Ethynylcytidine (ECyD), a nucleoside analog and a potent inhibitor of RNA synthesis, inhibits RNA polymerases I, II and II. Ethynylcytidine has robust antitumor activity in a wide range of models of cancer[1][2][3]. Ethynylcytidine is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.
