Metabolism of aromatic hydrocarbons

Cerniglia CE, JP Freeman, RK Mitchum (1982b) Glucuronide and sulfate conjugation in the fungal metabolism of aromatic hydrocarbons. Appl Environ Microbiol 43 1070-1075. 

Cerniglia CE, SA Crow (1981) Metabolism of aromatic hydrocarbons by yeasts. Arch Microbiol 129 9-13. 

Whereas the metabolism of aromatic hydrocarbons takes place by dioxygenation, their biotransformation by yeasts and fungi is normally initiated by monooxygenation to the epoxide followed by hydrolysis to the trani-dihydrodiols. Phenols may subsequently be formed either by elimination or by nonenzymatic rearrangement of the epoxide ... 

In connection with the chemistry of the reactive transient species, nitrene, the chemistry of azepines is well documented u. Also, the chemistry of oxepins has been widely developed due to the recent interest in the valence isomerization between benzene oxide and oxepin and in the metabolism of aromatic hydrocarbons 2). In sharp contrast to these two heteropins, the chemistry of thiepins still remains an unexplored field because of the pronounced thermal instability of the thiepin ring due to ready sulfur extrusion. Although several thiepin derivatives annelated with aromatic ring(s) have been synthesized, the parent thiepin has never been characterized even as a transient species3). 

Disposition and Metabolism of Aromatic Hydrocarbons in Marine Organisms... 

Cerniglia, C. E., Sutherland, J. B. Crow, S. A. (1992). Fungal metabolism of aromatic hydrocarbons. In Microbial Degradation of Natural Products, ed. G. Winkelmann, pp. 193-217. Weinheim VCH Press. 

The microbial metabolism of aromatic hydrocarbons has been reviewed extensively since... 

It is nevertheless generally admitted that [dihydro]diols are probably intermediates in the metabolism of aromatic hydrocarbons... 

Malik Z, Jones C JP, Connock M J (1987) Assay and subcellular localization of H2O2 generating mannitol oxidase in the terrestrial slug Arion ater. J Exp Zool 242 9-15 Malins DC (1977) Metabolism of aromatic hydrocarbons in marine organisms. Ann NY Acad Sci 298 484-498... 

Malins DC, Roubal WT (1982) Aryl sulfate formation in sea urchins (Strogylocentrotusdroebachiensis) ingesting marine algae (Fucus distichus) containing 2,6-dimethylnaphthalene. Env Res 27 290-297 Malins DC, Collier TK, Sanborn HR (1979) Disposition and metabolism of aromatic hydrocarbons in marine organisms. In Khan MAQ, Lech JJ, Menn JJ (eds) Pesticide and xenobiotic metabolism in aquatic organisms. Am Chem Soc Ser 99 57-75... 

Malins, D.C. 1977b. Metabolism of aromatic hydrocarbons in marine organisms. In H.F. Kraybill, C.J. Dawe, J.C. Harshbarger, and R.G. Tardiff (Eds.), Aquatic pollutants and biological effects with emphasis on neoplasia. Annals of the New York Academy of Science 298 482-496. 

The role played by dihydrodiols in the metabolic formation of phenols and their conjugated derivatives from aromatic substances is at present undecided. In theory, upon dehydrating a dihydrodiol, the phenolic hydroxyl should remain at that carbon most activated toward electrophilic substitution (14,625). This criterion of mechanism is satisfied in some instances (i.e., the halogenobenzenes (379, 682) and benzonittile (681). Furthermore, compounds that arise from the metabolism of aromatic hydrocarbons also arise from metabolism of dihydrodiols which are formed from them (94,163). However, hver slices and Uver microsomes capable of forming dihydrodiol from naphthalene form neg%ible amounts of naphthol (95,558). 

Gibson DT, JR Koch, CL Schuld, RE Kallio (1968) Oxidative degradation of aromatic hydrocarbons by microorganisms. II. Metabolism of halogenated aromatic hydrocarbons. Biochemistry 7 3795-3802. 

Madsen EL, CT Thomas, MS Wilson, RL Sandoli, SE Bilotta (1996b) In situ dynamics of aromatic hydrocarbons and bacteria capable of PAH metabolism in a coal tar-waste-contaminated field site Environ Sci Technol 30 2412-2416. 

Tabak HH, Chambers CW, Kabler PW. 1964. Microbial metabolism of aromatic compounds. I. Decomposition of phenolic compounds and aromatic hydrocarbons by phenol-adapted bacteria. J Bacteriol 87 910- 919. 

The metabolism of thiophene (100) was first studied in 1886 by Heffter (1886MI10900), who administered it orally to dogs and noted the increased output of ethereal sulfates in urine. This is typical of aromatic hydrocarbons conversion to phenolic products which are excreted in urine as sulfate conjugates. When fed to rabbits, there was no increase in the ethereal sulfate output, but there was some indirect evidence of the presence in urine of dihydrodiols and thienylmercapturic acids (45MI10900). This was confirmed by Bray and coworkers (71MI10906,68BJ(109)11P>, who studied thiophene and benzothiophene metabolism in rabbits and rats. The only identifiable metabolites in urine were the thienylmercapturic acids (101) and (102), which are probably formed via conjugation of the intermediate... 

Ah receptor (AHR) A protein coded for by a gene of the Ah locus. The initial location of the Ah receptor is believed to be in the cytosol and, after binding to a ligand such as TCDD, is transported to the nucleus. Binding of aromatic hydrocarbons to the Ah receptor of mice is a prerequisite for the induction of many xenobiotic metabolizing enzymes, as well as for two responses to TCDD epidermal hyperplasia and thymic atrophy. Ah-responsive mice have a high-affinity receptor, whereas the Ah-nonresponsive mice have a low-affinity receptor. 

There have been a few reports of aerobic bacterial species which will grow on dibenzothiophene as their sole carbon source (51,52)- However, most studies have focused on its co-metabolism (22,52,54) which appears to be a more common phenomenon. Intermediates of the biodegradation have been identified in a number of studies (55-57). Figure 10 is a simplification of the proposed pathway for dibenzothiophene metabolism showing the two endproducts 3-hydroxy-2-formylbenzothiophene (HFBT), which is the more abundant, and dibenzothiophene-sulfoxide. [For a more complete pathway see (56) or (58)1. This pathway shows 1,2-dihydroxydibenzothiophene as an intermediate and this is analogous to the diols found as intermediates of aromatic hydrocarbons. 

Anderson LM, Jones AB, Riggs CW, Ohshima M (1985) Fetal mouse susceptibility to transplacental lung and liver carcinogenesis by 3-methylcholanthrene Positive correlation with responsiveness to inducers of aromatic hydrocarbon metabolism. Carcinogenesis, 6(9) 1389-1393. 

Mikesell L MD, Kukor JJ, Olsen RH. 1993. Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer. Biodegradation 4(4) 249-259. 

Sato A, Nakajima T, Koyama Y. 1980. Effects of chronic ethanol consumption on hepatic metabolism of aromatic and chlorinated hydrocarbons in rats. Br J Ind Med 37 382-386. 

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