Discovery of Novel Thiophene-arylamide Derivatives as DprE1 Inhibitors with Potent Antimycobacterial Activities.
Wang P, Batt SM, Wang B, Fu L, Qin R, Lu Y, Li G, Besra GS, Huang H.
In this study, we report the design and synthesis of a series of novel thiophene-arylamide compounds derived from the noncovalent decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1) inhibitor TCA1 through a structure-based scaffold hopping strategy. Systematic optimization of the two side chains flanking the thiophene core led to new lead compounds bearing a thiophene-arylamide scaffold with potent antimycobacterial activity and low cytotoxicity. Compounds <b>23j</b>, <b>24f</b>, <b>25a</b>, and <b>25b</b> exhibited potent <i>in vitro</i> activity against both drug-susceptible (minimum inhibitory concentration (MIC) = 0.02-0.12 μg/mL) and drug-resistant (MIC = 0.031-0.24 μg/mL) tuberculosis strains while retaining potent DprE1 inhibition (half maximal inhibitory concentration (IC<sub>50</sub>) = 0.2-0.9 μg/mL) and good intracellular antimycobacterial activity. In addition, these compounds showed good hepatocyte stability and low inhibition of the human ether-à-go-go related gene (hERG) channel. The representative compound <b>25a</b> with acceptable pharmacokinetic property demonstrated significant bactericidal activity in an acute mouse model of tuberculosis. Moreover, the molecular docking study of template compound <b>23j</b> provides new insight into the discovery of novel antitubercular agents targeting DprE1.