Oxygen free radicals removal

Benzoyl peroxide can help remove dead skin cells, which in turn prevents the pores from clogging up. It also kills the Propionibac-terium acnes bacterium that causes acne. It has anti-inflammatory effects and reduces oxygen free radicals and fatty acids on the skin. 

Hyperlipidemia and the recruitment of inflammatory cells into the atherosclerotic arterial wall are suggested to cause excessive production of oxygen flee radicals [19]. Ohara et al. found that aortas from rabbits that had been fed a high cholesterol diet for several weeks produced several fold more oxygen free radicals than did control aortas [19,24]. Furthermore, removal of the endothelium resulted in reduction of free radical production, suggesting that the endothelium is a major source of the reactive oxygen species in this model. It was hypothesized that the abnormal redox state in the arterial wall may be a fundamental metabolic feature of atherosclerosis [19]. 

Butadiene reacts readily with oxygen to form polymeric peroxides, which are not very soluble in Hquid butadiene and tend to setde at the bottom of the container because of their higher density. The peroxides are shock sensitive therefore it is imperative to exclude any source of oxygen from butadiene. Addition of antioxidants like /-butylcatechol (TBC) or butylated hydroxy toluene (BHT) removes free radicals that can cause rapid exothermic polymerizations. Butadiene shipments now routinely contain about 100 ppm TBC. Before use, the inhibitor can easily be removed (247,248). Inert gas, such as nitrogen, can also be used to blanket contained butadiene (249). 

Reversible electron addition to the enone forms the radical anion. Rate determining protonation of the radical anion occurs on oxygen to afford an allylic free radical [Eq. (4b) which undergoes rapid reduction to an allylic carbanion [Eq. (4c)]. Rapid protonation of this ion is followed by proton removal from the oxygen of the neutral enol to afford the enolate ion [Eq. (4c)]. 

In all experiments, unless otherwise stated, approximately 5% oxygen was added to the reaction mixture to remove free radicals from the system and thereby simplify the derivation of the modes of formation of the hydrocarbon products. 

Salim, A.S. (1990a). Removing oxygen-derived free radicals stimulates healing of ethanol-induced erosive gastritis in the rat. Digestion 47, 24—28. 

The removal of an electron from a carbanion oxidizes it to a free radical and sometimes, in the presence of oxygen, to a peroxide. Organometallic compounds give many radical-like reactions of course, and a possible oxidation mechanism for such compounds is a preliminary dissociation into radicals followed by oxidation of the radicals and the metal. 

It therefore appears that for at least domains 4 and 6, hCP possesses metal binding sites in addition to the six integral copper atoms. Binding of ferrous iron at these sites could result in its oxidation and its removal from the plasma or in the reduction of oxygen-based free radicals. Binding of copper could result in its transport through the plasma (vide infra). 

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