NMR Relaxation Study of Cholesterol Binding with Plant Metabolites

Nuclear magnetic resonance relaxation technique has been applied to study the interaction of cholesterol and its oxidation products with plant metabolite, glycyrrhizic acid. In all cases, the decay kinetics of echo signal shows bi-exponential behavior. It was demonstrated that the fast component of the decay kinetics belongs to the complex with stoichiometry of 1:2. The stability constants and thermodynamic parameters of these complexes have been measured. We propose that the complexation with glycyrrhizic acid could be an effective approach to regulate the cholesterol level inside and outside of cage membranes. In addition, the importance of this approach as a tool for reducing the cytotoxicity of the oxidation products of cholesterol is under discussion.