title: Rapid on-column analysis of glucosamine and its mutarotation by microchip capillary electrophoresis.
abstract: A novel electrophoretic microchip method for analyzing alpha- and beta-d-glucosamine and their interconversion in solution is presented. d-Glucosamine is labeled with fluorescamine and analyzed by capillary electrophoresis in under 2 min revealing its pH-dependent mutarotation between the alpha- and beta-anomers. The forward interconversion rates for the labeled sugars, based on an iterative analysis of the plateau heights between the peaks, are 0.72+/-0.09, 1.3+/-0.1, and 2.2+/-0.3 x 10(-3)s(-1) at pH 8.99, 9.51 and 10.01, respectively. In a separate experiment, the mutarotation of the unlabeled alpha-d-anomer was followed; the relative intensities of the alpha- and beta-peaks as a function of reaction time at pH 9.51 give a forward rate constant of 0.6+/-0.1 x 10(-3)s(-1). These results demonstrate that fast microchip separations, previously exploited for amine, amino acid, and nucleobase analysis, can also be used to analyze amino sugars and their mutarotation.
authors.affiliation: Department of Chemistry, University of California, MS 1460, Berkeley, CA 94720, USA.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Skelley
authors.forename: Richard A
authors.initials: RA
authors.lastname: Mathies
mesh_terms: D046209:Electrophoresis, Microchip / Q000379:methods*; D005944:Glucosamine / Q000032:analysis* / Q000737:chemistry; D009904:Optical Rotation
chemical_list: D005944:Glucosamine