Jump to main content
Jump to site search

Issue 40, 2017
Previous Article Next Article

Comparison of the Ca2+ complexing properties of isosaccharinate and gluconate – is gluconate a reliable structural and functional model of isosaccharinate?

Author affiliations

Abstract

The calcium complexation and acid–base properties of α-D-isosaccharinate (Isa) in neutral and in (hyper)alkaline solutions have been investigated via potentiometric titrations, multinuclear NMR, ESI-MS and quantum chemical calculations. Isa is the primary alkaline degradation product of cellulose, and may be present in radioactive waste repositories and therefore, it could contribute to the mobilization of radioactive nuclei. Because of its limited availability, D-gluconate (Gluc) is commonly used as a structural and functional model of Isa. Therefore, the thermodynamic and structural data obtained for Isa were compared with those of Gluc. The formation constants of the CaIsa+ and CaGluc+ complexes present in neutral solutions are practically identical, but the binding sites are in different positions and the CaIsa20 solution species cannot be detected. The stepwise formation constant of the CaIsaH−10 complex (forming in alkaline medium) is somewhat larger than that of CaGlucH−10, which is in line with the observation that IsaH−12− is a stronger base than GlucH−12−. The most striking difference is that, unlike Gluc, Isa does not form polynuclear complexes with Ca2+. The structural reason for this is that the alcoholate groups on C2 and C3 adjacent to the carboxylate moiety on Gluc are able to simultaneously bind Ca2+, making the formation of polynuclear Ca-complexes possible. On Isa, only the alcoholate on C2 is involved, while the other one on C6 is not (supposedly for steric reasons). In conclusion, during the interactions of Gluc and Isa with Ca2+, differences rather than similarities prevail.

Graphical abstract: Comparison of the Ca2+ complexing properties of isosaccharinate and gluconate – is gluconate a reliable structural and functional model of isosaccharinate?

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Aug 2017, accepted on 16 Sep 2017 and first published on 18 Sep 2017


Article type: Paper
DOI: 10.1039/C7DT03120C
Citation: Dalton Trans., 2017,46, 13888-13896
  • Open access: Creative Commons BY license
  •   Request permissions

    Comparison of the Ca2+ complexing properties of isosaccharinate and gluconate – is gluconate a reliable structural and functional model of isosaccharinate?

    C. Dudás, B. Kutus, É. Böszörményi, G. Peintler, Z. Kele, I. Pálinkó and P. Sipos, Dalton Trans., 2017, 46, 13888
    DOI: 10.1039/C7DT03120C

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements