A biocatalytic platform for the synthesis of 2′-functionalized nucleoside analogues

Nucleosides functionalized at the 2′-position play a crucial role in therapeutics, serving as both small molecule drugs and modifications in therapeutic oligonucleotides. However, the synthesis of these molecules often presents significant synthetic challenges. In this study, we present an approach to the synthesis of 2′-functionalized nucleosides based on enzymes from the purine nucleoside salvage pathway. Initially active-site variants of DERA aldolase were generated for the highly stereoselective synthesis of D-ribose-5-phosphate analogs with a broad range of functional groups at the 2-position. Thereafter these 2-modified pentose phosphates were converted into 2′-modified purine analogs by construction of one-pot multi-enzyme cascade reactions, leading to the synthesis of guanosine (2′-OH) and adenosine (2′-OH, 2′-Me, 2′-F) analogues. Our findings demonstrate the capability of these biocatalytic cascades to efficiently generate 2′ functionalized nucleosides, starting from simple starting materials.