Abstract:
8-Nitro-1,3-benzothiazin-4-ones (BTZs), with BTZ043 and PBTZ169 as the most advanced compounds, represent a new
class of potent antitubercular agents, which irreversibly inhibit decaprenylphosphoryl-β-D-ribose-2′-epimerase (DprE1),
an enzyme crucial for cell wall synthesis in the pathogen Mycobacterium tuberculosis. Synthesis, structural
characterization and in vitro testing against Mycobacterium aurum DSM 43999 and M. tuberculosis H37Rv of
halogenated 2-(4-ethoxycarbonylpiperazin-1-yl)-1,3-benzothiazin-4-ones lacking a nitro group are reported. X-ray
crystallography reveals that the structure of the BTZ scaffold can significantly deviate from planarity. In contrast to recent
reports, the results of the present study indicate that further investigation of halogenated non-nitro BTZs for antitubercular
activity is less than a promising approach.