- Synthesis of Rare Polyunsaturated Fatty Acids: Stearidonic and ω-3 Arachidonic
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Total chemical syntheses of the rare natural ω-3 C18 and C20 fatty acids, which possess potential antiinflammatory activity, were elaborated for subsequent studies of their biological activity.
- Golovanov,Ivanov,Groza,Myagkova
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p. 1038 - 1041
(2016/02/18)
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- Concise syntheses of three ω-3 polyunsaturated fatty acids
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The synthesis of the three ω-3 polyunsaturated fatty acids, eicosatetraenoic acid (3), docosapentaenoic acid (4), and stearidonic acid (5) has been achieved using eicosapentaenoic acid or docosahexaenoic acid as the starting materials.
- Jakobsen, Martin Gjerde,Vik, Anders,Hansen, Trond Vidar
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supporting information
p. 5837 - 5839
(2013/01/13)
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- Multiple genes for functional 6 fatty acyl desaturases (Fad) in Atlantic salmon (Salmo salar L.): Gene and cDNA characterization, functional expression, tissue distribution and nutritional regulation
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Fish are the primary source in the human food basket of the n-3 long-chain polyunsaturated fatty acids, eicosapentaenoate (EPA; 20:5n-3) and docosahexaenoate (DHA; 22:6n-3), that are crucial to the health of higher vertebrates. Atlantic salmon are able to synthesize EPA and DHA from 18:3n-3 through reactions catalyzed by fatty acyl desaturases (Fad) and elongases of very long chain fatty acids. Previously, two cDNAs encoding functionally distinct 5 and 6 Fads were isolated, but screening of a genomic DNA library revealed the existence of more putative fad genes in the Atlantic salmon genome. In the present study, we show that there are at least four genes encoding putative Fad proteins in Atlantic salmon. Two genes, 6fad_a and 5fad, corresponded to the previously cloned 6 and 5 Fad cDNAs. Functional characterization by heterologous expression in yeast showed that the cDNAs for both the two further putative fad genes, 6fad_b and 6fad_c, had only 6 activity, converting 47 % and 12 % of 18:3n-3 to 18:4n-3, and 25 and 7 % of 18:2n-6 to 18:3n-6, for 6Fad_b and 6fad_c, respectively. Both 6fad_a and 6fad_b genes were highly expressed in intestine (pyloric caeca), liver and brain, with 6fad_b also highly expressed in gill, whereas 6fad_c transcript was found predominantly in brain, with lower expression levels in all other tissues. The expression levels of the 6fad_a gene in liver and the 6fad_b gene in intestine were significantly higher in fish fed diets containing vegetable oil compared to fish fed fish oil suggesting up-regulation in response to reduced dietary EPA and DHA. In contrast, no significant differences were found between transcript levels for 6fad_a in intestine, 6fad_b in liver, or 6fad_c in liver or intestine of fish fed vegetable oil compared to fish fed fish oil. The observed differences in tissue expression and nutritional regulation of the fad genes are discussed in relation to gene structures and fish physiology.
- Monroig, Oscar,Zheng, Xiaozhong,Morais, Sofia,Leaver, Michael J.,Taggart, John B.,Tocher, Douglas R.
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experimental part
p. 1072 - 1081
(2011/10/30)
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- Substrate specificity and regioselectivity of Δ12 and ω3 fatty acid desaturases from Saccharomyces kluyveri
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Δ12 and ω3 fatty acid desaturases are key enzymes in the synthesis of polyunsaturated fatty acids (PUFAs), which are important constituents of membrane glycerolipids and also precursors to signaling molecules in many organisms. In this study, we determined the substrate specificity and regioselectivity of the Δ12 and ω3 fatty acid desaturases from Saccharomyces kluyveri (Sk-FAD2 and Sk-FAD3). Based on heterologous expression in Saccharomyces cerevisiae, it was found that Sk-FAD2 converted C16-20 monounsaturated fatty acids to diunsaturated fatty acids by the introduction of a second double bond at the ν + 3 position, while Sk-FAD3 recognized the ω3 position of C18 and C20. Furthermore, fatty acid analysis of major phospholipids suggested that Sk-FAD2 and Sk-FAD3 have no strong substrate specificity toward the lipid polar head group or the sn-positions of fatty acyl groups in phospholipids.
- Oura, Takahiro,Kajiwara, Susumu
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experimental part
p. 3174 - 3179
(2009/04/07)
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