Docosahexaenoate

Z,Z,Z,)-9,12,15-octadecatrienoic acid). Fish oils contain esters of eicosanoic and docosanoic acids with four to six double bonds separated by single methylene groups, eg, (i7//-Z)-4,7,10,13,16,19-docosahexaenoic acid [6217-54-5] in menhaden oil (4). The fatty acid with conjugated double bonds in tung oil is a-eleostearic acid [506-23-0] ((F,Z,F)-9,ll,13-octadecatrienoic acid) the predominant fatty acid in oiticica oil is licanic acid [17699-20-6] (4-oxo-(F,Z,F)-9,ll,13-octadecatrienoic acid). In all oils, other fatty acids including palmitic acid [57-10-3] (hexadecanoic acid), stearic acid [57-11-4] (octadecanoic acid), and oleic acid [112-80-1] ((Z)-9-octadecenoic acid) also are present. 

Figure 10 Models of complexes between BLBP and two different fatty acids. The fatty acid ligand IS shown in the CPK representation. The small spheres in the ligand-bmdmg cavity are water molecules, (a) Model of the BLBP-oleic acid complex, in which the cavity is not filled, (b) Model of the BLBP-docosahexaenoic acid complex, m which the cavity is filled. The figure was prepared using the program MOLSCRIPT [236].

Arachidonic acid is present in membranes and accounts for 5-15% of the fatty acids in phospholipids. Docosahexaenoic acid (DHA 0)3, 22 6), which is syn-... 

Diethylenetriaminepentaacetic acid DFMO al-Difluoromethyl ornithine DFP Diisopropyl fluorophosphate DFX Desferrioxamine DGLA Dihomo-y-linolenic acid DH Delayed hypersensitivity DHA Docosahexaenoic acid DHBA Dihydroxybenzoic acid DHR Delayed hypersensitivity reaction... 

Speaking of food that is good for the body, scientists have also found an acid (called docosahexaenoic acid, or DHA) present in fish that they believe plays a very important role in the way the brain functions. DHA is an omega-3 fatty acid. About 60% of the human brain is made up of fat, and most of that appears to be DHA fat. 

Johnson, E. J., H. Y. Chung et al. (2008a). The influence of supplemental lutein and docosahexaenoic acid on serum, lipoproteins, and macular pigmentation. Am. J. Clin. Nutr. 87(5) 1521-1529. 

Johnson, E. J., K. A. McDonald et al. (2008b). Cognitive findings of an exploratory trial of docosahexaenoic acid and lutein supplementation in older women. Nutr. Neurosci. 11(2) 75-83. 

Chucair, AJ, Rotstein, NP, Sangiovanni, JP, During, A, Chew, EY, and Politi, LE, 2007. Lutein and zeaxanthin protect photoreceptors from apoptosis induced by oxidative stress Relation with docosahexaenoic acid. Invest Ophthalmol Vis Sci 48, 5168-5177. 

DFO, desferrioxamine Dfx, desulfoferrodoxin DHA, docosahexaenoic acid DHE, dihydroethidium DHLA, dihydrolipoic acid DHR, dihydrorhodamine 123... 

Unsaturated fatty acids are probably the most abundant oxidizable endogenous substrates. In the past it was erroneously believed that unsaturated fatty acids are just products of lipid peroxidation. Now, it has been shown that they have dietary origin. Family of unsaturated fatty acids includes linoleic (Ci8), arachidonic (C2o), docosahexaenoic (C22), and other fatty acids containing two, three, four, five, or six double bonds. Some acids can be in vivo converted into others for example, linoleic acid can be metabolized to linolenic and eicosa-trienoic acids [78]. 

Synaptic stimulation, ischemia or seizure activates phospholipase A2 and releases arachidonic and docosahexaenoic acids 578 Secretory phospholipases A2 are of relatively low molecular weight and have a high number of disulfide bridges, making them relatively more resistant to denaturation 579 There are high-affinity receptors that bind secretory phospholipase A2 579... 

Free arachidonic acid, along with diacylglycerols and free docosahexaenoic acid, is a product of membrane lipid breakdown at the onset of cerebral ischemia, seizures and other forms of brain trauma 585... 

Brain and retina are the tissues containing the highest contents of docosahexaenoic acid 586... 

Rhodopsin in photoreceptors is immersed in a lipid environment highly enriched in phospholipids containing docosahexaenoic acid, which is essential for rhodopsin function 587... 

Docosahexaenoic-acid-containing phospholipids are a target for lipid peroxidation 587... 

Docosanoids, enzyme-derived docosahexaenoic acid metabolites, were identified initially in the retina 587... 

Under physiologic conditions, the balance of membrane lipid metabolism, particularly that of arachidonoyl and docosahexaenoyl chains, favors a very small and tightly controlled cellular pool of free arachidonic acid (AA, 20 4n-3) and docosahexaenoic acid (DHA, 22 6n-3), but levels increase very rapidly upon cell activation, cerebral ischemia, seizures and other types of brain trauma [1, 2], Other free fatty acids (FFAs) in addition to AA, released during cell activation and the initial stages of focal and global cerebral ischemia, are stearic acid (18 0), palmitic acid (16 0) and oleic acid (18 1). 

Free arachidonic acid, along with diacylglycerols and free docosahexaenoic acid, is a product of membrane lipid breakdown at the onset of cerebral ischemia, seizures and other forms of brain trauma. Because polyunsaturated fatty acids are the predominant FFA pool components that accumulate under these conditions, this further supports the notion that fatty acids released from the C2 position of membrane phospholipids are major contributors to the FFA pool, implicating PLA2 activation as the critical step in FFA release [1,2] (Fig. 33-6). 

Docosahexaenoic-acid-containing phospholipids are targets for lipid peroxidation. As a result of free-radical-catalyzed peroxidation, F4-isoprostanes are formed [75, 76]. F2-isoprostanes are also derived from free-radical-catalyzed peroxidation, although from AA instead [77]. 

Mukherjee, P. K., Marcheselh, V. L., Serhan, C. N. and Bazan, N. G. Neuroprotectin Dl a docosahexaenoic add-derived doco-satriene protects human retinal pigment epithelial cells from oxidative stress. Proc. Natl Acad. Sci. U.S.A 101,8491-8496,2004. 

Bazan, N. G., Scott, B. L., Reddy, T. S. and Pelias, M. Z. Decreased content of docosahexaenoate and arachidonate in plasma phospholipids in Usher s syndrome. Biochem. Biophys. Res. Commun. 141 600-604,1986. 

Anderson, R. E., Maude, M. B., Alvarez, R. A, Acland, G. and Aguirre, G. D. A hypothesis to explain the reduced blood levels of docosahexaenoic acid in inherited retinal degenerations caused by mutations in genes encoding retina-specific proteins. Lipids 34, S235-S237,1999. 

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