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'Singlet O xygen' in keywords
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1985 (1)
1984 (2)
1Author    T. B. Melø, G. Reisaeter, A. Johnsson, M. JohnssonRequires cookie*
 Title    Photodestruction of Propionibacterium acnes Porphyrins  
 Abstract    The fluorescence spectra o f colonies o f Propionibacterium acnes were studied under various experimental conditions. The spectra contained peaks at 580 nm and 620 nm. These bands were due to two different components; the 580 nm component was likely to be a m etalloporphyrin, and there are ind ica­ tions that the 620 nm component could be a coproporphyrin. The 580 nm fluorescence was destroyed by the com bined action o f light and oxygen (no destruction under strict anaerobic conditions). A dark period interrupting the bleaching light stopped the destruction o f this component for the time o f the dark period. The initial production o f the 620 nm com ponent was due to the oxygen exposure. U pon light irradiation this component was later destroyed by the com bined action o f oxygen and light. 
  Reference    Z. Naturforsch. 40c, 125—128 (1985); received October 22 1984 
  Published    1985 
  Keywords    Propionibacterium acnes, Fluorescence, Porphyrin, Photobleaching, Singlet-O xygen 
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 TEI-XML for    default:Reihe_C/40/ZNC-1985-40c-0125.pdf 
 Identifier    ZNC-1985-40c-0125 
 Volume    40 
2Author    S. G. Mauriño, M. A. Vargas, C. Echevarría, P.J A Paricio, J.M M AldonadoRequires cookie*
 Title    Red-Light Effects Sensitized by Methylene Blue on Nitrate Reductase from Spinach (Spinacia oleracea L.) Leaves  
 Abstract    Nitrate reductase from spinach (Spinacia oleracea L.) leaves, w hich had been inactivated in vitro by incubation with N A D H and cyanide, was fully reactivated in m inutes when irradiated in anaerobic conditions with red light in the presence o f m ethylene blue. Both the rate and the extent o f reactivation increased with light intensity (6 to 100 W -m " 2) and dye concentration (1 to 10 jiM). On the contrary, photoreactivation was com pletely abolished when N A D H or ethylenediaminetetra-acetic acid were present during irradiation. W e propose that m ethylene blue, when photo excited, exhibits a redox potential positive enough to reoxidise the CN~-re-duced molybdenum complex settled in the inactive enzym e, thus causing its reactivation. On the other hand, prolonged irradiation o f nitrate reductase, under air and in the presence o f methylene blue, promoted an oxygen-dependent irreversible inactivation o f the two partial activities o f the enzyme. This inactivation was m arkedly enhanced in 77% deuterated water and greatly prevented by azide, which indicates that singlet oxygen is the species primarily involved in the photooxidative inactivation o f the enzym e. 
  Reference    Z. Naturforsch. 39c, 1079—1084 (1984); received July 27 1984 
  Published    1984 
  Keywords    Methylene Blue, Nitrate Reductase, Photosensitization, Singlet O xygen, Spinacia 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-1079.pdf 
 Identifier    ZNC-1984-39c-1079 
 Volume    39 
3Author    MichaelP. Percival, A. Lan, D. D. OdgeRequires cookie*
 Title    Photodynamic Damage to Isolated Chloroplasts: A Possible Model for in vivo Effects of Photosynthetic Inhibitor Herbicides  
 Abstract    The breakdown o f chlorophylls, carotenoids, and linolenic acid together with the form ation o f malondialdehyde and ethane was followed in isolated pea chloroplast membranes. Breakdown was enhanced by light, oxygen, D 20 and rose bengal, but retarded by crocetin. The results are discussed in relationship to the role o f singlet oxygen in prom oting dam age in vivo. 
  Reference    Z. Naturforsch. 39c, 482 (1984); received Decem ber 5 1983 
  Published    1984 
  Keywords    Chloroplast Membranes, Lipid Peroxidation, Singlet O xygen, H erbicide D am age, Chloroplast Pigments 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0482.pdf 
 Identifier    ZNC-1984-39c-0482 
 Volume    39