text: Isolation and structural analyses of positional isomers of 6(1),6m-di-O-alpha-D-mannopyranosyl-cyclomaltooctaose (m = 2-5) and 6-O-alpha-(n-O-alpha-D-mannopyranosyl)-alpha-D-mannopyranosyl- cyclomaltooctaose (n = 2, 3, 4, and 6).
  Eight positional isomers of 6(1),6m-di-O-alpha-D-mannopyranosyl-cyclomaltooctaose (gamma CD) (m = 2-5) and 6-O-alpha-(n-O-alpha-D-mannopyranosyl)-D-mannopyranosyl-gamma CD (n = 2, 3, 4, and 6) in a mixture of products from gamma CD and D-mannose by condensation reaction of alpha-mannosidase from jack bean were isolated by HPLC. The structures of four isomers of 6-O-alpha-(n-O-alpha-D-mannopyranosyl)-D-mannopyranosyl-gamma CD were elucidated by NMR spectroscopy. On the other hand, four positional isomers of 6(1),6m-di-O-alpha-D-mannopyranosyl-gamma CD were determined by LC-MS analysis of degree of polymerization of the branched oligosaccharides produced by enzymatic degradation with bacterial saccharifying alpha-amylase (BSA), and combination of BSA and glucoamylase. Similarly cyclomaltodextrin glucanotransferase also digested these isomers.