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Paradox of omega‐3 PUFA oxidation
Author(s) -
Miyashita Kazuo
Publication year - 2014
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201400114
Subject(s) - chemistry , polyunsaturated fatty acid , docosahexaenoic acid , phosphatidylcholine , aqueous solution , micelle , linolenic acid , linoleic acid , solvent , molecule , liposome , aqueous two phase system , hydrogen bond , arachidonic acid , organic chemistry , medicinal chemistry , phospholipid , fatty acid , biochemistry , membrane , enzyme
The oxidative stability of polyunsaturated fatty acids (PUFAs) in micelles and in liposomes is dramatically different from that observed in the bulk phase and in organic solvents. In aqueous micelles, docosahexaenoic acid (DHA, 22:6n‐3) is oxidatively most stable followed by EPA (20:5n‐3), arachidonic acid (AA, 20:4n‐6), α‐linolenic acid (18:3n‐3), γ‐linolenic acid (18:3n‐6), and linoleic acid (LA, 18:2n‐6), respectively. In phosphatidylcholine (PC) liposomes, DHA‐PC showed the highest oxidative stability followed by AA‐PC and LA‐PC in that order. This order was completely opposite to that found in bulk and in organic solvent systems. NMR and GC‐MS analysis and a computer modelling approach to hydroperoxide isomer composition suggest that the physical and stereochemical characteristics of DHA molecules in the aqueous phase are related to its unusually high oxidative stability. The possible mechanisms are a tight packing conformation of DHA molecules and the presence of water molecule near the double bonds of DHA, which may inhibit hydrogen abstraction from the bis‐allylic positions of DHA. Effect of the relative location of the substrates and antioxidants and/or prooxidants on the lipid oxidation.