title: Phosphatidyl-hydroxytyrosol and phosphatidyl-tyrosol bilayer properties.
abstract: Hydroxytyrosol and tyrosol phospholipids were enzymatically synthesized and investigated for their bilayer properties. Dynamic light scattering demonstrated that hand extrusion at 100nm consistently resulted in liposomes of nearly 85nm diameter for both phosphatidyl-hydroxytyrosol (DOPHT) and phosphatidyl-tyrosol (DOPT). Transmission electron microscopy showed DOPT and DOPHT liposomes extruded at 100-nm to be spherical and non-distinctive from one another. Zeta potential measurements resulted in surface charges<-25mV, demonstrating both DOPT and DOPHT form highly stable liposomes. Quartz crystal microbalance with dissipation monitoring measurements demonstrated that liposomal adsorption was dependent on a combination of DOPT (or DOPHT) mole-percent and calcium ions concentration. Fluorescence anisotropy measurements indicated that melting temperatures of DOPT and DOPHT were below 4°C, suggesting that adsorption behavior and liposome formation was limited by electrostatic interactions and not gel-state formation.
authors.affiliation: Renewable Products Research Unit, USDA, Agriculture Research Service, National Center for Agricultural Utilization Research Center, 1815N. University Street, Peoria, IL 61604, USA. Electronic address: kervin.evans@ars.usda.gov.
authors.forename: Kervin O
authors.initials: KO
authors.lastname: Evans
authors.affiliation: Renewable Products Research Unit, USDA, Agriculture Research Service, National Center for Agricultural Utilization Research Center, 1815N. University Street, Peoria, IL 61604, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Compton
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; C005975:3,4-dihydroxyphenylethanol; C011867:4-hydroxyphenylethanol; D010626:Phenylethyl Alcohol
keywords: Phosphatidyl-hydroxytyrosol; Phosphatidyl-tyrosol; Quartz crystal microbalance with dissipation monitoring; Transmission electron microscopy; Zeta potential