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Author Nakano, Y., Asada, K. file  url
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Title Hydrogen Peroxide is Scavenged by Ascorbate-specific Peroxidase in Spinach Chloroplasts Type Journal Article
Year 1981 Publication Plant and Cell Physiology Abbreviated Journal  
Volume 22 Issue 5 Pages 867-880  
Keywords Spinach; Chloroplasts; Hydrogen peroxide; Peroxidase; Ascorbate  
Abstract Intact spinach chloroplasts scavenge hydrogen peroxide with a peroxidase that uses a photoreductant as the electron donor, but the activity of ruptured chloroplasts is very low [Nakano and Asada (1980) Plant & Cell Physiol. 21 : 1295]. Ruptured spinach chloroplasts recovered their ability to photoreduce hydrogen peroxide with the concomitant evolution of oxygen after the addition of glutathione and dehydroascorbate (DHA). In ruptured chloroplasts, DHA was photoreduced to ascorbate and oxygen was evolved in the process in the presence of glutathione. DHA reductase (EC 1.8.5.1) and a peroxidase whose electron donor is specific to L-ascorbate are localized in chloroplast stroma. These observations confirm that the electron donor for the scavenging of hydrogen peroxide in chloroplasts is L-ascorbate and that the L-ascorbate is regenerated from DHA by the system: photosystem I-->ferredoxin-->NADP-->glutathione. A preliminary characterization of the chloroplast peroxidase is given.  
Call Number Serial 2173  
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Author Schoenfeld, J.D.; Sibenaller, Z.A.; Mapuskar, K.A.; Wagner, B.A.; Cramer-Morales, K.L.; Furqan, M.; Sandhu, S.; Carlisle, T.L.; Smith, M.C.; Abu Hejleh, T.; Berg, D.J.; Zhang, J.; Keech, J.; Parekh, K.R.; Bhatia, S.; Monga, V.; Bodeker, K.L.; Ahmann, L.; Vollstedt, S.; Brown, H.; Shanahan Kauffman, E.P.; Schall, M.E.; Hohl, R.J.; Clamon, G.H.; Greenlee, J.D.; Howard, M.A.; Schultz, M.K.; Smith, B.J.; Riley, D.P.; Domann, F.E.; Cullen, J.J.; Buettner, G.R.; Buatti, J.M.; Spitz, D.R.; Allen, B.G. file  url
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Title O2(-) and H2O2-Mediated Disruption of Fe Metabolism Causes the Differential Susceptibility of NSCLC and GBM Cancer Cells to Pharmacological Ascorbate Type Journal Article
Year 2017 Publication Cancer Cell Abbreviated Journal Cancer Cell  
Volume 31 Issue 4 Pages 487-500.e8  
Keywords Animals; Antineoplastic Combined Chemotherapy Protocols/therapeutic use; Ascorbic Acid/administration & dosage/adverse effects/*pharmacology; Brain Neoplasms/*drug therapy; Carcinoma, Non-Small-Cell Lung/*drug therapy/metabolism/mortality/radiotherapy; Cell Line, Tumor; Chemoradiotherapy/methods; Female; Glioblastoma/*drug therapy/metabolism; Humans; Hydrogen Peroxide/pharmacology; Iron/*metabolism; Lung Neoplasms/*drug therapy/metabolism/mortality/radiotherapy; Male; Mice, Nude; Oxygen/metabolism; Radiation-Sensitizing Agents/pharmacology; Xenograft Model Antitumor Assays; ferritin; glioblastoma multiforme; hydrogen peroxide; labile iron metabolism; non-small cell lung cancer; oxidative stress; pharmacological ascorbate; superoxide; superoxide dismutase; transferrin receptor  
Abstract Pharmacological ascorbate has been proposed as a potential anti-cancer agent when combined with radiation and chemotherapy. The anti-cancer effects of ascorbate are hypothesized to involve the autoxidation of ascorbate leading to increased steady-state levels of H2O2; however, the mechanism(s) for cancer cell-selective toxicity remain unknown. The current study shows that alterations in cancer cell mitochondrial oxidative metabolism resulting in increased levels of O2(-) and H2O2 are capable of disrupting intracellular iron metabolism, thereby selectively sensitizing non-small-cell lung cancer (NSCLC) and glioblastoma (GBM) cells to ascorbate through pro-oxidant chemistry involving redox-active labile iron and H2O2. In addition, preclinical studies and clinical trials demonstrate the feasibility, selective toxicity, tolerability, and potential efficacy of pharmacological ascorbate in GBM and NSCLC therapy.  
