Linolenic acid, structure

Nutraceutical lipids contain a variety of fatty acids that are of importance to health and nutrition. Fatty acids of interest include medium-chain fatty acids, long-chain n-3 fatty acids, and y-linolenic acid. Structured lipids produced via modification of common lipids may serve as important ingredients in functional foods and as therapeutic agents. Stability of nutraceutical oils may be achieved by incorporation of appropriate antioxidant/antioxidant systems and/or using relevant processing/packaging techniques. 

Draw the structures of (a) all the possible triacylglycerols that can be formed from glycerol with stearic and arachidonic acid, and (b) all the phosphatidylserine isomers that can be formed from palmitic and linolenic acids. 

Linoleic acid, structure of, 1062 Linolenic acid, molecular model of. 1063... 

Figure 23-1. Structure of some unsaturated fatty acids. Although the carbon atoms in the molecules are conventionally numbered—ie, numbered from the carboxyl terminal—the co numbers (eg, co7 in palmitoleic acid) are calculated from the reverse end (the methyl terminal) of the molecules. The information in parentheses shows, for instance, that a-linolenic acid contains double bonds starting at the third carbon from the methyl terminal, has 18 carbons and 3 double bonds, and has these double bonds at the 9th, 12th, and 15th carbons from the carboxyl terminal. (Asterisks Classified as "essential fatty acids.")...

FIGURE B-1 Structures of some fatty acids of neurochemical interest (see also Fig. 3-7 and text). The n minus nomenclature for the position of the double bond(s) is given here. Note that the position of the double bond from the carboxyl end can be indicated by the symbol A, so that linoleic acid may be also be designated as 18 2A9,12. The linolenic acid shown is the a isomer. 

Dietary polyunsaturated fatty acids (PUFAs), especially the n-3 series that are found in marine fish oils, modulate a variety of normal and disease processes, and consequently affect human health. PUFAs are classified based on the position of double bonds in their lipid structure and include the n-3 and n-6 series. Dietary n-3 PUFAs include a-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) whereas the most common n-6 PUFAs are linoleic acid, y-linolenic acid, and arachidonic acid (AA). AA is the primary precursor of eicosanoids, which includes the prostaglandins, leukotrienes, and thromboxanes. Collectively, these AA-derived mediators can exert profound effects on immune and inflammatory processes. Mammals can neither synthesize n-3 and n-6 PUFAs nor convert one variety to the other as they do not possess the appropriate enzymes. PUFAs are required for membrane formation and function... 

Figure 11.2 Structures of commonly occurring unsaturated fatty acids (i) oleic acid, C18 1 (ii) linoleic acid, C18 2 (iii) a-linolenic acid, C18 3.

The investigation carried out on some Chinese animals used for CNS symptoms similar to those seen in AD resulted in the isolation of long chain fatty acids from the centipede Scolopendra subspinipes mutilans which had weak AChEl activity.A series of fatty acids was tested to discern any structure-activity relationships and it was found that only free acids, not esters, had AChEl activity. The presence of unsaturated bonds and a chain length of not less than 16 C were was necessary for activity. The most active compound tested was linolenic acid (71) with IC50 of 59.9 xM against AChE. 

Melting Points of Lipids The melting points of a series of 18-carbon fatty acids are stearic acid, 69.6 °C oleic acid, 13.4 °C linoleic acid, - 5 °C and linolenic acid, - 11 °C. (a) What structural aspect of these 18-carbon fatty acids... 

It should be noted that both linoleic and a-linolenic acids form hydroperoxides that absorb UV radiation at 233 nm (i.e., the same wavelength as that of CDs). Furthermore, CDs are formed upon decomposition of hydroperoxides from a-linolenic acid, absorbing at 233 nm, whereas secondary oxidation products, particularly ethylenic diketones and a-unsatu-rated ketones, show a maximum absorbance at -268 nm. Carotenoid-containing oils may interfere in the assay by giving higher than expected absorbance values at 233 nm, due to the presence of double bonds in the conjugated structures of carotenoids. 

Alpha linolenic acid is an omega-3 unsaturated fatty acid. What does ome-ga-3 mean If linolenic acid has 18 carbon atoms and the positions of the double bonds are A9,12,15, what is the structure of alpha linolenic acid ... 

In addition, two unknown polyunsaturated methylketones were isolated in the volatiles of boiled small shrimp. They drew our particular interest because their structure contained a linolenic acid type component and because of their seafood-like odor. 

Linoleic acid and a-linolenic acid are two naturally occurring unsaturated fatty acids that are components of fats. Explain how many cis-trans isomers exist for each of these fatty acids. Interestingly, only the all-cis isomers of each occur naturally. Draw the structure of the naturally occurring stereoisomer of linoleic and a-linolenic acid using skeletal structures. 

On ozonolysis, linolenic acid (C,KI I1(l02) gives the products shown in the following equation. Show the structure of linolenic acid. 

It was reported earlier that strain ALA2 converted a-linolenic acid to 13,16-dihydroxy-12,15-epoxy-9(Z)-octadecenoic acid, and 7,13,16-trihydroxy-12,15-epoxy-9(Z)-octadecenoic acid (Hosokawa et aL, 2003b). From product structures obtained from the co-3 PUFAs EPA and DHA, it seems that strain ALA2 places hydroxyl groups at similar positions from the omega (co)-terminal end of the substrates and cyclizes them to related THF ring structures, despite their increased total carbon chain lengths (by 2 and 4 carbons, respectively) and numbers of double bonds (by 1 and 2 respectively). 

The products obtained from the co-6 fatty acids (linoleic acid, y-linolenic acid, and arachidonic acid) by in vivo reactions with strain ALA2 contain diepoxy bicyclic structures, tetrahydrofuranyl rings, and/or trihydroxy groups in their molecules. In contrast to these co-6 PUFAs, substrates classified as co-3 PUFAs (a-linolenic acid, EPA, and DHA) are only converted to hydroxyl THFAs by strain ALA2 with no diepoxy bicyclic or trihydroxy derivatives uncovered to date. Both the hydroxyl groups and cyclic structures derived there from appear to be placed at the same positions on the substrates from the co-carbon termini within each PUFA class, despite differences in carbon chain length and the number of double bonds in the specific PUFA substrates. 

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