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Reaction mechanisms of peroxyl and c-centered radicals with sulfhydryls 过氧基和c中心自由基与巯基的反应机理
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80074-5
Michael G. Simic, Edward P.L. Hunter
{"title":"Reaction mechanisms of peroxyl and c-centered radicals with sulfhydryls","authors":"Michael G. Simic,&nbsp;Edward P.L. Hunter","doi":"10.1016/S0748-5514(86)80074-5","DOIUrl":"10.1016/S0748-5514(86)80074-5","url":null,"abstract":"<div><p>Rate constants for reactions of a peroxyl (CCl<sub>3</sub>OO·) and C-centered radicals, that is, phenyl (·C<sub>6</sub>H<sub>4</sub>CH<sub>2</sub>COO<sup>−</sup>) and vinyl (uracil-5-yl), with an aromatic thiol (p-CH<sub>3</sub>OC<sub>6</sub>H<sub>4</sub>SH) were measured over a pH range (3–12) to include ArSH and ArS<sup>−</sup> forms. The pH dependence of these rate constants indicates that peroxyl radicals react by a redox mechanism while the C-centered radicals react by an H-atom transfer process. The different mechanisms encountered in the repair of various radicals suggest design features to be incorporated into antiagents, such as radioprotectors and anticarcinogens.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 3","pages":"Pages 227-230"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80074-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14693704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 22
The apparent inhibition of superoxide dismutase activity by quinones 醌类对超氧化物歧化酶活性的明显抑制作用
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/0748-5514(86)90127-3
John Butler, Brigid M. Hoey
{"title":"The apparent inhibition of superoxide dismutase activity by quinones","authors":"John Butler,&nbsp;Brigid M. Hoey","doi":"10.1016/0748-5514(86)90127-3","DOIUrl":"10.1016/0748-5514(86)90127-3","url":null,"abstract":"<div><p>It has been demonstrated that several quinones can modify the activity of bovine copper superoxide dismutase by undergoing equilibrium reactions with superoxide radicals. The extent of this apparent inhibition correlates with the one electron reduction potentials of the quinones and the equilibrium constants of the semiquinone radical/superoxide radical reactions. Various rate constants have been estimated including those for the reactions of semiquinone radicals with cytochrome c and with superoxide dismtuase. Semiquinone radicals cannot be dismutated by superoxide dismutase.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 1","pages":"Pages 77-81"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0748-5514(86)90127-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14889399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 35
Mechanism of antibacterial action: Electron transfer and oxy radicals 抗菌作用机制:电子转移和氧自由基
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80040-X
James R. Ames , Michael D. Ryan , Peter Kovacic
{"title":"Mechanism of antibacterial action: Electron transfer and oxy radicals","authors":"James R. Ames ,&nbsp;Michael D. Ryan ,&nbsp;Peter Kovacic","doi":"10.1016/S0748-5514(86)80040-X","DOIUrl":"10.1016/S0748-5514(86)80040-X","url":null,"abstract":"<div><p>Most of the main categories of bactericidal agents, namely, aliphatic and heterocyclic nitro compounds, metal derivatives and chelators, quinones, azo dyes, and iminium-type ions, are proposed to exert their action by a unified mechanism. The toxic effect is believed to result generally from the catalytic production of reactive oxygen radicals that usually arise via electron transfer. Cyclic voltammetry was performed on a number of these agents. Reductions were for the most part reversible, with potentials in the favorable range of −0.20 to −0.58 V.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 5","pages":"Pages 377-391"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80040-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14719408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 47
Pulse radiolytic study of α-tocopherol radical mechanisms in ethanolic solution α-生育酚自由基在乙醇溶液中的脉冲辐射分解机理研究
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80043-5
Daniel Jore , L.K. Patterson , C. Ferradini
{"title":"Pulse radiolytic study of α-tocopherol radical mechanisms in ethanolic solution","authors":"Daniel Jore ,&nbsp;L.K. Patterson ,&nbsp;C. Ferradini","doi":"10.1016/S0748-5514(86)80043-5","DOIUrl":"10.1016/S0748-5514(86)80043-5","url":null,"abstract":"<div><p>Pulse radiolytic studies of α-tocopherol (αTH) oxidation-reduction processes were carried out with low doses (5 Gy) of high-energy electrons in O<sub>2−</sub>, N<sub>2−</sub>, and air-saturated ethanolic solutions. Depending on the concentration of oxygen in solution, two different radicals, A· and B·, were observed. The first, A·, was obtained under N<sub>2</sub> and results from aTH reaction with solvated electron (<em>k</em><sub>aTH+c<sub>solv</sub><sup>−</sup></sub> = 3.4 × 10<sup>8</sup> mol<sup>−1</sup> liter s<sup>−1</sup>) and with H<sub>3</sub>C-ĊH-OH, (R·) (<em>k</em><sub>aTH + R·</sub> = 5 × 10<sup>5</sup> mol<sup>−1</sup> liter s<sup>−1</sup>). B·, observed under O<sub>2</sub>, is produced by αTH reaction with RO<sub>2</sub> peroxyl radicals (<em>k</em><sub>a</sub>TH + RO<sub>2</sub><sup>.</sup> = 9.5 × 10<sup>4</sup> mol<sup>−1</sup> liter s<sup>−1</sup>).</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 5","pages":"Pages 405-410"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80043-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14719411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 11
