Phenoxazine nucleoside derivatives with a multiple activity against RNA and DNA viruses.
Kozlovskaya LI, Volok VP, Shtro AA, Nikolaeva YV, Chistov AA, Matyugina ES, Belyaev ES, Jegorov AV, Snoeck R, Korshun VA, Andrei G, Osolodkin DI, Ishmukhametov AA, Aralov AV.
Emerging and re-emerging viruses periodically cause outbreaks and epidemics all over the world, eventually leading to global events such as the current pandemic of the novel SARS-CoV-2 coronavirus infection COVID-19. Therefore, an urgent need for novel antivirals is crystal clear. Here we present the synthesis and evaluation of an antiviral activity of phenoxazine-based nucleoside analogs divided into three groups: (1) 8-alkoxy-substituted, (2) acyclic, and (3) carbocyclic. The antiviral activity was assessed against a structurally and phylogenetically diverse panel of RNA and DNA viruses from 25 species. Four compounds (11a-c, 12c) inhibited 4 DNA/RNA viruses with EC<sub>50</sub> ≤ 20 μM. Toxicity of the compounds for the cell lines used for virus cultivation was negligible in most cases. In addition, previously reported and newly synthesized phenoxazine derivatives were evaluated against SARS-CoV-2, and some of them showed promising inhibition of reproduction with EC<sub>50</sub> values in low micromolar range, although accompanied by commensurate cytotoxicity.