25-Desacetyl rifampicin is a major active metabolite of the rifamycin antibiotic rifampicin .125-Desacetyl rifampicin is active againstM. smegmatis(MIC99= 2.66 μM). 1.Kigondu, E.M., Njoroge, M., Singh, K., et al.Synthesis and synergistic antimycobacterial screening of chlorpromazine and its metabolitesMed. Chem. Commun.5502-506(2014)