title: Surface properties of polyene glycol phospholipid monolayers.
abstract: We studied the surface properties of monolayers composed of polyunsaturated conjugated ethylene glycol phospholipids (carotenoid lipids), compared the data with monolayers of dipalmitoylphosphatidylcholine (DPPC) to which carotenoids were added and evaluated the impact of the unsaturated glycol lipids on monolayers with the glycerolipid DPPC. The carotenoid based glycol lipids formed monolayers at the air/water interface. Using the Langmuir method we obtained series of pressure-area (π-A) isotherms and determined the limiting area A per molecule of three glycol lipids, C30:9-C0A=42.6±1.4Å2, C30:9-C2A=76.1±2.5Ǻ2and C30:9-C12A=354.0±12.0Å2and their mixtures with DPPC at various mole fraction X. C30:9-C0and C30:9-C2did not affect significantly the shape of the isotherm, but caused their slight shift toward a lower and larger molecular area, respectively. C30:9-C12at mole fractions X>0.02 affected the shape of isotherm. The compressibility modulus Cs-1of monolayers depended on the surface pressure. Cs-1value was substantially higher for DPPC monolayers in comparison with those of pure glycol lipids. At low surface pressure π=5-10mN/m and low mole fractions X<0.02 the glycol lipids formed complexes with DPPC; at higher surface pressure the separation of pure components took place. The dipole potential of the monolayers composed of cationic glycol lipids C30:9-C2and C30:9-C12was higher in comparison with those of zwitterionic DPPC and C30:9-C0. This may be connected with various contributions of dipole moments of the molecules and their orientation in the monolayer.
authors.affiliation: Comenius University, Department of Nuclear Physics and Biophysics, Mlynská Dolina F1, 842 48 Bratislava, Slovak Republic. Electronic address: tibor.hianik@fmph.uniba.sk.
authors.forename: Tibor
authors.initials: T
authors.lastname: Hianik
authors.affiliation: Department of Chemistry, The Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Christer L
authors.initials: CL
authors.lastname: Øpstad
authors.affiliation: Comenius University, Department of Nuclear Physics and Biophysics, Mlynská Dolina F1, 842 48 Bratislava, Slovak Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Šandorová
authors.affiliation: Comenius University, Department of Nuclear Physics and Biophysics, Mlynská Dolina F1, 842 48 Bratislava, Slovak Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Garaiová
authors.affiliation: Department of Chemistry, The Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Vassilia
authors.initials: V
authors.lastname: Partali
authors.affiliation: Department of Chemistry, The Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Hans-Richard
authors.initials: HR
authors.lastname: Sliwka
mesh_terms: D006018:Glycols / Q000737:chemistry*; D015394:Molecular Structure; D010743:Phospholipids / Q000737:chemistry*; D011090:Polyenes / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D006018:Glycols; D010743:Phospholipids; D011090:Polyenes
keywords: Carotenoids; Diol phospholipids; Dipole potential; Langmuir monolayers; Polyenes; Surface pressure