gunstone the lipid handbook 3rd ed

[...]... bonds relative to the methyl or carboxyl ends of the chain In the biomedical literature, it is common to number the chain from the methyl end rather than the systematic numbering from the carboxyl end, to emphasise the biosynthetic relationship of different double bond patterns Numbering from the methyl end is written n-x or ωx, where x is the double bond carbon nearest the methyl end If there is more... components, the carbon atoms of glycerol are numbered stereospecifically When the glycerol molecule is drawn in a Fischer projection with the secondary hydroxyl group to the left of the central prochiral carbon atom, then the carbons are numbered 1, 2, and 3 from top to bottom Molecules that are stereospecifically numbered in this fashion have the prefix “sn” immediately preceding the term “glycerol” in the. .. sn-1-Alkyl-2,3-diacylglycerol Both the monoacyl and diacyl derivatives are found in Nature 1.2.2.2 (19) sn-1-Alk-1′-enyl-2-3-diacylglycerol Both the monoacyl and diacyl derivatives have been reported Alk-l-enyl ethers 1.2.2.3 As with the alkyl ethers of glycerol, the monoalk-1-enyl ethers predominate in Nature with small amounts of the dialk-1-enyl ethers, but no trialk-1-enyl ethers so far detected Ether lipids of Archaebacteria... relative to the fully extended saturated acid — TABLE 1.5 Width OH Length FIGURE 1.8 acids Length and width parameters of bent-chain fatty the shorter this distance, the more bent the molecule We can also define the “width” of the molecule as the distance from the midpoint of this line to carbons in the middle of the chain (Figure 1.8) This parameter is particularly useful when the bend in the molecule... double bond, a cis configuration, methylene-interrupted pattern is implied Although the n-x notation is recommended, both n-x and ωx are widely used in the current biomedical literature and wider nutritional contexts The ∆ notation is used to make it explicit that the numbering is from the carboxyl end Other substituents may also be included in the shorthand notation; for example 12-OH 18:1 9c for... at the ∆9 position, but not at ∆12 or ∆15; instead, further double bonds are introduced between the carboxyl group and the ∆9 position by ∆5 and ∆6 desaturase enzymes and the chain can then be extended in two carbon units at the carboxyl end of the molecule The resulting n-6 and n-3 polyenes are shown in Figure 1.2 The step leading to DHA appears to be the result of a ∆4 desaturase, but is usually the. .. 1.2.2.4 1.2.3.1 Betaine lipids The compounds are named after and contain structures that are based on phosphatidic acid (3-sn-phosphatidic acid) The X moiety attached to the phosphate includes nitrogenous bases (amino alcohols) or polyols In Table 1.6 the major phosphoglycerides are listed Some of the less common compounds are indicated in the remarks within the table Two betaine lipids, diacylglycerol-O-(N,N,N-trimethyl)... dehydrosphingosine-based variants have been reported However, all contain inositol linked via a phosphodiester linkage to the ceramide and via a glycosidic bond to a chain of sugar residues of variable composition (Hetherington and Drobak, 1992) The components were previously called “phytoglycolipids,” but Laine and Hsieh (1987) suggested that the term “glycophosphosphingolipid” be used to distinguish them from other... V.M (1996) Betaine ether-linked glycerolipids: chemistry and biology Prog Lipid Res 35, 1–51 Kates, M (1972) Ether-linked lipids in extremely halophilic bacteria In: Ether Lipids: Chemistry and Biology, F Snyder, Ed. , New York: Academic Press, pp 351–398 Kates, M (1990) Glyco-, phosphoglyco- and sulfoglycoglycerolipids of bacteria In: Handbook of Lipid Research, vol 6 M Kates, Ed. , Plenum: New York,... Membrane lipids of Archaea In: The Biochemistry of Archaea (Archeabacteria) M Kates, D.J Kushner, and A.T Matheson, Eds., Amsterdam: Elsevier, pp 261–295 Mangold, H K and Paltauf, F Eds (1983) Ether Lipids: Biochemical and Biomedical Aspects London: Academic Press Synder, F (1969) Biochemistry of lipids containing ether bonds Prog Chem Fats Other Lipids, 10, 287– 335 1.2.3 Phospholipids Man(α)–2 Phospholipids . alt="" The Lipid Handbook with CD-ROM Third Edition The Lipid Handbook with CD-ROM Third Edition Edited by Frank D. Gunstone John L. Harwood Albert J. Dijkstra CRC Press is an imprint of the Taylor. occurred in the past 10 years, but we sought to maintain the approach and organ- isation of material used in the earlier editions. Compared to the second edition, some chapters have been combined. ends of the chain. In the biomed- ical literature, it is common to number the chain from the methyl end rather than the systematic numbering from the carboxyl end, to emphasise the biosynthetic