Publications
565 results found
Sala S, Nitschke P, Masuda R, et al., 2024, Integrative molecular structure elucidation and construction of an extended metabolic pathway associated with an ancient innate immune response in COVID-19 patients, Journal of Proteome Research, Vol: 23, Pages: 956-970, ISSN: 1535-3893
We present compelling evidence for the existence of an extended innate viperin-dependent pathway, which provides crucial evidence for an adaptive response to viral agents, such as SARS-CoV-2. We show the in vivo biosynthesis of a family of novel endogenous cytosine metabolites with potential antiviral activities. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed a characteristic spin-system motif, indicating the presence of an extended panel of urinary metabolites during the acute viral replication phase. Mass spectrometry additionally enabled the characterization and quantification of the most abundant serum metabolites, showing the potential diagnostic value of the compounds for viral infections. In total, we unveiled ten nucleoside (cytosine- and uracil-based) analogue structures, eight of which were previously unknown in humans allowing us to propose a new extended viperin pathway for the innate production of antiviral compounds. The molecular structures of the nucleoside analogues and their correlation with an array of serum cytokines, including IFN-α2, IFN-γ, and IL-10, suggest an association with the viperin enzyme contributing to an ancient endogenous innate immune defense mechanism against viral infection.
Bouwmeester R, Richardson K, Denny R, et al., 2024, Predicting ion mobility collision cross sections and assessing prediction variation by combining conventional and data driven modeling, Talanta, Pages: 125970-125970, ISSN: 0039-9140
Mosley JD, Schock TB, Beecher CW, et al., 2024, Establishing a framework for best practices for quality assurance and quality control in untargeted metabolomics, Metabolomics, Vol: 20, ISSN: 1573-3882
BACKGROUND: Quality assurance (QA) and quality control (QC) practices are key tenets that facilitate study and data quality across all applications of untargeted metabolomics. These important practices will strengthen this field and accelerate its success. The Best Practices Working Group (WG) within the Metabolomics Quality Assurance and Quality Control Consortium (mQACC) focuses on community use of QA/QC practices and protocols and aims to identify, catalogue, harmonize, and disseminate current best practices in untargeted metabolomics through community-driven activities. AIM OF REVIEW: A present goal of the Best Practices WG is to develop a working strategy, or roadmap, that guides the actions of practitioners and progress in the field. The framework in which mQACC operates promotes the harmonization and dissemination of current best QA/QC practice guidance and encourages widespread adoption of these essential QA/QC activities for liquid chromatography-mass spectrometry. KEY SCIENTIFIC CONCEPTS OF REVIEW: Community engagement and QA/QC information gathering activities have been occurring through conference workshops, virtual and in-person interactive forum discussions, and community surveys. Seven principal QC stages prioritized by internal discussions of the Best Practices WG have received participant input, feedback and discussion. We outline these stages, each involving a multitude of activities, as the framework for identifying QA/QC best practices. The ultimate planned product of these endeavors is a "living guidance" document of current QA/QC best practices for untargeted metabolomics that will grow and change with the evolution of the field.
King AM, Wilson ID, Plumb RS, et al., 2024, The rapid separation and characterization of sulfates of tyrosine and its metabolites in reaction mixtures and human urine using a cyclic ion mobility device and mass spectrometry., J Chromatogr A, Vol: 1715
Ion mobility (IM) separations, especially when combined with mass spectrometry, offer the opportunity for the rapid analysis and characterization of mixtures. However, the limited resolution afforded by many IM systems means that in practice applications may be limited. Here we have employed an IM separation on a high-resolution cyclic IM device with MS/MS to separate and characterize mixtures of sulfated isomers of tyrosine and associated metabolites containing multiple sulfated isoforms present in reaction mixtures. The cIMS device allowed ions, not resolved using a single pass, to be subjected to multiple passes, enabling the resolution of those with similar collision cross sections (CCS). Predicted single pass CCS values calculated for the isomers likely to be present in these mixtures showed only small differences between them, ranging between of between 0.1 - 0.7 % depending on structure. These small differences highlight the high degree of mobility resolution required for separating the isomers. Experimentally different isoforms of tyrosine sulfate and sulfated tyrosine metabolites could be sufficiently resolved via multipass separations (3-35 passes). This degree of separation provided resolving powers of up to 384 CCS/ΔCCS for sulfated dopamine which enabled good MS/MS spectra to be generated. In human urine the presence of a single sulfated form of tyrosine was detected and identified as the O-sulfate after 3 passes based on the synthetic standard. Of the other tyrosine-related sulfates for which synthetic standards had been prepared only dopamine sulfate was detected in this sample.
