Large-scale high-throughput screening revealed 5'-(carbonylamino)-2,3'-bithiophene-4'-carboxylate as novel template for antibacterial agents.

Herein, we present the results of high-throughput screening (HTS) campaign, that has been performed utilizing our HTS platform based on unique double-reporter system - pDualrep2. A large-scale small molecule library was designed and tested. As a result, 5'-(carbonylamino)-2,3'-bithiophene-4'-carboxylate derivates were observed as novel class of antibacterials with promising potency. One of the he most active compounds showed a minimal inhibitory concentration (MIC) value of 1.8 µg/mL and induced weak SOS response. Additional investigation displayed that the hit slightly inhibited prokaryotic translational machinery at a concentration of 16.7 µg/mL. Another hit with MIC value of 1.2 µg/mL exhibited high activity against S. aureus. Cytotoxic studies demonstrated a relatively good selectivity index for the most active compounds within the series towards a small panel of eukaryotic cells. The follow-up screening of several derivatives of the discovered scaffold elucidated the key structural features important for exhibiting antibacterial activity.