scholarly journals MASS SPECTROMETRIC CHARACTERIZATION OF PLASMA MEBEVERINE METABOLITES AND ITS SYNTHESIS

2019 ◽  
Vol 16 (32) ◽  
pp. 633-646
Author(s):  
Natalia E. MOSKALEVA ◽  
Roman M. KUZNETZOV ◽  
Pavel A. MARKIN ◽  
Svetlana A. APPOLONOVA
Keyword(s):  
Mass Spectrometry ◽  
Blood Plasma ◽  
Mass Spectra ◽  
Human Blood Plasma ◽  
Veratric Acid ◽  
First Order ◽  
Flight Mass Spectrometry ◽  
Before And After ◽  
Irritable Bowel

Mebeverine is a musculotropic antispasmodic drug that is widely used in the treatment of irritable bowel syndrome. As an ester of mebeverine alcohol and veratric acid, mebeverin is quickly metabolized and is practically undetectable in blood plasma. The main goal of this work was establishing the structure of the main metabolites of mebeverin in human blood plasma. The study was conducted by time-of-flight mass spectrometry (LC-IT-TOF MS), metabolites of mebeverine were extracted from plasma with acetonitrile. When comparing chromatograms of blood plasma obtained before and after drug administration, four main peaks of metabolites were detected. To establish the structure of the compounds, mass spectra of the first and second order were taken. The first-order spectra were used to calculate the metabolite formula and the structure was determined from the fragmentation spectra, as well as by comparing the fragmentation spectra of mebeverine and its proposed metabolites. The proposed compounds were synthesized, and their structure was confirmed using NMR and chromatography-mass spectrometry. Four main metabolites were found in this study: desmethylmebeverine acid (DMAC), glucuronide product of DMAC (DMAC-Glu), mebeverine acid (MAC) and mebeverine alcohol (MAL). The results complement the available literature data about the veratric acid metabolism, urine, and microsomal studies. According to the data obtained, the main metabolite of mebeverine in the blood is DMAC. The concentration of MAC after mebeverine administration is almost ten times less than DMAC, the content of MAL and DMAC-Glu is insignificant, and probably does not affect the pharmacological effect of mebeverine. Therefore, the concentration of DMAC is the main parameter to be monitored in pharmacokinetics studies.

Characterization of Linoleic Acid Nitration in Human Blood Plasma by Mass Spectrometry†

Biochemistry ◽  
2002 ◽  
Vol 41 (34) ◽  
pp. 10717-10722 ◽  
Author(s):  
Émersom S. Lima ◽  
Paolo Di Mascio ◽  
Homero Rubbo ◽  
Dulcineia S. P. Abdalla
Keyword(s):  
Mass Spectrometry ◽  
Linoleic Acid ◽  
Blood Plasma ◽  
Human Blood ◽  
Human Blood Plasma

Capillary ionic liquid electrospray: beam compositional analysis by orthogonal time-of-flight mass spectrometry

2021 ◽  
Vol 928 ◽  
Author(s):  
S.W. Miller ◽  
J.R. Ulibarri-Sanchez ◽  
B.D. Prince ◽  
R.J. Bemish
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Time Of Flight ◽  
Ion Source ◽  
High Mass ◽  
Atomic Mass Unit ◽  
Flow Rates ◽  
Charged Species ◽  
Flight Mass Spectrometry ◽  
Jet Breakup

Orthogonal time-of-flight mass spectrometry has been used to characterize the kinetic energy and charged species distributions from an in vacuo electrospray ion source for four different ionic liquids at volumetric flow rates between 0.3 and 3.3 nanolitres per second. In all cases, the mass spectra revealed charged species consisting of singly charged and multiply charged ions as well as two broad, unresolved droplet distributions occurring in the 104 to 106 atomic mass unit per charge range. The mean jet velocity and mean jet breakup potential were established from analysis of the energy profile of the high mass-to-charge droplets. At the jet breakup point, we find the energy loss and the jet diameter flow rate dependence of the electrospray beam to be similar to that determined by Gamero-Castaño (Phys. Fluids, vol. 20, 2008, 032103; Phys. Rev. Fluids, vol. 8, 2021, 013701) for 1-ethyl-3-methylimidazolium bis(trifluromethylsulfonyl)imide at similar volumetric flow rates. Similar trends are observed for all four liquids over the flow regime. A jet instability analysis revealed that jet electrification and viscous effects drive the jet breakup from the case of an uncharged, inviscid jet; jet breakup occurs at droplet and jet radius ratios that deviate from 1.89. Using the analytically determined ratio and the beam profile, different species are modelled to reconstruct the mass spectra; primary droplets constitute only a fraction of the total species present. The populations of the species are discussed.

scholarly journals Characterization of gas-phase organics using proton transfer reaction time-of-flight mass spectrometry: fresh and aged residential wood combustion emissions

2016 ◽  
Author(s):  
Emily A. Bruns ◽  
Jay G. Slowik ◽  
Imad El Haddad ◽  
Dogushan Kilic ◽  
Felix Klein ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reaction Time ◽  
Biomass Burning ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Wood Combustion ◽  
Flight Mass Spectrometry ◽  
Combustion Emissions ◽  
Organic Gases

Abstract. Organic gases emitted during the flaming phase of residential wood combustion are characterized individually and by functionality using proton transfer reaction time-of-flight mass spectrometry. The evolution of the organic gases is monitored during photochemical aging. Primary gaseous emissions are dominated by oxygenated species (e.g., acetic acid, acetaldehyde, phenol and methanol), many of which have deleterious health effects and play an important role in atmospheric processes such as secondary organic aerosol formation and ozone production. Residential wood combustion emissions differ considerably from open biomass burning in both absolute magnitude and relative composition. Ratios of acetonitrile, a potential biomass burning marker, to CO are considerably lower (~ 0.09 pptv ppbv−1) than those observed in air masses influenced by open burning (~ 1–2 pptv ppbv−1), which may make differentiation from background levels difficult, even in regions heavily impacted by residential wood burning. Considerable formic acid forms during aging (~ 200–600 mg kg−1 at an OH exposure of (4.5–5.5) × 107 molec  cm−3 h), indicating residential wood combustion can be an important local source for this acid, the quantities of which are currently underestimated in models. Phthalic anhydride, a naphthalene oxidation product, is also formed in considerable quantities with aging (~ 55–75 mg kg−1 at an OH exposure of (4.5–5.5) × 107 molec  cm−3 h). Although total NMOG emissions vary by up to a factor of ~ 9 between burns, SOA formation potential does not scale with total NMOG emissions and is similar in all experiments. This study is the first thorough characterization of both primary and aged organic gases from residential wood combustion and provides a benchmark for comparison of emissions generated under different burn parameters.

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