Synthesis and SAR evaluation of novel thioridazine derivatives active against drug-resistant tuberculosis

The neuroleptic drug thioridazine has been recently repositioned as possible anti-tubercular drug. Thioridazine showed anti-tubercular activity against drug resistant mycobacteria but it is endowed with adverse side effects. A small library of thioridazine derivatives has been designed through the replacement of the piperidine and phenothiazine moieties, with the aim to improve the anti-tubercular activity and to reduce the cytotoxic effects. Among the resulting compounds, the indole derivative 12e showed an antimycobacterial activity significantly better than thioridazine and a cytotoxicity 15-fold lower.