Considering
the large negative change in heat capacity that is observed during the binding of c-cyclodextrin, the
main driving force for the binding is hydrophobic interactions with dehydration, which is typical for
inclusion complex. NMR experiments showed that c-cyclodextrin interacts with the central part of the
aglycone moiety, not the glucuronic acid moieties, resulting in high binding affinity. It should also be
noted that the two distinct complexes of glycyrrhizic acid with c-cyclodextrin would exist in aqueous
solution.