Nitrite reduction mediated by the complex RuIII(EDTA).

Area of Science:

• Inorganic Chemistry
• Biochemistry
• Coordination Chemistry

Background:

• Biological thiols, such as cysteine and glutathione, play crucial roles in cellular processes.
• Nitrite is a biologically relevant molecule with diverse signaling functions.
• Ruthenium complexes are explored for their catalytic and therapeutic potential.

Purpose of the Study:

• To investigate the O-atom transfer capabilities of a ruthenium(III)-complex with biological thiols.
• To characterize the reaction products and intermediates involved in the O-atom transfer process.
• To explore the influence of pH on the stability and reactivity of the ruthenium complex.

Main Methods:

• Synthesis and characterization of the ruthenium(III)-complex, Ru(III)(EDTA).
• Spectroscopic analysis to identify reaction products, including [Ru(III)(EDTA)(NO(+))](0).
• pH-dependent studies to examine the stability of the complex and its intermediates.

Main Results:

• The Ru(III)(EDTA) complex successfully mediated O-atom transfer from nitrite to cysteine and glutathione.
• The reaction yielded a nitrosyl ruthenium species, [Ru(III)(EDTA)(NO(+))](0).
• At pH below 5.0, proton-assisted decomposition of the coordinated nitrite led to the formation of the [Ru(III)(EDTA)(NO(+))](0) species.

Conclusions:

• Ru(III)(EDTA) is the first reported ruthenium complex capable of mediating O-atom transfer from nitrite to biological thiols.
• The complex exhibits reactivity towards biologically relevant molecules, suggesting potential applications.
• The formation of the nitrosyl species is pH-dependent, highlighting the importance of reaction conditions.