Docosahexaenoic acid methyl esters

FIGURE 1.21 Effect of initial molar ratio of various fatty acid esters to a-CD on the inclusion fraction of fatty acid esters in a-CD. O CAPME, A CPRME, MYRME, <> LINME, V EPAEE, DHAEE. Abbreviations CAPME, -caproic acid methyl ester CPRME, n-caprylic acid methyl ester LINME, linoleic acid methyl ester EPAEE, ethyl eicosapentae-noate DHAEE, ethyl docosahexaenoate. (From Yoshii, H. et ah, Oyo Toshitsu Kagaku, 42, 243, 1995. With permission.)... 

Figure 1.2 High-performance thin-layer chromatogram of methyl esters of fatty acids, showing separation based on unsaturation. The plates were developed in the solvent system hexane/ diethyl ether, 92 8 vol./vol. a = a standard mixture of tetracosaenoic (24 1 vol./vol.) and docosahexaenoic (22 6 vol./vol.) fatty acid methyl esters b = sea scallop lipids c = dogfish liver d = menhaden e = redfish f=rapeseed g = cod liver. Reproduced with permission from Shantha, N. C. and Ackman, R. G., Silica gel thin-layer chromatographic method for concentration of longer-chain polyunsaturated fatty acids from food and marine lipids, Canadian Institute oj Food Science and Technology Journal, 24, 156-60, 1991.

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. 

Omega-3 fatty acids as DHA (docosahexaenoic acid) and EPA (eicosapen-taenoic acid) are known for their wholesome impact on blood circulation. Eskimo people do not often suffer heart attacks despite of the fatty nourishment. This is due to the Omega-3 fatty acids present in the polar fish. As the glycerides cannot be distilled they are first converted into methyl- and/or ethyl-esters. Distillation... 

Radiation Biochemistry of Lipids. The rancidity that develops in stored fish is the result of oxidative reactions. Work being done with methyl docosahexaenoate shows that irradiation per se does not cause observable or measurable changes in this long-chain fatty acid ester. However, changes involving fatty acids go on at a higher rate in irradiated fishery products than in the nonirradiated counterparts (16). 

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