Anti-human immunodeficiency virus activities of the beta-L enantiomer of 2',3'-dideoxycytidine and its 5-fluoro derivative in vitro

Antimicrob Agents Chemother. 1994 Jun;38(6):1292-7. doi: 10.1128/AAC.38.6.1292.


The L enantiomer of 2',3'-dideoxycytidine (DDC) was recently shown to inhibit selectively human immunodeficiency virus type 1 (HIV-1) in vitro. In the current study, the potent anti-HIV activity of L-DDC was confirmed and extended to several HIV-1 and HIV-2 strains in various cell culture systems, including primary human lymphocytes and macrophages. Furthermore, its 5-fluoro congener, beta-L-2',3'-dideoxy-5-fluorocytidine (L-FDDC), was found to have more potent anti-HIV activity and a higher therapeutic index in acutely infected human peripheral blood mononuclear cells. These compounds had no marked activity against HIV-1 isolates resistant to the oxathiolane pyrimidine nucleosides (-)-beta-L-2',3'-dideoxy-5-fluoro-3'-thiacytidine [(-)-FTC] and (-)-beta-L-2',3'-dideoxy-3'-thiacytidine, but 3'-azido-3'-deoxythymidine (AZT)-resistant viruses were susceptible to L-DDC and L-FDDC. Cytotoxicity studies with human myeloid progenitor cells indicated that L-DDC and L-FDDC had median inhibitory concentrations comparable to those of AZT, DDC, and FDDC, but L-DDC and L-FDDC were significantly less toxic than AZT, DDC, and FDDC when erythroid progenitor cells were used. L-FDDC had the highest selectivity indices (6,000 and 9,000 for erythroid and myeloid progenitor cells, respectively) of all the compounds evaluated. Further preclinical development of L-FDDC is warranted in order to determine its potential usefulness in the treatment of HIV infections.

Publication types

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

MeSH terms

  • Antiviral Agents / pharmacology*
  • Bone Marrow / drug effects
  • Cell Line
  • Drug Resistance
  • HIV / drug effects*
  • Humans
  • Stereoisomerism
  • Zalcitabine / analogs & derivatives*
  • Zalcitabine / pharmacology*
  • Zalcitabine / toxicity


  • Antiviral Agents
  • 2',3'-dideoxy-beta-5-fluorocytidine
  • Zalcitabine