Symmetrical and unsymmetrical analogues of isoxyl; active agents against Mycobacterium tuberculosis

Symmetrical and unsymmetrical analogues of the antimycobacterial agent isoxyl-have been synthesized and tested against Mycobacterium tuberculosis H37Rv and Mycobacterium bovis BCG, some showing an increased bactericidal effect. In particular, compounds 1-(p-n-butylphenyl)-3-(4-propoxy-phenyl) thiourea (10) and 1-(p-n-butylphenyl)-3-(4-n-butoxy-phenyl) thiourea (11) showed an approximate 10-fold increase in in vitro potency compared to isoxyl, paralleled by increased inhibition of mycolic acid biosynthesis in M. bovis BCG. Interestingly, these isoxyl analogues showed relatively poor inhibition of oleate production, suggesting that the modifications have changed the spectrum of biological activity.

Graphical abstractAnalogues of isoxyl with symmetrical and unsymmetrical modifications have significantly enhanced activity against both Mycobacterium tuberculosis and Mycobacterium bovis BCG.Figure optionsDownload full-size imageDownload as PowerPoint slide