Nitrobenzothiazinones (e.g. BTZ043) are currently considered to be the most potent active substances against the tuberculosis pathogen Mycobacterium tuberculosis. A completely new metabolite of BTZ043 has been discovered, which has the potential to open the way to a new generation of antituberculosis agents. This metabolite is to be comprehensively characterised and further effective derivatives produced by targeted modifications and tested for their anti-infective activity.