Comprehensive characterization of amino acids and water‐soluble vitamins in a pentylenetetrazole‐induced seizures rat model

Abstract

Epilepsy is a complex neurological disease characterized by spontaneous recurrent seizures that affect around 1% of the global population. Despite the significant progress in the mechanisms of epileptogenesis, there is still about 60% of cases in which the cause is unknown. Thus, revealing the molecular mechanisms of epileptogenesis will greatly improve the development of epilepsy treatment. Since the comprehensive characterization of amino acids and watersoluble vitamins is important in understanding the underlying mechanisms of epilepsy or seizures, we developed two liquid chromatography-tandem mass spectrometry methods to quantify 17 water-soluble vitamins and 46 amino acids and applied them to our pentylenetetrazole-induced kindling rat model. All water-soluble vitamins were detected with a linearity of r > 0.992 and limits of quantitation between 0.1 and 5 ng/ml except for nicotinic acid. For amino acids, the linearities obtained were good with correlation coefficients higher than 0.99, and matrix effects were between 85.3% and 110%. To handle the multidimensional data more effectively, multivariate statistical analysis approaches used in non-targeted metabolomics were creatively exploited in the visualization, interpretation, and exploration of the results.

A simple ion chromatography‐mass spectrometry method for amino acid analysis in beer

“…Hydrophilic interaction liquid chromatography (HILIC)-MS using amide functionalized columns is the current benchmark in the analysis of underivatized AAs as it provides sufficient retention, good peak shape, and MS compatibility for all AAs [13][14][15]. Recent improvements in AA analysis led to applications in the field of metabolomics [16][17][18] and clinical analysis [19]. However, complex sample matrices can require another separation mode or a more stable column chemistry for robust quantification or method validation.…”

“…The method demonstrated the potential to overcome the most common issues in the LC-MS analysis of AAs. Contrary to RPLC [17] or ion-pair chromatography (IPC) [35], neither pre-nor post-column derivatization of the analytes was required. The stationary phase chemistry based on a polymer substrate proved to be robust in terms of retention time and stable under a broad range of eluent compositions, which was a major advantage in comparison to typical HILIC and mixed-mode columns [12,21,[36][37][38].…”

Integration of a derivatization protocol and LC–MS sequential window acquisition of all theoretical mass spectra strategy for amino acid determination in human plasma

“…Altered plasma circulating AA levels have been associated with certain types of cancer [1], irritable bowel syndrome [2], and several metabolic disorders. Thus, nowadays, AA profiling finds a great number of applications, from the diagnosis of physiological disorders [3], nutrition research [4], and lately in targeted metabolomics studies [5,6]. Derivatization has been a major issue in AA analysis, given that most traditional detectors (UV, FLR) require the presence of a chromophore group [7].…”

Quantitative analysis of the glutathione pathway cellular metabolites by targeted liquid chromatography‐tandem mass spectrometry

“…However, GSH, other thiol metabolites, their derivatives as well as their precursors and intermediates from the GSH biosynthesis pathway are quite polar in nature. They show favorable characteristics for hydrophilic interaction liquid chromatography (HILIC) [30,31]. Not surprisingly, HILIC was therefore the method of first choice in the recent literature using Sulfobetaine and Amide column chemistries [1,23,25].…”

“…In one study, Forgacsova et al showed the rapid analysis of 4 thiols by sub-2 μm HILIC-Amide MS/MS in 2.5 min run time. A critical factor in quantitative LC-electrospray ionization-MS (LC-ESI-MS) in the biological matrix is ion suppression and matrix effect (ME), respectively [30]. Stable isotope-labeled internal standards are a good strategy to adequately correct for these MEs.…”