A Modular Synthetic Route Involving N-Aryl-2-nitrosoaniline Intermediates Leads to a New Series of 3-Substituted Halogenated Phenazine Antibacterial Agents

J Med Chem. 2021 Jun 10;64(11):7275-7295. doi: 10.1021/acs.jmedchem.1c00168. Epub 2021 Apr 21.

Abstract

Pathogenic bacteria demonstrate incredible abilities to evade conventional antibiotics through the development of resistance and formation of dormant, surface-attached biofilms. Therefore, agents that target and eradicate planktonic and biofilm bacteria are of significant interest. We explored a new series of halogenated phenazines (HP) through the use of N-aryl-2-nitrosoaniline synthetic intermediates that enabled functionalization of the 3-position of this scaffold. Several HPs demonstrated potent antibacterial and biofilm-killing activities (e.g., HP 29, against methicillin-resistant Staphylococcus aureus: MIC = 0.075 μM; MBEC = 2.35 μM), and transcriptional analysis revealed that HPs 3, 28, and 29 induce rapid iron starvation in MRSA biofilms. Several HPs demonstrated excellent activities against Mycobacterium tuberculosis (HP 34, MIC = 0.80 μM against CDC1551). This work established new SAR insights, and HP 29 demonstrated efficacy in dorsal wound infection models in mice. Encouraged by these findings, we believe that HPs could lead to significant advances in the treatment of challenging infections.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aniline Compounds / chemistry*
  • Animals
  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Biofilms / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Disease Models, Animal
  • Drug Design
  • Female
  • Halogenation
  • Humans
  • Iron / chemistry
  • Iron Deficiencies
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / physiology
  • Mice
  • Mice, Inbred BALB C
  • Mycobacterium tuberculosis / drug effects
  • Phenazines / chemistry*
  • Phenazines / pharmacology
  • Phenazines / therapeutic use
  • Staphylococcal Infections / drug therapy
  • Structure-Activity Relationship
  • Wound Healing / drug effects

Substances

  • Aniline Compounds
  • Anti-Bacterial Agents
  • Phenazines
  • Iron
  • aniline