Enzymatic Glycoside Synthesis and Transglycosylation Processes

The enzymatic synthesis of glycosides and the allied transglycosylation reactions represent a cornerstone of modern glycoscience, combining the selectivity of biocatalysis with the complexity of carbohydrate structures. In these processes, glycosyl hydrolases—particularly retaining enzymes—can be exploited under controlled conditions to favour transfer of a sugar moiety from an activated donor to a defined acceptor rather than simple hydrolysis. Advances in enzyme engineering, directed evolution and mechanistic understanding have yielded variants with enhanced transferase activity, expanded substrate scope and reduced side hydrolysis. This enables the rapid assembly of oligosaccharides, glycolipids and glycoconjugates under mild conditions, avoiding extensive protecting-group chemistry. Applications span from the synthesis of tailored glycomimetics and pharmacological leads to the generation of functional surfactants, nutraceuticals and biomaterials. By tuning active-site architecture and reaction parameters, researchers now achieve high regio- and stereocontrol as well as eco-friendly processes with broad industrial relevance.

Research from Nature Portfolio

Recent studies have demonstrated the conversion of a fungal GH3 β-xylosidase into a thioglycoligase with unusually broad acceptor promiscuity. Through targeted active-site mutations, the engineered enzyme readily forms O-, N-, S- and Se-glycosidic linkages as well as sugar esters and phosphoesters with moderate to high yields. Analysis revealed that acceptor pKa and active-site electrostatics govern transfer efficiency, while the preserved oxocarbenium transition-state geometry underpins stereochemical retention. This work expands the range of accessible glycoconjugates and underscores the potential of thioglycoligases for green biocatalysis of complex glycosides.

Enzymatic Glycoside Synthesis and Transglycosylation Processes publication trend

The graph below shows the total number of articles in enzymatic glycoside synthesis and transglycosylation processes across all publications each year (not limited to Nature Index journals).

Technical terms

Glycosyl hydrolase: Enzyme that cleaves glycosidic bonds via hydrolytic mechanisms.

Transglycosylation: Enzymatic transfer of a glycosyl residue from a donor substrate to an acceptor, forming new glycosidic linkages.

Retaining mechanism: Catalytic pathway in glycosidases that preserves the stereochemistry at the anomeric centre through double-displacement.

Glycosynthase: Engineered glycosidase lacking hydrolytic activity, utilising activated glycosyl donors to synthesise glycosidic bonds selectively.

Thioglycoligase: Mutated glycosidase variant that preferentially forms glycosidic bonds with thiol or other non-water acceptors, broadening conjugate diversity.

References

1. A Hitchhiker’s Guide to Problem Selection in Carbohydrate Synthesis. ACS Central Science (2023).
2. Flavonoids as Aglycones in Retaining Glycosidase-Catalyzed Reactions: Prospects for Green Chemistry. Journal of Agricultural and Food Chemistry (2023).
3. Synthesis of Glycosides by Glycosynthases. Molecules (2017).
4. Thioglycoligase derived from fungal GH3 β-xylosidase is a multi-glycoligase with broad acceptor tolerance. Nature Communications (2020).