title: Effects of ursolic acid on the structural and morphological behaviours of dipalmitoyl lecithin vesicles.
abstract: Effects of ursolic acid on the structural and morphological characteristics of dipalmitoyl lecithin(DPPC)-water system was studied by using differential scanning calorimetry (DSC), small- and wide-angle X-ray scattering (SWAXS), freeze-fracture method combined with transmission electron-microscopy (FF-TEM) and infrared spectroscopy (FT-IR). The surface of the uncorrelated lipid system is rippled or grained and a huge number of small, presumably unilamellar vesicles are present if the UA/DPPC molar ratio is 0.1 mol/mol or higher. Besides the destroyed layer packing of regular multilamellar vesicles, non-bilayer (e.g. cubic or hexagonal) local structures are evidenced by SAXS and FF-TEM methods. The ability of UA to induce non-bilayer structures in hydrated DPPC system originates from the actual geometry form of associated lipid and UA molecules as concluded from the FT-IR measurements and theoretical calculations. Beside numerous beneficial e.g. chemopreventive and chemotherapeutic effect of ursolic acid against cancer, their impact to modify the lipid bilayers can be utilized in liposomal formulations.
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Research Group of Biological Nanochemistry, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Lőrincz
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Research Group of Biological Nanochemistry, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: Judith
authors.initials: J
authors.lastname: Mihály
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Research Group of Biological Nanochemistry, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: Csaba
authors.initials: C
authors.lastname: Németh
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Research Group of Biological Nanochemistry, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Wacha
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Research Group of Biological Nanochemistry, 1117 Budapest, Magyar tudósok körútja 2, Hungary. Electronic address: bota.attila@ttk.mta.hu.
authors.forename: Attila
authors.initials: A
authors.lastname: Bóta
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives* / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D005614:Freeze Fracturing; D008081:Liposomes; D008567:Membranes, Artificial; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles; D053838:Scattering, Small Angle; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014315:Triterpenes / Q000737:chemistry* / Q000494:pharmacology; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D000097245:Ursolic Acid
chemical_list: D015060:1,2-Dipalmitoylphosphatidylcholine; D008081:Liposomes; D008567:Membranes, Artificial; D014315:Triterpenes; D014867:Water; D000097245:Ursolic Acid; C081581:colfosceril palmitate
keywords: DPPC; Freeze-fractured transmission electron-microscopy (FF-TEM); Non-bilayer lipid structure; Small- and wide-angle X-ray scattering (SWAXS); Ursolic acid