Phospholipid-Alcohol Interactions: Effects of Chain-Length and Headgroup Variations

Introduction: Solvated phospholipids exhibit a rich polymorphism which depends not only on the lipid chemical structure but also on the characteristics of the bathing solution [1]. This is due to the strong and influential interactions between the lipid headgroups and the solvent or solute molecules. Particularly efficient in this respect are various cationic molecules or molecules with a high propensity to hydrogen bond formation which all bind avidly to the lipid phosphate groups. The di- and polyvalent cations, for example, are electrostatically attracted by the negative electronic cloud around the (typically ionized) PO 4 −-group; protons donating or accepting molecules, such as the amino-compounds or the molecules with the readily accessible OH-residues, bind directly to the OH-groups on the phosphates via H-bonds. Water and various alcohols are the most prominent examples for this latter type of interaction.