A biocatalytic platform for nucleotide monophosphate synthesis in continuous flow

Nucleoside monophosphates (NMPs) are the first nucleotides required for the conversion of nucleosides into nucleoside triphosphates. Biocatalysis can offer an environmentally sustainable route to NMPs, but process development is a key consideration towards ensuring full efficiency. Herein we demonstrate a continuous biocatalytic platform using a promiscuous nucleoside kinase, DmDNK, to enable scalable production of a panel of non-natural NMPs in flow. The system takes advantage of enzyme immobilization to enable a dual-enzyme cascade for in situ ATP recycling, improved enzymatic productivity versus batch and accessing multi-milligram scale production of several important NMPs; isolated yields exceed 70% for 2′-deoxy-2′-fluorouridine, cytarabine and gemcitabine NMPs, with space time yields all over 22.5 g L-1 h-1. This platform provides a basis for the expansion of biocatalytic NMP production towards a sustainable delivery of these essential building blocks, including those underpinning to therapeutically relevant nucleoside triphosphates.