Identification of Novel Tricyclic Benzo[1,3]oxazinyloxazolidinones as Potent Antibacterial Agents with Excellent Pharmacokinetic Profiles against Drug-Resistant Pathogens.
Wu Y, Wang B, Lu H, Zhao H, Yang B, Li L, Lu Y, Zhang D, Sun N, Huang H.
A series of conformationally constrained novel benzo[1,3]oxazinyloxazolidinones were designed, synthesized, and evaluated on their activities against <i>Mycobacterium tuberculosis</i>, Gram-positive bacteria, and Gram-negative bacteria. The studies identified a new compound <b>20aa</b> that displayed good to excellent antibacterial and antitubercular profiles against drug-resistant TB strains (MIC = 0.48-0.82 μg/mL), MRSA (MIC = 0.25-0.5 μg/mL), MRSE (MIC = 1 μg/mL), VISA (MIC = 0.25 μg/mL), and VRE (MIC = 0.25 μg/mL) and some linezolid-resistant strains (MIC 1-2 μg/mL). Compound <b>20aa</b> was demonstrated as a promising candidate through ADME/T evaluation including microsomal stability, cytotoxicity, and inhibition of hERG and monoamine oxidase. Notably, <b>20aa</b> showed excellent mouse PK profile with high plasma exposure (AUC<sub>0-∞</sub> = 78 669 h·ng/mL), high peak plasma concentration (<i>C</i><sub>max</sub> = 10 253 ng/mL), appropriate half-life of 3.76 h, and superior oral bioavailability (128%). The present study not only successfully provides a novel benzo[1,3]oxazinyloxazolidinone scaffold with superior druggability but also lays a good foundation for new antibacterial drug development.