title: Positional distribution of highly unsaturated fatty acids in triacyl-sn-glycerols of Artemia nauplii enriched with docosahexaenoic acid ethyl ester.
abstract: This paper presents the positional distribution of fatty acids in triacyl-sn-glycerols (TAG) of Artemia nauplii used in aquaculture as a live food for marine fish larvae. The nauplii were enriched with docosahexaenoic acid (DHA) ethyl ester (EE) in the form of gelatin-acacia microcapsules for 4, 18, and 24 h. TAG of the initial, enriched, and unenriched Artemia nauplii were subjected to stereospecific analysis. A remarkable increase of DHA content in the enriched Artemia TAG confirmed the view that DHA-EE is effectively assimilated and incorporated into the TAG fraction of Artemia nauplii. TAG of the nauplii enriched with 25 mg/L of DHA-EE contained DHA at concentrations of 5.9-6.8, 4.3-6.0, and 14.3-22.3 mol% in the sn-1, sn-2, and sn-3 positions, respectively. When the nauplii were enriched with 100 mg/L of DHA-EE, proportions of DHA in the sn-1, sn-2, and sn-3 positions were 5.2-8.6, 3.9-6.0, and 12.2-25.4 mol%, respectively. In all of the enriched Artemia, DHA was preferentially located in the sn-3 position followed in sequence by the sn-1 and sn-2 positions. The lower content of DHA in the sn-1 and sn-2 positions was consistent with low content of this acid in 1,2-diacyl-sn-glycerophospholipids. When fish larvae are reared on Artemia nauplii enriched with EE-type DHA oil, the larvae feed on DHA esterified in TAG with a positional distribution pattern similar to that of marine mammals (sn-3 >> sn-1 > sn-2) rather than that of fish or marine invertebrates (sn-2 >> sn-3 > sn-1).
authors.affiliation: Division of Marine Biosciences, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Japan. ando@pop.fish.hokudai.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Ando
authors.forename: Y
authors.initials: Y
authors.lastname: Oomi
mesh_terms: D000818:Animals; D001156:Artemia / Q000737:chemistry*; D004032:Diet; D004281:Docosahexaenoic Acids / Q000008:administration & dosage* / Q000032:analysis; D015118:Eicosapentaenoic Acid / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D014280:Triglycerides / Q000032:analysis*
chemical_list: D005231:Fatty Acids, Unsaturated; D014280:Triglycerides; D004281:Docosahexaenoic Acids; C067518:4,7,10,13,16,19-docosahexaenoic acid ethyl ester; D015118:Eicosapentaenoic Acid