Synthesis and biological evaluation of 2',3'-didehydro-2',3'- dideoxy-5-fluorocytidine (D4FC) analogues: discovery of carbocyclic nucleoside triphosphates with potent inhibitory activity against HIV-1 reverse transcriptase

J Med Chem. 1999 Mar 11;42(5):859-67. doi: 10.1021/jm980510s.


The discovery of a novel cytosine nucleoside, beta-D-2', 3'-didehydro-2',3'-dideoxy-5-fluorocytidine (D-D4FC), as a potent antihuman immunodeficiency virus (HIV) agent led us to synthesize a series of analogues and derivatives of beta-D-D4FC that could be more selective and also possess increased glycosidic bond stability. The synthesized D-D4FC analogues were evaluated for anti-HIV-1 activity, anticancer activity, and cytotoxicity in various cells. The biological data demonstrated that the 5-substitution of beta-D-D4FC with bromine (6c) and iodine (6d) resulted in the loss of antiviral activity, and the alpha-D anomer (7a) of D-D4FC was also devoid of activity. The 5-fluorouracil analogues (6b and 7b) of D-D4FC were less potent and more cytotoxic than the parent compound, whereas the beta-L-D4FU (11) showed both potent anti-HIV-1 activity and cytotoxicity. N4- and 5'-O-acyl derivatives (17, 15a-c) of beta-D-D4FC exhibited comparable antiviral activity to beta-D-D4FC. In contrast, the N4-isopropyl derivative (20) of beta-D-D4FC was not active against HIV-1, even at 100 microM. The carbocyclic analogues (26a,b) of D4FC demonstrated weak activity against HIV-1 and no toxicity in various cells. The triphosphates (27a,b) of the carbocyclic nucleosides demonstrated potent inhibitory activity against recombinant HIV-1 reverse transcriptase at submicromolar concentrations. Of the compounds tested as potential anticancer agents, beta-D-, alpha-D-, and beta-L-D4FU (6b, 7b, 11) showed inhibitory activity against rat glioma and modest activity against human lung carcinoma, lymphoblastoid, and skin melanoma cells.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anti-HIV Agents / chemical synthesis*
  • Anti-HIV Agents / chemistry
  • Anti-HIV Agents / pharmacology
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Drug Screening Assays, Antitumor
  • HIV Reverse Transcriptase / antagonists & inhibitors*
  • Humans
  • Organophosphates / chemical synthesis*
  • Organophosphates / chemistry
  • Organophosphates / pharmacology
  • Rats
  • Reverse Transcriptase Inhibitors / chemical synthesis*
  • Reverse Transcriptase Inhibitors / chemistry
  • Reverse Transcriptase Inhibitors / pharmacology
  • Stereoisomerism
  • Structure-Activity Relationship
  • Tumor Cells, Cultured
  • Zalcitabine / analogs & derivatives*
  • Zalcitabine / chemical synthesis
  • Zalcitabine / chemistry
  • Zalcitabine / pharmacology


  • Anti-HIV Agents
  • Antineoplastic Agents
  • Organophosphates
  • Reverse Transcriptase Inhibitors
  • Zalcitabine
  • HIV Reverse Transcriptase
  • dexelvucitabine