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Nitropyrenes

Nitropyrene Extracts of diesel exhaust gases were applied to [32]... [Pg.61]

Nitroindole 418 Nitrophenyl isocyanate reagent 77 1-Nitropyrene 61 N-Nitrosamines 107... [Pg.238]

Koizumi A, N Saitoh, T Suzuki, S Kamiyama (1994) A novel compound, 9-hydroxy-l-nitiopyrene, is a major photodegraded compound of 1-nitropyrene in the environment. Arch Environ Health 49 87-92. [Pg.43]

Reduction of nitroarenes has been demonstrated in species of Clostridium and Eubacte-rium, and was associated with the reduction in the mutagenic activity of 1-nitropyrene, and... [Pg.509]

Nitro polycyclic aromatic hydrocarbons are environmental contaminants which have been detected in airborne particulates, coal fly ash, diesel emission and carbon black photocopier toners. These compounds are metabolized Tn vitro to genotoxic agents through ring oxidation and/or nitroreduction. The details of these metabolic pathways are considered using 4-nitrobiphenyl, 1- and 2-nitronaphthalene, 5-nitro-acenaphthene, 7-nitrobenz[a]anthracene, 6-nitro-chrysene, 1-nitropyrene, 1,3-, 1,6- and 1,8-dinitro-pyrene, and 1-, 3- and 6-nitrobenzo[a] pyrene as examples ... [Pg.374]

Compared to the extensive data that have been obtained on the mutagenicity of nitro PAHs in S. typhimurium, relatively little is known about the metabolism of these compounds in this organism. Messier et al. (67) reported that incubation of 1-nitropyrene with S. typhimurium TA98 yielded 1-aminopyrene and 1-acetylaminopyrene as major and minor metabolites, respectively. The reduction of 1-nitropyrene was slow and was accompanied by a slow formation of DNA adducts. When incubations were conducted with the nitroreductase-deficient strain, TA100 F50, both the extent of 1-amino-pyrene formation and DNA binding decreased. Howard ej al. (71,115) also found reduction of 1-nitropyrene to 1-aminopyrene in strains TA98, TA1538 and ATCC 14028. [Pg.380]

Although 1-aminopyrene is a reduced metabolite of 1-nitropyrene, this arylamine will not covalently bind to DNA in vitro (72). In contrast, when incubations were conducted with the intermediate reduction product, N-hydroxy-l-aminopyrene, extensive covalent binding to DNA was detected (72). This observation is consistent with the previous report that several N-hydroxy arylamines formed DNA adducts and induced mutations in S. typhimurium (116), and suggests that, at least for 1-nitropyrene, reduction to N-hydroxy-l-aminopyrene is a critical step in mutation induction. [Pg.380]

Recently, Bryant t al. (70) examined the metabolism of 1,8-dinitropyrene in several S. typhimurium strains and found reduction to l-amino-8-nitropyrene and 1,8-diaminopyrene. In addition, other unidentified metabolites were detected in strains which were sensitive to 1,8-dinitropyrene-induced mutations (TA98 and TA98NR) but not in the resistant strains, TA98/1,8-DNP and TA98NR/1,8-DNP6. [Pg.380]

Other bacteria. Intestinal bacteria may play a critical role in the metabolic activation of certain nitroaromatic compounds in animals (119) and several reports have appeared on the metabolism of nitro PAHs by rat and human intestinal contents and microflora (120-123). Kinouchi et al. (120) found that 1-nitropyrene was reduced to 1-aminopyrene when incubated with human feces or anaerobic bacteria. More recently, Kinouchi and Ohnishi (121) isolated four nitroreductases from one of these anaerobic bacteria (Bacteroides fragilis). Each nitroreductase was capable of converting 1-nitropyrene into 1-aminopyrene, and one form catalyzed the formation of a reactive intermediate capable of binding DNA. Howard ej al. (116) confirmed the reduction of 1-nitropyrene to 1-aminopyrene by both mixed and purified cultures of intestinal bacteria. Two additional metabolites were also detected, one of which appeared to be 1-hydroxypyrene. Recently, similar experiments have demonstrated the rapid reduction of 6-nitro-BaP to 6-amino-BaP (123). [Pg.381]

Nitropyrene. 1-Nitropyrene is the principal nitro PAH found in diesel exhaust (40) and, therefore, has been the subject of intense study. Nachtman and Wei (133) found that under anaerobic conditions, 1-nitropyrene was reduced by hepatic S9, cytosol or microsomes to principally 1-aminopyrene. Only limited reduction occurred in the absence of cofactors, while maximum metabolism was observed in the presence of both FMN and NADPH. Although the microsomal fraction had the greatest specific activity toward 1-nitropyrene metabolism, the cytosol had 30 times the total activity. [Pg.386]

Saito et al. (134) found that the cytosolic nitroreductase activity was due to DT-diaphorase, aldehyde oxidase, xanthine oxidase plus other unidentified nitroreductases. As anticipated, the microsomal reduction of 1-nitropyrene was inhibited by 0 and stimulated by FMN which was attributed to this cofactor acting as an electron shuttle between NADPH-cytochrome P-450 reductase and cytochrome P-450. Carbon monoxide and type II cytochrome P-450 inhibitors decreased the rate of nitroreduction which was consistent with the involvement of cytochrome P-450. Induction of cytochromes P-450 increased rates of 1-aminopyrene formation and nitroreduction was demonstrated in a reconstituted cytochrome P-450 system, with isozyme P-448-IId catalyzing the reduction most efficiently. [Pg.386]

Bond (135) found that S9 preparations from rat nasal tissue have twice the specific activity for the oxidative metabolism of 1-nitropyrene as liver S9 and 10 times the activity of lung S9. Each S9 preparation gave similar metabolic profiles with the... [Pg.386]


See other pages where Nitropyrenes is mentioned: [Pg.103]    [Pg.103]    [Pg.27]    [Pg.41]    [Pg.249]    [Pg.249]    [Pg.132]    [Pg.132]    [Pg.11]    [Pg.20]    [Pg.21]    [Pg.397]    [Pg.904]    [Pg.161]    [Pg.374]    [Pg.375]    [Pg.375]    [Pg.375]    [Pg.376]    [Pg.377]    [Pg.378]    [Pg.379]    [Pg.380]    [Pg.381]    [Pg.386]    [Pg.388]    [Pg.389]    [Pg.389]    [Pg.389]    [Pg.392]    [Pg.393]   
See also in sourсe #XX -- [ Pg.187 , Pg.205 ]

See also in sourсe #XX -- [ Pg.347 ]

See also in sourсe #XX -- [ Pg.187 , Pg.205 ]




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1 -Nitropyrene, reduction

1-Nitropyrene

1-Nitropyrene incubations

1-Nitropyrene mutagenicity

1-Nitropyrene nitration

1-Nitropyrene oxidative metabolism

Nitropyrenes detection

Nitropyrenes determination

Nitropyrenes, atmospheric production

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