Position Of Fatty Acids Research Articles

Acyl and alk-1'-enyl group composition of ethanolamine phosphoglycerides of human brain.

Abstract—Ethanolamine phosphogylcerides (EPG) of human brain gray and white matter were analyzed for their alk‐1′‐enyl group and fatty acid compositions in sn‐glycerol positions 1 and 2. Gray matter contained more 18:0 (54%) and less 18:1 (24.5%) alk‐1′‐enyl residues than white matter (16% and 57%. Sixty per cent of alk‐1′‐enyl 18.1 in gray matter was the (n‐7), against 71%, in white matter. Both gray and white matter contained small amounts of 18:1 (n‐5) and (n‐3) isomers.The fatty acids in position I of the phosphatidylethanolamines were more saturated than the corresponding alk‐1′‐enyl groups of the plasmalogens. The ratios of monoenoic fatty acid isomers in position 1 were markedly different from those of the corresponding alk‐1′‐enyl groups in gray matter. The fatty acid patterns in position 2 of plasmalogen and phosphatidylethanolamines of white matter were similar except for 22:4(n‐6) which was concentrated in the plasmalogen (16% against 10%, in the phosphatidyl ethanolamine). In gray matter, the same trend was noted.The data suggest that alk‐1′‐enyl residues and the fatty acids in position 1 as well as the fatty acids in position 2 of alk‐1′‐enyl acyl and diacyl type EPG in both gray and white matter are, at least in part, of different provenance.

The composition and structure of the lipids of sheep lymph.

AbstractPhosphatidylcholine was the principal phospholipid component in the intestinal lymph of sheep and was accompanied by small amounts of phosphatidylethanolamine, phosphatidylinositol, lysophosphatidylcholine and sphingomyelin. Stereo‐specific analysis of the triacylglycerols confirmed that palmitic acid was concentrated in position sn‐2 and showed that there was a higher proportion of the remaining saturated fatty acids in position sn‐1 than in position sn‐3. In the phosphatidylcholine, saturated fatty acids were concentrated in position sn‐1 and unsaturated in position sn‐2, contrary to an earlier report.

Letter: Introduction of labeled fatty acid in position 1 of phosphoglycerides.

Letter: Introduction of labeled fatty acid in position 1 of phosphoglycerides.

Studies on lipase. XII. Positional specificities of four kinds of microbial lipases.

Lipases from Aspergillus niger and Rhizopus delemar hydrolyzed triolein and produced l,2 (2,3)-diolein and 2-monoolein. These two lipases appears to have strong specificity towards the outer chains of the triglyceride. Comparing the proportions of fatty acids in position 1 (3) of cocoa butter with proportions of fatty acids liberated after limited hydrolysis of cocoa butter, it becomes clear that these two lipases do not hydrolyze the ester bond in position 2 of the triglyceride.On the other hand, lipases from Geotrichum candidum Link and Penicillium cyclopium Westring attacked the fatty acid chains regardless of their positions. Geotrichum candidum lipase liberated oleic acid and palmitic acid in preference to stearic acid from cocoa butter.

Reaction of ozone with phosphatidylcholine liposomes and the lytic effect of products on red blood cells

Ozone caused leakage of trapped glucose from liposomes made from egg yolk phosphatidylcholine. A comparison between the lytic activity of ozone and ozone treated liposomes on human red cells showed the liposomes to be by far the most active. Hydrogen peroxide was not responsible for the observed effect. Amount of malonaldehyde formed during ozonization of phosphatidylcholine was a much poorer index of reaction than amount of hydrogen peroxide formed, the latter probably close to reacted double bonds. Results obtained indicated that attack of ozone produced molecules in which the unsaturated fatty acid in position 2 was shortened at the double bond with the formation of aldehyde or acid as the terminal group. In order to explain some of the analytical data further ozonization of primary products is postulated.

Determination of fatty acids in position 3 of triglycerides.

