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'Umbelliferone' in keywords
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1994 (1)
1980 (1)
1Author    Ann Herm, Elisabeth Esterbauer, D. Schwarzl, Ieter GrillRequires cookie*
 Title    Umbelliferone in Needles of Picea abies  
 Abstract    A compound showing blue fluorescence under UV-light was isolated from spruce needles and identified as umbelliferone. Structure analysis was based on UV and mass spectroscopy as well as chromatographic comparison with authentic material. Quantitative evaluation by direct measure­ ment of the fluorescence of the umbelliferone spot separated by TLC revealed that the umbelliferone content shows great variation within different individual trees ranging from 0 .42-42 (ig/g fresh weight. Only minute amounts are present as free umbelliferone while the abundant part is present as /?-glucoside. 
  Reference    Z. Naturforsch. 35c, 682 (1980); received May 12 1980 
  Published    1980 
  Keywords    Umbelliferone, Quantitative Estimation, Picea abies, Genetic Families 
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 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-0682.pdf 
 Identifier    ZNC-1980-35c-0682 
 Volume    35 
2Author    D. Ieter, M. Üller-EnochRequires cookie*
 Title    Product Autofluorescence Activation in the Cytochrome P450 Monooxygenase System  
 Abstract    The relative increase of the 7-ethoxycoumarin-O-deethylase and the 6,7-dimethoxycouma-rin-O-demethylase activities were found 93 and 236% using a reconstituted cytochrome P4502B 1 :NADPH-P450 reductase system by adding to the reaction mixtures their own products. The assays were irradiated during the reactions with the excitation wavelength maximum of their products umbelliferone (X.E = 365 nm) or scopoletin (XE = 398 nm), re­ spectively. Addition of the products to the reaction mixtures without irradiation (dark reac­ tion) had no activating effect on the specific activities of the 7-ethoxycoumarin-O-deethylase or the 6,7-dimethoxycoumarin-O-demethylase. The relative increase of the specific activities is dependent on the excitation light intensities and was at maximum when the light intensity at the sample cuvette was 0.4 mW/cm2. The activation energies of the P 4502B 1-dependent 7-ethoxycoumarin-O-deethylation reaction obtained from Arrhenius plots with and without added umbelliferone and irradia­ tion with XE = 365 nm are 14.7 kJ/mol and 33.5 kJ/mol, respectively, in the temperature range of 27-37 °C. The irradiation energy of the fluorescent product umbelliferone change the catalytic mechanism, which has a two times lower activation energy in the presence of the irradiated product umbelliferone. Umbelliferone and scopoletin have highest fluorescence intensities in the wavelength range of the blue light (440-480 nm). The photochemical action spectrum of the 7-ethoxycoumarin-O-deethylase of the P4502B 1:reductase system is also found to be in the wavelength range of 420-470 nm. No activation effect was seen with irradiating light lower than 400 nm. Obvi­ ously the fluorescence light of the products are due for the extremely high activation effect. This is the first report that the products umbelliferone and scopoletin are photoreceptors and phototransducers. 
  Reference    Z. Naturforsch. 49c, 763—771 (1994); received August 1/September 2 1994 
  Published    1994 
  Keywords    Cytochrome P450, Blue Light Activation, Photoreceptor-Phototransducer, Umbelliferone, Scopoletin 
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 TEI-XML for    default:Reihe_C/49/ZNC-1994-49c-0763.pdf 
 Identifier    ZNC-1994-49c-0763 
 Volume    49