Interactions Study between the Copper II Ion and Constitutive Elements of Chitosan Structure by DFT Calculation
- 24 November 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in Biomacromolecules
- Vol. 7 (1), 31-37
- https://doi.org/10.1021/bm0504126
Abstract
Molecular modeling is particularly useful to understand interactions between various kinds of molecules and ions. This study is aimed at studying the interactions between one Cu2+ ion and one or several glucosamine residues. The geometries and the interaction energies of all of the complexes involving all of the dimers obtained from glucosamine and N-acetylglucosamine were computed by means of density functional theory (DFT) methods. In a first step, for the two dimers A−A and A−B (A for glucosamine and B for N-acetyl glucosamine), a starting geometry was built, and the energies were calculated using a rigid rotation of 30° intervals for each of the dihedral angles (Φ and Ψ) of the glycosidic bond, spanning the whole angular range. These calculations allowed us to retrieve the minimal energy conformation and investigate all possible conformations. The results were compared to some experimental data. In a second step, we investigated the interactions of Cu2+ with the different possible coordination sites of A. For all complexes considered, the Cu2+ site was completed with H2O and/or OH- ligands to have a global neutral charge. The calculations confirmed that the most stable interactions involved the free amino site in a “pending complex”. Another pending form was possible considering the participation of the heterocyclic O site, but the latter was less favored. On the other hand, we also showed that glucosamine could not act as a bidentate ligand and that N-acetyl glucosamine was not coordinating with Cu2+. Finally, our results evidenced a cooperative fixation of Cu2+ ions when considering the complexation of two successive metal ions on the two consecutive glucosamine residues of the dimer A−A.Keywords
This publication has 17 references indexed in Scilit:
- Physicochemical Behavior of Homogeneous Series of Acetylated Chitosans in Aqueous Solution: Role of Various Structural ParametersBiomacromolecules, 2004
- Chemistry with ADFJournal of Computational Chemistry, 2001
- Molecular and Crystal Structure of Hydrated ChitosanMacromolecules, 1997
- Interaction between Chitosan and Uranyl Ions. Role of Physical and Physicochemical Parameters on the Kinetics of SorptionLangmuir, 1997
- Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlationPhysical Review B, 1992
- Gaussian density functional calculations on hydrogen-bonded systemsJournal of the American Chemical Society, 1992
- Circular dichroism studies on .alpha.-L-glutamic acid oligomers in solutionJournal of the American Chemical Society, 1976
- Metal Complexes of D-Glucosamine and its Derivatives. III. Determinations of Acid Dissociation Constants of D-Glucosamine and its Three O-Methyl DerivativesCHEMICAL & PHARMACEUTICAL BULLETIN, 1965
- N herungsmethode zur L sung des quantenmechanischen Mehrk rperproblemsThe European Physical Journal A, 1930
- The Wave Mechanics of an Atom with a Non-Coulomb Central Field. Part I. Theory and MethodsMathematical Proceedings of the Cambridge Philosophical Society, 1928