Comparison of superoxide with other reducing agents in the biological production of hydroxyl radicals

Winterbourn, C C

doi:10.1042/bj1820625

Cited by 263 publications

(95 citation statements)

References 11 publications

(11 reference statements)

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“…The addition of N 3-at 20 mM (an efficient 10 2 quencher) to the oxygenated solution produced no significant change in signal intensity with illumination. When 1.25 x 10 .6 M Fe(III)EDTA was added to a i mM ascorbate solution, a gradual increase in the A'-signal was observed, in agreement with Halliwell's observation that ascorbate can reduce Fe(III)EDTA [15] and the observations of Winterbourn [39].…”

Section: Ah-supporting

confidence: 88%

Hydrogen peroxide and hydroxyl radical formation by methylene blue in the presence of ascorbic acid

Buettner¹,

Bannister²

1984

Radiat Environ Biophys

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Summary.Using ESR we have demonstrated the formation of the ascorbate free radical from sodium ascorbate, methylene blue and light. In oxygen uptake experiments we have observed the production of hydrogen peroxide while spin trapping experiments have revealed the iron catalyzed production of the hydroxyl free radical in this system. The presence of this highly reactive radical suggests that it could be the radical that initiates free radical damage in this photodynamic system.

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Section: Ah-supporting

confidence: 88%

Hydrogen peroxide and hydroxyl radical formation by methylene blue in the presence of ascorbic acid

Buettner¹,

Bannister²

1984

Radiat Environ Biophys

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“…13,14) The amount of O 2 ·Ϫ and suppression ratio for O 2 ·Ϫ can be calculated by measuring the absorbance at 560 nm. Solution of VitB 2 and NBT were prepared under the condition of avoiding light.…”

Section: ·ϫmentioning

confidence: 99%

Synthesis, Characterization, and the Antioxidative Activity of 4-{[(3,4-Dimethyl pyrrole-2-carbonyl)hydrazono](phenyl)methyl}-3-methyl-1-phenylpyrazol-5-ol and Its Zinc(II), Copper(II), Nickel(II) Complexes

Wang

Zhou

2008

CHEMICAL & PHARMACEUTICAL BULLETIN

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Reactive oxygen species (ROS), such as superoxide anion (O 2 ·Ϫ ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radical ( · OH), are generated by all aerobic cells during normal oxygen metabolism.1) Cumulative information has been proved that the oxidation induced by ROS can result in cell membrane disintegration, membrane protein damage and DNA mutation, which can further initiate or propagate the development of many diseases, such as cancer, liver injury and cardiovascular disease.2,3) Catalase, superoxide dismutase, glutathione and uric acid are examples of antioxidants produced by organisms under normal conditions as parts of a defense system against ROS-mediated cellular injury. However, if this defense system is challenged or overwhelmed by excessive generation of ROS, redox imbalance or oxidative stress may occur. 4) Numerous natural or synthetic antioxidants against ROS have been tested with success in various disease models.5) Among the antioxidants, the enzyme superoxide dismutase (SOD) plays a pivotal role in clinics, particularly in patients with inflammatory joint disease. SOD neutralizes O 2 ·Ϫ by transforming it into hydrogen peroxide (H 2 O 2 ), thereby preventing the formation of highly aggressive compounds such as peroxynitrite (ONOO Ϫ ) and hydroxyl radical ( · OH). 6)But, except for some concerns about price, as a treatment, SOD was found inadequate as it was unstable, did not penetrate into cells, and provoked an immune response. So searching for new types of antioxidants has come into focus. Some researches have shown that several compounds with related heterocyclic ring and their Schiff base possess biochemical and pharmacological properties, which are used widely to support reaction chemistry and catalysis by transition metal cations. 7,8) In addition, the Schiff bases derived from 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone (PMBP) and their transition metal complexes have great characters in the fields of antibacterial and antioxidative activities.9,10) As a continuation of our research, in this paper, a new ligand (H 3 L) both bearing pyrrole and PMBP unit, 4-{[(3,4-dimethylpyrrole-2-carbonyl)hydrazono](phenyl)-methyl}-3-methyl-1-phenylpyrazol-5-ol, and its three transition metals complexes have been synthesized and characterized. Additionally, the antioxidative activities (scavenging effects on O 2 ·Ϫ and · OH) of the ligand and its complexes have also been studied. The information obtained from this study will be helpful to develop some new antioxidants. ExperimentalInstrumentation and Materials Melting points of the compounds were determined on an XT4-100x microscopic melting point apparatus. Elemental analyses (C, H, N) were carried out on an Elemental Vario EL analyzer. IR spectra were obtained in KBr discs on a Thermo Nicolet FT-IR spectra 4000-400 cm Ϫ1 region.1 H-NMR spectra were recorded on a Bruker AM200 Hz spectrometer with TMS as an internal standard. All conductivity measurements were performed in DMF with a DDS-11A conductometer at 25°C. FAB-MS (fast atom bombardme...

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“…An alternative strategy to generate OH ⅐ was demonstrated [15], based on an interaction between the ferrous-EDTA complex and hydrogen peroxide in the presence of reducing agents such as ascorbate or dithiothreitol. Thus, hydroxyl radicals can be generated independent of superoxide [16]. The capability of protein-bound iron to catalyze ROS formation for transferrin was investigated [15,17], but controversy exists as to whether iron ions introduced into the protein lobes promote the production of OH ⅐ [18].…”

mentioning

confidence: 99%

Mass spectrometric characterization of transferrins and their fragments derived by reduction of disulfide bonds

Thevis

Loo

2003

J. Am. Soc. Mass Spectrom.

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Mass spectrometry, proteomics, and protein chemistry methods are used to characterize the cleavage products of 79 kDa transferrin proteins induced by iron-catalyzed oxidation, including a novel C-terminal polypeptide released upon disulfide reduction. Top-down electrospray ionization tandem mass spectrometry (ESI-MS/MS) of intact multiply-charged transferrin from a variety of species (human, bovine, rabbit, chicken) performed on a quadrupole time-of-flight mass spectrometer yields multiply-charged b n -products originating near residues 56 -69 from the N-terminal region, in addition to their complementary y n -products. Incubation of transferrin with reductants, such as dithiothreitol (DTT) or tris(2-carboxyethyl)-phosphine (TCEP), yields an increase in multiple charging observed by ESI-MS and an increase in molecular weight consistent with disulfide reduction. However, mammalian transferrins release a 6 -8 kDa fragment upon disulfide reduction. Protein acetylation and MS/MS sequencing demonstrate that the fragment originates from the C-terminus of the protein, and that it is a separate polypeptide linked via three disulfide bonds to the main transferrin chain. The existence of a separate C-terminal chain is not annotated in protein sequence databases and, to date, has not been reported in the literature. Iron-catalyzed cleavage induces fragments originating from both the N-and C-terminus of transferrin. (J Am Soc Mass Spectrom 2003, 14, 635-647)

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Comparison of superoxide with other reducing agents in the biological production of hydroxyl radicals

Cited by 263 publications

References 11 publications

Hydrogen peroxide and hydroxyl radical formation by methylene blue in the presence of ascorbic acid

Hydrogen peroxide and hydroxyl radical formation by methylene blue in the presence of ascorbic acid

Synthesis, Characterization, and the Antioxidative Activity of 4-{[(3,4-Dimethyl pyrrole-2-carbonyl)hydrazono](phenyl)methyl}-3-methyl-1-phenylpyrazol-5-ol and Its Zinc(II), Copper(II), Nickel(II) Complexes

Mass spectrometric characterization of transferrins and their fragments derived by reduction of disulfide bonds

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