LipidsVolume 8, Issue 7 p. 439-439 Letter to the Editor Determination of fatty acids in position 3 of triglycerides H. Brockerhoff, H. Brockerhoff Halifax Laboratory, Fisheries Research Board of Canada, Halifax, Nova Scotia, CanadaSearch for more papers by this author H. Brockerhoff, H. Brockerhoff Halifax Laboratory, Fisheries Research Board of Canada, Halifax, Nova Scotia, CanadaSearch for more papers by this author First published: 01 July 1973 https://doi.org/10.1007/BF02531724Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume8, Issue7July 1973Pages 439-439 RelatedInformation

Glycerophosphoryl diglucosyl diglyceride, a new phosphoglycolipid from Streptococci

1. 1. From Streptococcus faecalis var. faecalis, Streptococcus faecalis var. zymogenes, and Streptococcus hemolyticus (serogroup A) the more polar phosphoglycolipids were isolated. They were chromatographically identical and contained lucose, glycerol, fatty acid ester, and phosphate in a molar ratio of 2:2:2: I. 2. 2. The structure of all three compounds was shown to be 1(3)-O-[6''-(snglycero-1-phosphoryl)-2'-O-(α- d-glucopyranosyl)-α- d-glucopyranosyl]-diglyceride . The sn-glycerol- I-phosphate residue is heretofore unique in bacterial phosphoglycolipids. 3. 3. The deacylated core was studied by periodate oxidation, Smith degradation, alkaline hydrolysis, and enzymatic degradation. The location of the acyl groups was established by periodate oxidation and Smith degradation as well as by cleavage of the phosphodiester with HF (60%). 4. 4. The fatty acid composition was such as known for Lactobacillaceae. In the phosphoglucolipid from S. hemolyticus the fatty acids were randomly distributed, whereas the compounds from S. faecalis showed positional specificity with preference for longer-chain fatty acids in Position I and for shorter-chain fatty acids in Position 2 of the glycerol moiety. 5. 5. Methods are given for the determination of Smith degradation products and polyolphosphates by gas-liquid chromatography.

The structures of adipose tissue and heart muscle triglycerides in the domestic chicken (Gallus gallus).

AbstractChicken (Gallus gallus) perineal, subcutaneous (leg), perinephric and pericardial adipose tissue and heart muscle triglycerides were subjected to stereospecific analysis. All were found to be asymmetric with a preponderance of saturated fatty acids in position 1 and a preponderance of unsaturated fatty acids in position 2. Position 1, for example, contained 48–55% saturated acids while position 2 contained 17–22% and position 3, 33–41%. Stereospecific analysis of fractions of the perineal triglycerides separated by argentation chromatography indicated that the proportions of the individual molecular species could be calculated assuming that there was 1‐random, 2‐random, 3‐random arrangement of fatty acids in the triglycerides.

Stereospecific analysis of triglycerides.

AbstractStereospecific analysis determines how the fatty acids of triglycerides are distributed over the three different positions of the glycerol. The special problem is the differentiation of position I‐1 and L‐3 of glycerol. In the presently known methods, triglycerides are first degraded to mixtures of diglycerides, either by the action of a lipase or by degradation with a Grignard reagent. The isomeric diglycerides are then resolved with the help of a stereospecific enzyme, either a diglyceride kinase or (after conversion of the diglycerides to phospholipids) a phospholipase. It is then possible to analyze or calculate the fatty acid composition for each position on the glycerol. The key to a successful stereospecific analysis is the preparation of a representative diglyceride mixture by a truly random degradation of the triglyceride. The Grignard degradation is the most reliable method, but it is not always applicable, and it is accompanied by some isomerization of glycerides. There is room for improvement in the method. Analyse of natural fats have shown most of them to be asymmetric, i.e., the composition of fatty acids in position 1 differs markedly from that of position 3. Several rules of fatty acid distribution have become apparent.

