GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The NMR spectra of the carbanions of xanthene and thioxanthene. Evidence for paratropism (1974)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 245-249 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectra of the carbanions of xanthene [XH]- and thioxanthene [TxH]- have been recorded and interpreted. Paratropism in the central rings of [XH]- and [TxH]- is inferred from a comparison of the chemical shifts with those of the carbanion of 9,10-dihydroanthracene [AH]-. The contributions to the chemical shifts arising from n-electron excess charges, local dipoles and magnetic anisotropies are discussed. Numerical values for the various ring currents have been estimated by a least squares analysis of the observed chemical shifts after applying corrections for the excess charge effect. The results point to a strongly increasing paramagnetic ring current in the central ring in the order [AH]-, [TxH]-, [XH]-.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270060413
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The proton exchange reaction between indene and the indenyl anion (1974)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 574-576 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton exchange reaction between the indenyl carbanion and its parent compound indene has been studied by NMR as a function of temperature. The rate of this bimolecular reaction is very low and has been found to be strongly dependent on the polarity of the solvent. In solvents like dimethoxyethane (∊ = 7·2) and diglyme the reaction becomes manifest in the NMR spectrum only at elevated temperatures (T 〉 150°C). In hexamethylphosphortriamide (∊ = 30) the rate is much greater and line broadening may be observable at room temperature. The reaction in this solvent is characterised by a frequency factor f = 7 × 107 1 mol-1 s-1, an activation enthalpy ΔH ≠ = 9·5 kcal mol-1 and an entropy of activation ΔS≠ = -23 e.u. The low reaction rate and its solvent dependence are briefly discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270061104
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Annexin A11 is targeted by IgG4 and IgG1 autoantibodies in IgG4-related disease (2018)
    BMJ Publishing Group
    In: Gut
    Details
    Publication Date: 2018-03-09
    Description: Objective Immunoglobulin G4-related disease (IgG4-RD) is a multiorgan immune-mediated disease that predominantly affects the biliary tract (IgG4-associated cholangitis, IAC) and pancreas (autoimmune pancreatitis, AIP). We recently identified highly expanded IgG4+ B-cell receptor clones in blood and affected tissues of patients with IAC/AIP suggestive of specific (auto)antigenic stimuli involved in initiating and/or maintaining the inflammatory response. This study aimed to identify (auto)antigen(s) that are responsible for the clonal expansion of IgG4+ B cells in IgG4-RD. Design We screened sera of patients with IAC/AIP (n=50), in comparison to control sera of patients with primary sclerosing cholangitis (PSC) and pancreatobiliary malignancies (n=47), for reactivity against human H69 cholangiocyte lysates on immunoblot. Subsequently, target antigens were immunoprecipitated and analysed by mass spectrometry. Results Prominent reactivity against a 56 kDa protein was detected in human H69 cholangiocyte lysates exposed to sera of nine patients with IAC/AIP. Affinity purification and mass spectrometry analysis identified annexin A11, a calcium-dependent phospholipid-binding protein. Annexin A11-specific IgG4 and IgG1 antibodies were only detected in serum of patients with IgG4-RD of the biliary tract/pancreas/salivary glands and not in disease mimickers with PSC and pancreatobiliary malignancies. Epitope analysis showed that two annexin A11 epitopes targeted by IgG1 and IgG4 autoantibodies were shared between patients with IAC/AIP and IgG4 antibodies blocked binding of IgG1 antibodies to the shared annexin A11 epitopes. Conclusion Our data suggest that IgG1-mediated pro-inflammatory autoreactivity against annexin A11 in patients with IgG4-RD may be attenuated by formation of annexin A11-specific IgG4 antibodies supporting an anti-inflammatory role of IgG4 in IgG4-RD.
    Keywords: Gut
    Print ISSN: 0017-5749
    Electronic ISSN: 1468-3288
    Topics: Medicine
    Published by BMJ Publishing Group
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...