Abstract

A series of novel 4” -O-2-arylbenzimidazolyl derivatives of clarithromycin were synthesized and evaluated. These 4” -O-2-arylbenzimidazolyl derivatives demonstrated excellent activity against erythromycin-susceptible strains and showed remarkably improved activity against erythromycin-resistant strains compared with the references. In particular, compound 7c, which possesses the terminal 2-(2-methoxyphenyl)benzimidazolyl group on the C-4” bishydrazide side chain, not only presented the most potent activity against erythromycin-susceptible Streptococcus pneumoniae ATCC49619 and Staphylococcus aureus ATCC25923, exhibiting 4-fold and 4-fold higher efficacy than the parent clarithromycin, but also displayed the highest activity against erythromycin-resistant Streptococcus pneumoniae expressing the mef gene and the erm gene, which was 133-fold and 32-fold better than clarithromycin or azithromycin, respectively.

Keywords: Antibacterial activity, Benzimidazolyl derivatives, Carbamates, Clarithromycin, Resistance, Synthesis, erythromycin-susceptible strains, Streptococcus pneumoniae, Staphylococcus aureus, C-4 bishydrazide side chain, mef gene, erm gene, azithromycin, methyltransferase, macrolides, telithromycin