3-Aminobenzamide and 3-aminobenzoic acid, tags for capillary electrophoresis of complex carbohydrates with laser-induced fluorescent detection

• Published in: Journal of Chromatography A 1999-11, Vol.863 (2), p.205-218
• Main Authors: Kakehi, Kazuaki, Funakubo, Tadashi, Suzuki, Shigeo, Oda, Yasuo, Kitada, Yoshimi
• Format: Article
• Language: English
• Subjects: alpha-Fetoproteins - analysis; Aminobenzamides; Aminobenzoates; Aminobenzoic acids; Analytical chemistry; Benzamides; Carbohydrates; Carbohydrates - analysis; Chemistry; Chromatographic methods and physical methods associated with chromatography; Electrophoresis, Capillary - methods; Exact sciences and technology; Glycoproteins - analysis; Indicators and Reagents; Lasers; Mannose - analysis; meta-Aminobenzoates; N-Acetylneuraminic Acid - analysis; Oligosaccharides - analysis; Other chromatographic methods; Spectrometry, Fluorescence; Thyroglobulin - analysis; Transferrin - analysis
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(99)00978-4

The efficiencies in derivatization of reducing carbohydrates were compared by capillary electrophoresis using maltose as a model with nine monoaminobenzene derivatives by reductive amination in the presence of sodium cyanoborohydride. We found that aminobenzene derivatives substituted at the 3-position showed good reactivity with reducing carbohydrates as expected from the reaction mechanism, although the fluorescence intensities and molar absorptivities of these derivatives were not as high as those of 2- and 4-aminobenzene derivatives. The reagents, 3-aminobenzamide and 3-aminobenzoic acid, which showed the highest reactivity, were applied to the labeling of carbohydrate chains obtained from some sialic acid-containing glycoprotein samples, and also high-mannose and hybrid-type oligosaccharides. Capillary electrophoresis of these labeled carbohydrate chains in an inner surface-modified capillary with (50% phenyl)methylpolysiloxane allowed excellent separation of sialic acid-containing carbohydrate chains derived from fetuin and thyroglobulin as well as high mannose-type and hybrid-type carbohydrates derived from bovine pancreas ribonuclease B, soybean agglutinin and hen ovalbumin. The lower limit of calibration was as low as the 10 −16 mol (injected amount) with helium–cadmium laser induced detection.