docosapentaenoic-acid and 4-4-dimethyloxazoline

Phosphatidylethanolamine and phosphatidylcholine were major components in the foot lipids of the turban shell Turbo cornutus, while triacylglycerol was the major one in its viscera, which demonstrate the high level of lipid in all specimens. The major polyunsaturated fatty acids (PUFA) in the major lipid classes of T. cornutus were 20:4n-6 (arachidonic acid; ARA), 20:5n-3 (ecosapentaenoic acid; EPA), 22:4n-6, and 22:5n-3 (docosapentaenoic acid; n-3 DPA), with very low levels of 22:6n-3 (docosahexaenoic acid; DHA). The unusual high levels of ARA, 22:4n-6, and n-3 DPA found in both the triacylglycerols and phospholipids of all specimens suggest the influence of dietary algae on its tissue lipids. In the polar lipids, the total PUFA content was consistently high, with n-6 PUFA compensating for the fluctuation in the total n-3 PUFA levels. T. cornutus concentrated high levels of ARA in the visceral lipids from the dietary algae whose lipid content were very low. The viscera may effectively serve as a source of ARA for infant formulas. High levels of ARA, EPA, and n-3 DPA in the phospholipids of T. cornutus were observed. T. cornutus is a healthful marine food containing high levels of n-3 DPA.

Topics: Animals; Arachidonic Acid; Chromatography, Gas; Chromatography, Liquid; Dietary Fats; Docosahexaenoic Acids; Fatty Acids, Unsaturated; Food Analysis; Food Handling; Gastropoda; Magnetic Resonance Spectroscopy; Oxazoles; Phospholipids; Triglycerides

A series of unusual odd-chain fatty acids (OC-FA) were identified in two thraustochytrid strains, TC 01 and TC 04, isolated from waters off the south east coast of Tasmania, Australia. FA compositions were determined by capillary GC and GC-MS, with confirmation of polyunsaturated fatty acids (PUFA) structure performed by analysis of 4,4-dimethyloxazoline derivatives. PUFA constituted 68-74% of the total FA, with the essential PUFA; eicosapentaenoic acid (20:5ω3, EPA), arachidonic acid (20:4ω6, AA) and docosahexaenoic acid (22:6ω3, DHA), accounting for 42-44% of the total FA. High proportions of the saturated OC-FA 15:0 (7.1% in TC 01) and 17:0 (6.2% in TC 04) were detected. The OC-FA 17:1ω8 was present at 2.8% in TC 01. Of particular interest, the C₂₁ PUFA 21:5ω5 and 21:4ω7 were detected at 3.5% and 4.1%, respectively, in TC 04. A proposed biosynthesis pathway for these OC-PUFA is presented. It is possible that the unsaturated OC-PUFA found previously in a number of marine animals were derived from dietary thraustochytrids and they could be useful biomarkers in environmental and food web studies.

Topics: Arachidonic Acid; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Gas Chromatography-Mass Spectrometry; Molecular Structure; Oxazoles; Seawater; Stramenopiles; Tasmania