Lien vers Pubmed [PMID] – 31899839
Chembiochem 2020 Jan;
The structurally unique “fleximer” nucleosides were originally designed to investigate how flexibility in the nucleobase could potentially affect receptor-ligand recognition and function. Recently they have shown low to sub-micromolar levels of activity against a number of viruses including coronaviruses, filoviruses and flaviviruses. The synthesis of distal fleximers in particular, has thus far been quite tedious and low yielding. As a potential solution to this issue, a series of proximal fleximer bases (flex-bases) were successfully coupled to both ribose and 2′-deoxyribose sugars using the N -deoxyribosyltransferase II of Lactobacillus leichmannii ( Ll NDT) and E. coli purine nucleoside phosphorylase (PNP). To explore the range of this facile approach, transglycosylation experiments using a thieno-expanded tricyclic heterocyclic base, as well as several distal and proximal flex-bases were performed to determine whether the corresponding fleximer nucleosides could be obtained in this fashion, thus potentially significantly shortening the route to these biologically significant compounds. The results of those studies are reported herein.