A study of aqueous sodium cholate by ²H nmr

Abstract

Solutions of aqueous sodium 7- 2 H-cholate have been studied as a function of cholate concentration by 2 H nmr. Relaxation times and solution viscosities have been used to show that cholate is monomeric in solution at 0.1 M. Increasing concentration leads to tetramer formation which is complete at 0.1 M. The tetramer solutions are stable up to 55 °C. Solutions of cholate in aqueous pyridine also form tetramers in the same fashion. Evidence was found, however, for a weak hydrogen bonding interaction between the two.