Docosenoic acids positional isomers

Upcn hydrogenation, fish oils, especially the longer chain fatty acids (C22 s), form many new positional and geometric isomers. In some cases, partially hydrogenated fish oils may contain as many as 50% of the docosenoic acids in the trans form as opposed to the naturally occurring cis form. It is these trans isomers which may be responsible for the lipidosis of heart and skeletal muscle found in monkeys. Epidemiological studies of populations with high intakes of docosenoic acids. 

Comparison of Myocardial Necrosis Induced by Different Positional Isomers of Docosenoic Fatty Acids in Male Rats... 

In summary, it appears that the positional isomers of docosenoic acid are equivalent in their cardiopathogenic properties, and to date there is no convincing evidence that real differences exist when fish oils or rapeseed oils, with the same concentration of docosenoic fatty acid isomers are fed to rats. 

Therefore, one may conclude that all the docosenoic acid isomers, whether geometric or positional, are about equally cardiopathogenic in rats, provided that allowance is made for differences in digestibility. 

Positional and geometric isomers of docosenoic acid and other unsaturated fatty acids cannot in general be separated, identified and quantified by conventional packed column GLC, because the short columns do not possess the necessary powers of resolution. In consequence the more efficient techniques of capillary GLC and TLC have been applied to the problem of determining erucic acid in the presence of other docosenoic acid isomers. 

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