King A, Gethings LA, Vissers JPC, et al., 2024, Increasing coverage of the urinary polar metabolome using ultra high-performance hydrophobic interaction liquid chromatography combined with linear and cyclic travelling wave ion mobility and mass spectrometry., J Chromatogr A, Vol: 1714
The use of HILIC-based separations for the analysis of polar metabolites in metabolic phenotyping studies is well established. Here, we demonstrate the increased coverage of the polar metabolome obtained by travelling wave (TW) ion mobility (IM) instruments combined with HILIC and mass spectrometry (MS) for metabotyping rat and mouse urine samples. Profiling was performed using either a linear TW IM-MS based instrument with a path length of 40 cm or an instrument with a cyclic travelling wave analyser (cIM) with a path length of 95 cm. Due to the added resolution afforded by using both the linear and cyclic IM geometries with MS detection (IM-MS) significant increases in feature count (m/z-tR pairs) were generally obtained compared to HILIC-MS alone. In addition, the use of both linear and cyclic IM-MS improved the quality of the mass spectra obtained as a result of the separation of co-eluting analytes. As would be expected from the increased path length of the cyclic IM-MS instrument compared to the linear device, the largest gains in feature detection were obtained for the HILIC-cIM-MS combination. By increasing the resolution of coeluting components, the cyclic IM-MS instrumentation also provided the largest improvement in the quality of the mass spectral data obtained. When applied to mouse urines obtained from both control and gefitinib-dosed mice, time-related changes were detected in those obtained from the treated animals that were not seen in the controls. Polar metabolites affected by drug administration included, but were not limited to, hypoxanthine, 1,3-dimethyluracil and acetylcarnitine. The changes seen in the relative concentrations of these endogenous metabolites appeared to be related to drug concentrations in the plasma and urine suggesting a pharmacometabodynamic link.
Wilson ID, Broeckling C, Gethings LA, et al., 2024, Development of a single mobile phase for LC-IM-MS-based discovery lipidomics and metabolic phenotyping: Application to methapyrilene hepatotoxicity in the rat., J Chromatogr A, Vol: 1714
The untargeted global profiling of endogenous metabolites and lipids has the potential to increase knowledge and understanding in many areas of biology. LC-MS/MS is a key technology for such analyses however, several different LC methodologies, using different mobile phase compositions, are required to cover the diversity in polarity and analyte structure encountered in biological samples. Most notably many lipid screening methods make use of isopropanol (IPA) as a major component of mobile phases employed for comprehensive lipidomic profiling. In order to increase laboratory efficiency, and minimize opportunities for errors, a suite of methods, based on a single acetonitrile (ACN)-aqueous buffer mobile phase combination, has been developed. This mobile phase can be used for hydrophobic interaction liquid chromatography on an amide stationary phase (for polar analytes), reversed-phase (RP) LC analysis on a C8 stationary phase (for moderately polar-non-polar compounds) and RPLC using a CSH phenyl-hexyl bonded column (for lipids). All of these sub 10 minute separations had good throughput and reproducibility with CV's of analyte response <25 % whilst eliminating the need for complex mobile phase preparation and the use of IPA as an organic modifier for lipidomics. Advantages of removing IPA and replacing it with the ACN-based method were a 58 % increase in peak capacity for lipids, with improved resolution for the di- and triglycerides and cholesterol esters compared to current methods. Compared to the IPA-containing solvent system the ACN-based mobile phase also resulted in a 61 % increase in lipid feature detection. The utility of this "universal" mobile phase approach was demonstrated by its application to a rat toxicology study investigating the consequences of methapyrilene administration through on the endogenous metabolite profiles of plasma and urine. Methapyrilene and its metabolites were also profiled in these samples.
