Identification ofcis-Ethanesemidione as the Organic Radical Derived from Glycolaldehyde in the Suicide Inactivation of Dioldehydrase and of Ethanolamine Ammonia-Lyase†

Biochemistry ◽  
2000 ◽  
Vol 39 (20) ◽  
pp. 6250-6257 ◽  
Author(s):  
Andreas Abend ◽  
Vahe Bandarian ◽  
George H. Reed ◽  
Perry A. Frey
Keyword(s):  
Organic Radical ◽  
Suicide Inactivation

Development of new magnetic organic conductors based on donor molecules with stable organic radical part

2004 ◽  
Vol 114 ◽  
pp. 533-535 ◽  
Author(s):  
H.-J. Lee ◽  
H.-B. Cui ◽  
H. Fujiwara ◽  
H. Kobayashi ◽  
E. Fujiwara ◽  
...  
Keyword(s):  
Organic Conductors ◽  
Organic Radical

Nitroxyl Modified Tobacco Mosaic Virus as a Metal-Free High-Relaxivity MRI and EPR Active Superoxide Sensor

2018 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
André F. Martins ◽  
Zhuo Chen ◽  
Philip M. Palacios ◽  
Chance M. Nowak ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Single Molecule ◽  
Biological Fluids ◽  
Cellular Respiration ◽  
Organic Radical ◽  
Paramagnetic Resonance ◽  
Metal Free ◽  
Disease States

Superoxide overproduction is known to occur in multiple disease states requiring critical care yet non-invasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by “click conjugating” paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced <i>in vivo</i> to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species—in particular superoxide—and are largely unaffected by peroxides and molecular oxygen. Unfortunately, single molecule ORCAs typically offer weak MRI contrast. In contrast, our data confirm that the macromolecular ORCA-TMV conjugates show marked enhancement for <i>T<sub>1</sub></i> contrast at low field (<3.0 T), and <i>T<sub>2</sub></i> contrast at high field (9.4 T). Additionally, we demonstrated that the unique topology of TMV allows for “quenchless fluorescent” bimodal probe for concurrent fluorescence and MRI/EPR imaging, which was made possible by exploiting the unique inner and outer surface of the TMV nanoparticle. <a>Finally, we show TMV-ORCAs do not respond to normal cellular respiration, minimizing the likelihood for background, yet still respond to enzymatically produced superoxide in complicated biological fluids like serum.</a>

Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Side Effects ◽  
Magnetic Resonance ◽  
Tobacco Mosaic Virus ◽  
Contrast Agents ◽  
Single Molecule ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

Exciton Funneling Amplified Photoluminescence Anisotropy in Organic Radical-Doped Microcrystals

2021 ◽  
Author(s):  
Zhonghao Zhou ◽  
Chan Qiao ◽  
Jiannian Yao ◽  
Yongli Yan ◽  
Yong Sheng Zhao
Keyword(s):  
Molecular Structures ◽  
Organic Radical ◽  
Doping Ratio

We demonstrate a controllable photoluminescence anisotropy amplification in organic luminescent radical-doped microcrystals via exciton funneling. The widely tunable doping ratio resulting from very similar molecular structures between hosts and guests...

scholarly journals New Radical Cation Salts Based on BDH-TTP Donor: Two Stable Molecular Metals with a Magnetic [ReF6]2− Anion and a Semiconductor with a [ReO4]− Anion

2021 ◽  
Vol 7 (4) ◽  
pp. 54
Author(s):  
Nataliya D. Kushch ◽  
Gennady V. Shilov ◽  
Lev I. Buravov ◽  
Eduard B. Yagubskii ◽  
Vladimir N. Zverev ◽  
...  
Keyword(s):  
Radical Cation ◽  
Low Temperatures ◽  
Ac Susceptibility ◽  
Slow Relaxation ◽  
Organic Radical ◽  
Inorganic Anion ◽  
Distinctive Features ◽  
Metallic Character ◽  
Radical Cation Salts ◽  
Partial Population

Three radical cation salts of BDH-TTP with the paramagnetic [ReF6]2− and diamagnetic [ReO4]− anions have been synthesized: κ-(BDH-TTP)4ReF6 (1), κ-(BDH-TTP)4ReF6·4.8H2O (2) and pseudo-κ″-(BDH-TTP)3(ReO4)2 (3). The crystal and band structures, as well as the conducting properties of the salts, have been studied. The structures of the three salts are layered and characterized by alternating κ-(1, 2) and κ″-(3) type organic radical cation layers with inorganic anion sheets. Similar to other κ-salts, the conducting layers in the crystals of 1 and 2 are formed by BDH-TTP dimers. The partial population of positions of Re atoms and disorder in the anionic layers of 1–3 are their distinctive features. Compounds 1 and 2 show the metallic character of conductivity down to low temperatures, while 3 is a semiconductor. The ac susceptibility of crystals 1 was investigated in order to test the possible slow relaxation of magnetization associated with the [ReF6]2− anion.

Multi-electron redox reaction of an organic radical cathode induced by a mesopore carbon network with nitroxide polymers

2013 ◽  
Vol 15 (48) ◽  
pp. 20921 ◽  
Author(s):  
Qian Huang ◽  
Daiwon Choi ◽  
Lelia Cosimbescu ◽  
John P. Lemmon
Keyword(s):  
Redox Reaction ◽  
Organic Radical ◽  
Carbon Network

Pressure induced enhancement of ordering temperature of a ferromagnetic organic radical crystal: p-CDTV

1996 ◽  
Vol 46 (S4) ◽  
pp. 2107-2108 ◽  
Author(s):  
M. Mito ◽  
H. Nakano ◽  
M. Hitaka ◽  
T. Kawae ◽  
K. Konishi ◽  
...  
Keyword(s):  
Organic Radical
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