Electron Paramagnetic Resonance Detection of Radicals in Biology and Medicine

Davies, Michael J.

doi:10.1002/9780470432235.ch11

Cited by 4 publications

(4 citation statements)

References 102 publications

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“…A single crystal of the title compound was installed on a Bruker ER218G1 goniometer, and angle-dependent electron paramagnetic resonance (EPR) spectra were recorded on a Bruker ELEXSYS 500 equipped with a Bruker ER4141VT temperature controller in the X-band at 9.4 GHz and 100 K using liquid nitrogen as a coolant. Crystalline 2,2-diphenyl-1-picrylhydrazyl (dpph with a g -value of 2.0036) , was used as reference material.…”

Section: Methodsmentioning

confidence: 99%

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family

2011

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Large single crystals of the garnet imanite, Ca(3)Ti(2)Si(3)O(12), were synthesized by a floating zone technique. Near-infrared to visible spectroscopy presents an optical gap of 1.65 eV at 4 K, proving the insulating character of this garnet compound. Electron paramagnetic resonance data indicate that the d(1) electron of Ti(3+) exhibits an orbital contribution to the spin moment (g = 1.859(1)). An antiferromagnetic state is observed below T(N) = 7 K, confirmed by magnetic susceptibility and specific heat data. X-ray diffraction investigations on powders and single crystals of imanite reveal that the crystal structure agrees well with expectations: the cubic symmetry Ia3d describes all obtained single crystal and powder diffraction data.

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Section: Methodsmentioning

confidence: 99%

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family

2011

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“…EPR is a magnetic resonance-based method that detects only species with unpaired electrons. To detect a short-lived free radical, a spin-trap, generally a nitrone, is added to a system to react with the free radical and thus forms a spin-adduct, a nitroxide radical that is longer-lived than the original radical [ 7 , 8 ], and consequently more conveniently detected. The identity of free radicals can be inferred from the particular EPR spectrum using EPR constants, such as g values and hyperfine splitting constants.…”

Section: Introductionmentioning

confidence: 99%

“…Because there is no existing universal spin trap (able to trap and provide a signature for all types of free radical), we assembled a cocktail of different traps: N-tert-butyl-α-phenylnitrone (PBN), α(4-pyridil-1-oxide)-N-tert-butylnitrone (POBN), 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO), and 5-ethoxycarbonyl-5-methyl-pyrroline-N-oxide (EMPO) ( Fig 2 ). The rationale for using this cocktail was that it would cover a wide range of biologically relevant free radicals and have a large range of hydrophilicity and lipophilicity (coefficient of partition between octanol and phosphate buffer from 0.15 to 10) in order to trap free radicals produced in different cellular compartments [ 8 ]. The selected spin traps offer a large variety in the EPR spectra of the spin adducts, without mutual interferences in order to discriminate as much as possible the free radicals involved.…”

Section: Introductionmentioning

confidence: 99%

Use of a cocktail of spin traps for fingerprinting large range of free radicals in biological systems

et al. 2017

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It is well established that the formation of radical species centered on various atoms is involved in the mechanism leading to the development of several diseases or to the appearance of deleterious effects of toxic molecules. The detection of free radical is possible using Electron Paramagnetic Resonance (EPR) spectroscopy and the spin trapping technique. The classical EPR spin-trapping technique can be considered as a “hypothesis-driven” approach because it requires an a priori assumption regarding the nature of the free radical in order to select the most appropriate spin-trap. We here describe a “data-driven” approach using EPR and a cocktail of spin-traps. The rationale for using this cocktail was that it would cover a wide range of biologically relevant free radicals and have a large range of hydrophilicity and lipophilicity in order to trap free radicals produced in different cellular compartments. As a proof-of-concept, we validated the ability of the system to measure a large variety of free radicals (O-, N-, C-, or S- centered) in well characterized conditions, and we illustrated the ability of the technique to unambiguously detect free radical production in cells exposed to chemicals known to be radical-mediated toxic agents.

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“…Typical examples in this context are reactive oxygen species (ROS) -by-products of the normal oxygen metabolism -that are involved in cell signalling and homeostasis, but -if ROS levels are increased under unfavourable conditions or in disease -can result in significant damage to the cell, and are according to the free-radical theory thought to be a major contributor to the organism's functional decline in aging. Applications of EPR spectroscopy in biomedical research and also its clinical use have been already reviewed in the past [19,39,62,84], but usually with a focus on specific techniques or applications.…”

Section: Introductionmentioning

confidence: 99%

Biomedical applications of electron paramagnetic resonance (EPR) spectroscopy

Klare

2012

Biomedical Spectroscopy and Imaging

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EPR spectroscopy is the most straightforward-to-use technique for studying free radicals and other paramagnetic species and has therefore established itself in biomedical research and for clinical applications. EPR found its applications in oximetry, where this technique allows repeated measurements of oxygen in tissues -also in vivo and in combination with imaging techniques. The direct detection of paramagnetic species like transition metal ions by EPR allows elucidation of their specific roles in disease, for example how copper ions might be involved in the formation of amyloid-or amyloid-like fibrils in neurodegenerative diseases. For investigations on the structures of this protein aggregates, but also of other proteins or protein complexes with medical relevance the technique of site-directed spin labeling (SDSL) -the site-specific introduction of paramagnetic reporter groups into proteins or nucleic acids -is nowadays frequently used, especially in cases where other structural techniques are not applicable. Moreover, by direct detection of free radicals -also in combination with spin trapping methods, or application of SDSL, EPR spectroscopy can be also used for diagnostic purposes, e.g. in cancer diagnostics. This review gives an up-to-date overview about how EPR spectroscopy is currently used in biomedical research and clinical applications, with special emphasis on biomedical applications of SDSL EPR.

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Electron Paramagnetic Resonance Detection of Radicals in Biology and Medicine

Cited by 4 publications

References 102 publications

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family

Use of a cocktail of spin traps for fingerprinting large range of free radicals in biological systems

Biomedical applications of electron paramagnetic resonance (EPR) spectroscopy

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Electron Paramagnetic Resonance Detection of Radicals in Biology and Medicine

Cited by 4 publications

References 102 publications

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca3Ti2Si3O12: The Lost Child of the Garnet Family

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca3Ti2Si3O12: The Lost Child of the Garnet Family

Use of a cocktail of spin traps for fingerprinting large range of free radicals in biological systems

Biomedical applications of electron paramagnetic resonance (EPR) spectroscopy

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Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family

Antiferromagnetic Ground State of Quantum Spins in the Synthetic Imanite, Ca₃Ti₂Si₃O₁₂: The Lost Child of the Garnet Family