Spick M, Muazzam A, Pandha H, et al., 2023, Multi-omic diagnostics of prostate cancer in the presence of benign prostatic hyperplasia, Heliyon, Vol: 9, ISSN: 2405-8440
There is an unmet need for improved diagnostic testing and risk prediction for cases of prostate cancer (PCa) to improve care and reduce overtreatment of indolent disease. Here we have analysed the serum proteome and lipidome of 262 study participants by liquid chromatography-mass spectrometry, including participants diagnosed with PCa, benign prostatic hyperplasia (BPH), or otherwise healthy volunteers, with the aim of improving biomarker specificity. Although a two-class machine learning model separated PCa from controls with sensitivity of 0.82 and specificity of 0.95, adding BPH resulted in a statistically significant decline in specificity for prostate cancer to 0.76, with half of BPH cases being misclassified by the model as PCa. A small number of biomarkers differentiating between BPH and prostate cancer were identified, including proteins in MAP Kinase pathways, as well as in lipids containing oleic acid; these may offer a route to greater specificity. These results highlight, however, that whilst there are opportunities for machine learning, these will only be achieved by use of appropriate training sets that include confounding comorbidities, especially when calculating the specificity of a test.
Weidolf L, Wilson I, 2023, Minimizing the DILI potential of carboxylic acid-containing drugs: a perspective, MEDICINAL CHEMISTRY RESEARCH, Vol: 32, Pages: 2034-2047, ISSN: 1054-2523
Brookhart A, Arora M, McCullagh M, et al., 2023, Understanding mobile phase buffer composition and chemical structure effects on electrospray ionization mass spectrometry response, JOURNAL OF CHROMATOGRAPHY A, Vol: 1696, ISSN: 0021-9673
Sarmad S, Viant MR, Dunn WB, et al., 2023, A proposed framework to evaluate the quality and reliability of targeted metabolomics assays from the UK Consortium on Metabolic Phenotyping (MAP/UK), NATURE PROTOCOLS, Vol: 18, Pages: 1017-1027, ISSN: 1754-2189
Lioupi A, Marinaki M, Virgiliou C, et al., 2023, Probing the polar metabolome by UHPLC-MS, Trends in Analytical Chemistry, Vol: 161, Pages: 1-10, ISSN: 0165-9936
Metabolomics is an interdisciplinary field with applications in many areas. Analytes include metabolites involved in pathways such as glycolysis, amino acid metabolism, the Krebs cycle, etc. However, the metabolites involved in these biosynthetic pathways are typically highly polar molecules, which represent a major challenge for chromatographic analysis. Whilst there have been significant efforts to address the difficulties involved in the determination of polar metabolites the comprehensive profiling of the polar metabolome remains problematic. The current review summarizes current approaches, advances and trends in the use of liquid chromatography/mass spectrometry as it attempts to address the major instrumental and intellectual challenges involved in mapping the polar metabolome.
Tanna N, Plumb RS, Molloy BJ, et al., 2023, Enhanced chromatographic efficiency obtained with vacuum jacketed columns facilitates the rapid UHPLC/MS/MS-based analysis of fasiglifam in rat plasma, TALANTA, Vol: 254, ISSN: 0039-9140
Trovato FM, Zia R, Artru F, et al., 2023, Lysophosphatidylcholines modulate immunoregulatory checkpoints in peripheral monocytes and are associated with mortality in people with acute liver failure., Journal of Hepatology, Vol: 78, Pages: 558-573, ISSN: 0168-8278
