The benzo[a]pyrene 4,5-, 7,8-, and 9,10-oxides and the six corresponding phenols (4-, 5-, 7-, 8-, 9-, and 10-hydroxybenzo[a]pyrene) have been tested for mutagenic and cytotoxic activity in bacteria and in a mammalian cell culture system. Benzo[a]pyrene 4,5-oxide (K-region) was highly mutagenic in two histidine-dependent strains (TA1537 and TA1538) of Salmonella typhimurium which detect frameshi...

A manganese(III)-mediated reaction between 2-benzoyl-1,4-benzoquinones and 1,3-dicarbonyl compounds that produces benzo[c]furan-4,7-diones and anthracene-1,4-diones with high chemoselectivity is described. With ethyl butyrylacetate, by changing the solvent, benzo[c]furan-4,7-diones and anthracene-1,4-diones can be generated in high chemoselectivities. With ethyl benzoylacetate, N ,N-dimethyl ac...

An atom-economic synthetic route to benzimidazolium salts is presented. The annulated polycyclic systems: 1,3-bis(2,4,6-trimethylphenyl)-1H-benzo[d]imidazol-3-ium chloride (1-Cl), 1,3-bis(2,6-diisopropylphenyl)-1H-benzo[d]imidazol-3-ium chloride (2-Cl), 1,3-diphenyl-1H-benzo[d]imidazol-3-ium chloride (3-Cl), and 1,3-di(pyridin-2-yl)-1H-benzo[d]imidazol-3-ium chloride (4-Cl) were prepared in a t...

The direct arylation of benzo[b]furan, benzo[b]thiophene, and indole has been studied by using aromatic bromides as the aryl source. The protocol employing common reagents and a Pd catalyst has led to the regioselective arylation of these heterocycles at the 2-position. A range of functional groups were tolerated, providing quick access to a variety of arylated benzo-fused heterocycles that wou...

Abstract Roasting is a crucial and essential step to produce quality coffee. However, it could lead the formation of toxic suspected carcinogenic or procancerogenic compounds, such as polycyclic aromatic hydrocarbons. In this work, simple easily automatable green procedure based on solid-phase microextraction coupled with gas chromatography for analysis acenaphthene, anthracene, benzo[ghi]peryl...

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a cytosolic protein that catalyzes metabolic detoxification of quinones and protects cells against redox cycling and oxidative stress. NQO1-null mice deficient in NQO1 protein showed increased sensitivity to 7,12-dimethylbenz(a)anthracene- and benzo(a)pyrene-induced skin carcinogenesis. In the present studies, we show that benzo(a)pyrene metabolite ben...

The effect of flavone and 7,8-benzoflavone on the metabolism of benzo[a]pyrene to fluorescent phenols by five cytochrome P-450 isozymes obtained from rabbit liver microsomes was determined. Benzo[a]pyrene metabolism was stimulated more than 5-fold by the addition of 600 microM flavone to a reconstituted monooxygenase system consisting of NADPH, cytochrome P-450 reductase, dilauroylphosphatidylc...

The fjord-region diol-epoxides of benzo(c)phenanthrene combine high mutagenic and carcinogenic activity with low chemical reactivity. To study whether this is a unique property of these compounds or a more general characteristic of fjord-region diol-epoxides, we have synthesized the anti- and syn-diastereomers of r-9,t-10-dihydroxy-11,12-oxy-9,10,11,12-tetrahydrobenzo(c)chrysene and r-11-t-12-d...

The addition of benzo(a)pyrene to cells obtained from Syrian hamster embryo cultures that had been plated to produce discrete colonies resulted in transformation. Altered colonies were not seen in controls. Prior irradiation of hamster embryo cells increased the transformation by benzo(a)pyrene, both per cell and per total colony. Maximum enhancement occurred when benzo(a)pyrene was added 48 hr...

Human bronchus is one target site for the carcinogenic action of tobacco smoke, which contains chemical carcinogens, including benzo(a)pyrene. Human bronchi were obtained from surgery or "immediate" autopsy and then cultured in a chemically defined medium. The cultured bronchi were exposed to either benzo(a)pyrene or its metabolites, and their levels of binding to DNA were measured. One of the ...