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1993 (1)
1984 (1)
1981 (1)
1Author    J. Firl, D. Frommeyer, E. F. ElstnerRequires cookie*
 Title    Isolation and Identification of an Oxygen Reducing Factor (ORF) from Isolated Spinach Choloroplast Lamellae  
 Abstract    From the water extracts of heat-treated spinach chloroplast lamellae, five compounds were isolated by column chromatography and identified by paper chromatography, UV-, IR-, 'H-NMR-and 13C-NMR spectrometry: besides the major component, sucrose, 1 g lyophilized material contained 197 mg oxalic acid, 4.6 mg uridine and uracil and 22 (ig lumiflavin. Only the isolated lumiflavin stimulated photosynthetic oxygen reduction and H20 2 production by illu­ minated chloroplast lamellae. Evidence is presented that the stimulation o f photosynthetic oxygen activation by water extracts o f heat-treated chloroplast lamellae is most likely due to flavin derivative(s) (probably FAD) released from thylakoid-bound ferredoxin-NADP reductase by heat-and other treatments. Lumiflavin is artifactually derived from the solubilized flavin coenzymes during the isolation procedure. 
  Reference    Z. Naturforsch. 36c, 284—2 (1981); received November 281980 
  Published    1981 
  Keywords    Oxygen Activation, Spinach Chloroplast Lamellae, Flavins, Photosynthetic Electron Transport 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0284.pdf 
 Identifier    ZNC-1981-36c-0284 
 Volume    36 
2Author    Ingrid Schneider, ErichF. ElstnerRequires cookie*
 Title    Antioxidative Properties of Phenazone Derivatives: Differentiation between Phenylbutazon and Mofebutazon  
 Abstract    Both phenylbutazon and mofebutazon inhibit oxidative fragmentation of the methionine derivative, 2-keto-4-methylthio-butyric acid (KMB) by xanthine oxidase -or diaphorase me­ diated OH radical production. Differentiation of the two non-steroidal antiinflammatory drugs is possible by means of determining oxygen reduction by xanthine oxidase or diaphorase in the presence o f the naphthoquinone, juglone, where only mofebutazon shows an inhibitory effect. 
  Reference    Z. Naturforsch. 48c, 542—544 (1993); received May 5/June 3 1993 
  Published    1993 
  Keywords    Mofebutazon, Phenylbutazon, Non Steroidal Antiinflammatory Drugs (NSAIDs), Oxygen Activation 
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 TEI-XML for    default:Reihe_C/48/ZNC-1993-48c-0542.pdf 
 Identifier    ZNC-1993-48c-0542 
 Volume    48 
3Author    EvaP. Aur, RichardJ Y Oungm An, E. Dm, L. En, G. Feld Er, ErichF E LstnerRequires cookie*
 Title    Mechanisms of Adriamycin-Dependent Oxygen Activation Catalyzed by NADPH-Cytochrome c*-(Ferredoxin)-Oxidoreductase  
 Abstract    Under aerobic conditions, 0 2 uptake and production o f 0 2~ and H 20 2 by isolated N A D P H -cytochrome c-(ferredoxin)-oxidoreductase from Euglena gracilis was strongly stim ulated by adriamycin. Further stim ulation was not observed with 0.1 m M F e 3+-EDTA. M ethionine fragmentation (measured as ethylene release), as a reliable indicator for the formation o f O H ' radical-like oxidants under aerobic conditions (1 0 0 |im o l 0 2 in a 10 ml reaction vessel) was strongly stimulated by 0.1 m M F e3+-ED TA or, in the absence o f iron, by partial anaerobiosis (1 (irnol 0 2 per vessel). The highest rate o f m ethionine fragm entation was observed under an­ aerobic conditions in the presence o f both reduced adriam ycin and added H 20 2. Aerobic methionine fragmentation in the presence o f adriam ycin and F e3+-ED TA was inhibited by superoxide dismutase and catalase by m ore than 90%, w hile m ethionine fragmen­ tation under semianaerobiosis in the absence o f F e 3+-E D T A was inhibited by superoxide dismutase to only about 50%, while catalase again inhibited by m ore than 90%. These results indicate that the adriamycin-catalyzed production o f a strong oxidant appears to be governed by different mechanisms depending on oxygen availability; nam ely the production o f a Fenton-type oxidant driven by adriamycin-catalyzed superoxide form ation and also, the formation o f the "crypto-OH' radical" by direct electron donation from the adriam ycin sem iquinone radical to H20 2 under oxygen limiting conditions. 
  Reference    Z. Naturforsch. 39c, 261—267 (1984); received D ecem ber 15 1983 
  Published    1984 
  Keywords    Adriamycin, Oxygen Activation, Oxygen Toxicity, Superoxide, H ydroxyl Radical 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0261.pdf 
 Identifier    ZNC-1984-39c-0261 
 Volume    39