BACKGROUND AND AIMS: Acute liver failure (ALF) is a life-threatening disease characterised by high-grade inflammation and immunoparesis with a high incidence of death from sepsis. Here, we aimed to describe the metabolic dysregulation in ALF and determine whether systemic immune responses are modulated via the lysophosphatidylcholine(LPC)-autotaxin(ATX)-lysophosphatidylcholinic acid (LPA) pathway. METHODS: 96 ALF patients, 71 healthy controls (HC), 104 patients with cirrhosis and 31 septic patients were recruited. The pathways of interest were identified based on multivariate statistical analysis of proton nuclear magnetic resonance (1HNMR) spectroscopy, untargeted ultraperformance liquid chromatography-mass spectrometry (UPLC-MS)-based lipidomics and validated with a targeted metabolomics panel. Peripheral blood mononuclear cells were cultured with LPA 16:0, 18:0, 18:1, and their immune checkpoint surface expression was assessed by flow cytometry. LPA receptor (LPAR) transcript-level expression of monocytes was investigated and the effect of LPAR antagonism was also examined in vitro. RESULTS: LPC 16:0 was found highly discriminant between ALF and HC. There was an increase in ATX and LPA in ALF compared to HC and sepsis. LPCs 16:0, 18:0 and 18:1 were reduced in ALF patients with poor prognosis. Treatment of monocytes with LPA 16:0 increased their PD-L1 expression and reduced CD155, CD163, MerTK levels, without effect on T and NK/CD56+T cells immune checkpoints. LPAR1 and 3 antagonism in culture reversed the LPA effect on monocyte expression of MerTK and CD163. MerTK and CD163, but not LPARs genes, were differently expressed and upregulated in monocytes from ALF patients compared to controls. CONCLUSION: Reduced amounts of LPCs are biomarkers of poor prognosis in patients with ALF. The LPC-ATX-LPA axis appears to modulate innate immune response in ALF via LPAR1 and LPAR3. Further investigations are required to identify novel therapeutic agents targeting these recept
Plumb RS, Gethings LA, Rainville PD, et al., 2023, Advances in high throughput LC/MS based metabolomics: A review, TrAC Trends in Analytical Chemistry, Vol: 160, Pages: 1-9, ISSN: 0165-9936
Properly implemented, metabolic and lipidomic profiling can provide a deeper understanding of mammalian, plant and bacterial biology. These omics-tools have developed and matured over the last 40-years and are now being deployed to provide valuable information in epidemiological studies, drug toxicology and pharmacology, disease biology and progression and patient stratification. LC/MS has become the technology of choice for both metabolic and lipid profiling, due to its speed, sensitivity and structural elucidation capabilities. In the preceding two decades there have been many technological and methodological advances in LC/MS that have facilitated the evolution of the technology into a rugged, reliable, and easily deployed tool. These advances include, but are not limited to, improvements in chromatography (phases, columns, and delivery system), instruments for mass spectrometry, optimization of sample preparation, the introduction of ion mobility, data analysis tools, metabolite databases, harmonized protocols, and the more widespread use of quality control methods and reference standards/matrices. Here, recent developments and advances in high throughput liquid chromatography/high resolution mass spectrometry for metabolic phenotyping are described. These advances which may provide improved feature detection, increased laboratory efficiency and data quality, as well as “biomarker” identification, are discussed in relation to their potential application to the analysis of large clinical studies, or biobank collections.
Theodoridis G, Gika H, Raftery D, et al., 2023, Ensuring fact-based metabolite identification in liquid chromatography-mass spectrometry-based metabolomics., Analytical Chemistry, Vol: 95, Pages: 3909-3916, ISSN: 0003-2700
Metabolite identification represents a major bottleneck in contemporary metabolomics research and a step where critical errors may occur and pass unnoticed. This is especially the case for studies employing liquid chromatography-mass spectrometry technology, where there is increased concern on the validity of the proposed identities. In the present perspective article, we describe the issue and categorize the errors into two types: identities that show poor biological plausibility and identities that do not comply with chromatographic data and thus to physicochemical properties (usually hydrophobicity/hydrophilicity) of the proposed molecule. We discuss the problem, present characteristic examples, and propose measures to improve the situation.
