Adducts of 6-methylbenzo[a]pyrene and 6-fluorobenzo[a]pyrene formed by electrochemical oxidation in the presence of deoxyribonucleosides
- Univ. of Nebraska Medical Center, Omaha, NE (United States)
Studies of the DNA adducts of benzo[a]pyrene and selected derivatives are part of the strategy to elucidate mechanisms of tumor initiation by aromatic hydrocarbons. Reference adducts formed by reaction of deoxyribonucleosides with electrophilic intermediates of 6-fluorobenzo[a]pyrene (6-FBP) and 6-methylbenzo[a]pyrene (6-CH[sub 3]BP) are investigated here because they are essential for identifying the structures of adducts formed in biological systems. Electrochemical oxidation of 6-FBP in the presence of deoxyribonucleosides led to adducts from the 6-FBP radical cation. With dG, a mixture of 6-FBP bound at C-1 or C-3 to the N-7 of Gua was formed in 10% yield, whereas 6-FBP plus dC gave a mixture of 3-(6FBP-1-yl)Cyt and 3-(6-FBP-3-yl)Cyt (15%). No adducts of 6-FBP were formed with dA or dT. Electrochemical oxidation of 6-CH[sub 3]BP in the presence of dG produced 8-(BP-6CH[sub 2]-yl)dG (5%) and a mixture of 7-(6-CH[sub 3]BP-1-yl)Gua and 7-(6-CH[sub 3]BP-3-yl)Gua (23%). The only adduct formed with dA was 3-(BP-6-CH[sub 2]-yl)Ade (9%). 6-CH[sub 3]Bp did not afford any adducts with dC or dT. The noncarcinogenic 6-ClBP and 6-BrBP did not afford any adducts with dG, dA, dC, or dT. These results are consistent with the chemical properties of the 6-FBP and 6-CH[sub 3]BP radical cations; that is, 6-FBP reacts at C-1 and C-3, whereas 6-CH[sub 3]BP reacts competitively at C-1 and C-3, as well as the 6-CH[sub 3] position. 18 refs., 7 figs., 1 tab.
- OSTI ID:
- 6955813
- Journal Information:
- Chemical Research in Toxicology; (United States), Journal Name: Chemical Research in Toxicology; (United States) Vol. 6:6; ISSN CRTOEC; ISSN 0893-228X
- Country of Publication:
- United States
- Language:
- English
Similar Records
[sup 32]P-Postlabeling analysis of the DNA adducts of 6-fluorobenz[a]pyrene and 6-methylbenz[a]pyrene formed in vitro
Synthesis of 1- and 3-fluorobenzo[a]pyrene
Related Subjects
560300 -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
AROMATICS
BENZOPYRENE
BIOLOGICAL PATHWAYS
CHEMICAL REACTION KINETICS
CONDENSED AROMATICS
DNA ADDUCTS
HYDROCARBONS
KINETICS
MUTAGENESIS
ORGANIC COMPOUNDS
REACTION KINETICS