title: Dispersion state of phospholipids and fluorescence production with peroxidation in organic solvents: investigated by time-resolved fluorescence technique.
abstract: Fluorescent substances were found to be produced efficiently when phospholipids containing phosphatidylethanolamine (PE) and linoleic chains were autoxidized in non-polar solvents. By using these fluorescent substances as intrinsic probes, the dispersion state of phospholipids was investigated in various organic solvents. Fluorescence anisotropy decay measurements indicated that the aggregation size of phospholipids was much larger in hexane than in chloroform, methanol and tert-butyl alcohol. The average diameter of phospholipid aggregates in hexane was calculated to be 4-6 nm, which was dependent on the lipid composition. A consistent result was obtained when N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-gly cer o-3- phosphoethanolamine (NBD-PE) was used as an extrinsic probe. Comparison of the fluorescence data with small-angle X-ray scattering (SAXS) data suggested that a reverse micellar structure of phospholipids formed in hexane. It was shown that phospholipid aggregation enhanced the extent of peroxidation as well as the production yield of fluorescent substances of phospholipid.
authors.affiliation: Biophysics Laboratory, Institute of Physical and Chemical Research, Saitoma, Japan.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Fujisawa
authors.forename: T
authors.initials: T
authors.lastname: Ueki
authors.forename: T
authors.initials: T
authors.lastname: Kouyama
mesh_terms: D002855:Chromatography, Thin Layer; D005453:Fluorescence; D015200:Fluoroimmunoassay; D006586:Hexanes; D015227:Lipid Peroxidation; D015394:Molecular Structure; D010743:Phospholipids / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D006586:Hexanes; D010743:Phospholipids