Extra-column band broadening can significantly reduce the performance of rapid ultra-high performance liquid chromatography-MS-based methods (UHPLC-MS). However, as we show here, UHPLC-MS/MS methods on short 2.1 mm i.
View Article and Find Full Text PDFOmics-based biomarker technologies, including metabolic profiling (metabolomics/metabonomics) and lipidomics, are making a significant impact on disease understanding, drug development, and translational research. A wide range of patho-physiological processes involve lipids and monitoring changes in lipid abundance can give valuable insights into mechanisms of drug action, off target pharmacology and toxicity. Here we report changes, detected by untargeted LC-MS, in the plasma lipid profiles of male C57Bl/6JRj mice following the PO and IV administration of the epidermal growth factor receptor (EGFR) inhibitor gefitinib.
View Article and Find Full Text PDFIon 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThere 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.
View Article and Find Full Text PDFMobile phase selection is of critical importance in liquid chromatography - mass spectrometry (LC-MS) based studies, since it affects retention, chromatographic selectivity, ionization, limits of detection and quantification, and linear dynamic range. Generalized LC-MS mobile phase selection criteria, suitable for a broad class of chemical compounds, do not exist thus far. Here we have performed a large-scale qualitative assessment of the effect of solvent composition used for reversed-phase LC separations on electrospray ionization (ESI) response for 240 small molecular weight drugs, representing various chemical compound classes.
View Article and Find Full Text PDFProstate cancer is the most common malignant tumour in men. Improved testing for diagnosis, risk prediction, and response to treatment would improve care. Here, we identified a proteomic signature of prostate cancer in peripheral blood using data-independent acquisition mass spectrometry combined with machine learning.
View Article and Find Full Text PDFMetabolite 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.
View Article and Find Full Text PDFThe use of vacuum jacketed LC columns (VJC) to minimize on- and post-column band broadening to maximize chromatographic performance has been evaluated as a potential route to improved high throughput (HT) analysis. Here the use of the "VJC" approach has been applied to the HT bioanalysis of the antidiabetic GPR40 agonist drug fasiglifam in rat plasma samples obtained following a 5 mg/kg IV dose. The data obtained from a 1 minute VJC/MS-based analysis showed significant improvements compared to that from a conventional 2 minute UHPLC method for the drug.
View Article and Find Full Text PDFLipids play a key role in many biological processes, and their accurate measurement is critical to unraveling the biology of diseases and human health. A high throughput HILIC-based (LC-MS) method for the semiquantitative screening of over 2000 lipids, based on over 4000 MRM transitions, was devised to produce an accessible and robust lipidomic screen for phospholipids in human plasma/serum. This methodology integrates many of the advantages of global lipid analysis with those of targeted approaches.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
June 2022
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.
View Article and Find Full Text PDFLiquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) has become the default platform for proteomics due to its specificity, sensitivity and sample compatibility. However, interactions between transition metals in LC systems and analytes containing phosphate groups result in poor chromatographic performance or even analyte loss. The use of systems where the metal surfaces had been treated with a hybrid inorganic/organic surface material to form an effective surface barrier mitigated these undesired interactions.
View Article and Find Full Text PDFThe use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITY™ UPLC™ system and column, designed to mitigate the chelation, poor peak shape and analyte loss seen with acidic phospholipids was investigated. Compared to a conventional system significant improvements in both sensitivity, recovery and peak shape were obtained following UPLC on a CSH C18 column when the HST was used for the analysis of lysophosphatidic acid (LPA), phosphatidic acid (PA), lysophosphatidylserine (LPS), phosphatidylserine (PS), phosphatidylinositol-monophosphates (PIP), ceramide phosphate (CerP) and sphingoid base phosphate (SPBP). The benefits in chromatographic performance provided by the HST were seen particularly at low concentrations of these analytes.
View Article and Find Full Text PDFLipids play an important role in the energy storage, cellular signaling, and pathophysiology of diseases such as cancer, neurodegenerative diseases, infections, and diabetes. Due to high importance of diverse lipid classes in human health and disease, manipulating lipid abundance and composition is an important target for metabolic engineering. The extreme structural diversity of lipids in real biological samples is challenging for analytical techniques due to large difference in physicochemical properties of individual lipid species.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
August 2021
Microsomal cytochrome P450 (CYP450) reductase enzymes play a major role in drug and xenobiotic metabolism. Mice which are deficient in hepatic CYP450 reductase serve as excellent models in understanding CYP450 drug metabolism and alterations in the underlying biology and function of these enzymes. A reversed-phase nano-bore UPLC-MS-based proteomic analysis, using an untargeted data independent approach (DIA), has been utilized for liver tissue extracts to evaluate differences between the proteomes of C57Bl6 wild type (WT) and hepatic P450 reductase mice (HRN™).
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
August 2021
The accurate determination of the pharmacokinetics (PK) of a candidate drug molecule is critical in both drug discovery and development. Over the last 30 years, the sensitivity and selectivity of LC/MS has resulted in it being established as the technology of choice for these studies. However, unwanted chemical interactions between analyte(s) and the metal components in a chromatography system can result in poor peak shape and reduction in signal response, which can adversely affect the analysis of low concentrations of drugs and their metabolites in biological samples.
View Article and Find Full Text PDFThe effects of intravenous gefitinib (10 mg/kg), an anilinoquinazoline thymidylate kinase inhibitor (TKI), selective for the epidermal growth factor receptor (EGFR), on the urinary metabotypes of mice were studied. We hypothesized that, in response to the administration of gefitinib, there might be significant changes in the excretion of many endogenous metabolites in the urine, which could be correlated with the plasma pharmacokinetics (PK) of the drug. In order to investigate this conjecture, urine from male C57 BL6 mice was collected before IV dosing (10 mg/kg) and at 0-3, 3-8, and 8-24 h post-dose.
View Article and Find Full Text PDF1-β--Acyl-glucuronides (AGs) are common metabolites of carboxylic acid-containing xenobiotics, including, ., many nonsteroidal anti-inflammatory drugs (NSAIDs). They are of concern to regulatory authorities because of the association of these metabolites with the hepatotoxicity that has resulted in drug withdrawal.
View Article and Find Full Text PDFThe detection, identification and quantification of drug metabolites plays a key role in drug discovery and development. Liquid chromatography (LC) coupled to mass spectrometry (MS) has become the primary technology for these studies due to its sensitivity and specificity. However, the presence of transition metals in the chromatography system and columns can result in non-specific and unwanted interactions with the drug and/or its metabolites, via electron-pair donation, leading to poor chromatography and analyte loss.
View Article and Find Full Text PDFThe deployment of proteomic analysis in clinical studies represents a significant opportunity to detect and validate biomarkers in translational medicine, improve disease understanding, and provide baseline information on population health. However, comprehensive proteome studies usually employ nanoscale chromatography and often require several hours of analysis/sample. Here, we describe a high-throughput liquid chromatography tandem mass spectrometry (LC/MS/MS) methodology using 1 mm scale chromatography requiring only 15 min/sample, coupled to ion mobility-enabled mass spectrometry.
View Article and Find Full Text PDFCognitive computing is revolutionizing the way big data are processed and integrated, with artificial intelligence (AI) natural language processing (NLP) platforms helping researchers to efficiently search and digest the vast scientific literature. Most available platforms have been developed for biomedical researchers, but new NLP tools are emerging for biologists in other fields and an important example is metabolomics. NLP provides literature-based contextualization of metabolic features that decreases the time and expert-level subject knowledge required during the prioritization, identification and interpretation steps in the metabolomics data analysis pipeline.
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