title: An EPR spin probe study of liposomes from sunflower and soybean phospholipids.
abstract: Comparative properties of lecithin-based liposomes prepared from the mixed phospholipids of sunflower seeds, soybean and egg yolk were investigated by electron paramagnetic resonance (EPR) spectroscopy. For these investigations, stable nitroxide radicals, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 5,7-dimethyladamantane-1-carboxylate (DMAC-TEMPO), 5-doxylstearic acid (5-DSA) and 16-doxylstearic acid (16-DSA) were used as spin probes. Binding of the spin probes to the liposome membranes resulted in a substantial increase of the apparent rotational diffusion correlation times. The EPR spectra of the incorporated nitroxides underwent temperature-dependent changes. For every spin probe, values of apparent enthalpy and entropy of activation were calculated from the temperature dependence of rotational diffusion correlation times via Arrhenius equation. In case of DMAC-TEMPO, the data point to differences between the phospholipid bilayer of liposomes derived from sunflower and soy lecithin, and some similarity between the sunflower and egg yolk liposomes. Anisotropic hyperfine interaction constants of DMAC-TEMPO and 16-DSA included in the liposomes have been analyzed and attributed to different micropolarity of the surroundings of the spin probes. The kinetics of EPR signal decay of DMAC-TEMPO in the presence of 2,2'-azobis(2-amidinopropane) suggest the better stability of the sunflower liposomes to lipid peroxidation as compared to the liposomes prepared from soy lecithin.
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .|b Department of Sorption and Fine Inorganic Synthesis , Institute for Sorption and Problems of Endoecology , NAS of Ukraine , Kyiv , Ukraine and.
authors.forename: Andrii K
authors.initials: AK
authors.lastname: Melnyk
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .
authors.forename: Olexandr V
authors.initials: OV
authors.lastname: Sukhoveev
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .
authors.forename: Lyudmyla A
authors.initials: LA
authors.lastname: Kononets
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .
authors.forename: Olexandr M
authors.initials: OM
authors.lastname: Khilchevsky
authors.affiliation: c Department of Industrial and Food Biotechnology , Institute for Food Biotechnology and Genomics of NAS of Ukraine , Kyiv , Ukraine.
authors.forename: Serhiy M
authors.initials: SM
authors.lastname: Shulga
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .
authors.forename: Valery P
authors.initials: VP
authors.lastname: Kukhar
authors.affiliation: a Department of Bioorganic Mechanisms , Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine , Kyiv , Ukraine .
authors.forename: Andriy I
authors.initials: AI
authors.lastname: Vovk
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D006368:Helianthus / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D013025:Glycine max / Q000737:chemistry*
chemical_list: D008081:Liposomes; D010743:Phospholipids
keywords: EPR; lipid peroxidation; liposomes; spin probe; sunflower and soybean phospholipids