title: Acid-base properties of the reaction product of sialic acid with fluorogenic reagent, 1,2-diamino-4,5-methylenedioxybenzene (DMB).
abstract: N-Acetylneuraminic acid (Neu5Ac) forms the highly fluorophoric quinoxalinone derivative (Q) when treated with 1,2-diamino-4,5-methylenedioxybenzene (DMB). Effects of protonation and deprotonation on the fluorescence of Q were examined at room temperature. The strong fluorescence was found to be caused by the neutral form Q but not the protonated form of its excited state [Q]* and at pH below 1 the emission was completely quenched. The deprotonated singlet form [Q-]* was a less efficient fluorescer than [Q]*.
authors: Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
authors: S L
authors: SL
authors: Lin
authors: S
authors: S
authors: Inoue
authors: Y
authors: Y
authors: Inoue
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D019158:N-Acetylneuraminic Acid / Q000737:chemistry*; D010655:Phenylenediamines / Q000737:chemistry*; D011522:Protons; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D005456:Fluorescent Dyes; D010655:Phenylenediamines; D011522:Protons; C058886:1,2-diamino-4,5-methylenedioxybenzene; D019158:N-Acetylneuraminic Acid