Isomerization Of Polyunsaturated Fatty Acids Research Articles

Analysis of fatty acid methyl esters on an sp 2340 glass capillary column

For the gas-liquid chromatographic separation of a complex mixture of fatty acid methyl esters, particularly the distribution of geometric isomers of unsaturated fatty acids, a glass capillary column coated with SP 2340 cyanopropylsiloxane stationary phase was prepared. Separations of 16:1ω 7c/16:1ω 7t, 22:1ω9c/22:1ω9t, of the group 18:ω9t, 18:ω7t, 18:lω9c, 18:ω7c, of all four geometric isomers of 18:2ω6 and other geometric and positional isomers of polyunsaturated fatty acids were achieved. The determination of the total serum fatty acids in healthy 10-year-old children and healthy 20-year-old adults was performed. In 35 min, over 100 peaks of serum fatty acids were detected. Increased levels of some saturated and mono-unsaturated fatty acids and decreased levels of linoleic acid and eicosadienoic acid (20:2ω6c,c) were found in the serum of adult subjects.

Polyunsaturated Fatty Acids in Incubating Chicken Egg Lipids ,

In essential fatty acid metabolism the isomers of polyunsaturated fatty acids (PUFA) play a vital role. Since certain structural features at the methyl end (ω) of the fatty acid chain are keys to the biological activity of unsaturated fatty acids, an abbreviated nomenclature has come into use which identifies the methyl carbon as number one. In this system (Mohrhauer and Holman, 1963) linoleic acid is designated as 18:2ω6, linolenic acid as 18:3ω3, and arachidonic acid as 20:4ω6. The first number respresents the number of carbons in the chain, the second the number of double bonds and the number following the ω as the position of the first double bond from the methyl end of the fatty acid. Holman (1964) has reviewed the work of his group which has clearly established the conversion of linoleate to 20:4ω6 and 22:5ω6; linolenate to 20:Sω3, 22:5ω3, and 22:6ω3, as well as the nonconvertibility of…

Further studies on the isomerization of polyunsaturated fatty acids by potassium tertiary butoxide

SummaryA temperature and time study revealed that the best conditions for the isomerization and estimation of polyunsaturated acids are heating in a sealed tube for 2 hrs. at 140° with potassium‐t‐butoxide in t‐butanol. Under these conditions conjugation of linolenic and arachidonic acids appears to have attained completion. With linoliec acid a higher degree of conjugation than by other methods and a shift of peak to lower wavelength (231–232 mμ) are observed. Extinction coefficients obtained by this method for isomerized pure linoleic (k232, 98.0) and linolenic (k268, 138.4) acids are the highest so far reported. Ultraviolet and infrared examination of the conjugated trienes isolated from isomerized linolenic acid concentrate showed that, under these conditions, trienes similar to both alpha‐ and beta‐eleostearic acids are produced. Analyses of samples of oils for component polyunsaturated acids, by this method, compare well with those by other methods. The presence of small amounts of a tetraenoic acid in linseed oil is noted.

Isomerization of polyunsaturated fatty acids and their esters by sodium amide in liquid ammonia

Isomerization of polyunsaturated fatty acids and their esters by sodium amide in liquid ammonia