Zalcitabine

(CC) Image: David E. Volk
Zalcitabine (ddC)

Zalcitabine, or Dideoxycytidine (DDC or CCCYD), is a dideoxynucleoside antiviral drug that is an analog of the natural DNA base cytosine. The lack of 3'-hydroxyl group makes it a viral DNA chain terminator. It also inhibits HIV-1 reverse transcriptase by binding to it and competing with the natural substrate deoxycytidine triphosphate (dCTP). The related drug lamivudine, which has a sulfur atom in place of the 3'-carbon present in zalcitabine.

Its IUPAC chemical name is 4-amino-1-[(2R,5S)-5-(hydroxymethyl)oxolan-2-yl]pyrimidin-2-one and it has molecular formula C₉H₁₃N₃O₃.