The structure of egg yolk triglycerides

The triglycerides isolated from egg yolk lipids were subjected to stereospecific analysis. A very high degree of asymmetry between positions 1 and 3 was found. Palmitic acid constituted over 70% of the fatty acids in position 1. Position 2 was occupied largely by oleic and linoleic acids and position 3 by oleic acid and a comparatively small amount of saturated fatty acids. The triglycerides were also separated according to degree of unsaturation by argentation chromatography and each fraction subjected to the stereospecific analysis procedure. Good agreement was found between the proportions of the various molecular species obtained in this way and those predicted assuming a 1-random, 2-random, 3-random arrangement of fatty acids in the intact triglycerides. There was evidence for some selectivity in the utilisation of fatty acids of different chain lengths in certain of the species, however. No simple biosynthetic relationship was apparent between the structure of the egg yolk triglycerides and the structures of egg phosphatidyl choline and ethanolamine reported by others, although there are some similarities in the arrangement of fatty acids in the triglycerides and phosphatidyl choline.

A comparison of the structures of triglycerides from various pig tissues

Triglycerides from a wide variety of pig tissues were subjected to stereospecific analysis. Those from all the adipose tissue sites examined and from the heart, kidney and adrenals had similar fatty acid distributions with most of the palmitic acid in position 2 and much of the remaining saturated fatty acids in position 1 Sow's milk triglycerides were similar although the difference between the 1- and 3-positions was less marked. Liver triglycerides had very much less palmitic acid in position 2 which was occupied largely by unsaturated fatty acids; most of the saturated fatty acids were in position 1. Blood triglycerides were somewhat similar but contained more palmitic acid in position 2. The triglycerides from the sow's milk, liver, blood and inner and outer back fats were fractionated according to degree of unsaturation by argentation chromatography and individual fractions were subjected to the stereospecific analysis procedure. The proportions of the various species obtained in this way were compared with those predicted assuming a 1-random, 2-random, 3-random arrangement of fatty acids in the intact triglycerides. Agreement was excellent for all except the blood triglycerides although there is evidence that there may be some selectivity in the utilisation of acids of different chain lengths in certain of the species. Such selectivity was greatest in the liver and blood triglycerides, less in the adipose tissue triglycerides and quite low in the milk triglycerides. Possible biosynthetic pathways are discussed.

Composition of rat liver triacylglycerols and diacylglycerols.

Different fractions of rat liver triacylglycerols and X‐1,2‐diacylglycerols were prepared by thin‐layer chromatography on silver nitrate‐containing silica gel. The positional distribution of fatty acids in these fractions and unfractionated triacylglycerols and diacylglycerols was analyzed by a scaled‐down version of Brockerhoff's method. Both in tri‐ and diacylglycerols position 1 contains mainly saturated fatty acids, while most fatty acids in position 2 are unsaturated. Position 3 in triacylglycerols contains mainly unsaturated fatty acids and has a large proportion of highly unsaturated fatty acids. The relative abundance of different 1,2‐diacyl‐sn‐glycerol units in diacylglycerols and triacylglycerols was similar except for highly unsaturated units. This suggests a random utilization of 1,2‐diacyl‐sn‐glycerols with 1–3 double bonds for triacylglycerol biosynthesis. The highly unsaturated diacylglycerols probably originate from phospholipids. From the positional distribution of fatty acids in total triacylglycerols the proportions of different triacylglycerol fractions were predicted from the assumption that each fatty acid in any position is combined with fatty acids in proportion to their relative amounts in the other positions. The observed distribution agreed well with the predicted one‐.

Structure of bovine milk fat triglycerides. II. Long chain lengths.

AbstractThe long chain triglycerides of bovine milk fat were isolated by thin layer chromatography, and their chemical structure determined by combined thin layer and gas liquid chromatography, and a stereospecific analysis of a molecular distillate of butteroil of comparable composition. The milk fat fraction (39% of total) contained C8–C20 fatty acids which were distributed among the glycerides of 40–56 acyl carbon atoms in a manner not unlike that found for the same acids in the short chain triglycerides. Although individual triglycerides were not identified, the specific distribution of the fatty acids could best be accounted for by assuming a common pool of long chain 1,2‐diglyceride precursors from which the bulk of both short and long chain triglycerides are synthesized by a stereospecific introduction of C4–C18 fatty acids in position 3 of sn‐glycerol. This hypothesis is compatible with the results of stereospecific analyses of the short and long chain fractions and of the total butteroil. It is supported by the nonrandom distributions demonstrated for the molecular weights of the milk fat triglycerides of different degrees of saturation.