Iron-induced peroxidative injury to isolated rat hepatic mitochondria 铁诱导离体大鼠肝线粒体的过氧化损伤
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80034-4
Bruce R. Bacon , Rosemary O'Neill , Chanho H. Park
{"title":"Iron-induced peroxidative injury to isolated rat hepatic mitochondria","authors":"Bruce R. Bacon ,&nbsp;Rosemary O'Neill ,&nbsp;Chanho H. Park","doi":"10.1016/S0748-5514(86)80034-4","DOIUrl":"10.1016/S0748-5514(86)80034-4","url":null,"abstract":"<div><p>Peroxidative injury to the mitochondrial inner membrane with resultant defects in oxidative metabolism may be partially responsible for hepatocellular injury in iron overload. We examined the effects of iron-induced lipid peroxidation in vitro on hepatic mitochondrial morphology and function and determined if various inhibitors of free-radical-mediated injury could be protective. Normal rat liver mitochondria were prepared by differential centrifugation and were incubated with 1, 2, and 3 <em>μ</em>M Fe<sup>2+</sup>, NADPH, and with and without oxygen radical scavengers, iron chelators, and antioxidants. There was a direct linear relationship between the concentration of added iron and the degree of lipid peroxidation as measured by malondialdehyde (MDA) production (<em>r</em> =.85). With 3 <em>μ</em>M Fe<sup>2+</sup> there was a decrease in the respiratory control ratio (RCR) for all four substrates tested; this decrease in RCR was due to a decrease in the state 3 respiratory rate for all substrates, with no changes in the state 4 respiratory rate for glutamate, β-hydroxybutyrate, or succinate. Oxygen radical scavengers failed to prevent iron-induced lipid peroxidation or to protect against associated mitochondrial dysfunction. Iron chelators and antioxidants prevented MDA formation and mitochondrial function was maintained. Iron-induced lipid peroxidation in vitro produces an irreversible inhibitory defect in mitochondrial electron transport that may be specific at complex IV (cytochrome oxidase).</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 5","pages":"Pages 339-347"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80034-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14719146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 70
Free radicals as possible mediators of the actions of interferon 自由基可能是干扰素作用的介质
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80068-X
Undurti N. Das , Greg Ells , Michael E. Bēgin , David F. Horrobin
{"title":"Free radicals as possible mediators of the actions of interferon","authors":"Undurti N. Das ,&nbsp;Greg Ells ,&nbsp;Michael E. Bēgin ,&nbsp;David F. Horrobin","doi":"10.1016/S0748-5514(86)80068-X","DOIUrl":"10.1016/S0748-5514(86)80068-X","url":null,"abstract":"<div><p>Interferons (IFNs), in addition to their antiviral action, have been shown to inhibit cell proliferation, induce differentiation of some tumor cells, activate NK cells and macrophages, and modulate phagocytosis. The exact mechanism(s) by which IFN can bring about these pleiotropic actions is not known. Recent studies, including our own (presented here), showed that IFN can augment free radical generation in the cells. Free radicals can stimulate lymphocytes mitogenically and activate macrophages and NK cells. It is also known that activated machophages and polymorphs produce oxidative metabolites, such as hydrogen peroxide, which is responsible for sterilizing action against microorganisms and cytotoxic activity against tumor cells. Free radicals are also known to inhibit cell division. Since IFN can augment free radical generation, it is suggested that free radicals mediate some of the actions of IFN.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 3","pages":"Pages 183-188"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80068-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13584487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 21
Oxygen free radicals play a role in cellular differentiation: An hypothesis 氧自由基在细胞分化中起作用:一个假设
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80067-8
R.S. Sohal , R.G. Allen , C. Nations
{"title":"Oxygen free radicals play a role in cellular differentiation: An hypothesis","authors":"R.S. Sohal ,&nbsp;R.G. Allen ,&nbsp;C. Nations","doi":"10.1016/S0748-5514(86)80067-8","DOIUrl":"10.1016/S0748-5514(86)80067-8","url":null,"abstract":"<div><p>Evidence from a variety of sources supports the view that oxygen free radicals play a role in cellular differentiation. It is postulated that cellular differentiation is accompanied by changes in the redox state of cells. Differentiated cells have a relatively more prooxidizing or less reducing intracellular environment than the undifferentiated or dedifferentiated cells. Changes in the redox balance during differentiation appear to be due to an increase in the rate of O<sub>2</sub><sup>−</sup> generation. Differentiated cells, in general, exhibit higher rates of cyanide-resistant respiration, cyanide-insensitive SOD activity, and peroxide concentration and lower levels of GSH as compared to undifferentiated cells. The effects of free radicals on cellular differentiation may be mediated by the consequent changes in ionic composition.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 3","pages":"Pages 175-181"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80067-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14675882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 71
Pulse radiolysis study of daunorubicin redox reactions: Redox cycles or glycosidic cleavage? 柔红霉素氧化还原反应的脉冲辐射分解研究:氧化还原循环还是糖苷裂解?
