Hydrophilic carotenoids: surface properties and aggregation of an astaxanthin-lysine conjugate, a rigid, long-chain, highly unsaturated and highly water-soluble tetracationic bolaamphiphile

Chem Phys Lipids. 2007 Aug;148(2):63-9. doi: 10.1016/j.chemphyslip.2007.04.006. Epub 2007 Apr 21.


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).

MeSH terms

  • Absorption
  • Carotenoids / chemistry*
  • Lysine / analogs & derivatives*
  • Lysine / chemistry
  • Optics and Photonics
  • Scattering, Radiation
  • Solubility
  • Surface Properties
  • Surface-Active Agents / chemistry*
  • Water / chemistry*
  • Xanthophylls / chemistry


  • Surface-Active Agents
  • Xanthophylls
  • astaxanthin-lysine conjugate Asly
  • Water
  • Carotenoids
  • astaxanthine
  • Lysine