Monosaccharides, ceramide

Dennis, R.D., Baumeister, S., Geyer, R., Peter-Katalinic, J., Hartmann, R., Egge, H., Geyer, E. and Wiegandt, H. (1992) Glycosphingolipids in cestodes - chemical structures of ceramide monosaccharide, disaccharide, trisaccharide and tetrasaccharide from metacestodes of the fox tapeworm, Taenia crassiceps (Cestoda Cyclophyllidea). European Journal of Biochemistry 207, 1 053-1 062. 

Kannan and coworkers also used M hydrochloric acid at 100° for the hydrolysis of neutral glycolipids 6 h was found sufficient for hydrolysis of galactolipids, but 12 h was required for complete cleavage of the glucose-ceramide bond. The use of standard ceramide mono- and di-hexosides subjected to hydrolysis for 12 h gave monosaccharide recoveries of >94%... 

Scheme 1. The Attachment of Different Monosaccharides to the Ceramide (Cer) Moiety.

The glycosphingolipids differ from sphingomyelin in that they do nflt contain phosphate, and the polar head function is provided by a monosaccharide or oligosaccharide attached directly to the ceramide by... 

Based on their carbohydrate structures, GSLs could be arranged in a series through sequential addition of single monosaccharide units. Typically, the first sugars linked to ceramide are p-linked Glc (GlcCer) and Gal (GalCer), which form the core unit of... 

Neutral oligoglycosylceramides that contain 3 and up to over 20 sugar units in the chain are characteristic of some animal tissues. Seven main types of these compounds exist based on their structural and biosynthetic relationships. In each type, glucose is the primary sugar linked to ceramide with galactose, N-acetylglucosamine, N-acetylgalactosamine or mannose as additional monosaccharides (2). 

Figure 26.4. Ganglioside G This ganglioside consists of five monosaccharides linked to ceramide one glucose...

Sphingoglycolipids are components of the cell membrane and play a significant role in various biological processes [1,2]. Sphingoglycolipids are composed of at least one monosaccharide residue and long-chain aliphatic components known as ceramides (Cer). A typical structure is illustrated in O Fig. 1. They have diverse stmctural variations on both the ceramide and saccharide residues, and they are classified into many types according to carbohydrate sequence. The representative families are summarized in O Table 1. In this section, recent syntheses... 

Figure 26.4 Ganglioside G i- This ganglioside consists of five monosaccharides linked to ceramide one glucose (Glc) molecule, two galactose (Gal) molecules, one N-acetylgalactosamine (GalNAc) molecule, and one N-acetylneuraminate (NAN) molecule.

Ganglioside Complex carbohydrate-rich glycosphingolipids containing three or more monosaccharides esterified to ceramide with at least one of the sugars being A-acetylneuraminic acid (sialic acid). Gangliosides are membrane components found on nerve endings. 

Influence of the Sugar Moiety on Surface Viscosity of Glycosphin-golipids. The series ceramide > gluco- or galactocerebroside > lacto-cerebroside > hematoside > ganglioside (Figure 3) indicates a decrease in surface viscosity with an increase in monosaccharide units. 

---