a cytoplasmic enzyme that participates in the biosynthesis of cell wall peptidoglycan.
The key enzymes of the cell wall peptidoglycan biosynthesis pathway are essential for the survival of many bacterial pathogens and the reisrenewedinterest in the search for novel the rapeutic targets for tacklingexistingdrug resistance.
Compound 1 also had some ability to impede efflux. The low accumulation of 14C-enoxacin by SA-1199B in the absence of inhibitors was expected and is the result of overexpression of NorA in this strain (Fig. 3). Compound 1 at 50M significantly increased enoxacin accumulation and this concentration was as effective, or perhapsevenmoreeffective,than33Mreserpine.Increasedaccumulation of enoxacin is consistent with interference with NorA. As such, it is clear that compound 1 is a NorA inhibitor. Use of con- centrations that surpassed the MIC of compound 1 for SA-1199B was not problematic based on time–kill assays, which revealed no effect of compound 1 at 50M on the viability of SA-1199B over 60min. The pharmacophore of compound 1 may provide a starting point towards the development of a more effective inhibitor, and its weak cytotoxic activity towards cancer and mammalian cell lines suggests that this class of compound may have potential in a topical formulation or, if antibacterial activity in the presence of blood can be enhanced through iterative chemistry, as a lead in the development of a new class of systemic antibiotics. Compounds that are antibacterial and can inhibit efflux processes of bacteria could have potential to treat infections due to multidrug-resistant strains.
Funding:TheHeptagonFundandUnionLifeSciencesfundedthis work. Competing interests: None declared. Ethical approval: Not required.