Molloy BJ, King A, Gethings LA, et al., 2023, Investigation of the pharmacokinetics and metabolic fate of Fasiglifam (TAK-875) in male and female rats following oral and intravenous administration, Xenobiotica: the fate of foreign compounds in biological systems, Vol: 53, Pages: 93-105, ISSN: 0049-8254
The metabolism and pharmacokinetics of fasiglifam (TAK-875, 2-[(3S)-6-[[3-[2,6-dimethyl-4-(3-methylsulfonylpropoxy)phenyl]phenyl]methoxy]-2,3-dihydro-1-benzofuran-3-yl]acetic acid), a selective free fatty acid receptor 1 (FFAR1)/GPR40 agonist, were studied following intravenous (5 mg/kg) and oral administration (10 and 50 mg/kg) to male and female Sprague Dawley rats.Following intravenous dosing at 5 mg/kg, peak observed plasma concentrations of 8.8/9.2 µg/ml were seen in male and female rats respectively.Following oral dosing, peak plasma concentrations at 1 h of ca. 12.4/12.9 µg/ml for 10 mg/kg and 76.2/83.7 µg/ml for 50 mg/kg doses were obtained for male and female rats respectively. Drug concentrations then declined in the plasma of both sexes with t1/2’s of 12.4 (male) and 11.2 h (female). Oral bioavailability was estimated to be 85-120% in males and females at both dose levels.Urinary excretion was low, but in a significant sex-related difference, female rats eliminated ca. 10-fold more drug-related material by this route.Fasiglifam was the principal drug-related compound in plasma, with 15 metabolites, including the acyl glucuronide, also detected. In addition to previously identified metabolites, a novel biotransformation, that produced a side-chain shortened metabolite via elimination of CH2 from the acetyl side chain was noted with implications for drug toxicity.
Gika H, Theodoridis G, Plumb RS, et al., 2023, Metabolic phenotyping (metabonomics/metabolomics) by liquid chromatography-mass spectrometry, Liquid Chromatography: Applications, Pages: 403-429, ISBN: 9780323983006
LC–MS is now the primary investigative technology, employing both targeted and untargeted approaches, used to obtain characteristic metabolic phenotypes (metabotypes) in metabonomic/metabolomic studies. Current applications use various modes of LC but reversed-phase (RP) separations remain the first choice. Hydrophilic interaction liquid chromatography (HILIC), and less frequently ion-pair (IP) and ion exchange (IE) LC, provide methods that are suitable for polar compounds poorly retained by RP phases. Ultra (high) performance liquid chromatography [U(H)PLC] is now becoming the predominant methodology in metabonomic/metabolomic applications, replacing the more traditional HPLC format. Allied with this has been a rise in the use of rapid profiling methods in both targeted and untargeted metabolomic profiles as sample numbers rise in application areas such as epidemiology, biobanking, and clinical analysis. However, the requirement for speed has not reduced the need for sensitive and high-resolution separations in order to provide high metabolome coverage. As a result, there is increased interest in the addition of ion mobility (IM) to the LC/MS toolbox. The current status of U(H)PLC/MS and UHPLC/IM/MS for untargeted metabotyping is considered and potential future directions are suggested.
Wilson ID, Poole CF, 2023, Planar chromatography - Current practice and future prospects, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, Vol: 1214, Pages: 1-15, ISSN: 1570-0232
Planar chromatography, in the form of thin-layer or high-performance thin-layer chromatography (TLC, HPTLC), continues to provide a robust and widely used separation technique. It is unrivaled as a simple and rapid qualitative method for mixture analysis, or for finding bioactive components in mixtures. The format of TLC/HPTLC also provides a unique method for preserving the separation, enabling further investigation of components of interest (including quantification/structure determination) separated in both time and space from the original analysis. The current practice of planar chromatography and areas of development of the technology are reviewed and promising future directions in the use of TLC/HPTLC are outlined.
Munjoma N, Isaac G, Muazzam A, et al., 2022, High Throughput LC-MS Platform for Large Scale Screening of Bioactive Polar Lipids in Human Plasma and Serum, JOURNAL OF PROTEOME RESEARCH, Vol: 21, Pages: 2596-2608, ISSN: 1535-3893
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- Citations: 4
Letertre M, Bhatt A, Harvey M, et al., 2022, Characterizing the metabolic effects of the selective inhibition of gut microbial β-glucuronidases in mice, Scientific Reports, Vol: 12, ISSN: 2045-2322
The hydrolysis of xenobiotic glucuronides by gut bacterial glucuronidases reactivates previously detoxified compounds resulting in severe gut toxicity for the host. Selective bacterial β-glucuronidase inhibitors can mitigate this toxicity but their impact on wider host metabolic processes has not been studied. To investigate this the inhibitor 4-(8-(piperazin-1-yl)-1,2,3,4-tetrahydro-[1,2,3]triazino[4′,5′:4,5]thieno[2,3-c]isoquinolin-5-yl)morpholine (UNC10201652, Inh 9) was administered to mice to selectively inhibit a narrow range of bacterial β-glucuronidases in the gut. The metabolomic profiles of the intestinal contents, biofluids, and several tissues involved in the enterohepatic circulation were measured and compared to control animals. No biochemical perturbations were observed in the plasma, liver or gall bladder. In contrast, the metabolite profiles of urine, colon contents, feces and gut wall were altered compared to the controls. Changes were largely restricted to compounds derived from gut microbial metabolism. This work establishes that inhibitors targeted towards bacterial β-glucuronidases modulate the functionality of the intestinal microbiota without adversely impacting the host metabolic system.
