Peroxide formation oxygen effect

In contrast to mammalian experience, rapid resumption of aerobic metabolism by the insects after cyanide treatment was detrimental to the insect. However, the surprising deleterious effects appeared to be due to one of the products of the aerobic metabolism of cyanide (B34) rather than to oxygen or peroxide formation. The inhibition of catalase by cyanide appeared to have no obvious relationship to the enhancement of toxicity by oxygen. 

Common to these photopolymer products was the use of coinitiators, such as 2-MBO, diacrylate and triacrylate monomers, binders, and other additives as required. In general, the film products were coated on a polyester support and a polyolefin sheet laminated to the coated material, to permit exposure of the films in an oxygen-free environment, as was required to obviate the chain-stopping effect of peroxide formation. 

In the photo sensitized oxygenation reactions of alkenes, not only the influence of the solvent on the reaction rate but also the effect of solvent on product distribution i.e. from competing hydroperoxide, 1,2-dioxetane, and entfo-peroxide formation) is rather small [550, 551],... 

Figure 24. Effect of oxygen and rose bengal on the rate of peroxide formation in wood photoirradiated for 24 h.

Pyrolysis of synthetic polyisoprene in the presence of oxygen also is expected to be identical to that of natural rubber. Thermal oxidation of natural rubber is assumed always to be associated with scission, although photo-oxidation at low temperature may involve peroxide formation without scission. The effect of oxygen is to increase the reaction rate of scission and therefore to decrease the temperature where the scission starts. The oxidation may take place after the initial formation of a free radical that reacts with oxygen ... 

Balchum et al. (1971) have provided evidence supporting the concept that the peroxidation or ozonization of unsaturated fatty acids in biological membranes is a primary mechanism of the deleterious effects of 03. The hypothesis is based on the tendency of 03 to react with the ethylene groups of unsaturated fatty acids, resulting in the formation of free radicals. The free radicals can, in the presence of molecular oxygen, cause peroxidation of unsaturated fatty acids. In support of this hypothesis is the evidence that after 03 exposure there was a relative decrease in unsaturated fatty acids as compared to saturated fatty acids, and the more unsaturated the fatty acid, the greater the loss. Furthermore, a deficiency of vitamin E increases the toxicity of 03 for the rat (Goldstein et al. 1970). 

Respiratory decline, characteristic of vitamin E-deficient liver tissue during the prenecrotic phase of dietary necrotic liver degeneration, consists of the breakdown of respiration in vitro, after brief, initial periods of normal oxygen consumption. The phenomenon is observed with liver slices and also homogenates, but not with isolated mitochondria from the livers of animals during the latent phase of the disease. Respiratory decline is not related to the rate of peroxide formation in the homogenate. Combination experiments disclosed that miorosomes exert a deleterious effect on the... 

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