Characterization of five isomers of branched cyclomaltoheptaose (β CD) having degree of polymerization (d.p.) = 9: Reinvestigation of three positional isomers of diglucosyl-β CD
✍ Scribed by Kyoko Koizumi; Toshiko Tanimoto (née Utamura); Yasuyo Okada; Noriko Nakanishi; Nagako Kato; Yosuke Tagaki; Hitoshi Hashimoto
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 715 KB
- Volume
- 215
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
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.