Abstract:
Using CBBR as the parent core constructed in our lab, we designed and synthesized 15 novel compounds with diverse structures for evaluation of anti-bacterial activities. Structure activity relationship studies revealed that ① ring C was essential for the activity; ② 7,8-or 8,13-disubstituted CBBR derivatives showed ideal activities, weaker or similar to those corresponding to 7-, 8-, or 13-monosubstituted CBBR derivatives. Among those, compound
9a showed the most potential activity against MRSA/VISA isolates with MIC values of 1-2 μg·mL
-1, much better than Lev.
9a also displayed higher stability in the plasma and liver microsomes. Molecular docking indicated that
9a might target bacterial DNA Topo IV ParE subunit, indicating a mode of action distinct from current antibacterial drugs on market. The results provided key scientific evidence for developing such compounds into a new family of anti-MRSA drugs.