Analytical and Bioanalytical Chemistry
○ Springer Science and Business Media LLC
All preprints, ranked by how well they match Analytical and Bioanalytical Chemistry's content profile, based on 17 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit. Older preprints may already have been published elsewhere.
Butenko, I. O.; Kitsilovskaya, N. A.; Vakaryuk, A. V.; Lazareva, A. A.; Gremyacheva, V. D.; Kovalenko, A. V.; Lebedeva, A. A.; Baraboshkin, N. M.; Chudinov, I. K.; Khchoian, A. G.; Kurylova, O. V.; Gorbunov, K. S.; Pavlenko, A.; Kozhemyakin, G. L.; Fedorov, O. V.; Ilina, E.; Govorun, V. M.
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In bottom-up proteomics peptide it was early shown that despite a certain protein is present in a sample, only a subset of its proteolytic peptide products will be detected with LC-MS analysis. Property of peptide being frequently detected given its source proteins identification was called proteotypicity. Much effort has been since applied to predict proteotypic peptides and summarize evidence on peptide detection. Nevertheless, when targeted proteomics method is being developed, prediction or inference from communal experience might be inaccurate and prior knowledge of true peptide proteotypicity in a selected setup for a selected population is necessary. In this work we test fully in-house approach for proteotypicity assessment including comprehensive peptide synthesis and detection verification. Proteotypicity and contribution of sample processing and biology-related factors are estimated in a model experiment for three plasma proteins, albumin, ceruloplasmin and C-reactive protein.
Brook, J. R.; Tong, X.; Wong, A. Y.; Weitman, M.; Boire, A.; Kanarek, N.; Petrova, B.
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IntroductionRetinoids are bioactive vitamin A derivatives that regulate cellular differentiation and gene expression, yet their reliable quantification remains challenging due to low abundance, structural isomerism, and sensitivity to ionization conditions while handling. ObjectivesIn this study, we performed a systematic optimization of liquid chromatography-mass spectrometry (LC-MS)-based detection of retinoids across tissues and biofluids. MethodsChromatographic separation, adduct formation, ionization parameters, fragmentation behavior, and extraction procedures were evaluated in an integrated workflow. ResultsChromatographic conditions influenced not only retention time but also the ionic species detected, affecting precursor selection for MS{superscript 2} analysis. Retinoids exhibited compound-dependent responses to electrospray ionization and collision energy, requiring tailored acquisition parameters. Extraction experiments demonstrated differential recovery among retinoid classes and revealed matrix-dependent behavior, indicating that protocols used for tissues cannot be directly transferred to low-abundance biofluids. Using optimized conditions, retinoids were detected in mouse cerebrospinal fluid (CSF) at concentrations approaching the analytical detection limit, where MS{superscript 2} confirmation was necessary for reliable identification. ConclusionTogether, our results provide a framework for reproducible retinoid profiling across biological matrices and enables comparative studies of retinoid biology in low-volume and low-abundance biofluids.
Cabrera, D.; Pujana Vaquerizo, M.; Martinez La Osa, B.; Zabala Letona, A.; Manuel Falcon, J.; Carracedo, A.; van Liempd, S.
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We describe a robust, fast and accurate method for the quantification of intra-cellular concentrations of the polyamines, putrescine, spermidine and spermine in cultured cells. Hydrophilic interaction liquid chromatography in combination with Time-of-Flight mass spectrometry was used to obtain high resolution data for the analytes. Assay performance was determined with respect to chromatographic resolution, quantification, analyte recovery and matrix effects. Furthermore, assay variability was determined in a biological context. Based on these variability measurements, minimal detectable effects (MDEs) which would lead to significant differences in a null-hypothesis significance test, were calculated. As such, changes in spermine could be determined with the highest sensitivity with point estimates for the MDEs of 32% between-days and 10% within-days. For spermidine, these values were 38% between-days and 16% within-days. Finally, effects for putrescine were measured least sensitive with 43% between-days and 36% within-days. Finally, we employed the method to analyze the impact of polyamine synthesis pathway inhibition and cell culture conditions which are relevant aspects for the interpretation of the biological role of polyamines.
Willey, J. C.; Morrison, T.; Austermiller, B.; Crawford, E. L.; Craig, D. J.; Blomquist, T. M.; Jones, W. D.; Wali, A.; Lococo, J. S.; Haseley, N.; Richmond, T. A.; Novoradovskaya, N.; Kusko, R.; Chen, G.; Li, Q.-Z.; Johann, D.; Deveson, I. W.; Mercer, T.; Wu, L.; Xu, J.
