The 69 compounds were evaluated in vitro against two Mycobacterium tuberculosis strains, a drug susceptible (H37Rv) and a MDR clinical isolate (CIBIN–99). Four selected compounds, those that exhibited the highest potency in vitro, were tested in vivo using a model of progressive TB in BALB/c mice infected with the drug susceptible strain, either alone or combined with conventional chemotherapy, as well as in mice infected with the MDR strain. The acute toxicity was evaluated on male and female adult BALB/c mice.
Ten of the evaluated compounds resulted more potent in vitro than ethambutol. The experimental compound 2b (2-aminopalmitol benzyl ether) was the most efficacious and also showed additive effects in combination with conventional chemotherapy. It did not exhibit toxicity (LD50 >2000 mg/kg).
Compound 2b can be considered as a new drug candidate to continue its development against M. tuberculosis MDR strains.