Docosahexaenoic acid , structure

Gawrisch K, Holte LL, Koenig BW, Polozov IV. Salley AMK. Teague WE. NMR Investigations of docosahexaenoic acid structure and flexibility. PUFA in Maternal and Child Health Conference, 2000. 

Lu, Y., H. Tian et al. 2010. Novel 14,21-dihydroxy-docosahexaenoic acids Structures, formation pathways, and enhancement of wound heaUng. 51(5) 923-932. 

Dietary polyunsaturated fatty acids (PUFAs), especially the n-3 series that are found in marine fish oils, modulate a variety of normal and disease processes, and consequently affect human health. PUFAs are classified based on the position of double bonds in their lipid structure and include the n-3 and n-6 series. Dietary n-3 PUFAs include a-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) whereas the most common n-6 PUFAs are linoleic acid, y-linolenic acid, and arachidonic acid (AA). AA is the primary precursor of eicosanoids, which includes the prostaglandins, leukotrienes, and thromboxanes. Collectively, these AA-derived mediators can exert profound effects on immune and inflammatory processes. Mammals can neither synthesize n-3 and n-6 PUFAs nor convert one variety to the other as they do not possess the appropriate enzymes. PUFAs are required for membrane formation and function... 

Haraldsson, G. G., Halldorsson, A., and Kulas, E. 2000. Chemoenzymatic synthesis of structured triacylglycerols containing eicosapentaenoic and docosahexaenoic acids /. Am. Oil Chem. Soc., 77,1139-1145. 

Some polyunsaturated fatty acids were tested for the production of hydroxy fatty acids by PR3 because polyunsaturated fatty acids contained a, 4-ds,cis-diene unit which could serve as a key structural element for the hydroxylation by lipoxygenase. When eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) carrying l,4-d c y-diene unit were used as substrates for bioconversion by PR3, new products were detected on TLC analysis as shown in... 

DNP dinitrophenyl CBZ carbobenzoxy OBzl benzylesters /3NA naphthyl amide TCP tetrachlorofluorescein amaryllis alkaloids crinine, powelline, and crinamidine vinca alkaloids vincamine and vincine structural isomers 2- and 6-nitro-3-acetamido-4-chlorobenzoic acid stereoisomers 4-methoxymethyl-l-methyl-cyclohexane carboxylic acid fish oil mixture of docosahexaenoic acid and eicosapentaenoic acid NDGA nordihydroguaiaretic acid. 

Role of Docosahexaenoic Acid in Determining Membrane Structure and Function... 

Docosahexaenoic acid has the potential to affect cell function by modulating two aspects of membrane proteins synthesis (particularly via transcriptional control) (Sellmayer et al., 1997) and structure (within the lipid milieu of the membrane). Although understanding the effect of DHA on proteins is still in its infancy, two examples, rhodopsin and protein kinase C (PKC), have been particularly well studied. The effect of DHA on rhodopsin is reviewed in detail in Chapter 2. 

Holte LL, Koenig BW, Strey HH, Gawrisch KBJ. Structure and dynamics ofthe docosahexaenoic acid chain in bilayers studied by NMR and X-ray diffraction. Biophys J 1998 74 A371. 

Pascale AW, Ehringer WD, Stillwell W, Sturdevant LK, Jenski LJ. Omcga-3 fatty acid modification of membrane structure and function. 11. Alteration by docosahexaenoic acid of tumor cell sensitivity to immune cytolysis. Nutr Cancer 1993 19 147-158. 

Aside from essential amino acids, the n-3 and n-6 fatty acids constitute the largest chemical component of the cerebral cortex and retina that can be obtained only from the diet. The body cannot synthesize either the n-3 or the n-6 structure. Once the basic n-3 structure is consumed in the form of linolenic acid (18 3), the body can synthesize the longer-chained and highly polyunsaturated fatty acid docosahexaenoic acid (22 6), which is the n-3 fatty acid so predominant in the nervous system. Similarly, in the n-6 series, linoleic acid (18 2) is converted to arachidonic acid (20 4), the predominant n-6 fatty acid... 

FA distribution in TAG as well as in phospholipids affects the physical properties, lipolitic and oxidative stability, and nutritional availability of lipids. In many TAG, the FA are arranged in a nonrandom distribution. In plants, monoenoic FA and PUFA are dominant at a sn-2 position (Orthoefer, 1996). In pig depot fat and in cow s milk, the TAG sn-2 position is occupied by palmitic acid. The distribution is also different in cattle and sheep depot fats (Love, 1996). In blubber seals, long-chain n-3 PUFA are esterified rather in sn-l,3 positions, whereas, in muscle, TAG in the sn-2 position that is typical for the lipid muscles of nearly all fish (Ackman, 1994). Enzymatic syntheses of structured TAG containing dY-5,8,ll,14,17-eicosapentaenoic acid (EPA) and dY-4,7,10,13,16,19-docosahexaenoic acid (DHA) in the sn-2 position with medium-chain FA at the end positions are particularly interesting (Halldorsson... 

Jenski, L.J., and Stillwell, W. (2001) Role of Docosahexaenoic Acid in Determining Membrane Structure and Function, in Fatty Acids Physiological and Behavioral Functions (Mostofsky, D.I., Yehuda, S., and Salem, N., eds.) pp. 41-62, Humana Press, Totowa, NJ. 

Pascale,A.W.,Ehringer,WD., StUwell W., Sturdevant,L.K., and Jenski, L.J. (1993) Omega-3 Fatty Acid Modification of Membrane Structure and Function n. Alteration by Docosahexaenoic Acid of Tumor Cell Sensitivity to Immune Cytolysis, iVirir. Cancer 19,147-157. 

Jennings, B.H., and Akoh, C.C. (1999) Enzymatic Modification of Triacylglycerols of High Eicosapentaenoic and Docosahexaenoic Acids Contents to Produce Structured Lipids, /. Am. Oil Chem. Soc. 76,1133 1137. 

Derivatization of Fatty Acids Derivatized fatty acids have been analyzed to improve ionization and fragmentation characteristics. The FAB spectra of these derivatives are structurally more informative, and fragmentations predominantly occur via CRF processes. One such example is the application of aminoethyl-triphenylphosphonium (AETPP) bromide derivatives to characterize fatty acids structurally by FAB-MS/MS [12]. Other examples include derivatives of aminon-aphthalenesulfonic acid (ANSA), aminobenzenesulfonic acid (ABSA), picolinyl ester, yV-methyl-2-alkylimidazoline (MIM), and dimethyl- (DMAE) and trimethy-laminoethyl (TMAE) esters [8, and references therein], ESI-MS/MS spectra of underivatized and ANSA derivatives of docosahexaenoic acid are compared in Figure 12.8. 

Figure 4. Structures of co-3 fatty acids, aoidseicosapentaenoic acid and docosahexaenoic acid.

Kim, H.-Y. and Salem, N. Jr (1989) Preparation and structural determination of hydroperoxy derivatives of docosahexaenoic acid and other polyunsaturates by thermospray LC/MS. Prostaglandins, 37, 105-19. 

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