Side Chain-modified Benzothiazinone Derivatives with Anti-Mycobacterial Activity

Tuberculosis (TB) is a leading infectious disease with serious antibiotic resistance. The benzothiazinone (BTZ) scaffold PBTZ169, an inhibitor of the decaprenylphosphoryl-β-D-ribose 2'-oxidase (DprE1) in Mycobacterium tuberculosis (Mtb), showed anti-TB potential in animal model and piloted clinical tests. Although highly potent, the BTZ type DprE1 inhibitors in general shows extremely low aqueous solubility, which adversely affect the drug like property. To improve the compounds physiochemical properties, we generated a series of BTZ analogues. Several optimized compounds had MIC values against Mtb in single digit nanomolar. The representative compound 37 displayed improved solubility and bioavailability compared to the lead compound. Additionally, compound 37 shows Mtb-killing ability in an acute infection mouse model.