Due to their ability to inhibit viral DNA or RNA replication, nucleoside analogues have been used for decades as potent antiviral therapeutics. However, one of the major limitations of nucleoside analogues is the development of antiviral resistance. In that regard, flexible nucleoside analogues known as "fleximers" have garnered attention over the years due to their ability to survey different amino acids in enzyme binding sites, thus overcoming the potential development of antiviral resistance.
View Article and Find Full Text PDFThis is the second of two invited articles reviewing the development of nucleoside analogue antiviral drugs, written for a target audience of virologists and other non-chemists, as well as chemists who may not be familiar with the field. As with the first paper, rather than providing a chronological account, we have chosen to examine particular examples of structural modifications made to nucleoside analogues that have proven fruitful as various antiviral, anticancer, and other therapeutics. The first review covered the more common, and in most cases, single modifications to the sugar and base moieties of the nucleoside scaffold.
View Article and Find Full Text PDFThis is the first of two invited articles reviewing the development of nucleoside-analogue antiviral drugs, written for a target audience of virologists and other non-chemists, as well as chemists who may not be familiar with the field. Rather than providing a simple chronological account, we have examined and attempted to explain the thought processes, advances in synthetic chemistry and lessons learned from antiviral testing that led to a few molecules being moved forward to eventual approval for human therapies, while others were discarded. The present paper focuses on early, relatively simplistic changes made to the nucleoside scaffold, beginning with modifications of the nucleoside sugars of Ara-C and other arabinose-derived nucleoside analogues in the 1960's.
View Article and Find Full Text PDFFleximers, a novel type of flexible nucleoside that have garnered attention due to their unprecedented activity against human coronaviruses, have now exhibited highly promising levels of activity against filoviruses. The Flex-nucleoside was the most potent against recombinant Ebola virus in Huh7 cells with an EC=2μM, while the McGuigan prodrug was most active against Sudan virus-infected HeLa cells with an EC of 7μM.
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