Radicals scavengers for

One can prove the intermediate existence of the silylene by the addition of a radical scavenger, for example, trimethylsilane me3SiH, which forms penta-methyldisilane 51 ) ... 

The effects of chromium(III) chloride and sodium chromate(VI) on the hepatotoxicity of carbon tetrachloride exposure to mouse hepatocytes were examined by Tezuka et al. (1995). Primary cultures of mouse hepatocytes were pretreated with 10 or 100 pM chromium for 24 hours followed by exposure to 1-5 mM carbon tetrachloride for up to 1 hour. Chromium(VI) pretreatment significantly reduced the cell toxicity as well as lipid peroxidation caused by carbon tetrachloride. Chromium(III) pretreatment did not have any effect on cell toxicity. About 50% of chromium(VI) was taken up and reduced in the cells by 90% to chromium(III) within 10 minutes. The initial uptake rate of chromium(HI) into cells was greater than 500-fold less than chromium(VI), and only about 5% was absorbed. The protection against carbon tetrachloride damage by chromium(VI) was attributed to its rapid uptake and conversion to chromium(III), and it was determined that chromium(III) acts as a radical scavenger for the free radicals generated by carbon tetrachloride within the cell. Furthermore, chromium(VI) pretreatment reduced the activity of NADPH cytochrome c reductase which metabolizes carbon tetrachloride to reactive species. 

The ability of diazonium salts to act as radical scavengers for nucleophilic alkyl radicals was first discovered in mechanistic studies on the Meerwein arylation [96]. Shortly after, this concept was applied for the functionalization of a limited group of activated alkenes [97-99]. The much greater synthetic potential of this functionalization type, which arises from the successful use of non-activated alkenes as substrates, has recently been investigated. In a typical reaction, as illustrated in Scheme 19, the diazonium salt 48 acts as source for aryl radicals 49 and as radical scavenger [100]. 

The radiolysis of water produces hydrated electrons (e q, G = 2.9), hydrogen atoms (G = 0.55) and hydroxyl radicals (G = 2.8) which react with the solute molecules. In addition, the radiolysis of aqueous solutions also yields H202 (G = 0.75), gaseous hydrogen (G = 0.45) and hydronium ions (H30+, G = 2.9). In most cases the molecular products do not interfere with the reactions of the radicals. To study the reaction of one radical with the solute without interference from other radicals, scavengers for the other radicals should be added7-10. 

A wide range of iron chelators have been shown to inhibit ribonucleotide reductase [144-146] and this is likely to be the explanation of the cytotoxic properties of such molecules. Some iron chelators may also function as free radical scavengers. For instance, hydroxyurea appears to inhibit the enzyme by this latter mode of action [144], Such inhibitory agents block the cell division cycle in the S-phase because replication of cellular DNA is arrested. This also suggests possible therapeutic applications. 

This may represent another alternative strategy to free-oxygen radical scavengers for limiting asbestos-induced lung damage. 

It is well-known that the overall quantum yield is near unity at 2537 A however, at 3130 A, it is less than 1 at low temperatures and approaches unity only above 100 C The overall quantum yields at 3130 A and 100 torr acetone pressure are 0.5, 0.7 and 1.0 at 0°, 25°, and 120 °C, respectively. (See further data of Heicklen and Noyes" as well as those of Cundall and Davies" .) The primary quantum yields can be determined, in principle, by studying the photolysis in the presence of radical scavengers. For such a purpose iodine has been mainly used, as it is known to decrease the value of 4>co to eliminate the formation of bi-... 

Combustion is a radical reaction, and halogens generated from flame retardants act as radical scavengers for the radical reaction. 

Proposed mechanisms of action of UV stabilizers are UV absorption, excited-state quenching, hydroperoxide decomposition and radical scavenging. For HAS the only mechanism that can be ruled out is UV absorption, because many very effective HAS stabilizers as, for example, LMW-HALS-1 do not absorb in the UV wavelength region... 

Pennstop . [Atochem N. Am.] N < Diethylhydioxylamine free radical scavenger for rubber industry as an emulsion polymerizatimi inhibitor va> por phase inhibitor fa olefin or styrene monomer recovery systens. 

The majority of primary antioxidants are sterically hindered phenols or secondary aromatic amines. They are capable of undergoing fat reaction with peroxy radicals and so are often called radical scavengers. For hindered phenols, for example, such reactions may be represented by the following scheme ... 

Rhodium(Il) porphyrins (8) have also been reported to be usable as reversible radical scavengers for control free radical polymerization of acrylic esters (20) under irradiation with a 300-W tungsten bulb. - For example, a benzene solution of 8 (X = Me) has been irradiated (> 350 nm) for several hours to generate the corresponding rhodium(ll) porphyrin (56) (Scheme 12A). Then 20 is vacuum-distilled to the above reaction mixture, whereupon a four-carbon-bridged dimer (57) is formed (Scheme 12B). Upon... 

Uses Botanical, antioxidant, free radical scavenger for cosmetics natural flavoring agent in foods... 

Uses Antioxidant, light stabilizer, free radical scavenger for polyolefins, polyesters, ABS, pipe, crates, drums,... 

CAS 8002-47-9 EINECS/ELINCS 232-309-3 Synonyms Vitulus Definition Extract of bovine livers Uses Biological additive, skin conditioner in cosmetics free radical scavenger for cosmetic anti-aging preps. 

In order to reduce phototoxicity due to free radicals forming by photobleach-ing of the fluorophores during time-lapse microscopy, ascorbic acid (1 (rg/ml) or oxyrase (30 mM) may be added to the medium as free radical scavengers. For long-term observations (longer than two hours) the culture medium should be covered with mineral oil (from Sigma) to avoid the culture medium drying out. 

While some compounds, like peroxides, help initiate radical reactions, compounds called radical inhibitors have the opposite effect. A radical inhibitor is a compound that prevents a chain process from either getting started or continuing. Radical inhibitors effectively destroy radicals and are therefore also called radical scavengers. For example, molecular oxygen (O2) is a diradical ... 

Slemmer JE, Shacka JJ, Sweeney MI, Weber JT (2008) Anti-oxidants and free radical scavengers for the treatment of stroke, traumatic brain injury and aging. Curr Med Chem 15 404 14... 

Kim BG, Kim S, Lee H, Choi JW (2014) Wisdom from the human eye a synthetic melanin radical scavenger for improved cycle life of Li-02 battery. Chem Mater 26 4757-4764... 

Figure 3.181 ionol (BFIT) C,5hl240, M 220, CAS 128-37-0. Occurrence antioxidant in plastics, stabilizer (radical scavenger) for ethers, THF, dioxan, technical mixture of isomers. 

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