Synthesis of New N-Containing Maltooligosaccharides, [alpha]-Amylase Inhibitors, and Their Biological Activities

Fifteen new N-containing maltooligosaccharides were obtained using the chemoenzymatic method. Among these compounds, maltooligosaccharides having 6-amino-6-deoxy-D-sorbitol residue, (3R, 4R, 5R, 6S)-hexahydro-3, 4, 5, 6-tetrahydroxy-1H-azepine residue, and (3R, 5R)-3, 4, 5-trihydroxypiperidine residue at the reducing end showed strong inhibitory activities for human pancreatic α-amylase (HPA) (EC 3.2.1.1) and human salivary α-amylase (HSA). The administration of (3R, 4R, 5R, 6S)-hexahydro-3, 5, 6-trihydroxy-1H-azepine-4-yl O-α-D-glucopyranosyl-(1->4)-α-D-glucopyranoside (13, IC50=4.3×10-5M for HPA, IC50=8.2×10-5M for HSA) and (3R, 5R)-3, 5-dihydroxypiperidine-4-yl O-α-D-glucopyranosyl-(1->4)-α-D-glucopyranoside (18, IC50=3.4×10-5M for HPA, IC50=4.6×10-5M for HSA) to ICR mice suppressed postprandial hyperglycemia.