Liquid chromatography-tandem mass spectrometric determination of a new antibacterial agent (AVE6971) in human white blood cells

Two Decades of Successful SAR-Grounded Stories of the Novel Bacterial Topoisomerase Inhibitors (NBTIs)

The emergence of bacterial resistance against life-saving medicines has forced the scientific community and pharmaceutical industry to take actions in the quest for novel antibacterials. These should not only overcome the existing bacterial resistance but also provide at least interim effective protection against emerging bacterial infections. Research into DNA gyrase and topoisomerase IV inhibitors has become a particular focus, with the description of a new class of bacterial topoisomerase type II inhibitors known as "novel bacterial topoisomerase inhibitors", NBTIs. Elucidation of the key structural modifications incorporated into these inhibitors and the impact these can have on their general physicochemical properties are detailed in this review. This defines novel bacterial topoisomerase inhibitors with promising antibacterial activities and potencies, which thus represent one potential example of the future "drugs for bad bugs", as identified by the World Health Organization.

Novel 3-fluoro-6-methoxyquinoline derivatives as inhibitors of bacterial DNA gyrase and topoisomerase IV

Novel (non-fluoroquinolone) inhibitors of bacterial type II topoisomerases (NBTIs) are an emerging class of antibacterial agents. We report an optimized series of cyclobutylaryl-substituted NBTIs. Compound 14 demonstrated excellent activity both in vitro (S. aureus MIC₉₀=0.125μg/mL) and in vivo (systemic and tissue infections). Enhanced inhibition of Topoisomerase IV correlated with improved activity in S. aureus strains with mutations conferring resistance to NBTIs. Compound 14 also displayed an improved hERG IC₅₀ of 85.9μM and a favorable profile in the anesthetized guinea pig model.

Synthesis, structures and antibacterial activities of benzoylthiourea derivatives and their complexes with cobalt

Four new thiocarbonyl fluorobenzamides and their complexes with cobalt have been synthesized and characterized by elemental analysis, FTIR, and (1)H NMR. Five crystal structures of the thioylbenzamides complexes of Co(PTCB)(3), Co(2FPTCB)(3), Co(4FPTCB)(3), Co(2FMTCB)(2) and Co(4FMTCB)(3) have been determined by X-ray diffraction. The antibacterial properties of these compounds against the bacteria, E. coli, Staphylococcus aureus, B. subtilis, P. aeruginosa, and Shewanella sp. were investigated. The experiments showed that both compounds and the complexes had the antibacterial activities against all of the studied bacteria. The thioylbenzamides had stronger controls for the bacteria of E. coli, S. aureus, B. subtilis and P. aeruginosa than their corresponding cobalt complexes. There was the contrary result against the bacteria of Shewanella sp. The para-substitution of fluorine atom increased antibacterial activities, while fluorine atom was substituted on ortho-benzoyl, the antibacterial activity weakened. The thioylbenzamides linked to piperidine instead of a morpholine group may increase the antibacterial activities.