N4-Aminocytidine, a nucleoside analog that has an exceptionally high mutagenic activity

Abstract
The reaction of cytidine with hydrazine to give N4-aminocytidine was greatly promoted by addition of a less-than-stoichiometric amount of bisulfite, and the product was isolated in a good yield. N4-Aminocytidine was strongly mutagenic to bacteria (Salmonella typhimurium TA100 and TA1535, and E. coli WP2 uvrA) and to phage (φX174 am3). The activity did not require the presence of mammalian microsomaT fraction 1n the system. The mutagenic potency of N4 -aminocytidine in these systems was two orders of magnitude greater than that of N4-amino-2'-deoxycytidine, and more than two orders of magnitude greater than that of N4-hydroxycyt1dine. The greater activity of the riboside than the deoxyriboside was ascribed to the lack of deoxycytidine kinase 1n these cells. This compound may be useful as a powerful mutagen to induce a transition mutation in microorganisms.