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  • Chemistry  (5)
  • Archaebacteria  (2)
  • Gas chromatography  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    FEBS Letters 176 (1984), S. 176-178 
    ISSN: 0014-5793
    Schlagwort(e): Amino acid sequence ; Archaebacteria ; DNA binding protein ; Sulfolobus solfataricus
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1612-1112
    Schlagwort(e): Discontinuous reversed-phase chromatography ; 50S subunit ribosomal proteins ; Sulfolobus acidocaldarius ; Archaebacteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The total protein of the 50S ribosomal subunit (TP50) from the archaebacterium Sulfolobus acidocaldarius was prefractionated by discontinuous reversed-phase HPLC with several column combinations. The purity of the eluted fractions was tested by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) or two-dimensional PAGE (2D-PAGE). With regard to the load capacity and selectivity, best results were obtained with a semi-preparative three-column combination (total length 67.5cm). Twelve A230 units of TP50 were separated into 35 fractions, 19 of which contained nearly pure proteins. When the sample load was increased to 176A230 units (109mg), 13 of 28 collected fractions still contained nearly pure proteins. The selectivity of a semi-preparative short-column combination (total length 12cm) was similar to that of the semi-preparative column combination, and separation time could be reduced to one third of that required for the longer column combination. The load capacity of the short-column combination was lower than that of the semi-preparative column combination.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Enantiomer separation ; Permethylated cyclodextrin stationary phases ; Side-chain fluorinated alkylbenzenes ; Thermodynamic data
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The separation of racemic side-chain fluorinated alkylbenzenes and bromofluorinated analogues by capillary gas chromatography using permethylated α, β and γ-cyclodextrins dissolved in polysiloxanes of different polarity as stationary phases is described. The influence of the achiral polysiloxane matrices on the separation of enantiomers is discussed in the light of the results obtained with the different phases. For a part of the tested compounds thermodynamic data are determined which describe the interaction of enantiomers with the stationary phase. The mechanism of separation is discussed on this basis and by comparison with data for structurally similar compounds.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Molecular modelling ; Molecular mechanics calculations ; Permethylated α-, β- and γ-cyclodextrins ; Interaction mechanism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The capillary gas chromatographic retention behavior of α-pinene and tricyclene has been investigated on stationary phases of different polarities. On all but one of the columns employed, tricyclene eluted before α-pinene; only permethylated β-cyclodextrins dissolved in moderately polar polisiloxanes gave a reversed elution order. The intermolecular interactions which caused the unexpected retention behavior were investigated in detail, applying methods of computer simulation. To achieve this, we have developed a calculation algorithm on the basis of molecular mechanical optimizations and programmed it in a macro. This makes it possible to systematically investigate a given configuration space in which all the possible interactions can take place. It was shown that permethylated β-cyclodextrin as host molecule for both guest molecules offers an optimum cavity size. As a result the number of energetically favorable contacts between host and guest molecules as well as the strength of the interactions in this stationary phase were larger. As a consequence the elution order, normally only influenced by the vapor pressure of the compounds at a given temperature, was changed. Nonspecific interactions played an especially important role for these kinds of substances.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 334 (1992), S. 41-48 
    ISSN: 0941-1216
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Gas Chromatographic Investigation of Stereoisomeric Cyclotrideca-1,5,9-trienesUsing achiral phases of different polarity in capillary gas chromatography on the one hand and a chiral cyclodextrine phase on the other hand it is demonstrated, that a ring-enlargement sequence starting from (E, E, Z)-cyclododeca-1,5,9-triene yields five of the six theoretically possible isomeric cyclotrideca-1,5,9-trienes and (E, Z)-trans-bicyclo[10.1.0]trideca- 4,8-diene. With all achiral phases only three of the isomeric trienes and the bicyclic isomer were separated from each other; (E, Z, E)- and (Z, E, Z)-cyclotrideca-1,5,9-triene are eluated in only one (the fifth) peak, these isomers were separated on the cyclodextrine phase. Moreover, this chiral phase separates the enantiomers of the bicyclic isomer.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 18 (1995), S. 259-262 
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective GC ; Permethylated α- and β-cyclodextrin stationary phases ; Flumecinol (3-trifluoromethyl-α-ethylbenzhydrol) ; α-Ethylbenzhydrol derivatives ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Flumecinol and related compounds can, without derivatization, be separated into their enantiomers by gas chromatography on cyclodextrin phases; permethylated β-cyclodextrin dissolved in OV-1701 can be particularly recommended. Thermodynamic data describing the different intensities of interaction of the individual enantiomers with the stationary phases were determined. The values measured imply different separation mechanisms for the compounds investigated.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 25 (1987), S. 928-928 
    ISSN: 0749-1581
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 426 (1976), S. 43-48 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Redetermination of the Crystal and Molecular Structure of Heptasulfur Imide, S7NHThe following data were obtained from a single crystal x-ray structure analysis of S7NH carried out at -160°C and leading to a R value of 0.026: space group Pbnm, lattice dimensions a = 7.607, b = 7,823, c = 13.091 Å, Z = 4, density 2.04 g · cm-3. The molecules consist of puckered rings of site symmetry Cs with average bond distances dSS = 2.053, dSN = 1,676, dNH = 0,91 Å. The coordination of the nitrogen is almost planar which ist rationalized in terms of a 3-center, π-bond. There are indications for weak intermolecular S…H hydrogen bonds.
    Notizen: Eine bei -160°C ausgeführte und bis zum R-Wert von 2,6% verfeinerte Röntgenstrukturanalyse von Heptaschwefelimid ergab folgende Kristalldaten: Raumgruppe Pbnm, Gitterkonstanten a = 7,607, b = 7,823, c = 13,091 Å, Z = 4, Dichte 2,04 g · cm-3. Die kronenförmigen S7NH-Moleküle besitzen die Lagesymmetrie Cs; die mittleren Kernabstände sind dSS = 2,053, dSN = 1,676, dNH = 0,91 Å. Das Stickstoffatom ist nahezu planar koordiniert, was mit einer Dreizentren-π-Bindung erklärt wird. Die Struktur enthält keine N…H-, wohl aber schwache intermolekulare S…H-Wasserstoffbrücken.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 25 (1987), S. 1092-1092 
    ISSN: 0749-1581
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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