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Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
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Thiol and H2S-Mediated NO Generation from Nitrate at Copper(II).
Pokhraj Ghosh1,2, Molly Stauffer1,2, Md Estak Ahmed1,2
1Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States.
Journal of the American Chemical Society
|May 24, 2023
Summary
Thiols reduce nitrate to nitric oxide (NO) using a copper(II) catalyst. This process generates signaling molecules, offering insights into biological pathways and environmental management.
Area of Science:
- Inorganic Chemistry
- Biochemistry
- Environmental Chemistry
Background:
- Nitrate reduction is crucial for environmental and biological systems but remains chemically challenging.
- Thiols are abundant biological reductants with potential roles in nitrate transformation.
Purpose of the Study:
- To investigate the mechanism of nitrate reduction to nitric oxide (NO) mediated by thiols at a copper(II) center.
- To explore the formation of signaling molecules during this reaction and its implications for biological crosstalk.
Main Methods:
- Utilized a copper(II) β-diketiminato complex for nitrate reduction studies.
- Investigated reactions with various thiols (RSH) and hydrogen sulfide (H2S).
- Characterized reaction intermediates including copper(II) nitrite and sulfenic acid.
Main Results:
- Demonstrated that thiols convert nitrate to nitric oxide (NO) at a copper(II) center under mild conditions.
- Identified key intermediates: copper(II) nitrite, sulfenic acid, and S-nitrosothiols.
- Showed that hydrogen sulfide (H2S) also reduces nitrate to NO at copper(II), revealing NO3-/H2S crosstalk.
Conclusions:
- Thiols effectively reduce nitrate to NO via copper(II) catalysis, releasing biologically relevant signaling molecules.
- The findings provide a mechanistic understanding of nitrate-thiol-copper interactions and their role in biological signaling.
- This work offers potential strategies for managing nitrate in environmental and biological contexts.
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