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1Author    Andre BucheRequires cookie*
 Title    Wavelength Shifts Correlation between Near Infrared and Ultraviolet Regions of the LHII Bacteriochlorophyll Spectrum from Ectothiorhodospira sp  
 Abstract    Bacteriochlorophyll a has a maximum at 258 nm previously related to the ring E ester system interacting with the Ji-system of the macrocycle. In this work, we compared the effect o f lauryldimethylamine-N-oxide (LD AO) and alkaline pH on both the near infrared and the ultraviolet region of the LHII spectrum from E ctothiorhodospira sp. While LDAO induces only a shift of the 850 nm band arising from the Q y transition of the bacteriochlorophyll a, alkaline pH also causes a concomitant and reversible 10-nm shift from 258 to 248 nm. Both shifts have similar apparent pKs (12.3 and 12.6, respectively). Interestingly, the presence of NaCl reduces these pKs values to 11.4 and 11.7. 
  Reference    Z. Naturforsch. 56c, 363 (2001); received D ecem ber 11 2000/January 23 2001 
  Published    2001 
  Keywords    Bacteriochlorophyll, Ectothiorhodospira, Light-Harvesting Complex 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0363.pdf 
 Identifier    ZNC-2001-56c-0363 
 Volume    56 
2Author    Thorsten Kemmer, Hans Brockmann, Nikolaus RischRequires cookie*
 Title    Die Einzelkomponenten der Bacteriophäophorbidmethylester von Bacteriochlorophyll c und d The Individual Components of Bacteriophaeophorbide Methyl Esters from Bacteriochlorophyll c and d  
 Abstract    The preparative column chromatographic separation on small grained silica gel of the bacteriophaeophorbide-c-and -d-methyl esters into their homologous and isomeric components is described. The influence of particular regions of the molecule, which carry different alkyl-substituents, on the chromatographic separability is selectively enhanced through the variation of the eluent. Mass and ifl NMR spectra of the pure components are discussed. Einführung Von den in Chlorobiaceae vorkommenden Bacterio-chlorophyllen c und d ist schon seit den Untersuchun-gen von Holt und Mitarbeitern [1, 2] bekannt, daß sie in der Natur als komplexe Gemische isomerer und homologer Verbindungen vorkommen. Eine Trennung in die einzelnen Komponenten ist für die aus den Chlorophyllen durch Hydrolyse leicht zu-gänglichen Phäophorbide durch Verteilen zwischen Ether und Salzsäure an Celite-Säulen beschrieben worden [3-5]. Wieweit dabei die einzelnen Kompo-CH3 nenten wirklich in reiner Form erhalten wurden, ist heute schwer zu überprüfen; bei den sich anschlie-ßenden physikalischen und chemischen Untersu-chungen wurden nämlich zum Teil widersprüchliche Resultate erhalten [6, 7]. Dennoch konnten Holt und Mitarbeiter [1, 2] aus ihren Untersuchungs-ergebnissen die Konstitutionsformeln 1 und 2 für die Bacteriochlorophylle c und d ableiten, die trotz zeitweiliger Kritik [7-9] durch neuere Arbeiten nur bestätigt wurden [10, 11]. Chlorobium-Bacteriochlorophylle cd) und d(2) 
  Reference    Z. Naturforsch. 34b, 633—637 (1979); eingegangen am 10. August 1978 
  Published    1979 
  Keywords    Chromatography, Separation, Bacteriochlorophylls, X H NMR 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0633.pdf 
 Identifier    ZNB-1979-34b-0633 
 Volume    34 
3Author    Steiner, W. Schäfer, I. Bios, H. W. Ieschhoff, H. ScheerRequires cookie*
 Title     
 Abstract    Bacteriochlorophyll b (bchl b) has been isolated from the halophilic photosynthetic bacterium, Ectothiorhodospira halochloris. The pigment and a series o f derivatives thereof are different from Bchl b from Rhodopseudomonas viriais by HPLC analysis, but similar by uv-vis spectroscopy. The chromatographic difference originates in different esterifying alcohols in the two pigments. The one from Rp. viridis (Bchl bp) is esterified with zl2-phytaenol (phytol), that from E. halochloris (Bchl b42,io) with zf2,10-phytadienol. The structure o f the latter has been established by isolation of the alcohol from the purified pigment, followed by (i) gaschromatography-mass spectroscopy and (ii) ozonolysis and dinitrophenylhydrazon-formation o f the cleavage products, which were identified by gaschromatography-mass spectroscopy as 6-methyl-heptan-2-one, and 4-methyl-nona-1,8-dione. 
  Reference    Z. Naturforsch. 36c, 417 (1981); received February 26 1981 
  Published    1981 
  Keywords    Photosynthesis, Photosynthetic Bacteria, Halophilic Bacteria, Bacteriochlorophylls, Diterpenoid Alcohols 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0417.pdf 
 Identifier    ZNC-1981-36c-0417 
 Volume    36 
4Author    R. Steiner, E. Cm, H. ScheerRequires cookie*
 Title    Chemistry of Bacteriochlorophyll b: Identification of Some (Photo)Oxidation Products  
 Abstract    Photoreactions o f bacteriochlorophyll b have been studied. They all arise from reactions at the A8,8' double-bond. The A7,8-isom erisation product 3 is formed under anaerobic conditions. Irradiation in the presence o f oxygen leads to three products arising from an autoxidation reaction involving singlet oxygen. The structures o f two o f them (4, 5) have been established from their m ethylpheophorbides 10 and 11 containing an 8-acetyl and 8-(m eth)oxyethyl-substituent, respectively, in addition to the isom erized A7,8-double bond. 
  Reference    Z. Naturforsch. 38c, 748—7 (1983); received June 15 1983 
  Published    1983 
  Keywords    Bacteriochlorophyll, Ethylidene Group, Isomerisation, O xidation, Photosynthesis 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0748.pdf 
 Identifier    ZNC-1983-38c-0748 
 Volume    38