N-acetyl-D-neuraminic acid

Fig. 34.— 13C-N.m.r. Spectra of Native, Partly Acetylated Polysaccharide from Neisseria meningitidis Serogroup C (A) and the a-D-(2— 9)-Linked N-Acetyl-D-neuraminic acid Polymer (32) Obtained on O-Deacetylation (B). (Solvent, D20, pD 7, at 31° chemical shifts are expressed relative to external tetramethylsilane.)...

N-acetyl-D-neuraminic acid GlcNAc+pyravate Neu5Ac-aldolase... 

Structure of N-acetyl-D-neuraminic acid in three different representations (a) Fischer projection (b) Haworth projection, and (c) conformational formula. 

N-acetyl-D-neuraminic acid results from the formation of a C-C bond between the C-1 of N-acetyl-D-mannosamine and the C-3 of phospho-enolpyruvate. This and other derivatives of neuraminic acid are collectively called sialic acids and are widely found in bacteria and animals. 

Rodriguez-Aparicio LB, Ferrero MA, Reglero A. N-acetyl-D-neuraminic acid synthesis in Escherichia coli K1 occurs through condensation of N-acetyl-D-mannosamine and pyruvate. Biochem J 1995 308 501-505. 

The n.m.r. spectrum of the a-anomer of N-acetyl-D-neuraminic acid was obtained by enzymic cleavage of the glycosyl azide in the... 

N-Acetyl-D-Neuraminic acid open chain form... 

Biosynthesis of Eight- and Nine-Carbon Sugars N-Acetyl-D-Neuraminic Acid, N-Acetyl-o-Muramic Acid, and 2-Keto-3-Deoxy-D-Mannooctulosonic Acid (KDO)... 

A -acetyl-D-neuraminic acid is biosynthesized from A -acetyl-D-mannosamine and phosphoenol pyruvate, catalyzed by N-acetyl-D-neuraminic acid synthase. The first step involves the addition of an electron pair from the double bond of the phosphoenol pyruvate to the aldehyde group to give an aldol-type condensation (see Fig. 10.8A). The product is the nine-carbon sugar acid, A -acetyl-D-neuraminic acid [23]. In some instances the enzyme requires A-acetyl-D-mannosamine-6-phosphate as the substrate and forms A-acetyl-D-neuraminic acid-9-phosphate. Various hydroxyl groups on C-4, -7, -8, and -9 can be acetylated by specific acetyl transferases using acetyl CoAas the donor. KDO (2-keto-3-deoxy-D-mannooctulosonic acid) is biosynthesized by a very similar condensation between D-arabinose-5-phosphate and pyruvic acid, catalyzed by KDO synthase (see Fig. 10.8B) [24]. 

Haverkamp, J., Schauer, R., Wember, M., Kamerling, J. P., and Vliegenthart, J. F. G., 1975, Synthesis of 9-O-acetyl- and 4,9-di-O-acetyl derivatives of the methyl ester of N-acetyl- -D-neuraminic acid methylglycoside. Their use as models in periodate oxidation studies, Hoppe-Seyl. Z. 356 1575. 

Holmquist, L., and Brossmer, R., 912a. On the specificity of neuraminidase. The carboxymethyl a-ketoside of N-acetyl-D-neuraminic acid, a Vibrio cholerae neuraminidase substrate having two anionic sites, FEBS Lett. 22 46. 

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