Synthesis and antiviral evaluation of 2′,3′-dideoxy-2′,3′-difluoro-D-arabinofuranosyl 2,6-disubstituted purine nucleosides

The synthesis of new 2,6-disubstituted purine 2′,3′-dideoxy-2′,3′-difluoro-D-arabino nucleosides is reported. Their ability to block HIV and HCV replication along with their cytotoxicity toward Huh-7 cells, human lymphocyte, CEM and Vero cells was also assessed. Among them, β-2,6-diaminopurine nucleoside 25 and guanosine derivative 27 demonstrate potent anti-HIV-1 activity (EC 50 = 0.56 and 0.65 μ m ; EC 90 = 4.2 and 3.1 μ m ) while displaying only moderate cytotoxicity in primary human lymphocytes.