Lipids sphingosine, derivatives

More complex structures, often related to natural products are prepared by organic synthesis. Among them can be mentioned (f )-3-hydroxytetradecanoic acid (the double-tail hydrophobic moiety of lipid A), sphingosine derivatives related to the ceramides or 1,2- and l,3-dialkyl(acyl)glycerols related to glyco-glycerolipids, glycerophospholipids, and GPI anchors of membrane proteins. The preparations of the above derivatives were reported several years ago but some improvements have been published more recently. 

Glycolipids (or sphingolipids) are derived from the lipid sphingosine (see Figure 6-15). This class of compounds includes cerebrosides and gangliosides. Some bacterial toxins and viruses use them as receptors. 

Sphingolipids, another major group of membrane lipids, are derivatives of sphingosine, an amino alcohol that contains a long, unsaturated hydrocarbon chain. Sphingosine Is... 

Glycolipids are derivatives of the lipid sphingosine. These sphingolipids include the cerebrosides and the gangliosides (Fig. 30.15 see also Fig. 5.22). They contain ceramide, with carbohydrate moieties attached to its hydroxymethyl group. 

Another important group of lipids is derived from sphingosine the derivatives are called sphingolipids. Two sphingolipids, a typical sphingomyelin and a typical cerehroside, are shown in Fig. 23.10. 

FIGURE 13.1 Survey of lipids occurring in cellular membranes. The head group structures of the relevant phospholipids (derived from PA shown at the top) are shown in the left table, whereas the structures of selected sphingosin-derived lipids are shown at the right. Please note that only PC and PE represent neutral (zwitterionic) phospholipids, while all others are acidic phospholipids. R and R represent varying fatty acyl residues. At the bottom, some apolar lipids (regularly present in cellular extracts) are additionally shown. 

Figure 8.17. High-temperature GC of derivatized plasma lipids on a WCOT column (8 m x 0.3 mm) of fused silica, coated with SE-54, and temperature-programmed to a maximum of 340 C [647]. Abbreviations A, TMS ester derivatives of free acids B, TMS ethers of monoacylglycerols (derived from lysophosphatidylcholine) C, TMS ether of cholesterol D, tridecanoin (internal standard) E, TMS ether of 16 0-sphingosine (derived from sphingomyelin) F, TMS ethers of diacylglycerols (derived from phosphatidylcholine) and ceramides G, more TMS ethers of ceramides H, cholesterol esters J, triacylglycerols. (Reproduced by kind permission of the authors and of the Journal of Biochemical and Biophysical Methods, and redrawn from the original paper).

Glycerolipids are derivatives of glycerol and fatty acids 34 In sphingolipids, the long-chain aminodiol sphingosine serves as the lipid backbone 37... 

Figure 2 Chemical structures of the more common lipids found in biological membranes a) lipids derived from Diacylglycerols b) lipids derived from sphingosine c) the more common sterols d) some unusual lipids.

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