Molecular orbital studies on nucleoside antibiotics VIII. Conformation of 5-substituted uridines

Abstract

5-Substituted uridines generally occur in the wobble position of the anticodon in tRNAs. Among these, 5-aminouridine exhibits a wide range of biological activity and it inhibits the growth of tumors and viruses, PCILO investigations have been carried out on the conformational preferences of this nucleoside antibiotic as well as on two other 5-substituted uridines: 5-nitro- and 5-methyl-uridines and compared with those of the parent nucleoside: uridine. The results indicate a striking similarity in their conformational behavior which gives rise to their biological activity. This study further confirms the correlation between the biological activity and conformational similarity obtained from earlier studies on the conformational preferences of nucleoside antibiotics.