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'Field Desorption Mass Spectrometry' in keywords
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1981 (1)
1979 (1)
1978 (1)
1Author    I. Lüderwald, M. Przybylski, H. Ringsdorf, D. SilberhornRequires cookie*
 Title    Untersuchung yon Dipeptiden durch Elektronenstoß-und Felddesorptions-Massenspektrometrie Investigation of Dipeptides by Electron Impact and Field Desorption Mass Spectrometry  
 Abstract    The combined application of field desorption and electron impact ionization techniques in the mass spectrometry of free dipeptides can be used to obtaine informations about primary structure and molecular weight. Characteristic fragmentation pathways of dipeptides are discribed and the mechanism of diketopiperazine formation is discussed. 
  Reference    Z. Naturforsch. 33b, 805—808 (1978); eingegangen am 20. Januar 1978 
  Published    1978 
  Keywords    Electron Impact, Field Desorption Mass Spectrometry, Sequence Determination of Dipeptides, Diketopiperazine Formation from Dipeptides 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0805.pdf 
 Identifier    ZNB-1978-33b-0805 
 Volume    33 
2Author    Michael Przybylski, Ingo Lüderwald, Ekkehard Kraas, Wolfgang Voelter, SidneyD. NelsonRequires cookie*
 Title    Field Desorption Mass Spectra of Gastrine Peptides and Glutathione Derivatives  
 Abstract    the sequence of the C-terminal tetrapeptide of gastrine, Trp-Met-Asp-Phe-NH2, and several derivatives of glutathione, y-Glu-Cys(SR)-Gly, were characterized by field desorption mass spectrometry. The field desorption mass spectra obtained at various field ion emitter temperatures reveal abundant molecular ions and fragmentation reactions that yield partial sequence information. In the series of gluta-thione derivatives investigated, characteristic ions formed by cleavage of the y-Glu-Cys peptide bond determine the substituent at the Cys residue and can therefore be used to identify corresponding conjugation products of drug metabolites with glutathione. Introduction A variety of mass spectrometric methods for the structure analysis of oligopeptides has been devel-oped and tested in the last years [1-3]. Particularly, derivatization reactions to enhance the notoriously low volatility of peptides for mass spectral analysis have been studied extensively [4]. The most ad-vanced approach developed by Biemann et al. [5] involves multiple derivatization steps that enable the analysis of complex mixtures of di-to tetra/penta-peptides by gas chromatography-mass spectro-metry (g. c.-m.s.) using electron impact (e.i.) ioniza-tion. The value of this approach to the sequence elucidation of polypeptides containing up to 50 amino acid residues has been demonstrated [5, 6]. However, major limitations of derivatization proce-dures for the mass spectral analysis of peptides are that they require relatively large amounts of sample and present difficulties with certain polar amino acid residues. Moreover, information about chain-terminal or side chain substituents that frequently 
  Reference    Z. Naturforsch. 34b, 736—743 (1979); received December 28 1978 
  Published    1979 
  Keywords    Field Desorption Mass Spectrometry, Oligopeptides, Gastrine Peptides, Glutathione Conjugates, Molecular Ions Oligopeptides comprising 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0736.pdf 
 Identifier    ZNB-1979-34b-0736 
 Volume    34 
3Author    H.-R SchultenRequires cookie*
 Abstract    A combined 13 C nuclear magnetic resonance and field desorption mass spectrometric investigation of algae grown on 13 C02 has shown that the isotopic enrichment of amino acids extracted therefrom is neither uniform nor statistical. The use of these two indepen-dent techniques allows a new, detailed and accurate insight into the label distribution resulting from biosynthesis. The observed deviations from the statistical abundances are systematic. A system for classifying each member of the complex ensemble of isotopic species has been devised, so that the isotopomers may be ordered according to their relative probability of occurrence. 
  Reference    Z. Naturforsch. 36b, 1289—1296 (1981); received May 20 1981 
  Published    1981 
  Keywords    13 C Enriched Amino Acids, Biosynthesis, Label Distribution, NMR Spectra, Field Desorption Mass Spectrometry 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1289.pdf 
 Identifier    ZNB-1981-36b-1289 
 Volume    36