Kirwan JA, Gika H, Beger RD, et al., 2022, Quality assurance and quality control reporting in untargeted metabolic phenotyping: mQACC recommendations for analytical quality management, Metabolomics, Vol: 18, Pages: 1-16, ISSN: 1573-3882
BackgroundDemonstrating that the data produced in metabolic phenotyping investigations (metabolomics/metabonomics) is of good quality is increasingly seen as a key factor in gaining acceptance for the results of such studies. The use of established quality control (QC) protocols, including appropriate QC samples, is an important and evolving aspect of this process. However, inadequate or incorrect reporting of the QA/QC procedures followed in the study may lead to misinterpretation or overemphasis of the findings and prevent future metanalysis of the body of work.ObjectiveThe aim of this guidance is to provide researchers with a framework that encourages them to describe quality assessment and quality control procedures and outcomes in mass spectrometry and nuclear magnetic resonance spectroscopy-based methods in untargeted metabolomics, with a focus on reporting on QC samples in sufficient detail for them to be understood, trusted and replicated. There is no intent to be proscriptive with regard to analytical best practices; rather, guidance for reporting QA/QC procedures is suggested. A template that can be completed as studies progress to ensure that relevant data is collected, and further documents, are provided as on-line resources.Key reporting practicesMultiple topics should be considered when reporting QA/QC protocols and outcomes for metabolic phenotyping data. Coverage should include the role(s), sources, types, preparation and uses of the QC materials and samples generally employed in the generation of metabolomic data. Details such as sample matrices and sample preparation, the use of test mixtures and system suitability tests, blanks and technique-specific factors are considered and methods for reporting are discussed, including the importance of reporting the acceptance criteria for the QCs. To this end, the reporting of the QC samples and results are considered at two levels of detail: “minimal” and “best reporting practice” le
Kerins A, Koszyczarek M, Smith C, et al., 2022, The <i>in vitro</i> metabolism and <i>in vivo</i> pharmacokinetics of the bacterial β-glucuronidase inhibitor UNC10201652, XENOBIOTICA, Vol: 52, Pages: 904-915, ISSN: 0049-8254
Wilson ID, Gethings LA, Plumb RS, 2022, Defining The Pharmacometabodynamics of Gefitinib after Intravenous Administration to the Mouse by UHPLC/MS and UPLC-IMMS Study, Publisher: ELSEVIER, Pages: S52-S52
Yang J, Wilson I, Rainville P, 2022, Evaluation of hybrid surface technology for the analysis of the B-group vitamins by LC-ESI-MS/MS, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, Vol: 1204, Pages: 123336-123336, ISSN: 1570-0232
Recently, a novel hybrid surface technology (HST) has been developed to mitigate metal analyte adsorption in liquid chromatography. The HST provides a hybrid organic-inorganic surface on the metal fluidic path, from injection to detector and including the column frits and wall, to mitigate the interaction between analytes and metals. Here the impact of the HST on the analysis of B group vitamins using liquid chromatography coupled with electrospray tandem mass spectrometry (LC-ESI-MS/MS) has been evaluated. Significant improvements in analyte intensity, limit of quantification (LOQ), carry-over, and peak shape were observed using an LC-ESI-MS/MS system and column that incorporated the HST. The key observed improvements include a 3-10 times increase in sensitivity (providing a lower LOQ) for riboflavin, thiamine, nicotinamide, FMN, PLP, and 5MTHF, no carry-over, and a more symmetrical peak for thiamine. When applied to the analysis of B group vitamins in energy drinks and B vitamin dietary supplement samples, the HST system demonstrated excellent accuracy and repeatability.
