Isolation by HPLC of the positional isomers of 6 1,2 n-di- O- α-d- galactopyranosylcyclomaltohexaose ( n = 1–6) and determination of their structures by enzymatic degradation

Abstract

The six positional isomers of 6 1,2 n -di- O- α-d- galactopyranosylcyclomaltohexaose (α-cyclodextrin, αCD, n = 1–6), which were produced from αCD and melibiose by transgalactosylation with coffee bean α-galactosidase, were isolated by HPLC on a reversed-phase column and a graphitized carbon column. The structures of those isomers were elucidated by LC-MS analyses of enzymatic degradation products with cyclomaltodextrin glucanotransferase and α-galactosidase.