Call Number Serial 2122  
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Author Imlay, J.A.; Chin, S.M.; Linn, S. file  url
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Title Toxic DNA damage by hydrogen peroxide through the Fenton reaction in vivo and in vitro Type Journal Article
Year 1988 Publication Science (New York, N.Y.) Abbreviated Journal Science  
Volume 240 Issue 4852 Pages 640-642  
Keywords Bacteriophage lambda; Chemical Phenomena; Chemistry; *DNA Damage; DNA Repair; DNA, Bacterial/*drug effects; Escherichia coli/drug effects/*genetics; Ferrous Compounds; Free Radicals; Hydrogen Peroxide/administration & dosage/*pharmacology; Hydrogen-Ion Concentration; Hydroxides; Hydroxyl Radical; Oxidation-Reduction  
Abstract Exposure of Escherichia coli to low concentrations of hydrogen peroxide results in DNA damage that causes mutagenesis and kills the bacteria, whereas higher concentrations of peroxide reduce the amount of such damage. Earlier studies indicated that the direct DNA oxidant is a derivative of hydrogen peroxide whose formation is dependent on cell metabolism. The generation of this oxidant depends on the availability of both reducing equivalents and an iron species, which together mediate a Fenton reaction in which ferrous iron reduces hydrogen peroxide to a reactive radical. An in vitro Fenton system was established that generates DNA strand breaks and inactivates bacteriophage and that also reproduces the suppression of DNA damage by high concentrations of peroxide. The direct DNA oxidant both in vivo and in this in vitro system exhibits reactivity unlike that of a free hydroxyl radical and may instead be a ferryl radical.  
Call Number Serial 1583  
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Author Ge, L.; Zhu, Z.; Shao, Z.; Wang, S.; Liu, S. file  url
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Title Effects of preparation methods on the oxygen nonstoichiometry, B-site cation valences and catalytic efficiency of perovskite La0.6Sr0.4Co0.2Fe0.8O3-δ Type Journal Article
Year 2009 Publication Ceramics International Abbreviated Journal Ceramics International  
Volume 35 Issue 8 Pages 3201-3206  
Keywords La0.6Sr0.4Co0.2Fe0.8O3− δ Oxygen nonstoichiometry; Hydrogen peroxide decomposition  
Abstract La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) powders were synthesized respectively by an EDTA (ethylenediaminetetraacetic acid)–Citrate sol–gel process and a low-temperature auto-combustion process. The samples were characterized by XRD, SEM, BET, TGA and instant temperature analysis. The iodometric titration was used to determine the average valence of Co and Fe ions and the oxygen nonstoichiometry of the prepare powders. The catalytic properties of the synthesized powders were investigated by the hydrogen peroxide catalytic decomposition. Pure-perovskite structure was formed by both synthesis methods. The oxygen nonstoichiometry of the samples prepared by the auto-combustion process is larger than that by the sol–gel process. The catalytic activities of the powders from two synthesis processes also differed largely due to the different oxygen nonstoichiometry, surface area and crystalline sizes.  
Call Number Serial 1408  
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Author Gong, M.; Chen, Bo.; Li, Z.-G.; Guo, L.-H. file  url
doi  openurl
Title Heat-shock-induced cross adaptation to heat, chilling, drought and salt stress in maize seedlings and involvement of H2O2 Type Journal Article
Year 2001 Publication Journal of Plant Physiology Abbreviated Journal Journal of Plant Physiology  
Volume 158 Issue 9 Pages 1125-1130  
Keywords cross adaptation; heat shock; hydrogen peroxide; Zea mays  
Abstract A heat-shock pretreatment at 42 °C for 4 h followed by a 4-h recovery significantly enhanced survival rates of seedlings from two varieties of maize that differ in stress resistance. The procedure mitigated electrolyte leakage of primary roots and alleviated vitality loss of coleoptiles under severe heat, chilling, drought and salt stress, indicating that heat-shock pretreatment can induce cross adaptation. The heat-shock pretreatment, that induced cross adaptation, also produced an endogenous H2O2 peak in maize seedlings. Exogenous H2O2 treatments simultaneously enhanced multi-resistance to heat, chilling, drought and salt stress, implying that H2O2 may play a signalling role in triggering cross adaptation of maize seedlings to various stresses.  
Call Number Serial 865  
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