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'Hydroxylamine' in keywords
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1991 (1)
1980 (2)
1Author    Oemer Saygin, Peter DeckerRequires cookie*
 Title    Nonenzymatic Catalysis by Metal Ions and Phosphoric Acid Esters of Hydroxamic Acid Formation*  
 Abstract    Nonenzymatic catalysis by bivalent ions of Be, Mg, Ca, Zn, Mn, Ni and Co and bio-organic phosphates of the formation of hydroxamic acids from acetate or amino acids has been studied systematically. Increased yields of hydroxamate were observed at particular combinations of reactants. The most prominent increase (ca. 15-fold) was found with acetate and Ni++, and with a combination of ATP and Be++. Among others especially ribose-5-phosphate and glucose-5-phosphate enhanced yields in the presence of most metal ions. Since no release of inorganic phosphate was observed, this effect cannot be interpreted as an evidence for intermediate transhosphorylation reactions; it may also result from simple catalytic effects of metal sugar complexes. 
  Reference    Z. Naturforsch. 35b, 727—730 (1980); received February 7 1980 
  Published    1980 
  Keywords    Prebiological Evolution, Bioids, Transphosphorylation, Hydroxylamine, Acylate Activation 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0727.pdf 
 Identifier    ZNB-1980-35b-0727 
 Volume    35 
2Author    Günter LazarRequires cookie*
 Title    Light-Induced Valence Change of a Manganese-Containing Chlorophyll Derivative  
 Abstract    K3(Mn-(III)-chlorin e6) acetate, a water-soluble chlorophyll derivative with manganese as central atom was prepared. The influence o f reducing agents, light, and bicarbonate on the oxida­ tion states of manganese in the chlorin complex was investigated. In alkaline solutions the central Mn3+ was reducible to Mn2+. The illumination of the partially reduced complex first accelerated the reduction (light reduction: Mn3+ -> Mn2+), which was then followed by a strong reoxidation (light oxidation: Mn2+ -* Mn3+) continuing after switching off the light. This redox effect o f light was obtained only in presence o f hydroxylamine as reducing agent. Illumination time, intensity, and frequency had an influence on this effect. In the light/dark change the process was reversible. In regard to the requirement of manganese for the photosynthetic oxygen evolution the observed valence change o f manganese in the chlorin complex was compared to the supposed reaction mechanism on the donor side o f photosystem II. 
  Reference    Z. Naturforsch. 35c, 470—476 (1980); received December 17 1979/March 19 1980 
  Published    1980 
  Keywords    Mn-(III)-chlorin, Photosynthesis, Photoreduction, Photooxidation, Hydroxylamine 
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 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-0470.pdf 
 Identifier    ZNC-1980-35c-0470 
 Volume    35 
3Author    J. Messinger, S. Pauly, H. T. WittRequires cookie*
 Title    The Flash Pattern of Photosynthetic Oxygen Evolution after Treatment with Low Concentrations of Hydroxylamine as a Function of the Previous Sj/So-Ratio Further Evidence that N H 2O H Reduces the Water Oxidizing Complex in the Dark  
 Abstract    Flash induced oxygen evolution patterns o f isolated PS II complexes from the cyanobacteri­ um Synechococcus were measured with a Joliot-type electrode. By suitable preflash and dark adaptation procedures, samples were prepared in the state Si (100%), as well as enriched in S0 (60% S0, 40% S,). After treatment with low concentrations o f N H 2O H (< 100 jjm), the two flash patterns were identical. This is further evidence for a reduction o f the water oxidizing complex by hydroxylamine in the dark. Two reduced states (S_, and S_2) below S0 are formed by this reduction. 
  Reference    Z. Naturforsch. 46c, 1033—1038 (1991); received June 6 1991 
  Published    1991 
  Keywords    Photosynthesis, Oxygen Evolution, Hydroxylamine, S-States ( Synechococcus) 
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 TEI-XML for    default:Reihe_C/46/ZNC-1991-46c-1033.pdf 
 Identifier    ZNC-1991-46c-1033 
 Volume    46