Yoon Seung-Heon, Robyt John F
Laboratory of Carbohydrate Chemistry and Enzymology, 4252 Molecular Biology Bldg, Iowa State University, Ames, IA 50011, USA.
Carbohydr Res. 2002 Nov 19;337(21-23):2245-54. doi: 10.1016/s0008-6215(02)00224-0.
It was found that Bacillus macerans cyclomaltodextrin glucanotransferase (CGTase) reacts with cyclomaltohexaose (alpha-cyclodextrin, alpha-CD) to give a series of cyclomaltooligosaccharides (cyclomaltodextrins, CDs), having seven to more than 20 D-glucose residues and maltooligosaccharides (maltodextrins, MDs) from G5 to G12+. When D-glucose (Glc) was added to the alpha-CD at very low molar ratios (1:100) of Glc to alpha-CD, the predominant products (95%) were CDs, some of which were macrocyclic MDs with 20-60 D-glucose residues, along with MDs that also had high molecular weights, containing 10-75 D-glucose residues and gave a blue iodine-iodide color. As the molar ratio of Glc to alpha-CD was increased, the amount of CDs progressively decreased and MDs proportionately increased in the range of G2-G12. At 25 mM alpha-CD and Glc to alpha-CD molar ratio of 1:1, a 75% yield of MDs, G1-G12, each in approximately equal amounts, was obtained; and at 20 mM and a 5:1 ratio, a 97% yield of MDs, G2-G9, was obtained but in unequal amounts. At higher ratios (10:1), the CDs completely disappeared, and at very high ratios (50:1 to 100:1) only low-molecular-weight MDs, G2-G4, were formed.
已发现浸麻芽孢杆菌环麦芽糊精葡糖基转移酶（CGTase）与环麦芽六糖（α-环糊精，α-CD）反应生成一系列环麦芽寡糖（环糊精，CDs），其具有7至20多个D-葡萄糖残基以及从G5到G12 +的麦芽寡糖（麦芽糊精，MDs）。当以非常低的摩尔比（1:100）将D-葡萄糖（Glc）添加到α-CD中时，主要产物（95％）是CDs，其中一些是具有20 - 60个D-葡萄糖残基的大环MDs，以及也具有高分子量的MDs，其含有10 - 75个D-葡萄糖残基并呈现蓝色碘化碘颜色。随着Glc与α-CD的摩尔比增加，CDs的量逐渐减少，而MDs在G2 - G12范围内相应增加。在25 mM α-CD且Glc与α-CD摩尔比为1:1时，获得了75％产率的MDs，G1 - G12，每种含量大致相等；在20 mM且比例为5:1时，获得了97％产率的MDs，G2 - G9，但含量不相等。在更高比例（10:1）时，CDs完全消失，而在非常高的比例（50:1至100:1）时，仅形成低分子量的MDs，G2 - G4。
