Étude Structurale par Microspectrométries Raman et Infrarouge de Figures Myéliniques Formées á Partir des Systémes Acide 2-g Octadécénoique/Solution D'Hydrazine 5M et Cholesterol Monohydraté/Solution Saturée d'Oléate de Sodium

Abstract

Abstract Myelin forms, i.e. multilayer structures (Lα) grown in tubular fashion, prepared from pure Z-9 octadecenoic acid and hydrazine 5M aqueous solution (system I) and from solid monohydrated cholesterol and sodium oleate saturated aqueous solution (system II) have been studied by means of Raman and infrared microspectrometry. In both systems, significant spectroscopic evidences show that numerous hydrogen bonds occur in the interfacial zone, which contribute to the stability of the lipidic sheets, i.e. to the decrease of their permeability. In the system I, the structural molecular unit is formed by one oleic acid molecule and one oleate ion linked by acid salt type asymmetric hydrogen bond; in the system II, the hydrogen bonding occurs between the cholesterol 3β-hydroxyl functions and the oleate carboxylate groups. In both systems, the hydrophilic zone is surrounded by a water belt arising from hydration of the amphiphilic molecules polar groups; in addition to these interactions, in the system I wat...