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The primary objective of the FDA-led Sequencing and Quality Control Phase 2 (SEQC2) project is to develop standard analysis protocols and quality control metrics for use in DNA testing to enhance scientific research and precision medicine. This study reports a targeted next generation sequencing (NGS) method that enables more accurate detection of actionable mutations in circulating tumor DNA (ctDNA) clinical specimens. This advancement was enabled by designing a synthetic internal standard spike-in for each actionable mutation target, suitable for use in NGS following hybrid-capture enrichment and unique molecular index (UMI) or non-UMI library preparation. When mixed with contrived ctDNA reference samples, internal standards enabled calculation of technical error rate, limit of blank, and limit of detection for each variant at each nucleotide position, in each sample. True positive mutations with variant allele fraction too low for detection by current practice were detected with this method, thereby increasing sensitivity.
Lentjes, E. G. W. M.; Pratt, M. S.; Kema, I. P.; van Faassen, M.; Musson, R. E. A.; Vos, M. J.
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ObjectiveGeneration and testing of IGF1 reference materials (RM), suitable for the harmonization of immunoassay (IA) and LC-MS/MS methods for the IGF1 determination in blood. In addition, establishment of age related reference intervals for men and women. MethodsIn a split sample study of 42 patients, and 30 healthy volunteers we tested the commutability of four RMs for IGF1, using four commercial IAs and an LC-MS/MS method. A new set of age dependent reference intervals was established using Lifelines biobank samples, based on the IGF1 LC-MS/MS method. ResultsThe four RMs were found to be commutable, except the RM with the lowest concentration measured with the Siemens Immulite method. The value assignment of the RMs was based on the IGF1 LC-MS/MS method, which was calibrated against WHO international standard 02/254. LC-MS/MS results were on average about 0 to 60% lower than those of the immunoassays. Combining the recalculated IGF1 results in patient samples from a former study with the data from healthy volunteers in this study, showed a reduction in the variation of the data points (standard error of estimate) of 42% and 62% respectively. ConclusionCommutable RMs for IGF1 can be made from serum of healthy blood donors. However, it remains necessary to test the commutability of these RMs in IAs that were not included in this study. By harmonizing methods using the four RMs, the same age-related reference intervals can be used.
Elamin, I.; Rao, M. S.; Figliozzi, R. W.; Maahs, J. C.; Balish, M.; Hsia, S. V.; Fugolin, A. P. P.; Fan, J.
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Circulating cell-free DNA (cfDNA) consists of small fragments of extracellular DNA from mammalian and bacterial cells found in bodily fluids such as blood and saliva, and it has been strongly recognized as a critical biomarker for various disease diagnoses, prognoses, and therapeutic monitoring. In this study, we present a reproducible protocol for efficiently isolating cfDNA from murine saliva using an innovative swabbing method in conjunction with the QIAamp MinElute ccfDNA Mini Kit. The quantification of isolated cfDNA is detected by a Qubit Fluorometer. Moreover, qualification assessment is conducted through BioAnalyzer analysis. This protocol facilitates research on saliva-derived cfDNA in the context of oral and systemic diseases in murine models. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/645839v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@19ce903org.highwire.dtl.DTLVardef@85fa20org.highwire.dtl.DTLVardef@1e869eaorg.highwire.dtl.DTLVardef@181c340_HPS_FORMAT_FIGEXP M_FIG C_FIG
Hooshmand, K.; Ismoilova, V.; Wretlind, A.; Simonsen, A. H.; Hasselbalch, S. G.; Legido-Quigley, C.
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N-acylethanolamines (NAEs) and primary fatty amides (PFAMs) are of a great interest due to the range of physiological effects they exhibit, potentially serving as neuromodulators. However, they are present at nano and picomolar concentrations in human cerebrospinal fluid (CSF) samples, posing challenges for detection and measurement using conventional Ultra-high performance liquid chromatography systems coupled to tandem mass spectrometry (UHPLC-MS). UHPLC-MS was used in dynamic multiple reaction monitoring (dMRM) mode. Seven deuterated NAEs internal standards were used to develop the method. Six solvent combinations were tested for extraction efficiency, accuracy, precision, matrix effect, linearity, limits of detection. Lastly the method was applied to CSF from healthy individuals (n=33) to estimate their natural range of concentrations. Extraction with acetonitrile/acetone showed the highest efficiency and recovery. The presented method was able to measure the following 17 NAEs and PFAMs in human CSF: linoleoyl ethanolamide, heptadecanoyl ethanolamide, stearoyl ethanolamide, palmitoyl ethanolamide, dihomolinolenoyl ethanolamide, eicosatrienoic acid ethanolamide, behenamide, octadecanamide, lauramide, tetradecanamide, erucamide, linoleamide, palmitamide, myristic monoethanolamide, pentadecanoyl ethanolamide, oleamide and palmitoleoyl ethanolamide. In healthy individuals the concentrations ranged three-fold from pg/mL to mg/mL. Further studies could apply this method to clinical CSF samples.
