ACID-CATALYZED REDUCTIVE AMINATION OF ALDOSES WITH 8-AMINOPYRENE-1,3,6-TRISULFONATE

The reductive amination of monosaccharides with 8-aminopyrene-1,3,6-tr isulfonate (APTS) in seven different organic acids including the commo nly used acetic acid was investigated by capillary electrophoresis (CE ) with laser-induced fluorescence (LIF) detection. The correlation bet ween the yields of the saccharide-APTS adducts and pK(a) of the organi c acid catalyst is consistent with general acid catalysis of the rate- determining step of the reductive amination reaction. Derivatization i n the presence of organic acids of higher strength than acetic acid pr oduced substantially higher yields of APTS-sugar adducts, an effect wh ich is more pronounced for N-acetylamino sugars. Optimum yields were o btained using citric acid as a catalyst. Conversion of a few nanomoles of neutral saccharides to the APTS derivatives is achieved at 75 degr ees C in less than 60 min.