Capillary Electrophoresis, ROESY NMR and Molecular Modelling Study of the Inclusion Complex Beta-Cyclodextrin/Lipoic acid
Academic Article
Publication Date:
2002
abstract:
The interaction of lipoic acid with b-cyclodextrin (b-CD) has been studied
by capillary electrophoresis in aqueous phosphate buffer (20 mM, pH = 9.0)
at 20 °C. The results allowed us to detect the formation of an inclusion
complex with a 1:1 lipoic acid/ b-CD stoichiometry and an association
constant of 1645 M-1. The geometry of the inclusion complex in D2O was
investigated by means of 2D-ROESY (Rotating-frame Overhauser Enhancement
Spectroscopy) NMR experiments, which showed the occurrence of a bimodal
complexation of lipoic acid inside the b-CD cavity. Semi-empirical
calculations using the PM3 method show that the orientations of the
included lipoic acid are very close in energy, thus confirming the
experimental observations.
by capillary electrophoresis in aqueous phosphate buffer (20 mM, pH = 9.0)
at 20 °C. The results allowed us to detect the formation of an inclusion
complex with a 1:1 lipoic acid/ b-CD stoichiometry and an association
constant of 1645 M-1. The geometry of the inclusion complex in D2O was
investigated by means of 2D-ROESY (Rotating-frame Overhauser Enhancement
Spectroscopy) NMR experiments, which showed the occurrence of a bimodal
complexation of lipoic acid inside the b-CD cavity. Semi-empirical
calculations using the PM3 method show that the orientations of the
included lipoic acid are very close in energy, thus confirming the
experimental observations.
Iris type:
01.01 Articolo in rivista
List of contributors:
Saielli, Giacomo
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