Li, X.; Pierson, N. A.; Hua, X.; Patel, B. A.; Olma, M. H.; Strulson, C. A.; Letarte, S.; Richardson, D. D.
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The use of Multi-attribute method (MAM) for identity and purity testing of biopharmaceuticals offers the ability to complement and replace multiple conventional analytical technologies with a single mass spectrometry (MS) method. Method qualification and phase-appropriate validation is one major consideration for the implementation of MAM in a current Good Manufacturing Practice (cGMP) environment. We developed an improved MAM workflow with optimized sample preparation using Lys-C digestion for therapeutic monoclonal antibodies. In this study, we qualified the enhanced MAM workflow for mAb-1 identity, product quality attributes (PQAs) monitoring and new peak detection (NPD). The qualification results demonstrated the full potential of the MAM for its intended use in mAb-1 characterization and quality control in regulated labs. To the best of our knowledge, this is the first report of MAM qualification for mAb identity, PQA monitoring, and new peak detection (NPD) in a single assay, featuring 1) the first full qualification of MAM using Lys-C digestion without desalting using a high-resolution MS, 2) a new approach for mAb identity testing using MAM, and 3) the first qualification of NPD for MAM. The developed MAM workflow and the approaches for MAM qualification may serve as a reference for other labs in the industry.
Suzuki, T.; Judai, N.; Ishihara, M.; Kajimoto, K.
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ObjectiveDrug poisoning cases due to overdoses of over-the-counter (OTC) medications are increasing, and comprehensive measurement of blood drug concentrations, including OTC drugs, is important in emergency medicine and forensic science. In this study, we developed a simultaneous quantification method for blood drug levels using LC-MS/MS with solid-phase mini-cartridge SmartSPE for sample preparation. MethodsThe target analytes were acetaminophen, caffeine, flunitrazepam, 7-aminoflunitrazepam, risperidone, and phenobarbital. Internal standards (IS) used were acetaminophen-d4, caffeine-d9, diazepam-d5, and phenobarbital-d5. For solid-phase extraction, three types of Smart-SPE columns (AiSTI Science Co., Ltd.) were employed. 100 {micro}L of blank whole blood samples were subjected to protein precipitation using methanol and acetonitrile, and the supernatant obtained after centrifugation was processed using Smart-SPE for sample cleanup. Chromatographic separation was performed on a CAPCELL PAK INERT ADME-HR column (Osaka Soda), and detection was carried out in both positive and negative ESI modes. ResultsLinearity was observed for all drugs across the therapeutic to coma-death concentration ranges, with correlation coefficients exceeding 0.99 in all cases. Intra-day accuracy ranged from 98.06% to 110.87%, with precision between 0.19% and 17.37%. Inter-day accuracy ranged from 97.82% to 112.35%, with precision between 0.53% and 9.18%. Recovery rates varied from 72.9% to 95.1%, and matrix effects ranged from 91.2% to 113.0%. DiscussionThe validation results demonstrated satisfactory performance for all analytes, suggesting that this simultaneous quantification method may serve as a reliable analytical approach. Further investigations into sample stability are planned, and if analyses of actual specimens confirm its applicability, the method can be reported as a novel approach for simultaneous quantification of blood drug levels using a new sample pretreatment technique.
Pichler, P.; Kurnikowski, A.; Matzinger, M.; Mechtler, K.
