Glycolipids classification

The glycoproteins, together with the glycolipids, constitute the class of the glycoconjugates, the classification of which is given in Fig. 1 that is, the glycoconjugates are the products of association between a carbohydrate, which is called a glycan, with either a protein or a lipid. 

Myelin is approximately 75% lipid and 25% protein. Carbohydrate residues are associated with both the lipid and the protein components of myelin. High proportions of cholesterol, phospholipid, and glycolipid are found in the lipid fractions. Phospholipids include ethanolamine phosphatides, phosphatidylserine, and phosphatidylinositol glycolipids include both neutral (cerebroside, sulfatide, galactosyldiglyceride) and polar (gangliosides, especially GMj and GMJ lipids. A classification and discussion of the metabolism of brain lipids is beyond the scope of this article readers are referred to Lajtha (1969), Davison (1968), Awasthi and Srivastava (1980), and Suzuki (1981). 

GL-4. Classification of Glycolipids Rased on Their Lipid Moieties. 314... 

Classification and Structure M.l. can be classified structurally in several different ways The present classification (Fig.l) divides them into phospholipids, glycolipids and Sterols (see). The phospholipids are divided into glycerophospholipids and sphingophos-pholipids, the ycolipids into glyceroglycolipids and sphingoglycolipids each of these subclasses is then divided into subsubclasses Phospholipids and glycolipids can be described as acylated-M.I. because they have at least one fatty acyl residue (R.C = O where R is a hydrocarbon chain) in their structure in this they differ from sterols which occur in biomembranes in non-acylated form. 

SwEELEY and Klionsky (1963, 1964, 1966) isolated from organs of ACD patients two glycolipids, which they identified as ceramide-dihexoside and ceramide-trihexoside. Their findings confirmed the assumption of Ruiter et al. (1947) who suggested classification of ACD as a lipid storage disease. They did not confirm the postulate that the stored material was a phospholipid. 

SwEELEY, C. C., and B. Klionsky Fabry s disease Classification as a sphingolipidosis and partial characterization of a novel glycolipid. J. biol. Chem. 238, 3148 (1963). 

Lipids are present as ingredients in most foods and play key nutritional roles, being crucial for many physiological functions, they also can be used as food quality markers. For these reasons, the characterization of the lipid fraction present in fats and oils is important for the food industry. Following a general lipid classification, triacylglycerols (mono- and diderivatives), phospholipids, glycolipids, waxes, and sterol esters are included in the saponifiable fraction, whereas the nonsaponifiable... 

Biosurfactants are classified based on their chemical composition and microbial origin. The chemical structure of biosurfactants contains hydrophilic and hydrophobic groups. Amino acids, peptides and polysaccharides can be present as hydrophilic moieties and saturated or unsaturated fatty acids can be present as hydrophobic moieties in the structure. Structure based classification has following major classes of biosurfactants (Guerra-Santos et al., 1987 Kooper and Goldenberg, 1987) (i) Glycolipids (Rhamnolipids, Trehalolipids and Sophorolipids) (ii) Lipopeptide and lipoprotein (iii) Fatty acids, phospholipids and neutral lipids (iv) Pol5mieric biosurfactants, and (v) Particulate biosurfactants. 

The lipids described in sections 6.2.2 and 6.2.3 were based on a glycerol backbone. However, another important group of acyl lipids have sphingosine-based structures. Both glycolipids and phospholipids are found, with some compounds capable of dual classification, i.e. phospholipids which contain sugar residues. 

Following the biogenetic classification, we first address macrolactones, divided into the main family groups that have received synthetic attention via RCM (re-sorcinylic, salycilates, other antibiotic macrolides, macrocyclic musks, epothilones, amphidinolides, other polyketides, and natural cyclophanes), then the terpenoids, followed by the macrocycles obtained from the amino acid metabolism (lactams, depsipeptides, alkaloids), and finally the glycolipids. 

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