Radicals nitrogen monoxide

Nitrogen monoxide ( nitnc oxide ) is another stable free radical Although known for hundreds of years NO has only recently been discovered to be an extremely important biochemical messenger and moderator of so many biological processes that it might be better to ask Which ones is it not involved m ... 

The 3-morpholinosydnonimine system generates superoxide radicals and nitrogen monoxide, forming peroxynitrite, which releases ethane from KMB (a-keto-y-methiolbutyric acid). This method was used by Lavelli and others (1999) to investigate the radical-scavenging activity of fresh and air-dried tomatoes. 

Nitrogen monoxide (NO) is a short-lived radical that functions as a locally acting mediator (see p. 370). 

Nitrogen monoxide has held the attention of scientific community from the time this small inorganic radical was discovered to play a... 

We recently studied the ESR spectra of the mixed heme complex 24, where the nitrogen monoxide radical is inserted into the sixth coordinate site of heme-iron as a probe28 in order to examine the electronic structure of the heme complex29. Figure 6(a) shows the ESR spectrum of the NO radical which coordinates to the imidazole-ferriheme complex. The hyperfine stmcture (hfs) due to the N of the... 

Nitrogen oxides (NOx= N02 and nitrogen monoxide NO) sources are mainly emitting NO into the troposphere. Thai, NO may be converted to N02 by reaction with hydrogen peroxy radical (H02) or with higher peroxy radicals (R02), produced from hydrocarbon oxidation. 

The reaction leads to a para-substituted product, entirely in accordance with the calculated distribution of spin density in the anion radical of ortho-dinitrobenzene (Todres 1990). It was established, by means of labeled-atom experiments and analysis of the gas produced, that azo-coupling is accompanied by conversion of one of the nitro groups into the hydroxy group and liberation of nitric oxide. In other words, the initial radical product of azo-coupling is stabilizing by elimination of the small nitrogen monoxide radical to give the stable nonradical final product (Todres, Hovsepyan et al. 1988), Scheme 1-5. 

The azo coupling just mentioned is accompanied by the conversion of one of the nitro groups into the hydroxyl group. Hence, the radical product is stabilized by elimination of the nitrogen monoxide radical. All the radicals are prone to stabilize, expelling a small radical particle. This is the case too. And nitrogen mono-oxide was established as a gas-phase product of the reaction (Todres, Hovsepyan, Ionina 1988). 

As Barr et al. (2003) pointed out, the importance of such emissions is determined mainly by their impact on the three processes taking place in the atmosphere. The first consists in that such NMHCs as isoprene form in the course of carboxylization in plants and contribute much thereby to the formation of biospheric carbon cycle. The second process is connected with NMHCs exhibiting high chemical activity with respect to such main oxidants as hydroxyl radicals (OH), ozone (03), and nitrate radicals (N03). Reactions with the participation of such components result in the formation of radicals of alkylperoxides (R02), which favor efficient transformation of nitrogen monoxide (NO) into nitrogen dioxide (N02), which favors an increase of ozone concentration in the ABL. Finally, NMHC oxidation leads to the formation of such carbonyl compounds as formaldehyde (HCHO), which stimulates the processes of 03 formation. Finally, the oxidation of monoterpenes and sesquiterpenes results in the intensive formation of fine carbon aerosol with a particle diameter of <0.4 pm... 

Nitrogen monoxide also undergoes several cGMP-independent reactions, mainly related to toxicological events. The two most important direct reactions of NO responsible for its toxicity in cells are interaction with metal centers of proteins (other than guanylyl cyclase) and reaction with radical intermediates of biologi-... 

Eq. 4.56 shows the formation of 7-lactam (156) from imino bromide (155), through the formation of an acyl radical with monoxide, 5-exo-trig ring closure at the nitrogen atom by the nucleophilic acyl radical, and finally abstraction of a hydrogen atom from Bu3SnH [147]. 

S. M. Aldoshin (Director). This session included four presentations. Professor N.P. Konovalova reported on antioxidants and donors of nitrogen monoxide (antitumor effects of nitroxides and NO-donors) the report of N.A. Sanina and S.M. Aldoshin was concerned with a new class of NO-donors (synthesis, structure, properties, and practical use of sulfur-nitrosyl complexes of iron). Free-radical mechanisms of induction and development of secondary necrosis after gun wounds were the subject of the lecture by G.N. Bogdanov L.D. Smirnov reported on pharmacological properties and promising clinical application of antioxidants of the heteroaromatic array. 

The mechanistic situation is complicated by the competing photolysis of nitrite, which results in the formation of nitrogen monoxide and oxide radical anions (Eq. 6-9). The latter are immediately protonated in water at pH <12 to yield hydroxide and hydroxyl radicals according to Eq. 6-8. 

Nitric oxide or nitrogen monoxide (NO) is a colorless gas. It has a boiling point (bp) of —151.8°C (at 1 atm) and molecular weight of 30.0 g mol h Because it has an odd number of electrons, NO is a very reactive molecule (a so-called radical) (Greenwood and Earnshaw, 1984). It is rapidly oxidized within a few minutes to nitrogen dioxide (NO2), thus NO and NO2 are usually referred to as... 

W. H. Koppenol, The Basic Chemistry of Nitrogen Monoxide and Peroxynitrite. Free Radic Biol. 3/et/2S (1998) 385-91. 

Nitric oxide (also known as nitrogen monoxide, NO) is a diatomic mono-radical with a N—O bond length of 1.154 A and a 2H ground state (GS). Books and reviews on its general properties and... 

Inhibitory Oxidation and inhibition of zinc-finger transcription factors by hydrogen peroxide, peroxyl radicals, singlet oxygen, nitrogen monoxide, peroxynitrite [60]... 

These four reactions provide important loss processes for odd oxygen. Near the tropopause, the OH and HO2 radicals also react with carbon and nitrogen monoxide ... 

Nitrogen monoxide is a radical (structure 14.48), but Na2[Fe(CN)5(NO)] is diamagnetic the N—O distance of 113 pm is shorter, and the stretching wavenumber of 1947cm higher, than in free NO. Thus, the complex is formulated as containing an [NO] ligand. The addition of... 

A conversion of molecules A and B to the additive product BA is result of the two reactions. On the termination of the process the re-formed radical R" enters into a further cycle. After a sufficient number of cycles, the amount of the product formed may be much larger than the amount of different species of radicals present in the system. The rapid conversion of nitrogen monoxide to nitrogen dioxide, and accumulation of ozone in photooxidation smog are examples. 

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