunningham

et al. 2008

Polycyclic Aromatic Compounds

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Previous studies on the metabolic activation of polycyclic aromatic hydrocarbons have shown conclusively that activation to reactive electrophilic intermediates occurs via metabolism of the unsubstituted aromatic hydrocarbon to electrophilic diol-epoxide intermediates. These reactive electrophilic derivatives undergo reaction with various biological nucleophilic centers to form covalent modifications, which can be assessed by a variety of analytical techniques. While the formation of these adducts with various cellular nucleophiles has been clearly established, the relationships between relative rates of formation of various adducts in biological systems has not been significantly investigated. In the present study, we investigated the pharmacokinetics of reaction of the ultimate carcinogenic metabolite of benzo(a)pyrene, (±)-anti-7,8-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), with both male C57BL/6 mouse red cell hemoglobin and human red cells, in vitro. Comparative pharmacokinetic studies using both mouse and human hemoglobin were carried out by 143 Downloaded by [York University Libraries] at 23:40 02 January 2015 144 S. R. Myers et al.incubation of the packed red cells together with solutions of (±)-anti-7, 8-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene. Similar rate constants for the binding of the epoxide to hemoglobin in both mouse and human were found, suggesting a similarity of amino acids that were adducted in both species. Overall binding of (±) -anti-7,8-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene to mouse hemoglobin was found to be slightly higher than that found using human hemoglobin, suggesting the potential of a facilitation of the binding of the epoxide with mouse protein or an additional reactive amino acid to which the epoxide was bound. In parallel studies, mice were injected intraperitoneally with benzo(a)pyrene to compare the kinetics of binding of this carcinogen to hemoglobin, in vivo. Blood samples were obtained at specific intervals, and the kinetics of binding to hemoglobin characterized. These results suggested that the binding to hemoglobin in the in vivo studies was slightly lower than that compared to the in vitro assessments. However the differences in adduct levels strongly suggests that other metabolic pathways are involved in the metabolic activation of benzo(a)pyrene as well as other related carcinogenic compounds.

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Chemical and enzymatic oxidation of alkylated benzo[a]pyrenes

Cited by 6 publications

References 24 publications

Free Radicals of Benzo(a)pyrene and Derivatives

Free Radicals of Benzo(a)pyrene and Derivatives

Free radicals of benzo(a)pyrene and derivatives.

KINETICS OF FORMATION OF (±)-Anti-7, 8-Dihydroxy-9α,10α -EPOXY-7, 8, 9, 10-Tetrahydrobenzo[a]pyrene ADDUCTS WITH MOUSE AND HUMAN HEMOGLOBIN

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