Discovery and Hit-to-Lead Optimization of Benzothiazole Scaffold-Based DNA Gyrase Inhibitors with Potent Activity against Acinetobacter baumannii and Pseudomonas aeruginosa

J Med Chem. 2023 Jan 26;66(2):1380-1425. doi: 10.1021/acs.jmedchem.2c01597. Epub 2023 Jan 12.


We have developed compounds with a promising activity against Acinetobacter baumannii and Pseudomonas aeruginosa, which are both on the WHO priority list of antibiotic-resistant bacteria. Starting from DNA gyrase inhibitor 1, we identified compound 27, featuring a 10-fold improved aqueous solubility, a 10-fold improved inhibition of topoisomerase IV from A. baumannii and P. aeruginosa, a 10-fold decreased inhibition of human topoisomerase IIα, and no cross-resistance to novobiocin. Cocrystal structures of 1 in complex with Escherichia coli GyrB24 and (S)-27 in complex with A. baumannii GyrB23 and P. aeruginosa GyrB24 revealed their binding to the ATP-binding pocket of the GyrB subunit. In further optimization steps, solubility, plasma free fraction, and other ADME properties of 27 were improved by fine-tuning of lipophilicity. In particular, analogs of 27 with retained anti-Gram-negative activity and improved plasma free fraction were identified. The series was found to be nongenotoxic, nonmutagenic, devoid of mitochondrial toxicity, and possessed no ion channel liabilities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii* / metabolism
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Benzothiazoles
  • DNA Gyrase / metabolism
  • Escherichia coli / metabolism
  • Humans
  • Microbial Sensitivity Tests
  • Pseudomonas aeruginosa / metabolism
  • Topoisomerase II Inhibitors* / chemistry
  • Topoisomerase II Inhibitors* / pharmacology


  • Topoisomerase II Inhibitors
  • Anti-Bacterial Agents
  • Benzothiazoles
  • DNA Gyrase