Reactions of Nitric Oxide

Histories . The Na salt was first isolated by the reaction of nitric oxide on acet (Ref 2) later the same worker found that the action of nitric oxide and Na hydroxide on any compd contg the acetyl group would give Na MEDNA [compds treated were mesityl oxide, methylisopropyl ketone, acetophenone, and ethyl dimethyl-... 

Padmaja, S. and Huie, RE. (1993). The reaction of nitric oxide with organic peroxyl radicals. Biochem. Biophys. Res. Commun. 195, 539-544. 

Ford, P.C. and Lorkovic, I.M. (2002) Mechanistic aspects of the reactions of nitric oxide with transition-metal complexes, Chem. Rev., 102, 993, and references therein. 

Gabr, I., Patel, R.P., Symons, M.C.R., and Wilson, M.T. 1995. Novel reactions of nitric oxide in biological systems. J. Chem. Soc., Chem. Commun. 915-916. 

Gas phase third-order reactions are rarely encountered in engineering practice. Perhaps the best-known examples of third-order reactions are atomic recombination reactions in the presence of a third body in the gas phase and the reactions of nitric oxide with chlorine and oxygen (2NO T Cl2 -> 2NOC1 2NO + 02 -> 2N02). 

A blue, impure and probably polymeric solid, produced from reaction of nitric oxide and nickel carbonyl, decomposed with incandescence at 90° C. The structure is very doubtful but a dinitrosyl was tentatively postulated. A trinitrosyl, [115380-62-6], has been listed recently. 

Table 5 1,2,3-Oxazolidinone 3-oxides 117 by reaction of nitric oxide with alkynyllithium reagents (Equation 21) <2004CC16>...

Peroxynitrite (ONOO-) is a cytotoxic reactive species that is formed by the reaction of nitric oxide and superoxide. Methods for measuring the scavenging capacity of peroxynitrite usually depend on either the inhibition of tyrosine nitration or the inhibition of dihydrorhodamine 123 (DHR) oxidation to rhodamine 123 (MacDonalds-Wicks and... 

Brovkovych et al. [38] applied the electrochemical porphyrinic sensor technique for the direct measurement of NO concentrations in the single endothelial cell. It was found that NO concentration was the highest at the cell membrane (about 1 pmoll-1) and decreased exponentially with distance from the cell, becoming undetectable at the distance of 50 pm. Now we will consider the principal reactions of nitric oxide relevant to real biological systems. 

Reaction of nitric oxide with superoxide is undoubtedly the most important reaction of nitric oxide, resulting in the formation of peroxynitrite, one of the main reactive species in free radical-mediated damaging processes. This reaction is a diffusion-controlled one, with the rate constant (which has been measured by many workers, see, for example, Ref. [41]), of about 2 x 109 1 mol-1 s-1. Goldstein and Czapski [41] also measured the rate constant for Reaction (11) ... 

Nitric oxide is a physiological substrate for mammalian peroxidases [myeloperoxide (MPO), eosinophil peroxide, and lactoperoxide), which catalytically consume NO in the presence of hydrogen peroxide [60], On the other hand, NO does not affect the activity of xanthine oxidase while peroxynitrite inhibits it [61]. Nitric oxide suppresses the inactivation of CuZnSOD and NO synthase supposedly via the reaction with hydroxyl radicals [62,63]. On the other hand, SOD is able to modulate the nitrosation reactions of nitric oxide [64]. 

Scheme 3.11 Reaction of nitric oxide with carbanion.

Liu, X., Miller, M. J., Joshi, M. S., Thomas, D. D., Lancaster, J. R. Jr, Accelerated reaction of nitric oxide with 02 within the hydrophobic interior ofbiological membranes,... 

Reaction of nitric oxide with ferrohemoproteins produces paramagnetic NO-ligated heme proteins (S = 1/2, rhombic g tensors with principal values in the range 1.96-2.08). In many compounds studied so far by EPR the hf interaction of the NO nitrogen and of a second axial nitrogen is clearly resolved in the intermediate g-value region near... 

The technol( for the routine measurement of the nitrogen oxides (nitrogen dioxide and nitric oxide) is fairly well advanced. The epa is on the verge of officially proposing that chemiluminescence produced by the reaction of nitric oxide with ozone be the reference method for nitrogen dioxide.This method is even more suitable for nitric oxide. Because no national air quality standard has been promulgated for nitric oxide, no reference method will be specified. However, its measurement in the atmosphere is crucial for establishing the relation of its emission to the formation of atmospheric ozone and other photochemical oxidants. 

A very remote secondary H/D isotope effect has been measured for the 2 + 2-cycloaddition of TCNE to 2,7-dimethylocta-2,fran -4,6-triene. The reaction of nitric oxide with iV-benzylidene-4-methoxyaniline to produce 4-methoxybenzenediazonium nitrate and benzaldehyde is thought to proceed via a 2 + 2-cycloaddition between nitric oxide and the imine double bond. A novel mechanism for the stepwise dimerization of the parent silaethylene to 1,3-disilacyclobutane involves a low-barrier [1,2]-sigmatropic shift. Density functional, correlated ab initio calculations, and frontier MO analysis support a concerted 2 + 2-pathway for the addition of SO3 to alkenes. " The enone cycloaddition reactions of dienones and quinones have been reviewed. The 2 + 2-photocycloadditions of homochiral 2(5H)-furanones to vinylene carbonate are highly diastereoisomeric. ... 

