Current studies on the enzymatic preparation 2-O-α-d-glucopyranosyl-l-ascorbic acid with cyclodextrin glycosyltransferase

2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G) is one of the most important l-ascorbic acid derivatives because of its resistance to reduction and oxidation and its easy degradation by α-glucosidase to release l-ascorbic acid and glucose. Thus, AA-2G has commercial uses in food, medicines and cosmetics. This article presents a review of recent studies on the enzymatic production of AA-2G using cyclodextrin glycosyltransferase. Reaction mechanisms with different donor substrates are discussed. Protein engineering, physical and biological studies of cyclodextrin glycosyltransferase are introduced from the viewpoint of effective AA-2G production. Future prospects for the production of AA-2G using cyclodextrin glycosyltransferase are reviewed.