Oxidation of Lipids Induced by Dioctadecyl Hyponitrite and Di-<i>t</i>-butyl Hyponitrite in Organic Solution and in Aqueous Dispersions. Effects of Reaction Medium and Size of Radicals on Efficiency of Chain Initiation

Kigoshi, Makoto; Sato, Keizo; Niki, Etsuo

doi:10.1246/bcsj.66.2954

Cited by 11 publications

(9 citation statements)

References 23 publications

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“…These results allowed us to propose a reaction mechanism for the hydrolysis of 1b that includes dimerization of HNO to HO-NϭN-OH (3a) with a concomitant azo-type homolytic fission of the latter acid to N 2 and ⅐ OH (Scheme 4). A similar mechanism was established for the decomposition of dialkyl esters of 3a to RO ⅐ and N 2 (62). Within this mechanism, the effects of increasing concentrations of H ϩ on the formation of ⅐ OH can be explained with a shift in the equilibrium between 3a and 3b in favor of 3a (Scheme 1).…”

Section: Discussionmentioning

confidence: 53%

Formation of Nitroxyl and Hydroxyl Radical in Solutions of Sodium Trioxodinitrate

Ivanova

Salama

Clancy

et al. 2003

Journal of Biological Chemistry

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Despite its negative redox potential, nitroxyl (HNO) can trigger reactions of oxidation. Mechanistically, these reactions were suggested to occur with the intermediate formation of either hydroxyl radical ( ⅐ OH) or peroxynitrite (ONOO ؊ ). In this work, we present further experimental evidence that HNO can generate ⅐ OH. Sodium trioxodinitrate (Na 2 N 2 O 3 ), a commonly used donor of HNO, oxidized phenol and Me 2 SO to benzene diols and ⅐ CH 3 , respectively. The oxidation of Me 2 SO was O 2 -independent, suggesting that this process reflected neither the intermediate formation of ONOO ؊ nor a redox cycling of transition metal ions that could initiate Fenton-like reactions. In solutions of phenol, Na 2 N 2 O 3 yielded benzene-1,2-diol and benzene-1,4-diol at a ratio of 2:1, which is consistent with the generation of free ⅐ OH. Ethanol and Me 2 SO, which are efficient scavengers of ⅐ OH, impeded the hydroxylation of phenol. A mechanism for the hydrolysis of Na 2 N 2 O 3 is proposed that includes dimerization of HNO to cis-hyponitrous acid (HO-N‫؍‬N-OH) with a concomitant azo-type homolytic fission of the latter to N 2 and ⅐ OH. The HNO-dependent production of ⅐ OH was with 1 order of magnitude higher at pH 6.0 than at pH 7.4. Hence, we hypothesized that HNO can exert selective toxicity to cells subjected to acidosis. In support of this thesis, Na 2 N 2 O 3 was markedly more toxic to human fibroblasts and SK-N-SH neuroblastoma cells at pH 6.2 than at pH 7.4. Scavengers of ⅐ OH impeded the cytotoxicity of Na 2 N 2 O 3 . These results suggest that the formation of HNO may be viewed as a toxicological event in tissues subjected to acidosis.The biochemistry of nitroxyl (HNO) has attracted considerable interest in recent years. In cells, the biosynthesis of HNO is believed to proceed via reduction of NO ⅐ by superoxide dismutase (1) and cytochrome c (2), and reduction of S-nitrosoglutathione by low molecular weight and protein thiols (3-5). It has been suggested that HNO can affect the etiology of various pathophysiological conditions such as inflammation and neurodegenerative diseases, especially when H 2 O 2 and transition metal ions are present (6, 7). Similar to NO ⅐ and NO ϩ , HNO is a potent inducer of the antioxidant protein heme oxygenase 1 (8), exhibits vasorelaxant properties (9), and modulates the activity of thiol-containing proteins, such as aldehyde dehydrogenase (10, 11) and the N-methyl-D-aspartate receptor (12, 13). In in vivo experiments, Paolocci et al. (14) observed that HNO exerts positive inotropic and lusitropic action, which unlike NO ⅐ and nitrates is independent and additive to ␤-adrenergic stimulation and increases the release of plasma calcitonin gene-related peptide; these results suggest that donors of HNO are potential prodrugs for the treatment of heart failure (14). At high doses, HNO has been shown to induce DNA singlestrand breakage (15, 16) and a concentration-dependent cytotoxicity in murine thymocytes (16). This cytotoxicity was associated with activation of the nuclear nick sen...

