Sequential Analysis of Reducing Oligosaccharides Based on a Chemical Reaction Using 8-Amino-2-naphthalenesulfonic Acid

Abstract

A method for the sequential analysis of reducing sugars has been developed based on repetition of the following procedures: 1) derivatization of a reducing oligosaccharide with 8-amino-2-naphthalenesulfonic acid (ANS) to produce a Schiff base, 2) reduction of the base with sodium cyanoborohydride, 3) methoxycarbonylation of the secondary amino group, 4) cleavage of the glycoside bond next to the reducing end, through intramolecular acid hydrolysis by the action of a sulfonic acid group of the ANS derivative, 5) identification of the liberated reducing end by high-performance liquid chromatography (HPLC), and finally 6) recovery of the resultant oligosaccharide fragment from the cleavage reaction mixture. A satisfactory yield in the cleavage reaction and a quantitative recovery of the oligosaccharide fragments were obtained when the cleavage reaction of the ANS derivative was carried out at 140°C for 30 min in dioxane-dimethyl sulfoxide (7:3). The method was successfully applied to the sequential analysis of some reducing di- and trisaccharides.