Acetyl neuraminic acid

TV-Acetyl neuraminic acid (NANA, O-Sialic acid, 5-acetamido-3,5-dideoxy-D-g/ycero-D-g/acto-2-nonulosonic acid, lactaminic acid) [I3I-48-6JM 309.3, m 159°(dec), 181-... 

TV-Acetyl neuraminic acid aldolase [from Clostridium perfringens, TV-acetyIneuraminic acid pyruvate lyase] [9027-60-5] 32,000 [EC 4.1.3.3]. Purified by extraction with H2O,... 

Bossart-Whitaker P, Carson M, Babu YS, Smith CD, Laver WG, Air GM (1993) Three-dimensional structure of influenza A N9 neuraminidase and its complex with the inhibitor 2-deoxy 2,3-dehydro-V-acetyl neuraminic acid. J Mol Biol 232 1069-1083 Burmeister WP, Ruigrok RW, Cusack S (1992) The 2.2 A resolution crystal structure of influenza... 

Mahmoudian, M., Noble, D., Drake, C.S. etal. (1997) An efficient process for production of N-acetylneuraminic acid using V-acetyl neuraminic acid aldolase. Enzyme and Microbial Technology, 20 (5), 393—400. 

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. 

Figure 12.15 Gangliosides. The prefix mono-, di, tri- or tetra- denotes the number of sialic acid W-acetyl neuraminic acid, NANA) residues present in the molecule. The many different gangliosides have complex structures and for convenience shorthand notations are used. The two commonest were introduced by Svennerholm, who named the parent compound GM1, and Wiegnandt, who named it Ggnti. The latter system gives enough information for the structures to be worked out from the shorthand form once the symbols have been learnt. GalNAc represents N-acetyl galactosamine in the above structure.

From the GORGEMA-STD predictions based on the crystal structure, all protons in N-acetyl neuraminic acid and galactose show reasonable STD... 

The Glaxo synthesis of zanamivir (2) started with the esterification of commercially available A-acetyl-neuraminic acid (88) with methanolic HCl to give the methyl ester as shown in Scheme 7.14 (Chandler and Weir, 1993 Chandler et ah, 1995 Patel, 1994 Weir et al., 1994). Global acetylation of all the hydroxyl groups with acetic anhydride in pyridine with catalysis by 4-(dimethylamino)pyridine (DMAP) led to the penta-acetoxy compound 89. Treatment of 89 with trimethylsilyl triflate in ethyl acetate at 52°C introduced the oxazoline as well as the 2,3-double bond to provide 86. Addition of trimethysilyl azide to the activated allylic oxazoline group led to the stereoselective introduction of azide at the C-4 position to afford 83 as in Scheme 7.13. 

Vasella has applied the concept of anomeric anion stabilization by a nitro group to the /3-D-JV-acetyl-D-glucosamine derivative 177, available in four steps from N-acetyl-n-glucosamine [52] (Scheme 39). Reaction of the tetraethylammonium nitronate derived from 177 with aldehyde 178 provides anti-179 which then undergoes stereoselectively reduction (see Sect. 2.2.1) to provide -C-glycoside 180, intermediate in a synthesis of N-acetyl-neuraminic acid. 

However, two recent papers suggest that DMF is also a good solvent for this type of condensation under appropriate activation conditions of the donor. A simple and efficient method for the preparation of thioglycosides of N-acetyl-neuraminic acid has been developed [30]. This procedure involves the selective in situ S-deacetylation and activation of the 2-S-acetyl NeuSAc (24a) and the displacement of primary bromide of methyl glycosides (28a, 28b). The desired a(2->6) thioglycosides (29a,29b) were obtained in 75 and 82% yield. Condensation of the sodium salt (24b), freshly derived from (24 a) by selective S-deacetylation with sodium methoxide [16], with (28c) in DMF at 45 °C also gave the expected compound (29c) in 76% yield (Scheme 8) [31]. 

There also seemed to be no requirement for glycosylation of interferon for secretion, although a partial involvement cannot be strictly excluded. Interferon formed in the presence of glycosylation inhibitors showed less charge-heterogeneity, which is caused by. V-acetyl-neuraminic acid in the native molecules.333 534... 

The structures of TV-acetyl neuraminic acid (sialic acid Neu5Ac) and the 2-deoxy-2,3-dehydro-/V-acetyl neuraminic acid (Neu5Ac2en) inhibitor complexed with N2 neuraminidase [66] revealed the nature of the interactions of the... 

Fraction Galactose N-acetyl- galactosamine. V-acetyl- neuraminic acid Phosphate... 

A-Acetyl neuraminic acid aldolase [from Clostridium perfringens, A-acetylneuraminic acid pyruvate lyase] [9027-60-5] [EC 4.1.3.3]. Purified by extraction with H20, protamine pptn, (NH4)2S04 pptn, Me2CO pptn, acid treatment at pH 5.7 and pptn at pH 4.5. The equilibrium constant for pyruvate + n-acetyl-D-mannosamine ++ /V-acetylneuraminidate at 37° is 0.64. The Km for A-acetylneuraminic acid is 3.9mM in phosphate at pH 7.2 and 37°. [Comb and Roseman Methods in Enzymology 5 391 1962). The enzyme from Hogg kidney (cortex) has been purified 1700 fold by extraction with H20, protamine sulphate pptn, (NH4)2S04 pptn, heat treatment between 60-80°, a second (NH4)2S04 pptn and starch gel electrophoresis. The Km for A-acetylneuraminic acid is 1.5mM. [Brunetti et al. JBC 237 2447 1962). 

U. Kragl, D. Gygax, O. Ghisalba, and C. Wandrey, Enzymatic two-step synthesis of W-acetyl-neuraminic acid in the enzyme membrane reactor, Angew. Chem. Int. Ed. Engl. 30 827 (1992). 

H. S. Conradt, A. Biinsch, and R. Brossmer, Preparation of 9-fluoro-9-deoxy-Ai-[2-14C]acetyl-neuraminic acid, FEES Lett. 770 295 (1984). 

J. O. Nagy and M. D. Bednarski, The chemical-enzymatic synthesis of a carbon glycoside of W-acetyl neuraminic acid, Tetrahedron Lett. 32 3953 (1991). 

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