Abstract
We applied the alkaline o-phenylenediamine (OPD) method to β-1, 3-linked glucans such as curdlan, scleroglucan and schizophyllan in alkaline media under heating and deoxygenated conditions. In the case of curdlan and laminari-oligosaccharide, (2′S, 3′R)-2-(2′, 3′, 4′-trihydroxybutyl) quinoxaline (G-1) was formed from the glucose residues in the main-chain, and several quinoxaline derivatives including G-1 from the non-reducing end groups. In the case of scleroglucan, G-1 was formed from β-1, 3 linked sugar residues in the main-chain, and a quinoxaline, designated as QD-I, from the branching disaccharide units. The scleroglucan tested had a branch at intervals of every 2.3-2.6 glucose units along the main-chain residue.