Determination of N-acetylcysteine in human plasma by gas chromatography—mass spectrometry

Longo, A; Toro, M. Di; Galimberti, C.; Carenzi, A.

doi:10.1016/0378-4347(91)80614-i

Cited by 13 publications

(4 citation statements)

References 8 publications

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“…Sulfhydryl compounds are prevalent in pharmaceuticals and human metabolism. − Captopril, acetylcysteine, penicillamine, and mercaptopurine are all well-established drugs that are used to treat a variety of diseases ranging from hypertension to childhood leukemia . Typical doses of these drugs are in the range of milligrams of drug per kilogram of body weight, and concentrations in plasma are typically in the low micromolar range prior to excretion of the excess dose in the urine. − Other sulfhydryl compounds such as cysteine, homocysteine, glutathione, and cysteinylglycine are meaningful components of the human metabolome, with normal concentrations in the low to mid micromolar range . Therefore, it is not surprising that significant efforts have been made to analyze sulfhydryl compounds in biological matrices, most of which have utilized LC−MS or GC−MS following solution phase derivatization. − The five compounds shown in Figure are commonly studied sulfhydryl analytes that were chosen as a model set to illustrate the application of surface-enhanced TM-DESI-MS to biological matrices such as urine and plasma.…”

Section: Resultsmentioning

confidence: 99%

“…39 Typical doses of these drugs are in the range of milligrams of drug per kilogram of body weight, and concentrations in plasma are typically in the low micromolar range prior to excretion of the excess dose in the urine. [52][53][54] Other sulfhydryl compounds such as cysteine, homocysteine, glutathione, and cysteinylglycine are meaningful components of the human metabolome, with normal concentrations in the low to mid micromolar range. 55 Therefore, it is not surprising that significant efforts have been made to analyze sulfhydryl compounds in biological matrices, most of which have utilized LC-MS or GC-MS following solution phase derivatization.…”

Section: Methodsmentioning

confidence: 99%

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Rapid and Selective Screening for Sulfhydryl Analytes in Plasma and Urine Using Surface-Enhanced Transmission Mode Desorption Electrospray Ionization Mass Spectrometry

2010

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Nylon mesh substrates were derivatized to include VICAT SH , a biotinylated reagent that contains both a photolabile linking group and a thiol specific capture agent. The enhanced mesh substrates were then used to capture sulfhydryl analytes directly from urine and plasma samples via covalent reaction between the reactive thiols of the analytes and the iodoacetaminyl unit of VICAT SH . Photocleavage of the labile linker was followed by direct analysis of the mesh surface via transmission mode desorption electrospray ionization (TM-DESI). This chemoselective capture method promoted enrichment of sulfhydryl analytes and reduced matrix interferences, thereby resulting in increased analytical performance of surface enhanced TM-DESI-MS when compared to standard DESI-MS. The present work describes the manufacture of the derivatized mesh substrates and the quality control assessments made during the manufacturing process; the optimization of the chemoselective capture method; and results of experiments pertinent to biological applications. Integration of the chemoselective capture materials with ambient ionization and tandem mass spectrometry results in a powerful combination of speed and selectivity for targeted analyte screening.Chemoselective and affinity based capture methods are sample preparation techniques used throughout chemistry, biochemistry, and molecular biology to recover targeted analytes of interest from complex matrices, thereby increasing analytical specificity and sensitivity through analyte enrichment and the reduction of interferences. [1][2][3][4] For example, medical diagnostics and proteomics studies routinely employ affinity based capture methods to investigate the relationship between antibodies and antigens, often resulting in the development of detection assays for metabolic biomarkers, peptides and proteins. 1,2 Similarly, metabolite enrichment by tagging and proteolytic release (METPR), utilizes chemoselective probes to capture and covalently conjugate small molecule metabolites containing targeted functional groups to solid phase resins. 3,4 In some capture methods, such as western or Southern blotting techniques, the captured analytes are physically transferred to a secondary nitrocellulose surface for analysis. 5,6 In other cases, including METPR and various affinity chromatography methods, a secondary liquid extraction step is used to re-introduce the captured analytes to solution for standard LC-MS analysis. 3,4,7 In either of these scenarios, extraction of captured analytes from the affinity or chemoselective substrate to a secondary surface or solution inevitably results in some analyte loss; therefore, there is continued interest in developing methods to analyze capture surfaces directly (i.e., without additional extraction steps.) jbrodbelt@mail NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptFluorometry, surface plasmon resonance, and mass spectrometry are the detection methods most often utilized for direct analysis of capture surfaces. Due to i...

