FIG. 1.

Pseudosugar structures of NRTIs tested. (1) 2′,3′-Dideoxynucleosides (ddC, ddT, ddI, ddG); (2) 2′,3′-didehydro-2′3′-dideoxynucleosides (d4C, d4T); (3) 2′-fluoro-2′,3′-didehydro-2′3′-dideoxynucleosides (2′-F-d4FC, 2′-F-d4A); (4) 2′-deoxy-3′-oxa-4′-thiocytidines (dOTC); (5) dioxolane-nucleosides (DOC, DXG); (6) 2′,3′-dideoxy-3′-thiacytidines (3TC, FTC); (7) 3′-azido-3′-deoxynucleosides (AZT, AZC, AZG, AZA); (8) 3′-fluoro-3′deoxynucleosides (FLT, FLG); (9) 9-[2-(phosphonomethoxy)ethyl nucleotide (PMEA); (10) 9-[(R)-2-(phosphonomethoxy)propyl] nucleotide (PMPA).