Peroxidative degradation

The object of this study was to demonstrate the relationship of the surface area of the CoFoam composite and the rate of degradation of the hydrogen peroxide. Accordingly, several pieces of CoFoam of different sizes were placed in the vessel and the pressure monitored with respect to time. Pressure was converted to the amount of hydrogen peroxide degraded. Figure 8.3 reports the data in graphic form. 

Schaefer W, Harris T, Guengerich F. Characterization of the enzymatic and non-enzymatic peroxidative degradation of iron porphyrins and cytochrome P-450 heme. Biochem J 1985 24 3254—3263. 

In the DV of the parasite, free heme is rapidly converted to hematin, i.e., iron II is oxidized in iron III. During this process, electrons liberated promote the formation of reactive oxygen species (ROS) such as superoxide anion radicals and hydrogen peroxide [160], ROS can cause cellular damage. Hydrogen peroxide may also be used for the peroxidative degradation of heme. In this context, the influence of H2O2 on the redox behavior of FQ and implications for antimalarial activity was questioned. 

Roller G, Moder M, Czihal K (2000) Peroxidative degradation of selected PCB a mechanistic study. Chemosphere 41 1827-1834... 

The formation of halohydrins can be promoted by peroxidase catalysts.465 Recently 466 it has been shown that photocatalysis reactions of hydrogen peroxide decomposition in the presence of titanium tetrachloride can produce halohydrins. The workers believe that titanium(IV) peroxide complexes are formed in situ, which act as the photocatalysts for hydrogen peroxide degradation and for the synthesis of the chlorohydrins from the olefins. The kinetics of chlorohydrin formation were studied, along with oxygen formation. The quantum yield was found to be dependent upon the olefin concentration. The mechanism is believed to involve short-lived di- or poly-meric titanium(IV) complexes. 

Gruber, M. P., Klein, R. W. and Foxx, M. Infrared and thin-layer chromatography determination of benzoyl peroxide degradation products in pharmaceuticals. J. Pharm. Sci. 58 566-569, 1969. 

Common peroxide degradants and stabilizers used in controlled-rheology reactive extrusion are shown in Table 17.2 and 17.8 of Fink (2005). 

Loria, P., Miller, S., Foley, M., and Tilley, L. (1999). Inhibition of the peroxidative degradation of haem as the basis of action of chloroquine and other quinoline antimalarials. Biochem. ]. 339(Pt 2), 363-370. 

Peroxide value (P V) is the most commonly used measurement of lipid oxidation. The standard iodometric method requires a relatively large sample (5 g) when the lipid is only slightly oxidized. The ferric thiocyanate method, based on the oxidation of ferrous to ferric ion, involves colorimetric measurement of ferric thiocyanate. This method is more sensitive than the iodometric method and requires a relatively small sample (0.1 g). The PV is a useful measure for samples with low levels of oxidation and when the hydroperoxides are not decomposed. During prolonged oxidation, a maximum PV is reached and the value then begins to decrease due to peroxide degradation. This maximum value occurs early for soybean and rapeseed oil, due to the more rapid decomposition of the hydroperoxides of the polyunsaturated fatty acids. 

Nickel toxicity induced by parenteral administration of water-soluble, inorganic nickel compounds to rats induces peroxidative degradation of membrane lipids, as evidenced by increased concentrations of thiobarbitu-ric acid chromogens in liver, kidney, lung, spleen, and thymus increased concentrations of conjugated dienes in hepatic microsomal lipids and increased exhalation of ethane and ethylene (Donskoy et al. 1986, Kasprzak etal. 1986, Knight etal. 1986,... 

Ursini, F., Maiorino, M., Valente, M., Ferri, L. and Gregolin, C. (1982) Purification from pig liver of a protein which protects liposomes and biomembranes from peroxidative degradation and exhibits glutathione peroxidase activity on phosphatidylcholine hydroperoxides. Biochim. Biophys. Acta 1X0 197-211. 

PP peroxide degradation CORl or SSE Melt flow monitor (MEM) is needed Xanthos, 1992 Eiitz ... 

Peroxide, crosslinking Peroxide, decomposer Peroxide, degradation Peroxy free radicals PES (Poly-ether sulfone) PES blends... 

Merlo L, Ghiehni A, Cirillo L, Gebert M, Arcella V (2007) Resistance to peroxide degradation of Hyflon ion membranes. J Power Sources 171 140-147... 

Peroxide degrades some plastics, such as polypropylene (PP). Consequently, in peroxide crosslinked TPVs, polymers like PP degrade and polymers like polyethylene crosslink. In phenolic resin cured TPVs, thermoplastics like PP do not degrade but moisture is always an issue, because the stannous chloride or zinc chloride that are used as Lewis acid are hygroscopic. 

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