Possible intermediates of Cu(phen)-catalyzed C–O cross-coupling of phenol with an aryl bromide by in situ ESI-MS and EPR studies

2014 ◽  
Vol 43 (29) ◽  
pp. 11410-11417 ◽  
Author(s):  
Hong-Jie Chen ◽  
I-Jui Hsu ◽  
Mei-Chun Tseng ◽  
Shin-Guang Shyu
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Catalytic Reaction ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Ionization Mass ◽  
Aryl Bromide ◽  
Reaction Conditions ◽  
Esi Ms

Cu(phen) complexes were observed in the copper(i)-catalyzed C–O coupling reaction using K2CO3 as the base and phen as the ligand under the catalytic reaction conditions by in situ electrospray ionization mass spectrometry (ESI-MS) and EPR analysis.

Ligand free copper(i)-catalyzed synthesis of diaryl ether with Cs2CO3via a free radical path

2015 ◽  
Vol 44 (27) ◽  
pp. 12086-12090 ◽  
Author(s):  
Hong-Jie Chen ◽  
Mei-Chun Tseng ◽  
I-Jui Hsu ◽  
Wei-Ting Chen ◽  
Chien-Chung Han ◽  
...  
Keyword(s):  
Free Radical ◽  
Catalytic Reaction ◽  
Coupling Reaction ◽  
Reaction Conditions ◽  
Esi Ms ◽  
Ms Analysis ◽  
Diaryl Ether ◽  
Ligand Free

Complexes [Cu(i)(2,4-dimethylphenoxy)2]− (A) and [Cu(ii)(2,4-dimethylphenoxy)2(p-tolyl)]− (B) were observed by in situ ESI-MS analysis of the ligand free copper(i)-catalyzed C–O coupling reaction using Cs2CO3 under the catalytic reaction conditions.

scholarly journals Analysis of Inositol Phosphate Metabolism by Capillary Electrophoresis Electrospray Ionization Mass Spectrometry (CE-ESI-MS)

2020 ◽  
Author(s):  
Danye Qiu ◽  
Miranda S. Wilson ◽  
Verena B. Eisenbeis ◽  
Robert K. Harmel ◽  
Esther Riemer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Capillary Electrophoresis ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Inositol Phosphate ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Phosphate Metabolism ◽  
Esi Ms ◽  
Inositol Phosphate Metabolism

AbstractThe analysis of myo-inositol phosphates (InsPs) and myo-inositol pyrophosphates (PP-InsPs) is a daunting challenge due to the large number of possible isomers, the absence of a chromophore, the high charge density, the low abundance, and the instability of the esters and anhydrides. Given their importance in biology, an analytical approach to follow and understand this complex signaling hub is highly desirable. Here, capillary electrophoresis (CE) coupled to electrospray ionization mass spectrometry (ESI-MS) is implemented to analyze complex mixtures of InsPs and PP-InsPs with high sensitivity. Stable isotope labeled (SIL) internal standards allow for matrix-independent quantitative assignment. The method is validated in wild-type and knockout mammalian cell lines and in model organisms. SIL-CE-ESI-MS enables for the first time the accurate monitoring of InsPs and PP-InsPs arising from compartmentalized cellular synthesis pathways, by feeding cells with either [13C6]-myo-inositol or [13C6]-D-glucose. In doing so, we uncover that there must be unknown inositol synthesis pathways in mammals, highlighting the unique potential of this method to dissect inositol phosphate metabolism and signalling.

Developments in Electrospray Ionization Mass Spectrometry of Non-Covalent DNA–Ligand Complexes

2011 ◽  
Vol 64 (6) ◽  
pp. 705 ◽  
Author(s):  
Jennifer L. Beck
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Short Review ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Quadruplex Dna ◽  
Esi Ms ◽  
Selective Ligands ◽  
Ligand Interactions

Many anti-cancer drugs function by binding non-covalently to double-stranded (ds) DNA. Electrospray ionization mass spectrometry (ESI-MS) has emerged over the past decade as a sensitive technique for the determination of stoichiometries and relative binding affinities of DNA–ligand interactions. The chromosome contains nucleotide sequences, for example, guanosine-rich regions, that predispose them to the formation of higher order structures such as quadruplex DNA (qDNA). Sequences that form qDNA are found in the telomeres. The proposal that ligands that stabilize qDNA might interfere with the activity of telomerase in cancer cells has stimulated the search for ligands that are selective for qDNA over dsDNA. The insights gained from the development of ESI-MS methods for analysis of non-covalent dsDNA–ligand complexes are now being applied in the search for qDNA-selective ligands. ESI-MS is a useful first-pass screening technique for qDNA-binding ligands. This short review describes some experimental considerations for ESI-MS analysis of DNA–ligand complexes, briefly addresses the question of whether non-covalent DNA–ligand complexes are faithfully transferred from solution to the gas phase, discusses ion mobility mass spectrometry as a technique for probing this issue, and highlights some recent ESI-MS studies of qDNA-selective ligands.

scholarly journals A straightforward electrospray ionization high resolution mass spectrometry method for underivatized long chain polysaccharides

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Roxana M. Ghiulai ◽  
Mirela Sarbu ◽  
Constantin Ilie ◽  
Alina D. Zamfir
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Electrospray Ionization ◽  
High Resolution Mass Spectrometry ◽  
Average Molecular Weight ◽  
Ionization Mass ◽  
Esi Ms ◽  
Singly Charged ◽  
Charged Ions ◽  
Long Chain

AbstractStructural analysis of long chain polysaccharides by electrospray ionization mass spectrometry (ESI-MS) is challenging since these molecules do not contain readily ionizable groups. Their mass spectra are dominated by singly charged ions, limiting the detection of high molecular weight species. Derivatization can enhance ionization, but analyte loss on purification decreases sensitivity. We report a method based on nanoESI-MS and MS/MS by collision induced dissociation (CID) for underivatized long chain polysaccharides. The procedure was tested on underivatized polydisperse dextrans (average molecular weight 4,000) at 2.6 kV ESI voltage and CID MS/MS at energies between 30-60 eV. 113 ions corresponding to species from Glc2 to Glc35 were detected. Ions at m/z 1,409.48, 1,107.35 and 1,438.47, assigned to [G17+2Na]2+,[G20+H+Na+K]3+ and [G35+2H+Na+K]4+, were sequenced and characterized by MS/MS. The component containing 35 Glc repeats is the longest polysaccharide chain detected by ESI-MS and structurally analyzed by MS/MS without prior derivatization and/or separation.

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