Hydrophilic carotenoids: surface properties and aggregation of an astaxanthin-lysine conjugate, a rigid, long-chain, highly unsaturated and highly water-soluble tetracationic bolaamphiphile.
The surface and aggregation properties of a synthetic, highly water-soluble carotenoid, the tetracationic astaxanthin-lysine conjugate (Asly), have been examined through measurements of surface tension, optical absorption and dynamic light scattering. The following parameters were determined: critical aggregation concentration c(M), surface concentration Gamma, molecular area a(m), free energy of adsorption and aggregation (DeltaG(ad) degrees and DeltaG(M) degrees , respectively), and the aggregate size r(H). The compound forms true monomolecular solutions in water below c(M); aggregates emerge only at rather high concentrations (> or =2.18 mM).
Naess
Stine Nalum
SN
Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.
Sliwka
Hans-Richard
HR
Partali
Vassilia
V
Melø
Thor Bernt
TB
Razi Naqvi
K
K
Jackson
Henry L
HL
Lockwood
Samuel F
SF
D000042:Absorption; D002338:Carotenoids / Q000737:chemistry*; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry; D055095:Optics and Photonics; D012542:Scattering, Radiation; D012995:Solubility; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D024341:Xanthophylls / Q000737:chemistry
D013501:Surface-Active Agents; D024341:Xanthophylls; C523360:astaxanthin-lysine conjugate Asly; D014867:Water; D002338:Carotenoids; C005948:astaxanthine; D008239:Lysine