Sulpholipid

Diacylglycerols Monoacylglycerols Cerebrosides Glycosyl diacylglycerols Sulpholipids... 

Cerebrosides occur mainly in brain and nervous tissues. Sulphatides are the main sulpholipids in the brain, where they account for approximately 15% of the white matter. Gangliosides are particularly abundant in the cells of the central nervous system. They are believed to be the receptors (Figure A4.1 and Appendix 5) for toxins, such as cholera and tetanus toxins, and some viruses, such as the influenza virus. 

Depending upon the chemical groups they are further subdivided into phospholipids, glycolipids, sulpholipids and lipoproteins. 

Plant sulpholipids contain sulfated hexose with fatty acids and alcohol. 

Saccharic Acid, 54 Secondary-derived Proteins, 151 Simple Lipids, 80 Sphingolipids, 94 Structural Polysaccharides, 61 Sulpholipids, 85... 

Sulpholipids of various chemical composition have been isolated from diatoms (e.g. Anderson et al., 1975). Mono- and polyester glycosyl sulphates or phosphate diglycerides account for a group of polar lipids which are found in large amounts in certain Fucaceae (Liem and Laur, 1976). 

This compound, also known trivially as the plant sulpholipid, is the only lipid with a sulphonic acid linkage which has been reported so far. It contains more saturated fatty acids (mainly palmitic) than the plant galactosylglycerides. 

Figure 11.19 Sulpholipid synthesis and breakdown. Continuous lines show reactions that have been demonstrated dashed lines are possible pathways. Underlined compounds have been used in experiments on sulpholipid synthesis. APS, adenosine phosphosulphate PAPS, phosphoadenosine phosphosulphate. Adapted from Harwood (19806).

The deacylation step in sulpholipid breakdown is probably catalysed by a non-specific acyl hydrolase (cf. Galliard, 1980 Harwood, 1980). 

Studies on the turnover of molecular species of sulpholipid have been reported in Vida faba and Hordeum vulgare. In both of these plants, the more saturated species were turned over at high rates whereas the predominant 1-linolenoyl, 2-palmitoyl species has a low rate of turnover. These differences in metabolism may be related to the function of the sulpholipid-the fast-turning-over species being involved in a metabolic function while the trienoic species have a structural role (cf. Harwood, 1980). 

Sucrose esters, 229,233 Sugars, 163,280 Sully method, 263 Sulphonation, 484 Sulphatides, 33, 519, 522, 544-45 a-Sulpho fatty acids, 484 Sulpholipid, see Sulphoquinovosyldiacyl-glycerol... 

Where R and R = H or a fetty acyl group and X = H (acylglycerols), phosphate ester (phospholipid) or glycosyl residue (galactolipid, sulpholipid). 

The structures of the various sulpholipids have not yet been fully elucidated. The following formulae have been proposed ... 

Naturally occurring lipid mixtures have a composition of such extreme complexity that the analysis by chemical methods of a group of these substances or the determination of a single compound in such mixtures, appears hopeless. Up to about ten years ago, lipid mixtures were characterised by totals like acid-, saponification-, iodine-, thio-cyanogen- and diene- numbers . The determination of the amount of non-saponifiable matter after alkaline hydrolysis was a standard method in the analysis of fats. Phospholipids and sulpholipids were quantitatively determined as inorganic phosphate and sulphate after combustion. These methods were supplemented by detection of subsidiary fat constituents like lipochromes, sterols and resin acids, with the help of colour reactions. 

Whereas seeds often contain up to 60% fat, leaves and stems of green plants contain only about 1—5% lipids, principally phospholipids, sulpholipids and glycolipids. These compounds have to be extracted with relatively polar solvents. Since aliphatic ethers, ketones and esters... 

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