Fatty acid in lipids

The third approach to analyze amide-linked fatty acids in lipid A (187) is... 

It has recently been demonstrated (191) that the nature and location of lipid A primary fatty acids is determined by the specificity of the enzymes UDP-GlcpNAc-G-acyltransferase and UDP-3-6>-[(i )-hydroxyacyl]-GlcpN-N-acyltransferase for acyl - acyl carrier protein (acyl ACP). The analysis of the acyl ACP specificity of these O- and A-acyltransferases should, therefore, constitute a biochemical approach for elucidation of the location of primary fatty acids in lipid A (191). 

Lipoxygenases, of which the enzyme from soy beans has been studied the most, also catalyze oxidation of polyunsaturated fatty acids in lipids as indicated in Eq. 21-17. Formation of the hydroperoxide product is accompanied by a shift of the double bond and conversion from cis to trans configuration. Soybean lipoxygenase is a member of a family of related lipoxygenases that are found in all eukaryotes. All... 

Precautions should be taken to prevent oxidation during lipid analysis. Polyunsaturated fatty acids in lipid samples are easily attacked by active oxygen species (e.g., free radicals), exacerbated by the presence of strong light and metal ions. Therefore, it is arule of thumb while working with lipids that samples should be handled in a way that minimizes contact with air, light, and metals. To accomplish this, handle samples in glass vessels, use Teflon-lined or coated materials, and maintain the samples... 

Table 13.3 Distribution of fatty acids in lipids present in some macroalgae. Values are relative percentage of organic compounds.

Hooper, S.N., Paradis, M. and Ackman, R.G. (1973). Distribution of trans-6-hexade-cenoic acid, 7-methyl-7-hexadecenoic acid and common fatty acids in lipids of the ocean sunfish. Lipids 8,509-516. 

Qureshi, N., Honovich, J.P., Hara, H., Cotter, R.J., Takayama, K. Location of fatty acids in lipid A obtained from lipopolysaccharide of Rhodopseudomonas sphaeroides ATCC 17023. J Biol Chem 263 (1988) 5502-5504. 

The study was conducted on a series of lipids such as oils, tallow and butter. Figures 7-4 and 7-5 illustrate Raman spectra of sunflower, corn, sesame, rapeseed and olive oils and peanut, beef tallow and butter, respectively. The study determined that the iodine number of the lipid containing foodstuffs could be estimated by measuring the FT-Raman spectra. The presence of double bonds in the unsaturated fatty acids in lipids provides a method of... 

Hubbard, A.W. and Pocklington, W.D. (1968) Distribution of fatty acids in lipids as an aid to the identification of animal tissues. 1. Bovine, ovine and some avian species. J. Sci. Food Agric., 19, 571-577. 

Jeon, I.J. 1994. Flavor chemistry of dairy lipids review of free fatty acids. In Lipids in Food Flavors (C.T. Chang, T.G. Hartman, eds.), American Chemical Society, Washington, DC, pp. 196-207. 

Heinz E. Biosynthesis of polyunsaturated fatty acids. In Lipid Metabolism in Plants. Moore TSJr, ed.l993. CRC Press, Boca Raton, FL. 

Badings, H.T. De Jong, C. Glass capillary gas chromatography of fatty acid methyl esters. A study of conditions for the quantitative analysis of short- and long-chain fatty acids in lipids. J. Chromatogr. 1983, 279, 493-506. 

Silver ion TLC is a simple but reliable approach for separation, identification, quantification, and preparative isolation of fatty acids in lipid samples, depending on the number, configuration, position, and chain length (see Refs. [1-9] for additional information). 

Lioid Analysis. Fatty acids in lipids were first converted to methyl esters by reacting them with METH-PREP II (ALLTECH-Applied Science, Deerfield, IL) and then analyzed by GC. Methyl esters were analyzed by a Tracer GC equipped with a flame ionization detector (Tracer, Austin, TX) and a RSL 500, 30 meter FSOT column (ALLTECH, Deerfield, IL). Details of GC analysis conditions can be found elsewhere (11). 

