Epoxidation of 7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene during sulfite oxidation

Conference · Fri Feb 28 23:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5001847

Reed, G A; Curtis, J F; Mottley, C; Eling, T E; Mason, R P

Exposure to sulfite (S), whether due to its ingestion as an additive in foods and drugs or by the spontaneous hydration of the ubiquitous air pollutant sulfur dioxide, is unavoidable. S undergoes extensive autoxidation in neutral aqueous media via an oxygen-consuming pathway. Among the products of this pathway are /sup -/O/sub 3/SOO/sup ./ and /sup -/O/sub 3/SOOH, an inorganic peroxyl radical and peracid respectively. Inclusion of 7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (BP-7,8-diol) in the S autoxidation medium results in the production of diolepoxides, the ultimate carcinogenic form of benzo(a)pyrene (BP). The observed stereoselectivity of epoxidation is consistent with either a peroxyl radical or a peracid as the oxygen donor. The epoxidation is dependent on both the concentration of S and or O/sub 2/, and is blocked by butylated hydroxyanisole or DETAPAC, both of which block S oxidation. S-dependent epoxidation also occurs in the presence of ram seminal vesicle microsomes, providing preliminary evidence for the occurrence of this reaction in a biological milieu. These observations provide evidence that inorganic as well as organic peroxyl radicals and peracids are effective epoxidizing agents for BP-7,8-diol. As this reaction yields the ultimate carcinogenic form of BP, it may be a possible mechanism for the observed cocarcinogenic effect of S for BP-induced tumors.

• Research Organization: Univ. of Kansas Medical Center, Kansas City
• OSTI ID: 5001847
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:3; ISSN FEPRA
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR POLLUTION
AROMATICS
BENZOPYRENE
BIOLOGICAL PATHWAYS
CARCINOGENESIS
CHALCOGENIDES
CONDENSED AROMATICS
DISEASES
HYDROCARBONS
METABOLISM
NEOPLASMS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PATHOGENESIS
POLLUTION
SULFITES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES