Abstract
Two kinds of branched cycloisomaltooligosaccharides, P1 and P2, were synthesized from cycloisomaltoheptaose and maltose by the action of cyclodextrin glucanotransferase. P1 was hydrolyzed into glucose and cycloisomaltoheptaose with the same molar ratio by the action of glucoamylase. P2 was hydrolyzed into glucose and cycloisomaltoheptaose with a molar ratio of two to one. P2 was also hydrolyzed into maltose and cycloisomaltoheptaose by acid degradation. Their molecular weight were determined by mass spectra analysis to be 1296 and 1458, respectively. Carbon and proton magnetic resonance analysis suggested that they contained α-1, 4-glucosidic linkage. From these results, they were identified as 4-0-D-glucosyl-cycloisomaltoheptaose and 4-O-α-maltosyl-cycloiso-maltoheptaose. They had higher resistance to hydrolytic action by endo-dextranase than the parent cycloisomaltoheptaose.
