Negatively charged yellow-emitting 1-aminopyrene dyes for reductive amination and fluorescence detection of glycans.

1 - Aminopyrenes with three w-hydroxylated N-alkylsulfonamido or alkylsulfonyl residues in positions 3, 6 and 8 were prepared, O-phosphorylated and applied for reductive amination of oligosaccharides. The dyes (ε ~ 20000 M -1 cm -1 ) with six negative charges (pH ≥ 8) and low m/z ratios enable labeling and fluorescence detection of reducing sugars (glycans) related to the most structurally and functionally diverse class of natural products. Under excitation with a 488 nm laser, the new glycoconjugates emit yellow light of about 560 nm, outperforming (in respect of brightness and electrophoretic mobilities) the corresponding APTS derivatives (benchmark dye with green emission in conjugates)