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Rapid and Selective Screening for Sulfhydryl Analytes in Plasma and Urine Using Surface-Enhanced Transmission Mode Desorption Electrospray Ionization Mass Spectrometry

2010

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“…The capacity of TcyABC and TcyP to support growth on CSSC and Cys implies an extended substrate-binding potential. To test this further, we examined whether both systems support proliferation in medium supplemented with N-acetyl cysteine (NAC), a Cys-containing metabolite present in human blood (44). We cultured the S. aureus WT strain and tcyA::Tn, tcyP::Tn, or tcyAP::Tn mutants in PN supplemented with 50 M N-acetyl cysteine.…”

Section: Resultsmentioning

confidence: 99%

The Staphylococcus aureus Cystine Transporters TcyABC and TcyP Facilitate Nutrient Sulfur Acquisition during Infection

et al. 2020

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Staphylococcus aureus is a significant human pathogen due to its capacity to cause a multitude of diseases. As such, S. aureus efficiently pillages vital nutrients from the host; however, the molecular mechanisms that support sulfur acquisition during infection have not been established. One of the most abundant extracellular sulfur-containing metabolites within the host is cysteine, which acts as the major redox buffer in the blood by transitioning between reduced and oxidized (cystine) forms. We therefore hypothesized that S. aureus acquires host-derived cysteine and cystine as sources of nutrient sulfur during systemic infection. To test this hypothesis, we used the toxic cystine analogue selenocystine to initially characterize S. aureus homologues of the Bacillus subtilis cystine transporters TcyABC and TcyP. We found that genetic inactivation of both TcyA and TcyP induced selenocystine resistance. The double mutant also failed to proliferate in medium supplemented with cystine, cysteine, or N-acetyl cysteine as the sole sulfur source. However, only TcyABC was necessary for proliferation in defined medium containing homocystine as the sulfur source. Using a murine model of systemic infection, we observed tcyP-dependent competitive defects in the liver and heart, indicating that this sulfur acquisition strategy supports proliferation of S. aureus in these organs. Phylogenetic analyses identified TcyP homologues in many pathogenic species, implying that this sulfur procurement strategy is conserved. In total, this study is the first to experimentally validate sulfur acquisition systems in S. aureus and establish their importance during pathogenesis.

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“…Recent studies have revealed that NAC inhibits muscle fatigue and can be used to enhance performance in exercise and endurance training. [1][2][3] Analytical techniques like colorimetry, 4,5 chemiluminiscence, 6,7 electrochemical detection, [8][9][10][11][12][13][14][15] flurimetry, 16,17 turbidimetry and nephlometry, 18 liquid chromatography tandem mass spectrometry, 19-21-44 gas chromatography mass spectrometry, 22,23 and capillary electrophoresis [24][25][26] have been employed in literature for the quantification of acetyl cysteine. Acetyl cysteine has also been simultaneously quantified along with other drugs like clomiphene citrate, 27 arginine, 28 and cefexime trihydrate.…”

Section: Introductionmentioning

confidence: 99%

Development and Validation of an Analytical Method for Related Substances in N-acetyl–L-cysteine Effervescent Tablets by RP-HPLC

Mathew¹,

Ravi²,

Rameshwar³

et al. 2017

IJPER

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Background:The reported chromatographic methods for N-acetyl cysteine [NAC] are reverse phase HPLC and ion pair chromatography [IPC] for related substances test in bulk and in formulations. No reported stability indicating methods for the estimation of related substances in NAC effervescent formulation was found in literature. Objective: The present work was aimed at developing a selective, sensitive and reproducible stability indicating high-performance liquid chromatographic method for the quantitative determination of known, unknown impurities, degradation impurities and processrelated impurities of NAC effervescent formulation. Method: A reversed phase ion pair chromatographic method was developed employing Cadenza C18 column as the stationary phase and 0.01M octane sulphonate [pH 2.20], methanol and acetonitrile in the ratio 90:8:2 as the mobile phase. A gradient programme was followed with a run time of 55 minutes. 0.3 M hydrochloric acid was selected as the optimum diluent. The performance of the method was validated according to the ICHQ2R1 guidelines. Results: The method was found to be linear from 1.5 to 25µg/ml for impurities A, C and D and from 2.0 to 25 µg/ml for impurity B. The official impurities C and D were mapped in all stress conditions. Additionally, impurity B was also seen in acidic conditions. Conclusion: The results from the study demonstrate that the method is suitable for evaluating the stability of NAC effervescent tablet. Key words: N-acetyl cysteine, Reverse phase HPLC, Effervescent formulation, Ion pair chromatography, Related substances,Validation. Key message: An ion pair chromatographic method was developed for quantifying the related substances of N-acetyl cysteine effervescent Tablets. Selection of diluent was an important variable in the method development.

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Determination of N-acetylcysteine in human plasma by gas chromatography—mass spectrometry

Cited by 13 publications

References 8 publications

Rapid and Selective Screening for Sulfhydryl Analytes in Plasma and Urine Using Surface-Enhanced Transmission Mode Desorption Electrospray Ionization Mass Spectrometry

Rapid and Selective Screening for Sulfhydryl Analytes in Plasma and Urine Using Surface-Enhanced Transmission Mode Desorption Electrospray Ionization Mass Spectrometry

The Staphylococcus aureus Cystine Transporters TcyABC and TcyP Facilitate Nutrient Sulfur Acquisition during Infection

Development and Validation of an Analytical Method for Related Substances in N-acetyl–L-cysteine Effervescent Tablets by RP-HPLC

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