Enzyme catalysis in synthetic carbohydrate chemistry

Enzymes hold great potential for asymmetric synthesis of polyhydroxy species and their chiral intermediates. This article describes recent progress in the area, including the syntheses of monosaccharides, polysaccharides, nucleosides and their analogs, derivatives, conjugates, or intermediates based on combined chemical-enzymatic reactions. Highly regio- and stereoselective reactions in aqueous solutions or organic solvents with minimum protection and deprotection are demonstrated. Major applications are illustrated for the asymmetric synthesis and modification of carbohydrates and synthons based on lipases, esterases, proteases, and dehydrogenases, the effective preparation of monosaccharide-based compounds based on aldolases, and the stereocontrolled synthesis of oligosaccharides, nucleosides and derivatives based on glycosyltransferases. New strategies for changing reversible enzymatic reactions to irreversible processes, and for cofactor regeneration are also described.