131-48-6 Usage
Chemical Description
N-acetylneuraminic acid is a sialic acid that is commonly found in glycoproteins and glycolipids.
Description
N-acetylneuraminic acid is an N-acyl derivative of neuraminic or acid amino sugar derivative, derived from N-acetylmannosamine and pyruvic acid. It is an important constituent of glycoproteins and glycolipids. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria.
Physical properties
The numbering of the sialic acid structure begins at the carboxylate carbon and continues around the chain. The configuration which places the carboxylate in the axial position is the alpha-anomer. The alpha-anomer is the form that is found when sialic acid is bound to glycans, however, in solution it is mainly (over 90 %) in the beta-anomeric form. A bacterial enzyme with sialic acid mutarotase activity, NanM, has been discovered which is able to rapidly equilibrate solutions of sialic acid to the resting equilibrium position of around 90 % beta 10 % alpha.
Uses
N-Acetylneuraminic acid is an integral part of sialic acids (SAs), important functional sugars that play an important role in maintaining and improving brain health, detoxification, antibacterial, and immune enhancement. n-Acetylneuraminic acid is biologically useful for neurotransmission, leukocyte extravasation, viral or bacterial infection, and carbohydrate-protein recognition. n- Acetylneuraminic acid is used to study its biochemistry, metabolism and absorption in vivo and in vitro.
Definition
ChEBI: N-Acetylneuraminic acid is n-Acetylneuraminic acid with beta configuration at the anomeric centre. It has a role as an epitope. It is functionally related to a beta-neuraminic acid. It is a conjugate acid of a N-acetyl-beta-neuraminate.
Biosynthesis
In bacterial systems, sialic acids are biosynthesized by an aldolase enzyme. The enzyme uses a mannose derivative as a substrate, inserting three carbons from pyruvate into the resulting sialic acid structure. These enzymes can be used for chemoenzymatic synthesis of sialic acid derivatives.
Biological Functions
Sialic acid-rich glycoproteins (sialoglycoproteins) bind selectin in humans and other organisms. Metastatic cancer cells often express a high density of sialic acid-rich glycoproteins. This overexpression of sialic acid on surfaces creates a negative charge on cell membranes. This creates repulsion between cells (cell opposition) and helps these late-stage cancer cells enter the blood stream. Sialic acid also plays an important role in human influenza infections. Many bacteria also use sialic acid in their biology, although this is usually limited to bacteria that live in association with higher animals (deuterostomes). Many of these incorporate sialic acid into cell surface features like their lipopolysaccharide and capsule, which helps them evade the innate immune response of the host.[6] Other bacteria simply use sialic acid as a good nutrient source, as it contains both carbon and nitrogen and can be converted to fructose-6- phosphate, which can then enter central metabolism. Sialic acid-rich oligo saccharides on the glyco conjugates ( glyco lipids, glyco proteins, proteoglycans) found on surface membranes help keep water at the surface of cells . The sialic acid - rich regions contribute to creating a negative charge on the cells' surfaces. Since water is a polar molecule with partial positive charges on both hydrogen atoms, it is attracted to cell surfaces and membranes. This also contributes to cellular fluid uptake. Sialic acid can "hide" mannose antigens on the surface of host cells or bacteria from mannose - binding lectin . This prevents activation of complement. Sialic acid in the form of poly sialic acid is an unusual posttranslational modification that occurs on the neural cell adhesion molecules (NCAMs). In the synapse, the strong negative charge of the polysialic acid prevents NCAM cross-linking of cells.
Biochem/physiol Actions
Both sialic acid and neuraminic acid are loosely used to refer to conjugates of neuraminic acid. N-Acetylneuraminic acid is often found as the terminal sugar of cell surface glycoproteins. Cell surface glycoproteins have important roles in cell recognition and interaction as well as in cell adhesion. Membrane glycoproteins are also important in tumor growth and metastases.
Check Digit Verification of cas no
The CAS Registry Mumber 131-48-6 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,3 and 1 respectively; the second part has 2 digits, 4 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 131-48:
(5*1)+(4*3)+(3*1)+(2*4)+(1*8)=36
36 % 10 = 6
So 131-48-6 is a valid CAS Registry Number.
