New enzymatic synthesis of 6 3-modified maltooligosaccharides and their inhibitory activities for human α-amylases

Abstract

Ten new 6 3-modified maltopentaoses and tetraoses were synthesized by enzymatic reactions utilizing cyclodextrin glycosyltransferase (EC 2.4.1.19) and subsequent human salivary α-amylase (HSA) (EC 3.2.1.1). Among these compounds, α- d-glucopyranosyl-(1→4)- α- d-glucopyranosyl-(1→4)-(6-deoxy- α- d-glucopyranosyl)-(1→4)- α- d-glucopyranosyl-(1→4)- d-glucopyranose ( 11) and α- d-glucopyranosyl-(1→4)-(6-deoxy- α- d-glucopyranosyl)-(1→4)- α- d-glucopyranosyl-(1→4)- d-glucopyranose ( 12) showed strong inhibitory activities for human pancreatic α-amylase (HPA) and HSA. The IC 50 of 6 3-deoxymaltopentaose 11 (8.0×10 −5 M for HPA, 1.0×10 −4 M for HSA) and 6 3-deoxymaltotetraose 12 (2.0×10 −3 M for HPA, 2.0×10 −3 M for HSA) were lower than that of 6 3-deoxymaltotriose [(6-deoxy- α- d-glucopyranosyl)-(1→4)- α- d-glucopyranosyl-(1→4)- d-glucopyranose 13; 2.0×10 −3 M for HPA, 4.2×10 −2 M for HSA].