Glycolipids sialic acid

Sialic acid is a name for a group of compounds derived from or related to N-acetylneuraminic acid. Sialic acids are found in glycoproteins, gangliosides, and glycolipids. Sialic acid is activated for addition to a growing glycoprotein by reaction with CTP as follows ... 

In glycoproteins and glycolipids, sialic acids occupy generally terminal positions... 

Glycolipid-sialic acid has also been analyzed by GLC of the V-,0-trifluoroacetyl derivative after first cleaving sialic acid by heating 6 hr at 75-80° in 3% methanolic-HCl (Ando and Yamakawa, 1971). It should be emphasized that this GLC procedure as well as those described above have been applied only to ketosidically linked NANA. However, a... 

In about 1936, sialic acid was discovered by Blix, who found it to be a component of submaxillary-gland proteins, and who described many of its properties. However, little notice was taken of this work at the time it was published. In 1941, Klenk, who was working on glycolipids of the brain, described a compound, later shown to be a methyl glycoside of sialic acid, that had been obtained by treatment of a lipid fraction with 5% methanolic hydrogen chloride at 105°. In 1954, Klenk and Faillard reported the first isolation of pure N-acetyl-neuraminic acid from animal sources. 

Resorcinol A. 20 g 1 1 resorcinol in water B. Concentrated HC1 C. 0.1 mol 1 1 copper sulphate D. Water Mix A,B,C,D( 10 80 0.5 10) Gangliosides Compounds containing sialic acid residues react to give blue-violet spots. Other glycolipids give yellow spots... 

Gangliosides/glycolipids (ceramide + oligosaccharides + sialic acid)... 

N-Acetylneuraminic acid N-Acetylneuraminic acid (NANA) is a member of the family of sialic acids, each of which is acylated at a different site. These compounds are usually found as terminal carbohydrate residues of oligosaccharide side chains of glycoproteins, glycolipids, or, less frequently, of glycosaminoglycans. The]... 

Colominic acid (E. colt polyNeuNAc), sialic acids, mucoproteins, glycolipids... 

The procedure of isolating the glycosphingolipids is based on their physicochemical properties. The presence of the lipophilic, lipid moiety results in their solubility in such typical solvents for lipids as chloroform-methanol. On the other hand, the presence of the carbohydrate moiety imparts to them hydrophilic properties that increase with increase in the length of the carbohydrate chain and with the presence of such polar monosaccharides as sialic acid. This very property makes it possible to subdivide the glycolipids further, according to their polarity. In principle, the isolation of glycosphingolipids from marine animals does not differ from their isolation from other sources, a procedure comprehensively elucidated in a number of reviews.80 88... 

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