An X-Ray Diffraction Study of Lipid Films with ICHPHAN

Abstract

X-ray diffraction was used to study oriented films formed from solutions in chloroform of egg phosphatidylcholine, the synthetic hybrid antioxidant ICHPHAN-10-C-10, and their mixtures containing 12.5 and 32 wt % of ICHPHAN. The air-dried films obtained from phosphatidylcholine and ICHPHAN were multiphase and, in addition to nonlayered lipid phases, contained the crystalline phase of ICHPHAN. With an increase in the degree of hydration of such films, the formation of a single lamellar phase consisting of lipids and ICHPHAN occurred in them. The appearance and disappearance of the crystalline phase of ICHPHAN in the films with a change in their degree of hydration was reversible. The electron density profiles of lipid membranes calculated with a resolution of ~1.2 nm showed that in the presence of ICHPHAN, the membrane thickness was reduced and the ordering of lipid hydrocarbon chains in it decreased. The results we obtained indicated the ability of ICHPHAN to integrate from the crystalline phase into lipid membranes in large quantities.