Structure of di-O-alpha-maltosyl cyclodextrins produced from alpha-maltosylfluoride and cyclodextrins

The structures of di-O-alpha-maltosyl beta-cyclodextrins ((G2)2-beta-CDs), which were produced from alpha-maltosylfluoride (alpha-G2F) and cyclodextrin (CD) by the transfer action of debranching enzymes, were examined by the enzymic method using Bacillus subtilis saccharifying alpha-amylase (BSA). (G2)2-beta-CD was converted to (G1)2-beta-CD by treatment with glucoamylase before the examination. BSA completely hydrolyzed (G1)2-beta-CD to produce glucose, 6(3)-O-alpha-glucosylmaltotriose, and 6(3),6(5)-di-O-alpha-glucosyl maltopentaose. (G2)2-beta-CD was the mixture of 6A,6C-di-O-alpha-maltosyl beta-CD and 6A,6D-di-O-alpha-maltosyl beta-CD. The ratio of A,C/A,D in (G2)2-beta-CD synthesized with Pseudomonas isoamylase and Aerobacter pullulanase were 40:60-45:55 and 30:70, respectively. The content of 6A,6C-di-O-alpha-maltosyl gamma-CD in (G2)2-gamma-CD synthesized by isoamylase was about 35%.