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Section: Discussionmentioning

confidence: 53%

Formation of Nitroxyl and Hydroxyl Radical in Solutions of Sodium Trioxodinitrate

Ivanova

Salama

Clancy

et al. 2003

Journal of Biological Chemistry

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“…Hyponitrites, such as di-tert-butyl hyponitrite (DTBN), were often used to initiate lipid autoxidation (Barclay et al, 1986;Kigoshi et al, 1993) before the widespread adoption of MeOAMVN (Noguchi et al, 1998). The commercial availability of MeOAMVN, its well-characterized kinetics of radical generation in multiple systems, and ease of handling (it is crystalline at room temperature) has led to its adoption as the initiator of choice for lipid peroxidation studies.…”

Section: Use Of a Lipophilic Hyponitrite Initiator Completes A Predicmentioning

confidence: 99%

Beyond DPPH: Use of Fluorescence-Enabled Inhibited Autoxidation to Predict Oxidative Cell Death Rescue

Shah

Farmer

Zilka

et al. 2019

Cell Chemical Biology

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“…Etiologies of these disease states are thought to involve peroxidative alteration of bio-membrane lipids and other oxidizable cellular and extracellular components. Such peroxidation processes are identical to free radical sequences or chains of reactions involved in air oxidation of organic compounds, leading to the formation of peroxyl radicals [4][5][6][7][8][9][10][11][12]. Examination of the kinetics of the anti-oxidant reactivities of these lipophilic metalloelement chelates was urgently needed to investigate plausible mechanism(s) in accounting for their pharmacological activity.…”

Section: Introductionmentioning

confidence: 99%

“…for these chelates with the t-butylperoxyl radical were determined and support a mechanism for peroxyl radical chemical reduction by these chelates. To fully examine the anti-oxidant properties of these chelates in systems relevant to cellular compartments it was necessary to investigate their ability to inhibit peroxidative chain reactions involved in modeled lipid systems [4][5][6][7][8][9][10][11][14][15][16][17][18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Anti-oxidant and pro-oxidant reactivities of copper(II), manganese(II) and iron(III) 3,5-di-i-propylsalicylate chelates during peroxidation of alkylbenzenes

Tavadyan

Sedrakyan

Minasyan

et al. 2004

Transition Metal Chemistry

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Bioactive copper(II), iron(III), and manganese(II) 3,5-di-i-propylsalicylate (3,5-DIPS) chelates were investigated in order to determine their ability to inhibit the free radical initiated chain reactions leading to the peroxidation of isopropylbenzene (i-PrPh) and ethylbenzene (EtPh). Quantitative kinetic studies of these chelates established the following order of anti-oxidant reactivities: manganese(II)-(3,5-DIPS) 2 > iron(III)(3,5-DIPS) 3 > copper(II) 2 (3,5-DIPS) 4 >> 3,5-DIPS acid. The mechanism of anti-oxidant reactivity of these three chelates is established as being due, in part, to their chain-breaking capacity resulting from the chemical reduction of the generated peroxyl radical to yield alkybenzenelhydroperoxides via reaction of the 3,5-DIPS ligand with the peroxyl radical. In the case of manganese(II)3,5-di-i-propylsalicylate, the central metalloelement also interacts with the peroxyl radical. The manganese(II)-(3,5-DIPS) 2 and copper(II) 2 (3,5-DIPS) 4 chelates were also found to exhibit alkylhydroperoxide prooxidative reactivity leading to the formation of the alkylbenzeneperoxyl radical. In addition, the manganese(II) atom underwent oxidation to manganese(III) with the formation of the alkylbenzenehydroperoxide or superoxide with air oxygen oxidation. Amyl acetate and dipropylamine (n-Pr 2 NH) were added to the reaction mixture to model the biochemical presence of ester or amine cellular components. Addition of amyl acetate to the reaction mixture increased the anti-oxidant reactivity of manganese(II)-(3,5-DIPS) 2 while decreasing its pro-oxidant reactivity. The weaker anti-oxidant reactivites of iron(III)(3,5-DIPS) 3 and copper(II) 2 (3,5-DIPS) 4 were less affected by the addition of amyl acetate and the pro-oxidant reactivity of copper(II) 2 (3,5-DIPS) 4 was not changed by the addition of amyl acetate, while the pro-oxidant property of iron(III)(3,5-DIPS) 3 was eliminated. In contrast to 2,6-di-t-butyl-4-methylphenol, butylated hydroxy toluene (BHT), anti-oxidant reactivities of copper(II), iron(III), and manganese(II) 3,5-DIPS chelates were dramatically enhanced by the addition of n-Pr 2 NH to the reaction mixture. It is concluded that all three metalloelement chelates react with and remove alkylbenzeneperoxyl radicals and the hydroperoxyl radical. The manganese(II)-(3,5-DIPS) 2 and copper(II) 2 (3,5-DIPS) 4 chelates may also be useful in removing hydroperoxides in vivo. These reactivities, in addition to their established superoxide dismutase (SOD)-mimetic and catalase-mimetic reactivities, are suggested to possibly permit anti-oxidant and pro-oxidant reactivities in aqueous and organic cellular compartments.

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Oxidation of Lipids Induced by Dioctadecyl Hyponitrite and Di-t-butyl Hyponitrite in Organic Solution and in Aqueous Dispersions. Effects of Reaction Medium and Size of Radicals on Efficiency of Chain Initiation

Cited by 11 publications

References 23 publications

Formation of Nitroxyl and Hydroxyl Radical in Solutions of Sodium Trioxodinitrate

Formation of Nitroxyl and Hydroxyl Radical in Solutions of Sodium Trioxodinitrate

Beyond DPPH: Use of Fluorescence-Enabled Inhibited Autoxidation to Predict Oxidative Cell Death Rescue

Anti-oxidant and pro-oxidant reactivities of copper(II), manganese(II) and iron(III) 3,5-di-i-propylsalicylate chelates during peroxidation of alkylbenzenes

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