Stereoselective phosphorylation of branched cyclodextrins with inorganic cyclo-triphosphate
摘要:
The phosphorylation by inorganic sodium cyclo-triphosphate (P-3m) having a six-membered ring was examined for cyclomaltohexaose (alpha-cyclodextrin) and branched cyclodextrins (mono-6-O-alpha-D-glucopyranosylcyclomaltohexaose, mono-6-O-alpha-D-maltosylcyclomaltohexaose, mono-6-O-alpha-D-glucopyranosylcyclomaltoheptaose, and mono-6-O-alpha-D-maltosylcyclomaltoheptaose) in aqueous solution. For all cyclomaltooligosaccharides (cyclodextrins) studied, the 2-OH group was stereoselectively phosphorylated. In the reaction of branched cyclodextrins and P-3m, only the 2-OH on the alpha-D-glucopyranosyl group of the cyclodextrin rings was phosphorylated with maximum yields of more than 27%. The phosphorylation mechanism of branched cyclodextrins with P-3m is also discussed. (C) 2003 Elsevier Ltd. All rights reserved.
Transgalactosylated derivatives of cyclodextrins (CDs) and glucosyl and maltosyl CDs (G1- and G2-CDs) were synthesized by α-galactosidases from coffee bean and Mortierella vinacea (M. vinacea). The structures of the transfer products were analyzed by FAB-mass, 13C-NMR and methylation.Coffee bean α-galactosidase transferred a galactosyl residue not only to side chains of G1-CDs and G2-CDs, but also directly to CD rings. M. vinacea α-galactosidase transferred a galactosyl residue only to side chains of G2-CDs.
咖啡豆和葡萄孢霉(Mortierella vinacea)的α-半乳糖苷酶合成了环糊精(CD)以及葡萄糖基和麦芽糖基CD(G1-CD和G2-CD)的半乳糖基转移衍生物。咖啡豆α-半乳糖苷酶不仅能将半乳糖基残基转移到 G1-CDs 和 G2-CDs 的侧链上,还能直接转移到 CD 环上。葡萄孢α-半乳糖苷酶只将半乳糖基残基转移到 G2-CD 的侧链上。
Synthesis of branched cyclomaltooligosaccharide carboxylic acids (cyclodextrin carboxylic acids) by microbial oxidation
(cyclodextrin carboxylic acid) derivatives were synthesized by microbial oxidation using Pseudogluconobacter saccharoketogenes to oxidize five types of branched cyclodextrins, including maltosyl beta-cyclodextrin (maltosyl-beta-CyD). For each novel cyclodextrin carboxylic acid derivative synthesized, the hydroxymethyl group of the terminal glucose residue in the branched part of the molecule was regiospecifically
Preparation, isolation, and characterization of novel heterogeneous branched cyclomalto-oligosaccharides having β-d-galactosyl residue(s) on the side chain
Transgalactosylated products of branched cyclodextrins (glucosyl-alphaCD, -betaCD, -gammaCD, and maltosyl-alphaCD, -betaCD, -gammaCD)were synthesized by beta-D-galactosidases from Bacillus circulans and Penicillium multicolor using lactose as a donor substrate and branched CDs as acceptors. Eighteen beta-D-galactosylated branched CDs were isolated and purified by HPLC. Their structures were elucidated by FABMS and C-13 NMR spectroscopies, and methylation analysis. The chromatographic behavior of these novel heterogeneous branched CDs on three HPLC columns of different separation modes was compared.
Sakano, Yoshiyuki; Sano, Mutsumi; Kobayashi, Tsuneo, Agricultural and Biological Chemistry, 1985, vol. 49, # 12, p. 3391 - 3398