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5,5-Dimethyl-l-pyrroline-N-oxide

As a means of identifying the potent oxidant another approach was made. By the use of certain organic compounds one can infer the presence of a free radical by converting a highly unstable one such as OH to a much more stable compound which can accumulate in solution, rendering its detection by electron spin resonance possible. To measure the presence of OH the compound DMPO (5,5-dimethyl l-pyrroline-N-oxide) has been used The characteristic adduct of OH with... [Pg.55]

Britigan, B. E., and Hamill, D. R. (1989). The interaction of 5,5-dimethyl-l-pyrroline-N-oxide with human myeloperoxidase and its potential impact on spin trapping of neutrophil-derived free radicals. Arch. Biochem. Biophys. 275, 72-81. [Pg.40]

Spin-traps DMPO (5,5-dimethyl-l- pyrroline-N-oxide), MNP (2-methyl-2-nitroso-propane, dimer), dG (2 -deoxyguanosine monophosphate), 8-HOdG standard (8-hydroxy-2 -deoxyguanosine) and deferoxamine mesylate were purchased from Sigma phosphate buffer (pH 7.4), hydrogen peroxide (H2O2) (30%), were purchased from Merck. All other chemicals used were of analytical quality. [Pg.413]

Note Values were taken from A. B. Ross, NDRL/NIST Solution Kinetics Database, v. 2.0, Standard Reference Data, NIST, Gaithersburg, MD 20899, USA (http //allen.rad.nd.edu), also found in Ref. 32. DMPO stands for 5,5-dimethyl-l-pyrroline N-oxide. [Pg.506]

In addition to their broncho dilatory action in asthma, P-agonistically active substances of diphe-nolic structure offer radical scavenging properties toward reactive oxygen species as shown in a model system by electron paramagnetic resonance spectroscopy and photometric approaches (Zwicker et al. 1998). The substances under study showed activity in superoxide radical scavenging under aprotic and protic conditions as well. The efficiency of the reaction decreased in the order fenoterol > salbuta-mol > reproterol > terbutaline > oxyfedrine when 5,5-dimethyl-l-pyrroline-N-oxide (DMSO) was used as an aprotic solvent. In an aqueous system, the rate constants decreased in the order fenoterol > reproterol > salbutamol. [Pg.163]

Ethyl docosahexaenoate-treated foetal rat brain preparations exhibited an almost 70 % decrease in the amount of 5,5 -dimethyl-l.pyrroline-N-oxide-OH adducts compared to those from ethyl oleate-treated animals (Green et al. 2001). The decreased lipid peroxide production, as well as increased production of prostaglandin Ej and nitric oxide by the foetal brain following ethyl docosahexaenoate administration could be mimicked by a synthetic qui-none possessing both hydroxyl radical producing and lipid peroxide propagation inhibiting properties. [Pg.510]

Tetrachloro-l,4-benzoquinone, a carcinogenic metabolite of the wood-preservative pentachloro-phenol, when incubated with the spin-trapping agent 5,5-dimethyl-l-pyrroline N-oxide (DMPO) and H2O2 produced the DMPO/HO adduct (Zhu etal. 2002). The formation of DMPO/HO was markedly inhibited by the HO scavenging agents dimethyl sulphoxide (DMSO), ethanol, formate, and azide, with the concomitant formation of the characteristic DMPO spin trapping adducts with CHj, CH(CH3)0H, COO", and Nj, respectively. [Pg.641]

Reszka, K. J. and Chignell, C. F., Photochemistry of 2-mercaptopyridines. 3. EPR study of photoproduction of hydroxyl radicals by N-hydroxypyridine-2-thione using 5,5-dimethyl-l-pyrroline N-oxide in aqueous-solutions Photochem. Photobiol, 61, 269, 1995. [Pg.1348]

An unusual and high yielding formation of N-(2-cyclopropenyl)phthalimides 71 via this photosensitized decarboxylation method was reported (Scheme 26). The intermediacy of cyclopropenyl radicals was confirmed by a trapping reaction with 5,5-dimethyl-l-pyrroline-N-oxide and also by ESR spectroscopy. Most reasonably, the carboxyl radical of this cyclopropenyl radical intermediate undergoes rapid decarboxylation followed by initial trapping by the phthahmidyl radical within the solvent cage. [Pg.1708]


See other pages where 5,5-Dimethyl-l-pyrroline-N-oxide is mentioned: [Pg.261]    [Pg.1203]    [Pg.1203]    [Pg.91]    [Pg.260]    [Pg.251]    [Pg.522]    [Pg.316]    [Pg.86]    [Pg.151]    [Pg.668]    [Pg.469]    [Pg.1028]    [Pg.246]    [Pg.1713]   


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1-Pyrroline-1-oxides

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N 2,3-dimethyl

Pyrroline

Pyrroline N-oxides

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