BTZ043 mainly targets the enzyme decaprenylphosphoryl-b-D-ribose 2’-epimerase. Inhibition of this enzymatic activity abolishes the formation of decaprenylphosphoryl arabinose, a key precursor that is required for the synthesis of the cell-wall arabinans, thus provoking cell lysis and bacterial death.
BTZ043 displayed similar activity against all clinical isolates of M. tuberculosis that were tested, including multidrug-resistant and extensively drug-resistant strains. The MIC of BTZ043 against M. tuberculosis H37Rv and Mycobacterium smegmatis were 1 ng/ml (2.3 nM) and 4 ng/ml (9.2 nM), respectively, which compares favorably with those of the existing TB drugs isoniazid (INH) (0.02 to 0.2 mg/ml) and ethambutol (EMB) (1 to 5 mg/ml).

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