Positional Distribution Of Fatty Acids Research Articles

Positional distribution of fatty acids in galactolipids of Artemisia princeps leaves

Positional distribution of fatty acids in galactolipids of Artemisia princeps leaves

Fatty acids in phospholipids isolated from human red cells

Total lipids of packed erythrocytes from healthy men 22 to 25 years old were extracted with chloroform-methanol mixture. Phospholipid classes were separated from neutral lipids and pigments on a silicic acid column. Phosphatidyl inositol (PI) was freed of its contaminants phosphatidyl ethanolamine (PE) and phosphatidyl serine (PS) on an aluminum oxide column. Additional silicic acid columns with modified solvent systems were needed for complete separation of other overlapped phospholipid classes. The identification of phospholipids in each eluted fraction was accomplished by TLC, using the appropriate spray tests and reference compounds, and confirmed on each of the isolated phospholipids by IR spectrophotometry.The total content of phospholipids as determined by phosphorus analysis was found to be 2.63 mg/ml of packed cells. These phospholipids were found to have the following composition (in per cent of total phospholipid): PI, 2.3; PE, 13.4; ethanolamine plasmalogen (EP), 14.5; PS, 3.9; lecithin (L), 34.2; choline plasmalogen (CP), 1.4; sphingomyelin (Sph), 28.4 and lysolecithin (LL), 1.7. The fatty acid composition of each phospholipid was determined by GLC. The average number of double bonds per fatty acid in the isolated phospholipids was found to be as follows: PI, 1.5; PE, 1.9; EP, 3.6; PS, 2.1; L, 1.0; CP, 2.0; Sph, 0.2 and LL, 0.5. The positional distribution of fatty acids in both L and PE was ascertained by selective enzymatic hydrolysis with phospholipase A. Saturated fatty acids of L were esterified predominantly in the alpha'-position, whereas in PE only 63.9 mole per cent of the saturated fatty acids were found in this position.

Positional distribution of fatty acids in triglycerides of animal depot fats

Several animal depot fats were subjected to stereospecific analysis, i.e., the fatty acid distribution in positions 1, 2, and 3 of the triglycerides were determined. The distribution of fatty acids among the positions 1, 2, and 3 in the triglycerides of animal depot fats is non-random. The distribution between position 2 and positions 1 and 3 seems to be governed by chain length and unsaturation. The shorter and the more unsaturated fatty acids show a greater tendency to occupy the position 2. This rule applies also to the apparent exceptions, the fats of pig and marine mammals, but in these the influence of chain length overrides that of unsaturation. On the other hand, in the three birds investigated unsaturation seems to be the only directing factor. We found fats with asymmetrical distribution of fatty acids as well as symmetrical fats. All mammalian fats were asymmetrical, as were the fats of one amphibian, one fish, and one arthropod, whereas the fats of one fish, one arthropod, and three birds were symmetrical. All asymmetrical fats have an excess of palmitic acid in position 1 and of oleic acid in position 3,

Gas chromatographic resolution of butteroil and synthetic triglycerides beyond their carbon numbers.

AbstractPreparative gas chromatography was used to isolate the C26 to C38 triglycerides of butteroil in groups of uniform molecular weight. Determination of fatty acids allowed a preliminary assignment of triglyceride structure and an estimation of the relative proportions of the various glyceride types. A basis for a further gas chromatographic resolution of saturated triglycerides of identical molecular weight but differing in composition and positional distribution of fatty acids was recognized in the easy separation of various derivatives of 1‐ and 2‐monoglycerides. The study indicated that it might be practical to separate positional isomers of those triglycerides which contain fatty acids of both short and long chain lengths. Other promising routes to increased glyceride resolution were suggested by experiments using chromatographic conditions approaching gas‐solid systems.

The positional distribution of fatty acids i n the triglyce rides of intesti nal lymph, liver and adipose tissue of the sheep

The positional distribution of fatty acids i n the triglyce rides of intesti nal lymph, liver and adipose tissue of the sheep

COMPOSITION AND POSITIONAL DISTRIBUTION OF FATTY ACIDS IN PHOSPHOLIPIDS ISOLATED FROM PORK MUSCLE TISSUES.

AbstractThe composition and positional distribution of fatty acids in phospholipids isolated from four locations of a hog carcass is presented. Variations in fatty acid composition of phospholipids were found depending upon the location in the carcass. The total unsaturated fatty acid content averaged 34.3 mole % for lecithin, 52.5 mole % for phosphatidylethanolamine, 40.3 mole % for phosphatidylserine and 41.3 mole % in sphingomyelin. The cephalins had a much higher percentage of polyunsaturated fatty acids than lecithin. The chief saturated fatty acid in lecithin and sphingomyelin was palmitic and in cephalins it was stearic. A snake venom enzyme preparation(Crotalus adamanteus) hydrolyzed primarily unsaturated fatty acids in phosphoglycerides and the higher the percentage of unsaturation within the fatty acid the higher percentage of hydrolysis occurred. The unsaturated fatty acids were found chiefly at the theॆ‐position and the saturated fatty acids at thea‐position in the phosphoglycerides.

The positional distribution of fatty acids in triglycerides and lecithins of human chylomicrons.

The positional distribution of fatty acids in triglycerides and lecithins of human chylomicrons.

Positional distribution of fatty acids in fish and other animal lecithins

Phosphatidyl choline (lecithin) fractions were prepared from tuna, salmon, and menhaden muscle, from egg yolk, and from rat and beef liver. Hydrolysis by snake-venom phospholipase A (phosphatide acyl-hydrolase, EC 3.1.1.4) was used to determine the positional distribution of the fatty acids. The fatty acid composition of the hydrolyzed fatty acids (β position) and those remaining with the phosphatidyl moiety (α′ position) were separately determined by gas-liquid chromatography of the methyl esters. 36–86 mole % of the fatty acids esterified in the α′ position were saturated; 91–99 mole % of the fatty acids in the β position were unsaturated. Palmitic and stearic acids were the predominant saturated acids in the α′ position. Some similarity was noted in the β-position distribution of linoleic, arachidonic, eicosapentaenoic, docosaenoic, docosapentaenoic, and docosahexaenoic acids. This observation tends to support the hypothesis of the intechangeability of linoleic and arachidonic acids with “non-essential” polyenoic acids.