Preparation and Evaluation of Potent Pentafluorosulfanyl Substituted Anti-Tuberculosis Compounds

摘要

The global fight to stop tuberculosis (TB) remains a great challenge, particularly with the increase in drug resistant strains and a lack of funding to support the development of new treatments. To bolster a precarious drug pipeline, we have prepared a focused panel of eight pentafluorosulfanyl (SF5) compounds (>13 – 20) which were screened for their activity against Mycobacterium tuberculosis (Mtb) H37Rv in three different assay conditions and media. All eight compounds had sub-micromolar potency and four (>13, >15, >16, and >19) displayed MICs <100 nM. Seven compounds (>13 – 19) were evaluated against non-replicating and mono-drug-resistant Mtb, and for their ability to inhibit Mtb within the macrophage. The greatest potency was observed against intracellular Mtb (MIC <10 nM for >13, >15, and >17), which is often the most challenging to target. In general, the SF5-bearing compounds were very similar to their CF3 counterparts with the major differences observed being their in vitro ADME properties. SF5-bearing compounds >18 and >19 had greater protein binding than the corresponding CF3 compounds (>1 and >5) but also were less metabolized in human microsomes resulting in longer half-lives.