Ultrathin TiO2(B) Nanosheets as the Inductive Agent for Transfrering H2O2 into Superoxide Radicals

2017 ◽  
Vol 9 (18) ◽  
pp. 15533-15540 ◽  
Author(s):  
Zhen Wei ◽  
Di Liu ◽  
Weiqin Wei ◽  
Xianjie Chen ◽  
Qiang Han ◽  
...  
Keyword(s):  
Superoxide Radicals ◽  
Inductive Agent

The proteins RodA and PBP2b are implicated in the control of the ovoid-shape of Streptococcus thermophilus CNRZ368 and play a role in cells defence against superoxide radicals

2002 ◽  
Vol 22 (1-2) ◽  
pp. 75-85 ◽  
Author(s):  
Annabelle Thibessard ◽  
Annabelle Fernadez ◽  
Brigitte Gintz ◽  
Bernard Decaris ◽  
Nathalie Leblond-Bourget
Keyword(s):  
Streptococcus Thermophilus ◽  
Superoxide Radicals ◽  
In Cells

Sustained production of superoxide radicals by manganese oxides under ambient dark conditions

2021 ◽  
Vol 196 ◽  
pp. 117034
Author(s):  
Suhuan Zhang ◽  
Jitao Lv ◽  
Ruixia Han ◽  
Zhe Wang ◽  
Peter Christie ◽  
...  
Keyword(s):  
Manganese Oxides ◽  
Superoxide Radicals ◽  
Dark Conditions

scholarly journals Metal-free porous phosphorus-doped g-C3N4 photocatalyst achieving efficient synthesis of benzoin

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12682-12686
Author(s):  
Yuanjin Li ◽  
Shuhui Wang ◽  
Jin Wu ◽  
Qiuyan Wang ◽  
Changqiu Ma ◽  
...  
Keyword(s):  
Benzyl Alcohol ◽  
Conversion Rate ◽  
Oxygen Activation ◽  
Superoxide Radicals ◽  
Efficient Synthesis ◽  
Metal Free ◽  
Phosphorus Doped

Porous phosphorus-doped g-C3N4 (PCNT) has intensive oxygen activation ability to generate superoxide radicals, and can efficiently catalyze synthesis of benzoin from benzyl alcohol, with conversion rate and selectivity near to 100%.

Involvement of superoxide radicals on adrenochrome formation stimulated by arachidonic acid in bovine heart sarcolemmal vesicles

1985 ◽  
Vol 838 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Carlo Guarnieri ◽  
Carlo Ventura ◽  
Athanassios Georgountzos ◽  
Claudio Muscari ◽  
Rolando Budini
Keyword(s):  
Arachidonic Acid ◽  
Superoxide Radicals ◽  
Bovine Heart ◽  
Sarcolemmal Vesicles

scholarly journals Hypochlorite and superoxide radicals can act synergistically to induce fragmentation of hyaluronan and chondroitin sulphates

2004 ◽  
Vol 381 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Martin D. REES ◽  
Clare L. HAWKINS ◽  
Michael J. DAVIES
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Transition Metal Ions ◽  
Chloride Ions ◽  
Superoxide Radicals ◽  
Thermal Source ◽  
Site Specific ◽  
Trace Metal Ions ◽  
Electron Reduction ◽  
Polymer Fragmentation

Activated phagocytes release the haem enzyme MPO (myeloperoxidase) and also generate superoxide radicals (O2•−), and hence H2O2, via an oxidative burst. Reaction of MPO with H2O2 in the presence of chloride ions generates HOCl (the physiological mixture of hypochlorous acid and its anion present at pH 7.4). Exposure of glycosaminoglycans to a MPO–H2O2–Cl− system or reagent HOCl generates long-lived chloramides [R-NCl-C(O)-R′] derived from the glycosamine N-acetyl functions. Decomposition of these species by transition metal ions gives polymer-derived amidyl (nitrogen-centred) radicals [R-N•-C(O)-R′], polymer-derived carbon-centred radicals and site-specific strand scission. In the present study, we have shown that exposure of glycosaminoglycan chloramides to O2•− also promotes chloramide decomposition and glycosaminoglycan fragmentation. These processes are inhibited by superoxide dismutase, metal ion chelators and the metal ion-binding protein BSA, consistent with chloramide decomposition and polymer fragmentation occurring via O2•−-dependent one-electron reduction, possibly catalysed by trace metal ions. Polymer fragmentation induced by O2•− [generated by the superoxide thermal source 1, di-(4-carboxybenzyl)hyponitrite] was demonstrated to be entirely chloramide dependent as no fragmentation occurred with the native polymers or when the chloramides were quenched by prior treatment with methionine. EPR spin-trapping experiments using 5,5-dimethyl1-pyrroline-N-oxide and 2-methyl-2-nitrosopropane have provided evidence for both O2•− and polymer-derived carbon-centred radicals as intermediates. The results obtained are consistent with a mechanism involving one-electron reduction of the chloramides to yield polymer-derived amidyl radicals, which subsequently undergo intramolecular hydrogen atom abstraction reactions to give carbon-centred radicals. The latter undergo fragmentation reactions in a site-specific manner. This synergistic damage to glycosaminoglycans induced by HOCl and O2•− may be of significance at sites of inflammation where both oxidants are generated concurrently.

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