JV-Acetylneuraminic acid

Hydrolysis of caseins. During heating at 140°C there is a considerable increase in non-protein N (12% TCA-soluble), apparently following zero-order kinetics. K-Casein appears to be particularly sensitive to heating and about 25% of the JV-acetylneuraminic acid (a constituent of K-casein) is soluble in 12% TCA at the point of coagulation. 

The monomeric mechanism of chain assembly is characteristic for homopolysaccharides, which constitute the most difficult case for biosynthetic studies, as accumulation of intermediates could not be induced by removal of one of the glycosyl donors required for chain elongation. Among these polymers, the most extensive information has been obtained for polymers of JV-acetylneuraminic acid, namely, the capsular polysaccharides (36 and 37) of E. coli K1 (Ref. 354) and Neisseria meningitidis type c (Ref. 355), respectively. CMP-NeuAc serves as the glycosyl donor in the formation... 

JV-Acetylneuraminic acid aldolase (Neu5NAc aldolase or NeuA EC 4.1.3.3), also known as sialic acid aldolase, catalyzes the reversible addition of pyruvate... 

V,2. This is not the case with cytidine monophosphate JV-acetylneuraminic acid (49) (see Scheme 18), the activated form of JV-acetylneuraminic acid for sialoside synthesis, as no sialylation cycle has so far been achieved, and thus this precursor must be added to the system in stoichiometric quantity. Thus, the availability of 49 is still the limiting factor in the large-scale synthesis of sialosides. 

Scheme 19.—Enzymic Synthesis of Cytidine Monophosphate JV-Acetylneuraminic Acid Starting from CMP.

Sialyl residues in oligosaccharides are introduced by the reaction of cyti-dine monophosphate-V-acetylneuraminic acid (49) as the sugar donor with the appropriate substrate, in the presence of specific transferases. Three of these have been utilized in syntheses which may be considered to be preparative. None are readily available. The most common, which we have called STA (see Table I), catalyzes the transfer of a 5-acetamido-3,5-di-deoxy-D-g/ycm>-a -D-ga/arfo-2-hexulopyranosonic acid unit (the a-D-pyra-nose form of JV-acetylneuraminic acid) to the primary position of D-galactose in a JV-acetyllactosamine residue.86 This enzyme also transfers vV-acetyl-9-O-acetylneuraminic acid (20) and V-glycolylneuraminic acid (12) from the corresponding cytidine monophosphate derivatives.16 The commercial enzyme is rather expensive, but pork liver from a butcher is a... 

A novel approach to glycosidation with jV-acetylneuraminic acid was adopted by Sinay [268], Reaction of (385) with diazotrimethylphosphonoacetate in the presence of rhodium acetate gave the phosphonate (386) as a mixture of diastereoisomers which were allowed to react with the aldehyde (387) in the presence of sodium hydride in tetrahdrofuran to give a mixture of E- and Z-isomers (388) which were separated. The isopropylidene groups were hydrolysed and the products cyclised with mercury(II)... 

Fio. 1. (a) A view of the influenza virus hemagglutinin trimer showing jV-acetylneuraminic acid (3, in CPK form) bound, (b) The tetrameric unit of influenza A virus sialidase. The figures were generated using the PyMOL Molecular Graphics System (Delano, W.L. (2002) at http // www.pymol.org). 

T. Hagiwara, I. Kijima-Suda, T. Ido, H. Ohrui, and K. Tomita, Inhibition of bacterial and viral sialidases by 3-fluoro-jV-acetylneuraminic acid, Carbohydr. Res., 263 (1994) 167-172. 

P. Meindl, G. Bodo, P. Palese, J. Schulman, and H. Tuppy, Inhibition of neuraminidase activity by derivatives of 2-deoxy-2,3-dehydro-jV-acetylneuraminic acid, Virology, 58 (1974) 457 463. 

K. Ikeda, K. Sano, M. Ito, M. Saito, K. Hidari, T. Suzuki, Y. Suzuki, and K. Tanaka, Synthesis of 2-deoxy-2,3-didehydro-jV-acetylneuraminic acid analogues modified at the C-4 and C-9 positions and their behaviour towards sialidase from influenza virus and pig liver membrane, Carbohydr. Res., 330 (2001) 31 11. 

Moran, A.P., Rietschel, E.T., Kosunen, T.U., Zahringer U. Chemical characterization of Campylobacter jejuni lipopolysaccharides containing JV-acetylneuraminic acid and 2,3-diamino-2,3-dideoxy-D-glucose. J Bacteriol 173 (1991a) 618-626. 

A. Marra and P. Sinay, Stereoselective synthesis of 2-lhioglycosides of JV-acetylneuraminic acid, Carbohydr. Res. 187 35 (1989). 

The first synthesis of JV-acetylneuraminic acid has been reported by Cornforth, Firth and Gottschalk. ... 

Since the numbering of carbon atoms in JV-acetylneuraminic acid starts at the carboxylate group, to obtain the equivalent conformation of a hexopyranoside (Figure 2.6), 1 should be subtracted from the carbon numbers - but not the ring oxygen. Thus, sialic acid 2,5 is the counterpart of hexopyranoside 4, 82 the counterpart of and S the counterpart of... 

JV-acetylneuraminic acid— D-galacto-pyranosyl-(l—>4)-2-acetamido-2-deoxy-D-glucose and (1— 6) isomer of above... 

P. J. O Brien and F. Zilliken, Biochim. Biophys. Acta, 31, 543 (1959). Colominic acid is a polymer of JV-acetylneuraminic acid. 

J. Rothermel, B. Weber, and H. Faillard, Synthesis of a-JV-ketosides of JV-acetylneuraminic acid by using phase-transfer catalysis, Liebigs Arm. Chem. (1992) 799-802. 

The concentration of G in rabbit brain, thymus, lung, liver, stomach, intestine, kidney, testis, muscle, and erythrocyte tissues was determined. The neuraminic acid composition was also determined. iV-Glycolylneuraminic acid-containing Gm was found in thymus, lung, kidney, and intestine as well as A-acetylneuraminic acid-containing G, but JV-acetylneuraminic acid was the sole neuraminic acid of G from other tissue. 

Initially, the relative retentions and adjustment factors are determined. The procedure detailed below is suitable for the examination of biological materials containing fucose, xylose, mannose, galactose, glucose, iV-acetylgalactosamine, iV-acetylglucosamine and JV-acetylneuraminic acid. A similar procedure may also be used, however, for the analysis of other monosaccharides of interest. 

C8H17NO9P 302.197 Important intermed. in biosynth. of JV-Acetylneuraminic acid, A-20 in bacteria and higher animals. Powder. 

L-Alanine aminopeptidase has been purified from human kidney. The glycoprotein (mol. wt. 2.36 x 10 ) contains 21% carbohydrate, including residues of 2-amino-2-deoxy-D-glucose, jV-acetylneuraminic acid, and hexose. 

Hara S, Yamaguchi M, Taktanori Y, Furuhata K, Ogura H, Nakamura M (1989) Determina-titm of mtmo-O-acetylated JV-acetylneuraminic acids in human and rat sera by lluorometric high-performance liquid chromatography. Anal Biochem 179 162—166... 

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