Analysis of Polypropyleneglycols Using Electrospray Ionization Mass Spectrometry. Effects of Cationizing Agents on the Mass Spectra

2003 ◽  
Vol 9 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Shoji Okuno ◽  
Masayoshi Ohmoto ◽  
Ryuichi Arakawa
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Linear Structure ◽  
Ionization Mass Spectrometry ◽  
Cone Voltage ◽  
Ionization Mass ◽  
Esi Ms ◽  
Molecular Weights ◽  
Charged Ions

In electrospray ionization mass spectrometry (ESI-MS) of polypropyleneglycol (PPG), effects of cationizing agents were examined. When NaI was used as a cationizing agent, the distribution of multiply-charged ions in the spectra was greatly affected by the ratio of cationizing agent and PPG. However, the distribution was not affected by the use of CH3COONH4. With an increase of cone voltage, fragmentation occurred by in-source collision-induced dissociation (CID) when CH3COONH4 was used. On the contrary, no decomposition of the PPG backbone was observed with NaI. Instead, the intensity of the lower-charged ions, whose mass-to-charge ( m/z) ratios are larger, increased because of the elimination of Na+ with increase of cone voltage. Under optimum conditions for ESI-MS analysis, PPGs that have different molecular weights, different initiators or end groups were easily and accurately characterized. A tandem mass spectrometry (MS/MS) study of NH4+ adduct ions of PPG indicated that a vinyl-terminated linear structure is formed at the end group during the fragmentation.

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.

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