title: Characterization of five isomers of branched cyclomaltoheptaose (beta CD) having degree of polymerization (d.p.) = 9: Reinvestigation of three positional isomers of diglucosyl-beta CD.
abstract: It has been confirmed by methylation analyses and chemical syntheses that three isomers of branched cyclomaltoheptaose (beta CD) isolated from the mother liquors of a large-scale preparation of beta CD with Bacillus ohbensis cyclomaltodextrin glucanotransferase are 6(1),6(4)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (1), 6(1),6(3)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (2), and 6-O-(alpha-isomaltosyl)-cyclomaltoheptaose (4) instead of 6(1),6(2)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (3), which was erroneously characterized in an earlier paper. Compound 3 has been newly isolated from a glucosyl-beta CD mixture prepared by hydrolysis with glucoamylase of a maltosyl-beta CD mixture, synthesized from maltose and beta CD through the reverse action of pullulanase. Chromatographic behavior and spectral data (13C-n.m.r. and f.a.b.-m.s.) of these isomers of branched beta CD (1-4), as well as those of another isomer prepared by the reverse action of hydrolytic enzymes, 6-O-(alpha-maltosyl)-cyclomaltoheptaose (5), were compared.
authors.affiliation: Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Koizumi
authors.forename: T
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: N
authors.initials: N
authors.lastname: Nakanishi
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: Y
authors.initials: Y
authors.lastname: Takagi
authors.forename: H
authors.initials: H
authors.lastname: Hashimoto
mesh_terms: D002240:Carbohydrate Sequence; D002845:Chromatography; D003505:Cyclodextrins / Q000737:chemistry*; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D016339:Spectrometry, Mass, Fast Atom Bombardment; D047392:beta-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D047392:beta-Cyclodextrins; C065744:6(1),6(3)-di-O-(alpha-glucopyranosyl)cyclomaltoheptaose; C065743:6(1),6(4)-di-O-(alpha-glucopyranosyl)cyclomaltoheptaose; C065746:6(1),6(2)-di-O-(alpha-glucopyranosyl)cyclomaltoheptaose; C031215:betadex