Deposition of Triglycerides of Increased Carbon Number in Irradiated Rat Marrow

gamma radiation involves primarily the stimulation of triglyceride formation. This metabolic alteration appears morphologically as an increased number of fat cells, which reaches a maximum approximately 1 week after total-body irradiation (TBI). Triglycerides of femoral bone marrow, liver, plasma, and perirenal fat were isolated by preparative thin-layer chromatography (TLC) from control and irradiated (800 R) Carworth Farms Nelson strain rats. The purified triglyceride fractions were separated further by Ag (NH3)2+ TLC and by gas-liquid chromatography (GLC). Stereospecific fatty acid analysis of the triglycerides was also done. The period for maximal triglyceride biosynthesis was 3 to 4 days after TBI. The pattern of irradiated marrow triglycerides on the argentation layers was similar to the control pattern, but GLC showed that the newly formed triglycerides in the irradiated bone marrow had a higher carbon number than those in control marrow. This change was not found in the triglycerides of other tissues examined before and after TBI. In both control and irradiated animals, plasma and liver contained triglycerides of higher carbon number than did bone marrow and adipose tissue. Stereospecific analysis of the fatty acid positions of the triglycerides showed that the change in triglyceride type caused by irradiation was due to a shift in the distribution of the C-16 and C-18 fatty acids in positions 1 and 3. No change occurred in the fatty acid composition of position 2 after irradiation. 1Under contract with the U. S. Atomic Energy Commission. 142

Fatty acid distribution pattern of animal depot fats

1. 1. Triglyceride analyses are presented in diagrams showing the distribution of fatty acids between the different positions of the triglyceride. 2. 2. Positions 1,2 and 3 are shown for 8 mammals, position 2 for 3 birds with symmetrical fatty acid distribution. 3. 3. For several marine mammals, fish and inverterbrates, for which no stereospecific analyses are available, the relative concentrations of fatty acids in position 2 are plotted. 4. 4. In most fats, a short chain and unsaturation direct a fatty acid toward position 2. Exceptions are the fat of pig, where palmitic acid has a strong affinity to position 2; the fats of the marine animals, where chain length is the important directing factor; and the fats of the birds, where only unsaturation appears to be decisive. 5. 5. In fats of terrestrial mammals, position 1 is preferentially occupied by saturated acids. In position 3, the relative concentrations generally diverge less from the average of 33 per cent than in positions 1 and 2. There is a tendency towards longer chains in position 3. 6. 6. The concentration patterns in position 2 of most triglycerides are reminiscent of the distribution of fatty acids between polar and non-polar solvents; they also suggest a differentiation between endogeneous and exogenous acids. 7. 7. It is suggested that the affinity of fatty acid derivatives toward aqueous or lipoic phases may play a directing role in the biosynthesis of complex lipids, or that there may be a causal connexion between origin and position of fatty acids.

A stereospecific analysis of triglycerides

A method is presented for the analysis of the fatty acid compositions in each of the three positions of a triglyceride. Diglycerides are obtained from the triglyceride by lipolysis with pancreatic lipase, and converted to a mixture of d - and l -phosphatidyl phenol. The l -phosphatide is then hydrolyzed by phospholipase A, leaving a lysophosphatide with the fatty acid in position 1, free fatty acid from position 2, and unhydrolyzed d -phosphatidyl phenol. The fatty acid composition in position 3 of the original triglyceride is obtained by calculation. The method was tested on two triglyceride mixtures with known fatty acid distributions. A natural triglyceride, corn oil, was analyzed. The distribution of the major fatty acids between positions l and 3 was found to be nearly random.