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  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 12 (1977), S. 493-499 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The electron impact fragmentation is reported for 46 benzylidene acetals of hexopyranosides of the allo, altro, galacto, gluco, gulo and manno series and some of their mono-oxidation products. Besides the molecular ion, which is always present and is usually part of a triplet the previously reported ion formed by cleavage of C-1—C-2, C-4—C-5 and the benzylic C—O(C-4) bond is observed. Evidence is given for two complementary ruptures (C-1—C-2, C-3—C-4; C-1—O-5, C-2—C-3, fragmentations whose intensities depend on the substituents or functional groups present in the molecule. In most cases these fragmentations allow an assignment of the substitution mode of these 1,3,6-trioxa-bicyclo-[4.4.0]decane systems. The limitations of this method are discussed.
    Notes: La fragmentation en impact électronique est rapportée pour 46 benzylidéne-acétals d'hexopyranosides, appartenant aux séries allo, altro, galacto, gluco, gulo et manno ainsi que pour quelques produits de leur oxydation partielle. Indépendamment de l'ion moléculaire toujours présent et fréquemment partie d'un triplet ainsi que la rupture bien connu C-1—C-2, C-4—C-5 et (Ph)CH—O(C-4), on retrouvé généralement deux types de ruptures complémentaires (C-1—C-2, C-3—C-4; C-1—O-5, C-2—C-3, dont l'intensité varie selon la substitution ou selon la fonctionnalisation de la molécule. Ces fragmentations permettent dans la majorité des cas l'assignation des substitutions sur des systémes du type 1,3,6-trioxa-bicyclo[4.4.0]décane. Les limitations de cette méthode sont discutées.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 13 (1978), S. 477-482 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Twenty-nine α,β-(1 → 3) and (1 → 4) or β-(1 → 6) disaccharides, in the glucose series were analysed by electron impact mass spectrometry. In addition to the known mechanism, a few 13C labelled compounds led us to suggest that the ion c was formed from the reducing unit B and the C-1′ of the non-reducing residue A, while A was the starting point for rearrangement and fragmentation processes.
    Notes: Un ensemble de 29 dérivés disaccharidiques dans la série du D-glucose et présentant des liaisons glycosidiques α- et β- (1 → 3), α- et β- (1 → 4) et β- (1 → 6) a été analysé par spectrométrie de masse en impact électronique. Outre les mécanismes déjà connus le marquage au 13C de quelques composés conduit à proposer un mécanisme de formation pour un ion c formé de l'unité réductrice B avec rétention de C-1′ de l'unité non réductrice A d'où part la fragmentation et le réarrangement.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 28 (1993), S. 37-41 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron impact mass spectra of two series of 5-oxo-tetrahydro-5H-thiazolo [3,2-a]pyrimidine-6-ethylcarboxylates and 7-oxo-tetrahydro-7H-thiazolo [3,2-a]pyrimidine-6-ethylcarboxylates were measured and fragmentation patterns examined. Structures were assigned from analysis of oxo molecular ion fragmentations. Compounds of the 5-oxo series gave an [M - CO2C2H5]+ fragmentation whereas compounds of the 7-oxo series gave three characteristic cleavages. This decomposition was confirmed for one pair of isomers by high-resolution mass spectrometry and unimolecular mass-analysed ion kinetic energy spectrometry. Electron impact mass spectrometry is a convenient method for assigning structures of 5- and 7-oxo regioisomers of tetrahydrothiazolo[3,2-a]pyrimidine-6-carboxylates.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Glycoconjugate journal 16 (1999), S. 205-212 
    ISSN: 1573-4986
    Keywords: oligosaccharides ; glycosyltransferases ; glycobiology ; N-acetyllactosamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Scientific and commercial interest in oligosaccharides is increasing, but their availability is limited as production relies on chemical or chemo-enzymatic synthesis. In search for a more economical, alternative procedure, we have investigated the possibility of producing specific oligosaccharides in E. coli that express the appropriate glycosyltransferases. The Azorhizobium chitin pentaose synthase NodC (a β(1,4)GlcNAc-transferase), and the Neisseria β(1,4)galactosyltransferase LgtB, were co-expressed in E. coli. The major oligosaccharide isolated from the recombinant strain, was subjected to LC-MS, FAB-MS and NMR analysis, and identified as βGal(1,4)[βGlcNAc(1,4)]4GlcNAc. High cell density culture yielded more than 1.0 gr of the hexasaccharide per liter of culture. The compound was found to be an acceptor in vitro for βGal(1,4)GlcNAc α(1,3)galactosyltransferase, which suggests that the expression of additional glycosyltransferases in E. coli will allow the production of more complex oligosaccharides.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    ISSN: 1520-5118
    Source: ACS Legacy Archives
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 115 (1993), S. 10066-10076 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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