Time-resolved fluorometric analysis of carbohydrates labeled with amino-aromatic compounds by reductive amination

We examined the formation of complexes between terbium ion (Tb³⁺) and carbohydrates labeled with aminobenzene compounds. Of the examined compounds, carbohydrates labeled with 4-aminosalicylic acid showed intense fluorescence with Tb³⁺ in the presence of cetylpyridinium chloride at pH 6.0. Calibration curves for maltose derivative showed good linearity between 5 pmol and at least 600 pmol, with good reproducibility. We applied the proposed technique to binding studies between manno-oligosaccharides and Concanavalin A.