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'Chlorophyll Degradation' in keywords Facet   Publication Year 1981  [X]
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1981[X]
1Author    Siegrid Schoch2, Hugo Scheer3, JeromeA. Schiff2, W. Olfhart, R. Ü D Ig Er3, H. Arold, W. SiegelmRequires cookie*
 Title    Pyropheophytin a Accompanies Pheophytin a in Darkened Light Grown Cells of Euglena1  
 Abstract    Chromatography Light-grown non-dividing cells of Euglena gracilis Klebs var. bacillaris Cori form pheophytin a like pigments from chlorophyll a without loss of viability when they are allowed to incubate in darkness without shaking. This is accompanied by the loss of long-wavelength components in the red absorption band of intact cells. After extraction of these cells with acetone, transfer of the pigments to ether and treatment of the ether solution with dilute acid, two pigments can be separated by high performance liquid chromatography on reverse phase silica gel (RP-8) using methanol: water = 95:5 (v/v) as the eluting solvent: In addition to pheophytin a, the eluate contains an unknown pigment. With increasing times of incubation of the cells in darkness, the proportion of pheophytin a decreases and the proportion of the unknown increases suggesting, that the unknown is formed from pheophytin a. This pigment has been identified as pyropheophytin a. It has the same absorption spectrum as pyropheophytin a (prepared by pyridine pyrolysis of pheophytin a) and contains phytol as the longchain esterifying alcohol. On conversion to the methyl ester, the resulting methyl phorbide is identical with authentic pyromethylpheophorbide a by tic, hplc, absorption, absorption difference and mass spectros­ copy. This is the first report of pyropheophytin a or any pyrochlorophyll derivative from plants or oxygenic plant-like microorganisms where it may serve as an intermediate in chlorophyll degradation. 
  Reference    Z. Naturforsch. 36c, 827—833 (1981); received June 191981 
  Published    1981 
  Keywords    Euglena, Chlorophyll Degradation, Pyropheophytin, Photosynthesis, High Performance 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0827.pdf 
 Identifier    ZNC-1981-36c-0827 
 Volume    36 
2Author    H. K. Lichtenthaler, G. Burkard, G. Kuhn, U. PrenzelRequires cookie*
 Title    Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings  
 Abstract    Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation o f chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCPi_ 3, CPa, CPI and CPIa which have been found in other plants. Between LHCPj and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy. When the green plants are transferred to continuous darkness, chlorophylls and the chloro-phyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chloro­ phyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end o f the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control. The data indicate that at an early stage o f greening the light-harvesting chlorophyll a/b-protein LHCPj is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre­ dominantly chlorophyll a. The ratio chlorophyll a to /?-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCPj_ 3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter. 
  Reference    Z. Naturforsch. 36c, 421 (1981); received March 17 1981 
  Published    1981 
  Keywords    Chlorophyll a/b ratio, Chlorophyll Degradation, Chlorophyll-Proteins, Chloroplast Development, Stability of Chlorophylls 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0421.pdf 
 Identifier    ZNC-1981-36c-0421 
 Volume    36