Targeting Pathogenic Formate-Dependent Bacteria with a Bioinspired Metallo-Nitroreductase Complex

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Bioengineering

Background:

• Nitroreductases (NTRs) are oxidoreductase enzymes crucial for metabolizing nitro-containing compounds.
• Their unique properties offer potential in medicinal chemistry, chemical biology, and bioengineering for prodrug activation and specialized applications.
• Enzymatic nitroreduction involves hydride transfer reactions, inspiring the development of synthetic mimics.

Purpose of the Study:

• To design and synthesize a novel small-molecule nitroreductase system.
• To mimic the hydride transfer cascade of native NTRs using transition metal complexes and cofactors.
• To demonstrate the system's efficacy in reducing nitroaromatics and activating a prodrug in a biologically relevant context.

Main Methods:

• Development of a water-stable ruthenium-arene complex.
• Utilizing formate as a hydride source for transfer hydrogenation.
• Testing the complex's ability to reduce nitroaromatics to anilines in an aqueous buffer.
• Demonstrating prodrug activation of nitro-caged sulfanilamide in *Staphylococcus aureus*.

Main Results:

• The synthesized Ru-arene complex selectively and completely reduces nitroaromatics to anilines.
• The reduction occurs in a biocompatible, buffered aqueous environment.
• The complex successfully activated a nitro-caged sulfanilamide prodrug in *Staphylococcus aureus*.
• The system functions effectively in formate-abundant bacterial environments.

Conclusions:

• A novel synthetic nitroreductase system based on a Ru-arene complex has been successfully developed.
• This system enables targeted prodrug activation via bioinspired nitroreduction, offering a new therapeutic strategy.
• The findings present a promising approach for developing targeted antibacterial chemotherapeutics against resistant pathogens like MRSA.