Glycosyltransferase Cascades Made Fit For the Biocatalytic Production of Natural Product Glycosides

Glycosylation is a widespread modification in natural products. Methods to establish a well-defined glycosylation in synthetically prepared natural products are of high significance. Sugar nucleotide-dependent (Leloir) glycosyltransferases are powerful catalysts of glycosylation. Perceived limitation on glycosyltransferase applicability for glycoside production arises from the complexity of their overall reaction, difficult recombinant production, and rather low robustness of the enzymes to the process conditions used (e.g. use of cosolvents for substrate solubility enhancement). Here, the enzymatic synthesis of nothofagin via 3′-C-β-glucosylation of the dihydrochalcone phloretin is used to highlight advances made in the application of Leloir glycosyltransferase cascades for natural product glycosylation at a scale of ~100 g isolated product. The nothofagin process involves upstream and downstream processing optimized for efficient interconnected performance. The idea of holistic process development for biocatalytic production of flavonoid glycosides by Leloir glycosyltransferases is supported.