Poole C, Wilson ID, 2022, The state of the art in planar chromatography., Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, Vol: 1203, Pages: 1-2, ISSN: 1570-0232
Hughes CJ, Gethings LA, Wilson ID, et al., 2022, Access to the Phospho-proteome via the Mitigation of Peptide-Metal Interactions, JOURNAL OF CHROMATOGRAPHY A, Vol: 1673, ISSN: 0021-9673
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Lioupi A, Virgiliou C, Walter TH, et al., 2022, Application of a hybrid zwitterionic hydrophilic interaction liquid chromatography column in metabolic profiling studies, JOURNAL OF CHROMATOGRAPHY A, Vol: 1672, ISSN: 0021-9673
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- Citations: 5
Sagi-Kiss V, Li Y, Carey MR, et al., 2022, Ion-pairing chromatography and amine derivatization provide complementary approaches for the targeted LC-MS analysis of the polar metabolome., Journal of Proteome Research, Vol: 21, Pages: 1428-1437, ISSN: 1535-3893
Liquid chromatography coupled to mass spectrometry is a key metabolomics/metabonomics technology. Reversed-phase liquid chromatography (RPLC) is very widely used as a separation step, but typically has poor retention of highly polar metabolites. Here, we evaluated the combination of two alternative methods for improving retention of polar metabolites based on 6-aminoquinoloyl-N-hydroxysuccinidimyl carbamate derivatization for amine groups, and ion-pairing chromatography (IPC) using tributylamine as an ion-pairing agent to retain acids. We compared both of these methods to RPLC and also to each other, for targeted analysis using a triple-quadrupole mass spectrometer, applied to a library of ca. 500 polar metabolites. IPC and derivatization were complementary in terms of their coverage: combined, they improved the proportion of metabolites with good retention to 91%, compared to just 39% for RPLC alone. The combined method was assessed by analyzing a set of liver extracts from aged male and female mice that had been treated with the polyphenol compound ampelopsin. Not only were a number of significantly changed metabolites detected, but also it could be shown that there was a clear interaction between ampelopsin treatment and sex, in that the direction of metabolite change was opposite for males and females.
Claude E, Lafont R, Plumb RS, et al., 2022, High performance Reversed-Phase Thin-Layer Chromatography-Desorption electrospray ionisation - time of flight high resolution mass spectrometric detection and imaging (HPTLC/DESI/ToFMS) of phytoecdysteroids, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, Vol: 1200, Pages: 1-7, ISSN: 1570-0232
Reversed-phase high performance thin-layer chromatography (RP-HPTLC) on C18 bonded silica gel was combined with desorption electrospray ionization (DESI) and high resolution time of flight mass spectrometry (HRToFMS) to detect, characterize and image (MSI) phytoecdysteroids (plant-derived insect moulting hormones) in ethanolic extracts of members of the Silene plant family. As seen previously for silica gel, DESI provided a simple and convenient method for recovering polar polyhydoxysteroids from RP-HPTLC plates for the purposes of both the MS and MSI of extracts obtained from three species of the Silene family (Silene otites, S. nutans and S. viridiflora). Using RP-HPTLC/DESI/MSI/HRToFMS a number of ecdysteroids, including 20-hydroxyecdysone, polypodine-B, 2-deoxy-20-hydroxyecdysone and 2-deoxyecdysone were identified in these extracts. Differences were noted in the mass spectra obtained depending upon both the stationary phase on which they were separated, and the temperatures used in the heated transfer line used for introduction into the ion source. Ecdysteroids detected after chromatography on C18 bonded silica showed increased fragmentation due to water loss compared to those imaged from silica. In addition, the benefits of the additional resolution provided by 2-dimensional TLC for increasing spectral quality compared to a 1-dimensional separation are demonstrated.
Isaac G, Wilson ID, Plumb RS, 2022, Application of hybrid surface technology for improving sensitivity and peak shape of phosphorylated lipids such as phosphatidic acid and phosphatidylserine, JOURNAL OF CHROMATOGRAPHY A, Vol: 1669, ISSN: 0021-9673
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- Citations: 4
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