Synthesis and biological evaluation of 12 novel (-)-camphene-based 1,3,4-thiadiazoles against .

To evaluate the activity, cytotoxicity and efflux pumps inhibition of a series of 12 novels (-)-camphene-based 1,3,4-thiadiazoles (TDZs) against (). The minimum inhibitory concentration (MIC), cytotoxicity for three cell lines, ethidium bromide accumulation and checkerboard methods were carried out. Compounds (, , , , and ) showed significant anti- activity (MIC 3.9-7.8 μg/ml) and no antagonism with anti-TB drugs already used in the TB treatment. Selectivity index (SI) was also determined, with values reaching 42.9 for HRv strain and 97.1 for clinical isolate. Five compounds also showed bacterial efflux pumps inhibition and one showed modulator effect with three drugs. These six TDZs should be considered as new scaffolds to develop anti-TB drugs.