Chemical Synthesis of the Antiviral Nucleotide Analogue ddhCTP

3'-Deoxy-3',4'-didehydro- cytidine triphosphate (ddhCTP) is a novel antiviral molecule produced by the enzyme viperin as part of the innate immune response. ddhCTP has been shown to act as an obligate chain terminator of flavivirus and SARS-CoV-2 RNA-dependent RNA polymerases; however, further biophysical studies have been precluded by limited access to this promising antiviral. Herein, we report a robust and scalable synthesis of ddhCTP as well as the mono- and diphosphates ddhCMP and ddhCDP, respectively. Identification of a 2'-silyl ether protection strategy enabled selective synthesis and facile purification of the 5'-triphosphate, culminating in the preparation of ddhCTP on a gram scale.

Automated summary

ddhCTP is a novel antiviral molecule that acts as a chain terminator of flavivirus and SARS-CoV-2 RNA-dependent RNA polymerases. Limited access to this promising antiviral has hindered further biophysical studies, but a robust synthesis method has been developed to prepare ddhCTP on a gram scale.