Novel hydroxy- and amidino-substituted benzimidazoles and benzothiazoles as antibacterial and antiproliferative agents

Aim: The aim was synthesis of novel benzazoles bearing amidino and 2-hydroxyphenyl substituents to explore their biological activity. Methods: Condensation of 5-substituted salicylaldehydes and intermediates gave new benzazoles by previously published and developed procedures, which were tested for antibacterial and antiproliferative activity in vitro. Results: The best antibacterial activity showed benzimidazole with 2-imidazolinyl group 27 and benzothiazole with an unsubstituted amidine 48 (minimum inhibitory concentration 8 & mu;g/ml). Benzothiazole 53 proved most potent at inhibiting proliferation of all cancer cells (IC50: 1.2-2.0 & mu;M). Conclusion: Most active compounds have been recognized as lead compounds for additional optimization to improve their biological activity. The type of amidine moiety markedly influenced the biological activity. Benzothiazoles showed improved antiproliferative activity in comparison to benzimidazoles.

Automated summary

The aim of this study was to synthesize novel benzazoles with amidino and 2-hydroxyphenyl substituents and explore their biological activity. New benzazoles were synthesized by condensation of 5-substituted salicylaldehydes and intermediates using previously developed procedures, and were tested for antibacterial and antiproliferative activity in vitro. The results showed that benzimidazole with a 2-imidazolinyl group 27 and benzothiazole with an unsubstituted amidine 48 exhibited the best antibacterial activity (minimum inhibitory concentration 8 μg/ml). Benzothiazole 53 was found to be the most potent compound in inhibiting the proliferation of various cancer cells (IC50: 1.2-2.0 μM). In conclusion, the most active compounds have been identified as lead compounds for further optimization to enhance their biological activity. The type of amidine moiety significantly influenced the biological activity, with benzothiazoles showing superior antiproliferative activity compared to benzimidazoles.