The decomposition of peroxynitrite at physiological pH yielded a hydroxyl radical, which reacted rapidly with dimethyl sulfoxide (DMSO) to produce a methyl radical (*CH3), which was then trapped by a spin-label fluorophore nitroxide-linked naphthalene (NTEMPO), a carbon-centered radical probe with a low fluorescence intensity, and transformed to a stable diamagnetic O-alkoxyamine, a high-fluorescence compound. The fluorescence increment was proportional to the concentration of the hydroxyl radical, and then to the concentration of peroxynitrite. NTEMPO therefore was demonstrated to be capable of detecting hydroxyl radicals generated from peroxynitrite, and the method was proved to be simple and sensitive. The hydroxyl radical-mediated reactivities of peroxynitrite to several amino acids, such as tyrosine, phenylalanine and histidine, were then evaluated by the spin-labeling fluorophore NTEMPO at pH 7.4 and, 37 degrees C. The obtained data were in good agreement with the reference values, respectively.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.2116/analsci.21.553 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
EPR Characterization of the BlsE Substrate Radical Offers Insight into the Determinants of Reaction Outcome that Distinguish Radical SAM Dioldehydratases from Dehydrogenases.
J Am Chem Soc
January 2025
Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
A small but growing set of radical SAM (-adenosyl-l-methionine) enzymes catalyze the radical mediated dehydration or dehydrogenation of 1,2-diol substrates. In some cases, these activities can be interchanged via minor structural perturbations to the reacting components raising questions regarding the relative importance of hyperconjugation, proton circulation and leaving group stability in determining the reaction outcome. The present work describes trapping and electron paramagnetic resonance (EPR) characterization of an α-hydroxyalkyl radical intermediate during dehydration and dehydrogenation of cytosylglucuronic acid and its derivatives catalyzed by the radical SAM enzyme BlsE and its Glu189Ala mutant from the blasticidin S biosynthetic pathway.
View Article and Find Full Text PDFCatalyst-Free Nitrogen Fixation by Microdroplets through a Radical-Mediated Disproportionation Mechanism under Ambient Conditions.
J Am Chem Soc
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
Nitrogen fixation is essential for the sustainable development of both human society and the environment. Due to the chemical inertness of the N≡N bond, the traditional Haber-Bosch process operates under extreme conditions, making nitrogen fixation under ambient conditions highly desirable but challenging. In this study, we present an ultrasonic atomizing microdroplet method that achieves nitrogen fixation using water and air under ambient conditions in a rationally designed sealed device, without the need for any catalyst.
View Article and Find Full Text PDFPeroxidase-like activity of widely-used commercial inorganic pigments induces oxidative stress and antibiotic degradation: Implications for health risks.
Sci Total Environ
January 2025
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China. Electronic address:
Inorganic pigments, which often contain significant amounts of nanoparticles, are crucial chemicals for human life. They are produced in massive quantities and widely used in consumer products, food, and pharmaceuticals. Herein, we reported that a variety of commonly used commercial inorganic pigments possess peroxidase-like activity, catalyzing hydrogen peroxide (HO) decomposition into reactive oxygen species, primarily hydroxyl radical (OH) and superoxide radical anion (O).
View Article and Find Full Text PDFCatalytically Active Ti-Based Nanomaterials for Hydroxyl Radical Mediated Clinical X-Ray Enhancement.
Adv Sci (Weinh)
December 2024
Nanoparticle Systems Engineering Laboratory, Institute of Energy and Process Engineering (IEPE), Department of Mechanical and Process Engineering (D-MAVT), ETH Zurich, Sonneggstrasse 3, Zurich, 8092, Switzerland.
Nanoparticle radioenhancement offers a promising strategy for augmenting radiotherapy by locally increasing radiation damage to tumor tissue. While past research has predominantly focused on nanomaterials with high atomic numbers, such as Au and HfO, recent work has revealed that their radioenhancement efficacy decreases considerably when using clinically relevant megavoltage X-rays as opposed to the orthovoltage X-rays typically employed in research settings. Here, radiocatalytically active Ti-based nanomaterials for clinical X-ray therapy settings are designed.
View Article and Find Full Text PDFKinetic Insights into Boron-Based Materials Catalyzed Oxidative Dehydrogenation of Light Alkanes.
Precis Chem
May 2024
Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Article Synopsis
- Boron-based materials show high selectivity for alkenes in oxidative dehydrogenation (ODH) of light alkanes, making them promising catalysts, although key reaction mechanisms remain debated due to difficulties in capturing short-lived intermediates.
- The review highlights the investigation of reaction orders and activation energies, which could provide insight into reactions involving radical intermediates, an area that hasn't been deeply explored yet.
- Common features among different boron-based catalysts include alkene selectivity and active site formation, attributed to shared radical-mediated reaction pathways, indicating that apparent reaction orders and activation energies are reliable measures for understanding these mechanisms in boron-catalyzed ODH.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!