Li, D. Bode, O. Drummond, H. Sinclair, A.J. Omega-3 (n-3) fatty acids. In Lipids for Functional Foods and Nutraceuticals Gunstone, F.D., Ed. Oily Press Lipid Library Bridgwater, UK, 2003 225-262. 

Shimada, Y. Sugihara, A. Tominaga, Y. Enzymatic enrichment of polyunsaturated fatty acids. In Lipid Biotechnology Kuo, T.M., Gardner, H.W., Eds. Marcel Dekker New York, 2002 493-515. 

Beyond the initial damage to membranes, reaction of these radicals with double bonds of fatty acids in lipids produces peroxides that give rise to a,15-unsaturated aldehydes including malondialdehyde (MDA), 4-hydroxynonenal (HNE) and acrolein. These aldehydes covalently bind to proteins through reaction with thiol groups and alter their function. We have previously shown that CAi hippocampal neurons were HNE positive by immunohistochemistry after transient cerebral ischemia (Adibhatla and Hatcher, 2006). Recently, elevated levels of an acrolein-protein conjugate were demonstrated in plasma of stroke patients (Adibhatla and Hatcher, 2007, and references cited therein). 

Lipids are defined as organic substances soluble in solvents regarded as fat-like, i.e., chloroform, carbon tetrachloride, benzene, diethyl ether, petroleum ether, etc., and which are related actually or potentially to esters of the long-chain fatty acids. A simple classification scheme which illustrates the role of these fatty acids in lipid chemistry is given in Table VI. It can be seen that most combined lipids consist of esters with long-chain alcohols, sterols, vitamins or, most commonly, glycerol and its substituted derivatives, viz., RCOOM where R = alkyl chain and M is an alcoholic moiety. 

Feller SE, Gawrisch K, and MacKerell AD, Jr. (2002) Polyunsaturated fatty acids in lipid bilayers intrinsic and environmental contributions to their unique physical properties. J Am Chem Soc 124 318-26. 

As chlorinated fatty acids in lipid extracts cannot be separated from non-chlorinated matrix by routine cleanup techniques, because of the similarity in their chemical and physicochemical properties, chromatographic elution is often the sole effective means of separation for identification and quantitation of chlorinated fatty acids. As chlorinated fatty acids are present in biota extracts at trace levels, it is critical to have a detector that is highly specific for... 

Adlof, R.O. (1999) Isotopically Labelled Fatty Acids, in Lipids Synthesis and Manitfacture (Gunstone, F.D., ed.) pp. 46-93, Sheffield Academic Press, Sheffield, UK. 

Dry chlorine and wet chlorine (hypochlorous acid) will react with organic substances containing double or triple bonds to yield vicinal dichlorides and chlorohydrins respectively. For example, hypochlorous acid will react with fatty acids in lipids such as oleic acid at pH 2 to 10, to produce 9-chloro-lO-hydroxystearic acid, while dry chlorine will produce a mixture of chlorinated products. 

Ackman, R.G. and Hooper, S.N. (1973b) Non-methylene-interrupted fatty acids in lipids of shallow-water marine invertebrates a comparison of two molluscs Littorina littorea and Lunatia triseriata) with the sand shrimp (Crangon septemspinosus). Comp. Biochem. Physiol. 46B 153-165. 

Saturated fatty acids, such as lauric acid, contain only single bonds between carbons. Monounsaturated fatty acids have one double bond in the carbon chain, and polyunsaturated fatty acids have two or more double bonds. Table 18.2 lists some of the typical fatty acids in lipids. 

Each alga collected was washed with sea water, frozen in liquid nitrogen, ground and extracted by Bligh Dyer method. Positional distribution of fatty acids in lipids were determined by Arao et al.<1987). 

AraOjT.. Kawaguchi,A. and Yamada,M. (1907) Positional distribution of fatty acids in lipids of the marine diatom Phaeodactylum tricornutum Phytochemistry 26 2573-2576. 

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