title: Occurrence of geometrical isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids of rats fed heated linseed oil.
abstract: Mono trans geometrical isomers of 20:5 n-3 and 22:6 n-3 were detected in liver lipids of rats fed heated linseed oil. The isomers were identified as being 20:5 delta 5c,8c,11c,14c,17t and 22:6 delta 4c,7c,10c,13c,16c,19t. These fatty acids were isolated as methyl esters by preparative high-performance liquid chromatography (HPLC) on reversed phase columns followed by silver nitrate thin layer chromatography (AgNO3-TLC). The structures were identified using partial hydrazine reduction, AgNO3-TLC of the resulting monoenes, oxidative ozonolysis of each monoene band, and gas-liquid chromatography (GLC) of the resulting dimethyl esters and monomethyl esters. Fourier-transform-infrared spectrometry confirmed the trans geometry in isolated 20:5 and 22:6 isomers. The isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids probably resulted from desaturation and elongation of 18:3 delta 9c,12c,15t, a geometrical isomer of linolenic acid present in the heated dietary oil.
authors.affiliation: Station de Recherches sur la Qualite des Aliments de l'Homme, Dijon, France.
authors.forename: A
authors.initials: A
authors.lastname: Grandgirard
authors.forename: A
authors.initials: A
authors.lastname: Piconneaux
authors.forename: J L
authors.initials: JL
authors.lastname: Sebedio
authors.forename: S F
authors.initials: SF
authors.lastname: O'Keefe
authors.forename: E
authors.initials: E
authors.lastname: Semon
authors.forename: J L
authors.initials: JL
authors.lastname: Le Quére
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000032:analysis*; D015118:Eicosapentaenoic Acid / Q000032:analysis*; D005583:Fourier Analysis; D006358:Hot Temperature; D007536:Isomerism; D008043:Linseed Oil / Q000008:administration & dosage / Q000378:metabolism; D008099:Liver / Q000032:analysis*; D051381:Rats
chemical_list: D004042:Dietary Fats, Unsaturated; D004281:Docosahexaenoic Acids; D008043:Linseed Oil; D015118:Eicosapentaenoic Acid