Antioxidant Agents

Antioxidant agent Also called aging retardants. AOAs are of major importance to the plastic industry because they extend the plastic s (that are effected by oxygen) useful temperature range and service life during processing and/or product use. The variety of AOAs available and their specific uses are extensive. 

It is of special interest that rheumatoid arthritis is one of the first examples of the extensive antioxidant treatment of human patients. In previous years the most recommended pharmaceutical antioxidant agent has been SOD. In 1986, Wilsman [245] reviewed the results of 10 years of presumably successful clinical experience with CuZnSOD treatment of inflammatory disorders including RA. Niwa et al. [246] recommended the application of liposomal... 

As phenolics are well-known antioxidant agents, the Folin-Ciocalteau total phenolics assay was performed to assess phenolic content in ginseng roots. This assay was performed as described by Singleton et al. [20] with modifications [21]. Briefly, extract dissolved in 70% methanol was combined with Folin-Ciocalteau reagent, incubated for 5 min, and then 7.5% NaHCOs was added. Samples were transferred into microplate wells in triplicate, incubated in darkness for 2 h, and then absorbance read at 725 nm. Samples were blanked against a treatment with only solvent. A standard curve of quercetin was produced and data were expressed as quercetin equivalents. 

P5 Studies have shown that ebselen is an antiinflammatory and antioxidative agent. Its protective effect has been investigated in oxidative stress related diseases such as cerebral ischemia in recent years. However, experimental evidence also shows that ebselen causes cell death in several different cell types. Whether ebselen will have a beneficial or detrimental effect on cells under ischemic condition is not known. Herein, we studied the effect of ebselen... 

Sodium metabisulfite is an antioxidant agent widely used in pharmaceutical preparations to reduce or prevent oxidation. There are some studies, however, that have shown that metabisulfite, under specific conditions, may have indirect oxidant properties. Baker et al. [37] demonstrated that sulfite propofol emulsion, but not EDTA propofol emulsion, underwent chemical changes during a simulated intravenous infusion. Compounds were identified as propofol oxidation products. The increase of propofol oxidation products demonstrated that sulfite from metabisulfite created a strong oxidant environment when air was introduced. Lavoie et al. [38]... 

Saija A, Scalese M, Lanza M, Marzullo D, Castelli F. 1995. Flavonoids as antioxidant agents Importance of their interaction with biomembranes. Free Radic Biol Med 19 481-486. 

Sulfite Sulfite oxidase, sulfite dehydrogenase Wines Antioxidant agent... 

Next, some typical examples will be presented of how a DNA-electrochemical biosensor is appropriate to investigate the DNA damage caused by different types of substances, such as the antioxidant agent quercetin (Scheme 20.1), an anticancer drug adriamycin (Scheme 20.2) and nitric oxide. In all cases, the dsDNA damage is detected by changes in the electrochemical behaviour of the immobilized dsDNA, specifically through modifications of the purinic base oxidation peak current [3,5,40]. 

Sanaka T, Nakano Y, Nishimura H et al. (1997) Therapeutic effect of a newly developed antioxidative agent (OPC-15161) on experimental immune complex nephritis. Nephron 76 315-322... 

The purpose of this chapter is to present some of the evidence concerning the involvement of free radicals in acute CNS injury and their relationship to specific pathophysiological events. A great deal of this information has been obtained from investigations demonstrating the protective efficacy of lipid antioxidant agents in experimental models of acute spinal cord or head injury. 

Antioxidant Agent that inhibits oxidation and thus is used to prevent deterioration of preparations by oxidative process Ascorbic acid, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, hypophosphorus acid, monothioglycerol, propyl gallate, sodium ascorbate, sodium bisulfite, sodium formaldehyde, sulfoxylate, sodium metabisulfite... 

The carbazoquinodns are carbazole-3,4-quinone alkaloids and have been isolated from Streptomyces violaceus 2942-SVS3 [61]. They are strong antioxidative agents and thus represent potential drugs for the treatment of diseases initiated by oxygen-derived free radicals. We have developed an effident synthesis of carbazoquinodn C using palladium(II)-catalyzed oxidative cydization as the key step (Scheme 15.17, Table 15.2) [62]. 

Stefani HA, Oliveira CB, Almeida RB et al (2006) Dihydropyrimidin-(2//)-ones obtained by ultrasound irradiation a new class of potential antioxidant agents. Eur J Med Chem 41 513-518... 

As occurs with other plastic materials, elastomers, undergo certain processes before being used, such as cross-linking reactions, that lead to the formation of three-dimensional networks. Also it is necessary to incorporate certain chemical substances such as antioxidant agents, fillers, or plasticizers during their manufacture. These operations are aimed at improving the properties... 

Quinones and, in particular, naphthoquinone derivatives are industrially valuable products for further processing and for direct use due to their pronounced bioactivity [la,b], 2-Methyl-1,4-naphthoquinone, vitamin K3 ( menadione ), is the basis of the vitamin K group (coagulation vitamins). The skeleton of 2-methyl-1,4-naphthoquinone is common to all fat-soluble K vitamins. Derivatives of vitamin K promote the formation of prothrombin and other blood coagulation factors. They are used on an industrial scale as supplement in animal feed, but are also employed in the treatment of Melaena neonatorum in newborn babies. Trimethyl-p-benzoquinone is a key compound for the synthesis of vitamin E, active as antioxidant agent. As an example, the current method of the production of trimethyl-p-benzoquinone on an industrial scale is p-sulfo-nation of 2,3,6-trimethylphenol followed by stoichiometric oxidation using Mn02 [Ic]. 

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