Effect of Adamantyl Compounds on Dynamics of Spin Labelled Multilamellar Liposomes

Interactions of two adamantyl molecules: 3-(adamantan-1-yl)propan-1-aminium chloride (compound A) and 1-hydroxyadamantan (compound B) with multilayer liposomes composed of L-α-phosphatidylcholine, cholesterol and dicetylphosphate, spin labelled with n-doxylstearic acids (n = 5, 7, 10, 12, 16) were investigated. In the presence of aminium salt (A) or alcohol (B) the increased dynamics of 5-doxylstearic acids and 16-doxylstearic acids in the multilamellar liposomes were determined in the temperature range from 250 K to 295 K. The increased dynamics of 5-doxylstearic acids suggested that both adamantyl compounds influenced molecular motions in the interfacial region of the liposome. The increased motional properties of 16-doxylstearic acids, located in the core of the multilamellar liposomes, suggested that both adamantyl compounds induced the structural changes in the hydrophobic core as well.