title: [Nature of the interaction of Ca2+ with D-glucosamine: DFT quantum chemical study].
abstract: Geometric and electronic structure of D-glucosamine complexes with Ca2+ was studied with DFT (Density Functional Theory) method at B3LYP/6-31G(d) level of the theory. It was shown that in the most probable complex the cation interacts directly with oxygen atom of glucopyranose ring. The presence of six water molecules in the first hydration sphere of Ca2+ does not substantially affect the order of energetic favorability of complexes formed by different modes of cation coordination. Calculations within the frame of PCM model demonstrated that in aqueous solution the only stable complexes are those where Ca2+ interacts directly with glucopyranose ring oxygen. This interaction between the cation and glucosamine may be accompanied by deprotonation of O1H hydroxyl group and simultaneous protonation of amino group.
authors: M M
authors: MM
authors: Il'chenko
mesh_terms: D002118:Calcium / Q000737:chemistry*; D002413:Cations, Divalent; D056831:Coordination Complexes / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D011789:Quantum Theory; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D056831:Coordination Complexes; D014867:Water; D005944:Glucosamine; D010100:Oxygen; D002118:Calcium