Biological Activity of Amidino-Substituted Imidazo [4,5-b]pyridines

A series of cyano- and amidino-substituted imidazo[4,5-b]pyridines were synthesized using standard methods of organic synthesis, and their biological activity was evaluated. Biological evaluation included in vitro assessment of antiproliferative effects on a diverse selection of human cancer cell lines, antibacterial activity against chosen Gram-positive and Gram-negative bacterial strains, and antiviral activity on a broad panel of DNA and RNA viruses. The most pronounced antiproliferative activity was observed for compound 10, which contained an unsubstituted amidino group, and compound 14, which contained a 2-imidazolinyl amidino group; both displayed selective and strong activity in sub-micromolar inhibitory concentration range against colon carcinoma (IC50 0.4 and 0.7 mu M, respectively). All tested compounds lacked antibacterial activity, with the exception of compound 14, which showed moderate activity against E. coli (MIC 32 mu M). Bromo-substituted derivative 7, which contained an unsubstituted phenyl ring (EC50 21 mu M), and para-cyano-substituted derivative 17 (EC50 58 mu M) showed selective but moderate activity against respiratory syncytial virus (RSV).

Automated summary

A series of cyano- and amidino-substituted imidazo[4,5-b]pyridines were synthesized and evaluated for their biological activity. The compounds showed strong antiproliferative activity against colon carcinoma, with compound 10 and 14 displaying the most pronounced activity. Compound 14 also exhibited moderate antibacterial activity against E. coli, while other compounds lacked antibacterial activity. Derivatives 7 and 17 showed selective but moderate antiviral activity against respiratory syncytial virus (RSV).