Sialic acid analysis

Ito M, Ikeda K, Suzuki Y, Tanaka K, Saito M (2002) An improved fluorometric high-performance liquid chromatography method for sialic acid determination an internal standard method and its application to sialic acid analysis of human apolipoprotein E. Anal Biochem 300 260-266... 

Of the various fluorimetric assays available for sialic acid analysis, the method which allows the discrimination between sialic acids with or without 0-acyl groups at C8 and/or C9 may be of interest [6,265], After mild periodate oxidation, formaldehyde, derived from C9 in the case of non-substituted H09 and H08 is derivatized with acetylacetone in the presence of ammonium acetate, leading to the fluorigen 3,5-diacetyl-l,4-dihydro-2,6-dimethylpyridine (410nm excitation, 510nm emission). It is evident that all contaminants producing formaldehyde under the influence of periodate will interfere with this sialic acid analysis. 

Monosaccharides are released by acid hydrolysis then labeled with the flurophore to allow sensitive detection 2-aminobenzoic acid (2-AA) for the neutral monosachharides, or l,2-diamino-4,5-methylenedioxybenzene. 2HC1 (DMB) for the sialic acids. Analysis by reversed-phase liquid chromatography provides reproducible quantitative results. 

The initial attempts to develop a quantitative assay for sialic acids were colorimetric. The majority of these early methods were unsuitable because of their lack of specificity and/or sensitivity required for sialic acid analysis in biological materials or for enzymic assays. Some of these methods included diphenylamine (Ayala et al. 1951), tryptophane/perchloric acid (Seibert et al. 1948), sulphuric acid/acetic acid (Hess et al. 1957), hydrochloric acid (Folch et al. 1951) and the Ehrlich reagent, dimethyl-aminobenzaldehyde (Werner and Odin 1952). 

Sauter, N. K., Hanson, J. E., Glick, G. D., Brown, J. H., Crowther, R. L., Park, S. J., Skehel, J. J., and Wiley, D. C., 1992, Binding of influenza virus hemagglutinin to analogs of its cell surface receptor, sialic acid Analysis by proton nuclear magnetic resonance spectroscopy and X-ray crystallography. Biochemistry 31 9601-9621. 

Kim CU, Lew W, Wilhams MA, Liu H, Zhang L, Swaminathan S, Bischofberger N, Chen MS, Mendel DB, Tai CY, Laver WG, Stevens RC (1997) Influenza neuraminidase inhibitors possessing a novel hydrophobic interaction in the enzyme active site design, synthesis, and structural analysis of carbocyclic sialic acid analogues with potent anti-influenza activity. J Am Chem Soc 119 681-690... 

Analysis of 3- and 6-linked sialic acids in mixtures of gangliosides separation of 62... 

IonPac KC-811 column separated the labile compounds N-acetylneuraminic acid and N-glycolylneuraminic acid released by mild acid hydrolysis of bovine vitronectin.245 Sialic acid is extremely labile to conditions of handling and must be released by mild acid hydrolysis.246 Derivatization with phe-nylisothiocyanate and separation by reversed phase chromatography was found useful in analysis of hexosamines from gastric mucosa.247 A review on separation of sugars and other carbohydrates which covers many important aspects is available.248... 

Mrochek, J. E., Dinsmore, S. R., Tormey, D. C., and Waalkes, T. P., Protein-bound carbohydrates in breast cancer, liquid-chromatographic analysis for mannose, galactose, fucose, and sialic acid in serum, Clin. Chem., 22, 1516, 1976. 

The linkage of sialic acid to Gal, GlcNAc, or GalNAc may be determined on the microscale by methylation analysis before and after treatment with... 

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