Thermal Studies on Polymorphism of Phospholipids. I. Polymorphism of Lecithin-Water Mixtures

Abstract

DSC curves of mixtures of synthetic L-phosphatidyl choline and water were measured for samples prepared under various conditions. Various kinds of phase transition were detected and the values for transition temperature and transition enthalpy were obtained from the DSC curves. Between 25°and 140°, there are three lyotropic polymorphs each of which has several thermotropic polymorphs. For phosphatidyl choline with longer hydrocarbon chains, an additional polymorph in crystalline form, was found. On the basis of these experimental results, a phase diagram of phosphatidyl choline-water system was drawn.