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80056-3
C. Houée-Levin, M. Gardès-Albert, C. Ferradini
{"title":"Pulse radiolysis study of daunorubicin redox reactions: Redox cycles or glycosidic cleavage?","authors":"C. Houée-Levin,&nbsp;M. Gardès-Albert,&nbsp;C. Ferradini","doi":"10.1016/S0748-5514(86)80056-3","DOIUrl":"10.1016/S0748-5514(86)80056-3","url":null,"abstract":"<div><p>Two aspects of daunorubicin reactivity were investigated by pulse radiolysis. (i) The reactions of O<sub>2</sub> and O<sub>2</sub><sup>−</sup> with the semiquinone and the hydroquinone transients of daunorubicin were determined and their rate constants measured. Although O<sub>2</sub><sup>−</sup> can reduce the drug and its semiquinone form, it is a more powerful oxident towards the two reduced transients. (ii) The hydroquinone daunorubicin glycosidic cleavage in aqueous solution was studied. Three intermediates were seen and characterized by their absorption spectra, their formation and decay kinetics.</p><p>The competition beween these two main processes was evaluated in the conditions of pulse radiolysis. Even under low O<sub>2</sub> partial pressures the redox cycles are much more rapid than the glycosidic cleavage and a relatively high O<sub>2</sub><sup>−</sup> steady state is settled. Biological implications are discussed.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 2","pages":"Pages 89-97"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80056-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14162196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
Ceruloplasmin, extracellular-superoxide dismutase, and scavenging of superoxide anion radicals 铜蓝蛋白，细胞外超氧化物歧化酶，和清除超氧阴离子自由基
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80007-1
Stefan L. Marklund
{"title":"Ceruloplasmin, extracellular-superoxide dismutase, and scavenging of superoxide anion radicals","authors":"Stefan L. Marklund","doi":"10.1016/S0748-5514(86)80007-1","DOIUrl":"10.1016/S0748-5514(86)80007-1","url":null,"abstract":"<div><p>Ceruloplasmin and extracellular-superoxide dismutase are similar in physical properties. Both are found in extracellular fluids and both are scavengers of the superoxide radical. The relationship between the two proteins was further explored in the present investigation. Ceruloplasmin preparations were found to be commonly contaminated with extracellular-superoxide dismutase. In one preparation, 80% of the superoxide dismutase activity was due to extracellular-superoxide dismutase. Ceruloplasmin, freed from contaminating superoxide dismutase, was found to catalytically dismute the superoxide anion radical with a rate constant of about 1.0 × 10<sup>4</sup> M<sup>−</sup> s<sup>−1</sup> per copper atom. Under physiological conditions with a low rate of superoxide production, ceruloplasmin preferentially reacts stoichiometrically with the superoxide radical with a rate constant of about 2 × 10<sup>5</sup> M<sup>−1</sup> s<sup>−1</sup> per copper atom. Under such conditions, the reaction does not result in hydrogen peroxide formation. From the kinetic data obtained it was calculated that in normal human plasma, extracellular-superoxide dismutase will scavenge about twice as much superoxide as ceruloplasmin. Using immobilized antibodies toward extracellular superoxide dismutase and ceruloplasmin, no antigenic cross-reactivity between the two proteins could be detected.</p></div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 4","pages":"Pages 255-260"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80007-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14167879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 26
单线态O2(卷一，二，三，四)Aryeh A. Frimer CRC出版社，博卡拉顿。价格:四卷套装$395.00。
Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80064-2
Ph.D. Kelvin J.A. Davies
{"title":"","authors":"Ph.D. Kelvin J.A. Davies","doi":"10.1016/S0748-5514(86)80064-2","DOIUrl":"10.1016/S0748-5514(86)80064-2","url":null,"abstract":"","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 2","pages":"Page 149"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80064-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56236036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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