Exploiting Nuclear Spin Polarization to Investigate Free Radical Reactions via in situ NMR

Kuhn, Lars T.; Bargon, Joachim

doi:10.1007/128_2007_119

Cited by 15 publications

(11 citation statements)

References 43 publications

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“…To date, among magnetic resonance methods, only electron paramagnetic resonance (EPR) [1] and chemically induced dynamic nuclear polarization (CIDNP NMR) [2] have been used to evaluate the effects of free radicals on protein solutions. However these techniques require special sample preparation (freezing and drying) which is often destructive to native protein structure.…”

Section: Introductionmentioning

confidence: 99%

NMR Relaxation Measurements as a Tool for Observation of Oxidative Processes

2016

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Water proton relaxation times, T1 and T2, were measured to assess the kinetics of the oxidative processes in biological samples. The oxidation in aqueous solutions of albumins was promoted by an addition of 3% hydrogen peroxide (H2O2). Immediately following this addition a sharp exponential decrease of both relaxation times was observed. As we confirmed experimentally, the time course of relaxation depended on several essential factors like structure and the concentration of proteins and also the presence of antioxidants added to solution. In experiments with protein solutions containing a small amount of ascorbic acid, after reaching a minimum, relaxation time increased towards the initial (pre-addition H2O2) values. We conclude that this T1 and T2 recovery is a consequence of the presence of antioxidants and may be used to evaluate its action. This study demonstrates that nuclear magnetic resonance (NMR) relaxation measurements may be useful in evaluating free radicals reactions and antioxidants capacity.

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Section: Introductionmentioning

confidence: 99%

NMR Relaxation Measurements as a Tool for Observation of Oxidative Processes

2016

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“…The antioxidant activity of GA was also studied by CIDNP technique [ 74 , 95 ], which is one of the most informative experimental methods for studying free radical reactions in complex chemical and biochemical processes [ 96 – 98 ]. The authors traced the effect of GA on the behavior of paramagnetic species formed during UV irradiation of xenobiotics, including drug molecules (naproxen and ketoprofen), and found that the concentration of free radicals in solutions decreased in the presence of GA [ 74 , 95 ].…”

Section: Interaction Of Glycyrrhizin With Free Radicals and Solvate...mentioning

confidence: 99%

Physicochemical Approaches to the Study of the Antioxidant Activity of Glycyrrhizin

Polyakov

Leshina

2023

Russ. J. Phys. Chem.

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“…They are presented and compared with their experimental counterparts in Table 1. These 1 H-and 14 N hfcs do not only reflect the splittings established by EPR but they are also decisive for the CIDNP polarizations of the signals attributed to geminate radical pairs [48][49][50].…”

Section: Hyperfine Data Epr Spectra and Cidnp Polarizationsmentioning

confidence: 99%

Methionine-Based Radicals: Time Scales and Species

et al. 2022

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Abstractl-Methionine is an amino acid, which provides anti-oxidative properties. We report on radicals and radical cations being likely (short-lived) intermediates formed upon photo-oxidation reactions of methionine. In this context, we present photo-CIDNP experiments indicating that the character of the photooxidants is decisive for the observation of CIDNP effects based on methionine. Based on calculated hyperfine data and pKa values and on our experimental observations, we suggest that CIDNP polarizations are produced by an overlay of at least three geminal radical pairs, i.e., two α-thio carbon-centered radicals D· and G·, aminyl radical N·, and, possibly, 2c–3e radical cation SN.+ as short-lived reaction intermediates.

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Exploiting Nuclear Spin Polarization to Investigate Free Radical Reactions via in situ NMR

Cited by 15 publications

References 43 publications

NMR Relaxation Measurements as a Tool for Observation of Oxidative Processes

NMR Relaxation Measurements as a Tool for Observation of Oxidative Processes

Physicochemical Approaches to the Study of the Antioxidant Activity of Glycyrrhizin

Methionine-Based Radicals: Time Scales and Species

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