Abstract New inhibitors of mycobacterial dihydrofolate reductase (DHFR) have been developed. These compounds show high inhibitory activities against Gram-negative and mycobacterial DHFR exceeding that for the commercially available DHFR blockers. Amongst these compounds K-130 shows a 100-fold lower MIC against M lufu than the most active derivatives known so far (TMP, BDP). Mycobacterium lufu was used as a model for ...