InChI:InChI=1/C11H19NO9/c1-4(14)12-7-5(15)2-11(20,10(18)19)21-9(7)8(17)6(16)3-13/h5-9,13,15-17,20H,2-3H2,1H3,(H,12,14)(H,18,19)/t5-,6+,7+,8+,9+,11-/m0/s1
131-48-6Relevant articles and documents
Uncovering a novel molecular mechanism for scavenging sialic acids in bacteria
Angulo, Jesus,Bell, Andrew,Juge, Nathalie,Latousakis, Dimitrios,Lee, Micah,Monaco, Serena,Naismith, James H.,Severi, Emmanuele,Thomas, Gavin H.
, p. 13724 - 13736 (2020)
The human gut symbiont Ruminococcus gnavus scavenges host-derived N-acetylneuraminic acid (Neu5Ac) from mucins by converting it to 2,7-anhydro-Neu5Ac. We previously showed that 2,7-anhydro-Neu5Ac is transported into R. gnavus ATCC 29149 before being converted back to Neu5Ac for further metabolic processing. However, the molecular mechanism leading to the conversion of 2,7-anhydro-Neu5Ac to Neu5Ac remained elusive. Using 1D and 2D NMR, we elucidated the multistep enzymatic mechanism of the oxidoreductase (RgNanOx) that leads to the reversible conversion of 2,7-anhydro-Neu5Ac to Neu5Ac through formation of a 4-keto-2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid intermediate and NAD1 regeneration. The crystal structure of RgNanOx in complex with the NAD1 cofactor showed a protein dimer with a Rossman fold. Guided by the RgNanOx structure, we identified catalytic residues by site-directed mutagenesis. Bioinformatics analyses revealed the presence of RgNanOx homologues across Gram-negative and Gram-positive bacterial species and co-occurrence with sialic acid transporters. We showed by electrospray ionization spray MS that the Escherichia coli homologue YjhC displayed activity against 2,7-anhydro-Neu5Ac and that E. coli could catabolize 2,7-anhydro-Neu5Ac. Differential scanning fluorimetry analyses confirmed the binding of YjhC to the substrates 2,7-anhydro-Neu5Ac and Neu5Ac, as well as to co-factors NAD and NADH. Finally, using E. coli mutants and complementation growth assays, we demonstrated that 2,7-anhydro-Neu5Ac catabolism in E. coli depended on YjhC and on the predicted sialic acid transporter YjhB. These results revealed the molecular mechanisms of 2,7-anhydro-Neu5Ac catabolism across bacterial species and a novel sialic acid transport and catabolism pathway in E. coli.
Benzing-Nguyen,L.,Perry,M.B.
, p. 551 - 554 (1978)
Quantitative Standards of 4-O-Acetyl- and 9-O-Acetyl-N-Acetylneuraminic Acid for the Analysis of Plasma and Serum
Badia, Concepcion,Cheeseman, Jack,Gardner, Richard A.,Kuhnle, Gunter,Osborn, Helen M. I.,Spencer, Daniel I. R.,Thomson, Rebecca I.
, (2022/01/20)
N-Acetylneuraminic acid (sialic acid, Neu5Ac) is one of a large, diverse family of nine-carbon monosaccharides that play roles in many biological functions such as immune response. Neu5Ac has previously been identified as a potential biomarker for the presence and pathogenesis of cardiovascular disease (CVD), diabetes and cancer. More recent research has highlighted acetylated sialic acid derivatives, specifically Neu5,9Ac2, as biomarkers for oral and breast cancers, but advances in analysis have been hampered due to a lack of commercially available quantitative standards. We report here the synthesis of 9-O- and 4-O-acetylated sialic acids (Neu5,9Ac2 and Neu4,5Ac2) with optimisation of previously reported synthetic routes. Neu5,9Ac2 was synthesised in 1 step in 68 % yield. Neu4,5Ac2 was synthesised in 4 steps in 39 % overall yield. Synthesis was followed by analysis of these standards via quantitative NMR (qNMR) spectroscopy. Their utilisation for the identification and quantification of specific acetylated sialic acid derivatives in biological samples is also demonstrated.
