Design, synthesis, and antiviral activity of new 1H-1,2,3-triazole nucleoside ribavirin analogs

Ribavirin is a broad antiviral compound with demonstrated activity against herpes simplex virus (HSV), human immunodeficiency virus HIV-1, influenza virus, respiratory syncytial virus, and hepatitis C virus, among other viruses. However, routine clinical use of ribavirin is limited because this compound is considerably cytotoxic. Herein, we describe the design, synthesis, and antiviral activity of new nucleoside ribavirin analogs based on the following: (1) ring bioisosterism of a 1,2,4-triazole for a 1,2,3-triazole; (2) amide group exchange for other substituents, such as c-propyl, methyl carboxylate, or trifluoromethyl groups; and (3) the ribofuranose remained linked to the triazole ring. Compounds 5a–c were obtained with yields of 65–36 % and tested against Influenza A and HSV-1 replication as well as reverse transcriptase (RT) from human immunodeficiency virus type 1 (HIV-1 RT). Compound 5b (R = CO2CH3) was the most effective analog, with IC50 values 14 and 3.8 μM for Influenza A and HIV-1 RT, respectively.