title: Preservation of polyunsaturated fatty acyl glycerides via intramolecular antioxidant coupling.
abstract: Ferulic acid and its esters are known to be effective antioxidants. Feruloyl di-γ-linolenoylglycerol was assessed for its ability to serve as an antioxidant for preventing the oxidation of its γ-linolenoyl polyunsaturated fatty acyl groups in model membrane phospholipid vesicles. The molecule was incorporated into single-lamellar vesicles comprised of 1,2-dioleoyl-sn-glycero-3-phosphocholine. Feruloyl di-γ-linolenoylglycerol was found to be highly resistant to 2,2'-azobis(2-amidinopropane) dihydrochloride-initiated oxidation in comparison to di-γ-linolenoylglycerol. Analysis of the individual fatty acyl chains indicated that degradation of γ-linolenoyl groups from feruloyl di-γ-linolenoylglycerol proceeded much more slowly than loss of the entire molecule, indicating that the feruloyl moiety was preferentially oxidized. In vesicles incorporating di-γ-linolenoylglycerol and an equal amount (5 mol% each) feruloyl dioleoylglycerol, the extent of γ-linolenoyl protection was not as great as when the γ-linolenoyl groups were molecularly combined with a ferulate group. These findings indicate that the ferulate group of feruloyl di-γ-linolenoylglycerol expresses intramolecular antioxidant activity. Direct coupling of polyunsaturated fatty acids with phenolic antioxidants may improve the oxidative stability of sensitive fatty acids in food or topical uses.
authors.affiliation: Renewable Product Technology, USDA-Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University St., Peoria, IL 61604, USA. Joe.Laszlo@ars.usda.gov
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Laszlo
authors.forename: Kervin O
authors.initials: KO
authors.lastname: Evans
authors.forename: David L
authors.initials: DL
authors.lastname: Compton
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D003373:Coumaric Acids / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005989:Glycerides / Q000737:chemistry*; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D005231:Fatty Acids, Unsaturated; D005989:Glycerides; D008081:Liposomes; C004999:ferulic acid