Inclusion complexes of β-cyclodextrine with organic ligands: Molecular dynamics simulation of the thermodynamic stability in gas phase and in water solution

摘要

The double decoupling version of the thermodynamic integration procedure is applied to perform the molecular dynamical modelling of binding free energies of β-cyclodextrine (CD) with a number of organic ligands. Simulations for water solutions show a satisfactory agreement (within 1-2 kcal/mol) with the experimentally measured equilibrium binding constants. The values are also reported for the gas phase complexation of the same ligands, although no experimental data are available for such systems. These gas phase computations have revealed the large stabilisation effect for the CD complexes of ionic ligands. Only in this special case the attempt of a qualitative rationalising the obtained simulation data proved to be fairly successful. The problems specific for simulations for ionic ligands in water solution are discussed.