Nitrite reductase (NAD(P)H) [EC 1.6.6.4] catalyzes the reaction of three NAD(P)H with nitrite to yield three NAD(P)+, NH4OH, and water. Cofactors for this enzyme include FAD, non-heme iron, and siroheme. (2) Nitrite reductase (cytochrome) [EC 1.7.2.1] is a copper-depen-dent system that catalyzes the reaction of nitric oxide with two ferricytochrome c and water to produce nitrite and two ferrocytochrome c. (3) Ferredoxin-nitrite reductase [EC 1.7.7.1], a heme- and iron-dependent enzyme, catalyzes the reaction of ammonia with three oxidized ferredoxin to produce nitrite and three reduced ferredoxin. (4) Nitrite reductase [EC 1.7.99.3] is a copper- and FAD-dependent enzyme that catalyzes the reaction of two nitric oxide with an acceptor substrate and two water to produce two nitrite and the reduced acceptor. 

Nitrosyl chloride can be prepared by the reaction of nitric oxide with chlorine ... 

Lewis, R. S., and W. M. Deen, Kinetics of the Reaction of Nitric Oxide with Oxygen in Aqueous Solutions, Chem. Res. Toxicol., 7, 568-574 (1994). 

When nitric oxide is present in much lower concentrations than oxygen, the formation of nitrogen dioxide shown in Reaction 4 is initiated by the reversible reaction of nitric oxide with molecular oxygen to form nitrosyldioxyl radical. 

Possible equilibrium involved in the rapid activation of soluble guanylate cyclase and the slower inactivation by reaction of nitric oxide with oxygen. Nitric oxide dissolved in membranes may be more stable than in solution, because the nitrosyldioxyl radical cannot be stabilized by hydrogen bonding to water. 

In blood-containing vascular beds, the inactivation of nitric oxide by oxygen is of minor importance because of the rapid and irreversible reactions of nitric oxide with oxyhemoglobin in red blood cells. Any nitric oxide that diffuses into the vascular lumen will be quickly destroyed, making blood vessels effective sinks for nitric oxide. The half-life of nitric oxide is sufficiently long that nitric oxide diffusing into the vascular smooth muscle could also diffuse back out to the lumin to be inactivated by hemoglobin in red blood cells. 

The chemistry of the nitrogen oxides dates back to the days of the Reverend Joseph Priestley, who used the reaction of nitric oxide to measure the concentration of oxygen in air. As a consequence, many of the recommended lUPAC names for nitrogen species have common names. As a general rule, common names are used when they have been widely utilized in the biological literature and lUPAC names for less well-known chemical species. Table 3 should help facilitate translation among the different names. 

Although much of the biological literature focuses on nitrosating reactions of nitric oxide, chemically nitric oxide is a moderate one-electron oxidant, making formation of nitroxyl anion feasible under physiological conditions. The reduction potential to reduce nitric oxide to nitroxyl anion is +0.39 V, whereas it requires +1.2 V to oxidize nitric oxide to nitrosonium ion. Nitrosating reactions of nitric oxide are often mediated by conversion of nitric oxide to another nitrogen oxide species or by direct reaction with transition metals (Wade and Castro, 1990). 

The reaction of nitric oxide with superoxide dismutase is a simple reversible equilibrium, whereas the catalytic cycle with superoxide involves a two step sequence. Consequently, superoxide dismutase may be reduced by superoxide and then react with nitric oxide to form nitroxyl anion. Nitroxyl anion may react with molecular oxygen to form peroxynitrite anion (ONOO"). 

The spontaneous reaction of nitric oxide with thiols is slow at physiological pH and the final product under anaerobic conditions is not a nitrosothiol (Pryor et al., 1982). The reaction is slow because it involves the conjugate base of the thiol (R—S"). At pH 7.0, the oxidation of cysteine by nitric oxide required 6 hr to reach completion and yields RSSR and N 2O as the products. The synthetic preparation of nitrosothiols usually involves the addition of nitrosonium ion from acidified nitrite to the thiol, or oxidation of the thiol with nitrogen dioxide under anaerobic conditions in organic solvents. Nitric oxide will form nitrosothiols by reaction with ferric heme groups, such as found in metmyoglobin or methemoglobin (Wade and Castro, 1990). It is also possible that nitrosyldioxyl radical also reacts with thiols to form a nitrosothiol. 

Possibly, cellular thiols may be oxidized by the inactive adduct of nitric oxide and oxygen to regenerate a nitrosothiol or related species with EDRF activity. Some of the inconsistent results observed in bioassay systems may be due to the secondary and nonenzymatic formation of a nitrosothiols or other species capable of regenerating nitric oxide, which are leached into perfusion cascades. Consequently, bioassay systems should not be the gold standard to distinguish whether nitric oxide is the EDRF, because secondary reactions of nitric oxide decomposition products may regenerate nitric oxide. 

Four routes to form peroxynitrite from nitric oxide. The reaction of nitric oxide with superoxide is only one mechanism leading to the formation of peroxynitrite. Supetoxide could also reduce the nitrosyidioxyl radical. If nitric oxide is directly reduced to nitroxyl anion, it will react with molecular oxygen to form peroxynitrite. At acidic pH, nitrite may form nitrous acid and nitrosonium ion, which reacts with hydrogen peroxide to form peroxynitrite. 

Sharma, V. S., Traylor, T. G., Gardiner, R., and Mizukami, H. (1987). Reaction of nitric oxide with heme proteins and model compounds of hemoglobin. Biochemistry 26, 3837-3843. 

The Intracellular Reactions of Nitric Oxide in the Immune System and Its Enzymatic Synthesis... 

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