Enzymatic Synthesis of Oligosaccharides: A Powerful Tool for a Sweet Challenge

Carbohydrates are complex and structurally diverse compounds in nature with key roles in a broad range of life processes including signal transduction, carcinogenesis and immune responses. Many natural products contain oligosaccharides that are vital for their biological activity. Despite ongoing challenges, tremendous progresses have been made in recent years for the synthesis of carbohydrates. The chemical glycosylation methods have become more sophisticated and the synthesis of oligosaccharides has become more predictable. Nonetheless, thanks to their straightforward stereoselectivity and efficiency, carbohydrate-processing enzymes follow being a powerful practical alternative in a wide set of synthetic applications targeted to the obtainment of natural oligosaccharides, glycoconjugates and their analogues. In this review, recurring to many practical examples, a general updated overview of the behavior, the advantages and the drawbacks related to the application of glycosyltransferases, glycosylhydrolases and glycosynthases in the oligosaccharide synthesis will be provided.