Semiempirical Formula for the Estimation of Organic Radical Ion Mobility in Liquidn-Alkanes

2006 ◽  
Vol 110 (50) ◽  
pp. 13366-13369 ◽  
Author(s):  
Vsevolod I. Borovkov
Keyword(s):  
Ion Mobility ◽  
Organic Radical ◽  
Semiempirical Formula

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

Rapid Diagnosis of Parkinson’s Disease from Sebum using Paper Spray Ionisation Ion Mobility Mass Spectrometry

2020 ◽  
Author(s):  
Depanjan Sarkar ◽  
Drupad Trivedi ◽  
Eleanor Sinclair ◽  
Sze Hway Lim ◽  
Caitlin Walton-Doyle ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Ion Mobility ◽  
Neurodegenerative Disorder ◽  
Treatment Options ◽  
Ion Mobility Mass Spectrometry ◽  
Paper Spray ◽  
Molecular Features ◽  
Validation Set

Parkinson’s disease (PD) is the second most common neurodegenerative disorder for which identification of robust biomarkers to complement clinical PD diagnosis would accelerate treatment options and help to stratify disease progression. Here we demonstrate the use of paper spray ionisation coupled with ion mobility mass spectrometry (PSI IM-MS) to determine diagnostic molecular features of PD in sebum. PSI IM-MS was performed directly from skin swabs, collected from 34 people with PD and 30 matched control subjects as a training set and a further 91 samples from 5 different collection sites as a validation set. PSI IM-MS elucidates ~ 4200 features from each individual and we report two classes of lipids (namely phosphatidylcholine and cardiolipin) that differ significantly in the sebum of people with PD. Putative metabolite annotations are obtained using tandem mass spectrometry experiments combined with accurate mass measurements. Sample preparation and PSI IM-MS analysis and diagnosis can be performed ~5 minutes per sample offering a new route to for rapid and inexpensive confirmatory diagnosis of this disease.

Spatial Metabolomics of the Human Kidney Using MALDI Trapped Ion Mobility Imaging Mass Spectrometry

2020 ◽  
Author(s):  
Elizabeth Neumann ◽  
Lukasz Migas ◽  
Jamie L. Allen ◽  
Richard Caprioli ◽  
Raf Van de Plas ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility ◽  
Imaging Mass Spectrometry ◽  
Structural Complexity ◽  
Human Kidney ◽  
Resolving Power ◽  
Mobility Separation ◽  
Trapped Ion ◽  
Mobility Data ◽  
Ion Mobility Separation

<div> <div> <p>Small metabolites are essential for normal and diseased biological function but are difficult to study because of their inherent structural complexity. MALDI imaging mass spectrometry (IMS) of small metabolites is particularly challenging as MALDI matrix clusters are often isobaric with metabolite ions, requiring high resolving power instrumentation or derivatization to circumvent this issue. An alternative to this is to perform ion mobility separation before ion detection, enabling the visualization of metabolites without the interference of matrix ions. Here, we use MALDI timsTOF IMS to image small metabolites at high spatial resolution within the human kidney. Through this, we have found metabolites, such as arginic acid, acetylcarnitine, and choline that localize to the cortex, medulla, and renal pelvis, respectively. We have also demonstrated that trapped ion mobility spectrometry (TIMS) can resolve matrix peaks from metabolite signal and separate both isobaric and isomeric metabolites with different localizations within the kidney. The added ion mobility data dimension dramatically increased the peak capacity for molecular imaging experiments. Future work will involve further exploring the small metabolite profiles of human kidneys as a function of age, gender, and ethnicity.</p></div></div>

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>

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