Detoxification halogenated compounds

Simula, T.P, Glancey, M.J. Wolf, C.R. (1993) Human glutathione S -transferase-expressing Salmonella typhimurium tester strains to study the activation/detoxification of mutagenic compounds studies with halogenated compounds, aromatic amines and aflatoxin Bp Carcinogenesis, 14, 1371-1376... 

With biological material, it may also be aimed at destruction by chemical means via release of halogens, halogen compounds, and photocatalyst such as Ti02 [12] that would aid in detoxification by sunlight and antiviral material such as I2 and Ag... 

In this context, the electroreduction of halogenated organic compounds offers an effective route not only to the detoxification of wastes but also to their valorization as in the case of CFCs and, generally, of volatile organic halides. 

Further details of the pathways for the degradation of PAFIs are described in Chapter 6, Section 6.2.1 and in a review (Neilson and Allard 1998). It seems that most of the degradative enzymes are inducible, and this is consistent with the fact that most strains have been isolated after specific enrichment with the xenobiotic. The case of the partially constitutive synthesis of catechol 1,2-dioxygenase in the yeast Trichosporon cutaneum (Shoda and Udaka 1980) has been noted (Section 4.5.2). In the case of biotransformation, however, there are sporadic examples of the constitutive synthesis of enzymes. For example, the system carrying out the O-methylation of halogenated phenolic compounds was apparently constitutive (Neilson et al. 1988) this observation is consistent with the isolation of the strains by enrichment with Q compounds structurally unrelated to the halogenated substrates. The O-methylation reaction may function primarily as a detoxification system, so that in this case constitutive synthesis of the enzyme would clearly be advantageous to the survival of the cells. 

In this article we will outline in vitro metabolic studies which have been performed on representatives of several classes of carcinogens. These studies have been selected from the literature through 1979. Metabolic studies which employed various cellular subfractions, cell culture, or organ culture systems will be compared. The effect of species variations on in vitro metabolism will also be considered. The relationship of these in vitro studies to current concepts on metabolic activation and detoxification will be discussed for aromatic amines, polycyclic aromatic hydrocarbons, nitrosamines, hydrazines, azoxy compounds, halogenated hydrocarbons, and carcinogenic natural products. 

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