Site-Specific Antimicrobial Activity of a Dual-Responsive Ciprofloxacin Prodrug

J Med Chem. 2024 Jun 13;67(11):9599-9612. doi: 10.1021/acs.jmedchem.4c00724. Epub 2024 May 23.

Abstract

Bacterial infections create distinctive microenvironments with a unique mix of metabolites and enzymes compared with healthy tissues that can be used to trigger the activation of antibiotic prodrugs. Here, a single and dual prodrug masking the C3 carboxylate and C7 piperazine of the fluoroquinolone, ciprofloxacin, responsive to nitroreductase (NTR) and/or hydrogen sulfide (H2S), was developed. Masking both functional groups reduced the activity of the prodrug against Staphylococcus aureus and Escherichia coli, increasing its minimum inhibitory concentration (MIC) by ∼512-fold (S. aureus) and ∼8000-fold (E. coli strains), while masking a single group only increased the MIC by ∼128-fold. Bacteria subjected to prolonged prodrug exposure did not show any increase in resistance. Triggering assays demonstrated the conversion of prodrugs to ciprofloxacin, and in a murine infection model, responsive prodrugs showed antibacterial activity comparable to that of ciprofloxacin, suggesting in vivo activation of prodrugs. Thus, the potential for site-specific antibiotic treatment with reduced threat of resistance is demonstrated.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Ciprofloxacin* / pharmacology
  • Escherichia coli* / drug effects
  • Female
  • Mice
  • Microbial Sensitivity Tests*
  • Nitroreductases / metabolism
  • Prodrugs* / chemical synthesis
  • Prodrugs* / chemistry
  • Prodrugs* / pharmacology
  • Staphylococcus aureus* / drug effects

Substances

  • Ciprofloxacin
  • Prodrugs
  • Anti-Bacterial Agents
  • Nitroreductases