title: Hydrophilic carotenoids: surface properties and aqueous aggregation of a rigid, long-chain, highly unsaturated dianionic bolaamphiphile with a carotenoid spacer.
abstract: The water dispersibility of astaxanthin was greatly enhanced by converting it to a disodium disuccinate salt. This carotenoid salt behaved as a bolaamphiphile in water; dynamic light scattering (DLS) revealed the formation of stable aggregates with an average hydrodynamic radius close to 1 microm. Larger aggregates were observed in solutions of increased osmolarity. Absorption spectra demonstrated that the aggregates could withstand the addition of 20% acetonitrile before disintegrating to monomers. The physicochemical properties of this astaxanthin derivative in solution were comprehensively studied by measuring surface tension, critical aggregate concentration, surface concentration, molecule area, free energy of adsorption and micellation, adsorption-aggregate energy relationship, and equilibrium constants, and then compared with similar compounds reported previously in the literature.
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.
authors.forename: Bente Jeanette
authors.initials: BJ
authors.lastname: Foss
authors.forename: Hans-Richard
authors.initials: HR
authors.lastname: Sliwka
authors.forename: Vassilia
authors.initials: V
authors.lastname: Partali
authors.forename: Stine Nalum
authors.initials: SN
authors.lastname: Naess
authors.forename: Arnljot
authors.initials: A
authors.lastname: Elgsaeter
authors.forename: Thor Bernt
authors.initials: TB
authors.lastname: Melø
authors.forename: K Razi
authors.initials: KR
authors.lastname: Naqvi
authors.forename: Sean
authors.initials: S
authors.lastname: O'Malley
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Lockwood
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D005505:Food Coloring Agents / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water
chemical_list: D005505:Food Coloring Agents; D013501:Surface-Active Agents; D014867:Water; D002338:Carotenoids