Efficient Synthesis of Glucosyl-β-Cyclodextrin from Maltodextrins by Combined Action of Cyclodextrin Glucosyltransferase and Amyloglucosidase.

Instead of β-cyclodextrin (β-CD), branched β-CDs have been increasingly used in many aspects as they possess better solubility and higher bioadaptability. But most commercialized branched β-CDs were chemically synthesized. Thus, the glucosyl-β-cyclodextrin (G1-β-CD) prepared via enzymatic approach could be a nice substitute. However, the yield of G1-β-CD was low. Here, we reported a controlled two-step reaction to efficiently prepare G1-β-CD from maltodextrins by β-cyclodextrin glucosyltransferase (β-CGTase) and amyloglucosidase (AG). Compared to the single β-CGTase reaction, controlled two-step reaction caused a yield increase of G1-β-CD by 130%. Additionally, the percentage of G1-β-CD was enhanced from 2.4% to 24.0% and the side products α-CD and γ-CD were hydrolyzed because of the coupling activity of β-CGTase. Thus, this controlled two-step reaction might be an efficient approach for industrial production of pure G1-β-CD.