Comb-like derivatives of amylose having (1-6)-linked malto-oligosaccharide side-chains

The preparation of acetylated glycosyl bromide derivatives of the higher malto-oligosaccharides was studied by using beta-cyclodextrin or linear malto-oligosaccharides of d.p. 6 and 7. The products were treated with 2,3-di-O-phenylcarbamoyl-6O-tritylamylose in the presence of silver perchlorate (reaction A), and with 2,3-di-O-phenylcarbamoylamylose in the presence of mercuric cyanide and mercuric bromide (reaction B). After removal of the substituents, the branched molecules were characterized by their iodine-binding properties, beta-amylolytic degradation, and their priming activity in phosphorolytic synthesis. The distance between the branch points of the backbone chain was 25-55 and 100-150 units in the products from reactions A and B, respectively. Thus, the frequency of branching was considerably lower than in the comb-like molecules having D-glucose side-chains previously described.