Toxic oxygen

The process has two main sources of waste water. These are the condensate streams from the steam strippers. The principal pollutant in both wastewater streams is phenol. Phenol is of concern primarily because of its toxicity, oxygen depletion, and turbidity. In addition, phenol can cause objectionable taste and odor in fish flesh and potable water. 

Nifurtimox, a nitrofuran, is a prodrug that is reduced to unstable nitroanion radicals, which react to produce highly toxic oxygen metabolites, such as superoxide and peroxide. Oxidative stress subsequently kills the parasite, which seems to lack effective enzymatic pathways to detoxify oxygen metabolites. 

Halliwell, B. and Gutteridge, J.M.C. (1984). Oxygen toxicity, oxygen radicals, transition metals and disease. Biochem. J. 219, 1-14. 

Winyard, P.G., Perrett, D., Harris, G. and Blake, D.R, (1992). The role of toxic oxygen species in inflammation with special reference to DNA damage. In Biochemistry of Inflammation (eds. J.T. Whicher and S.W. Evans) pp. 109-129. MTP Press, Lancaster. 

Balia, G., Vercelloti, G.M. and Muller-Eberhard, U. (1991). Exposure of endothelial cells to free heme potentiates damage mediated by granulocytes and toxic oxygen species. Lab. Invest. 64, 648-655. 

Hiraishi, H., Razandi, M., Terano, A. and Ivey, K.J. (1990). Antioxidant defenses of culture gastric mucosal cells against toxic oxygen metabolites. Role of glutathione redox cycle and endogenous catalase. Gastroenterology 98, A544. 

Williams, J.G. (1990). Phagoeyftes, toxic oxygen metabolites and inflammatory bowel disease, implications for treatment. Ann. R, Coll. Sutg. Engl. 72, 253-262. 

Williams, J.G. and Hallett, M.B. (1989).Effect of sulphasalazine and its active metabolite, 5-aminosalicylic acid, on toxic oxygen metabolite production by neutrophils. Gut 30, 1581-1587. 

Several papers discuss the effects of oxygen alone or with other compounds on cyanide toxicity. Oxygen alone results in minimal antagonism in mice injected with potassium cyanide and only slightly enhances the antagonistic effects of sodium nitrite (Sheehy and Way 1968). The antidotal effect of sodium thiosulfate alone or in combination with sodium nitrite, was enhanced by oxygen. 

A number of 5-nitro-2-furaldehyde derivatives, called nitrofurans, are used in the treatment and/or prophylaxis of microbial infections, primarily in the urinary tract. Recent evidence suggests that the reduction of the 5-nitro group to the nitro anion results in bacterial toxicity. Intermediate metabolites modify various bacterial macromolecules that affect a variety of biochemical processes (e.g., DNA and RNA synthesis, protein synthesis) this observation may explain the lack of resistance development to these drugs. Evidence also indicates that the nitro anion undergoes recycling with the production of superoxide and other toxic oxygen compounds. It is presumed that the nitrofurans are selectively toxic to microbial cells because in humans, the slower reduction by mammalian cells prevents high serum concentrations. 

Nifurtimox Generation of toxic oxygen radicals Unknown... 

DFO is known to reduce the iron-dependent generation of toxic oxygen-derived radicals during reperfusion of ischemic tissue (40). It was shown experimentally that DFO reduces the early inflammatory reaction and improves myocardial microcirculation (41). Moreover, Dross et al, (42) showed that DFO s scavenging effect on superoxide anion could play a role in the cellular defense against oxygen radicals during cardiac operation. 

Moreover, in the membrane environments the tocopherols are present, which remove the toxic oxygen species (02,102, HOO and OH ). The tocopherols act here as sacrificial donors, ie scavengers, which are not restored in a subsequent reduction process but are destroyed by irreversible chemical conversion [125],... 

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