Synthesis and the combination effects of dihydropyridine analogs with selected antibiotics against resistant Staphylococcus aureus

Bacterial resistance is a major drawback in chemotherapy of infectious diseases. In this investigation a new series of 3,5-diarylamide dihydropyridines containing 2-benzylsulfonylimidazol at 4 position have been synthesized and studied for their enhancing effect on the antibacterial activities of different penicillins against a resistant clinical isolate of S. aureus using disc diffusion method. During preliminary screening, compound 6d showed the most enhancing effect on the antibacterial activity of amoxicillin against the test strain and the combination effect of this compound has been further studied with penicillin G and piperacillin against Staphylococcus aureus. The result of this evaluation showed that the antibacterial activities of penicillin G and piperacillin can be also enhanced by compound 6d suggesting a possible utilization of this compound in combination therapy against penicillin resistant S. aureus.