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Urine collection is painless and offers the potential for kidney liquid-biopsy(1), which appears particularly appealing with regard to the diagnosis of kidney disease (2) and patient follow-up after renal transplantation (3). From a nephrological point of view, urinary sediment and the soluble and exosome fractions of urine constitute different biological entities. We here describe a method that allows deep profiling of the protein content of the above-mentioned three fractions of urine by quantitative data-independent label-free proteomics. The method was evaluated using 19 urine samples from the Nephrology outpatient clinic at Vienna General Hospital, comprising a diverse set of chronic kidney disease (CKD) as well as patients after kidney transplantation (NTX). Peptide separation was accomplished through 60 min active gradients. A timsTOF Pro2 mass spectrometer was operated in DIA mode. The total analysis time per urine sample (three fractions) was around four hours. We demonstrate adequate technical and experimental reproducibility. Our data suggest that the protein information content of these three fractions is diverse, strengthening the importance of separate analysis. The depth of our quantitative proteomics approach permitted a detection of proteins characteristic for different parts of the nephron, such as Podocin, CD2-AP and Podocalyxin (Podocytes), SLC22A8 and SLC22A13 (proximal tubule) and Aquaporin-2 (collecting duct), suggesting that our method is sensitive enough to detect and quantify biologically relevant proteins that might serve as potential biomarkers. To the best of our knowledge, the ability to quantify up to 4000 protein groups per urine sample and more than 6000 protein groups in total makes our strategy the deepest proteome profiling study of urine to date. In conclusion, we established a method with promising figures of merit that we consider broadly applicable and useful for future clinical biomarker research studies in urine.
Emunyu, J.; Semigga, B.; Kisembo, S.; Namukwaya, B.; Namubiru, B.; Bakyayita, C.; Omony, E.
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Hypercholesterolemia and hypocholesterolemia are associated with mortality which warrants routine lipid profile testing. This financially burdens the already overwhelmed health sector especially in developing countries. Additionally, lipid profile test reagent stock-out or failure to afford all tests affects result interpretation. In 1972, James Friedewald published a statistical model to calculate low density lipo-protein. The study aim was to determine the percentage error of the James Friedewald equation in calculating all lipid profile test parameters. A retrospective study from 2018 was performed at Mildmay Uganda involving lipid profile results of 103 persons (48 HIV-positive and 55 HIV-negative) 50 years and older enrolled in a previous cross-sectional study. The Friedewald equation was used to calculate total cholesterol, high density lipoprotein, triglycerides and low density lipo-protein. The percentage error of calculated values in reference to measured values was ascertained. Pearson correlation between measured and calculated results was determined among all persons and classified by HIV status. The total error of calculated analytes was 7% (low density lipo-protein), 17% (high density lipo-protein), 39% (triglycerides) and 4% (total cholesterol). Pearson correlations were 0.98 (all persons), 0.98 (HIV-negative) and 0.98 (HIV-positive) for low density lipo-protein, 0.89 (all persons), 0.90 (HIV-positive) and 0.88 (HIV-negative) for high density lipo-protein, 0.75 (all persons), 0.76 (HIV-negative) and 0.77 (HIV-positive) for triglycerides, 0.99 (all persons), 0.98 (HIV-negative) and 0.99 (HIV-positive) for total cholesterol. In conclusion, Friedewald equation reliably calculated low density lipo-protein, total cholesterol (most accurate) and high density lipo-protein while triglycerides calculation was erroneous among persons aged [≥] 50 years.
Wood, C. S.; Abele, S. M.; Alsbach, J.; Gervalla, A.; Meinel, D. M.; Cuny, A. P.
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The development of chemiluminescent immunoassays (CLIAs) is a complex and iterative process that relies on costly laboratory infrastructure, limiting its accessibility and application across healthcare settings and disease areas. Here, we detail the CLIA Mobile Development Kit (CLIAMDK) a modular, mobile, and inexpensive platform to assess image sensors, smartphones and data processing workflows for CLIA development. For its demonstration, we developed two CLIAs targeting renin and aldosterone, key biomarkers for diagnosing primary aldosteronism. The results from our performance study, including 50 patient samples, demonstrate the potential of our platform in a real-world scenario. We found that the performance of our mobile reader platform is comparable to that of a state-of-the-art plate reader, with a Lower Limit-of-Detection (LLoD) approaching 41 femtomolar. We envision that our platform will help accelerate CLIA development, make it more accessible, and lay the foundations for novel, distributed, yet highly sensitive diagnostic tests.
Zhang, G.-F.; Slentz, D. H.; Lantier, L.; McGuinness, O. P.; Muoio, D. M.; Williams, A. S.
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ObjectiveA catheter-free, non-radiolabeled method that permits in vivo measurement of tissue-specific glucose uptake does not exist. To address this gap, we sought to develop and validate a new, higher throughput mass spectrometry (MS)-based method that combines an injection of insulin with a non-radiolabeled glucose tracer, 2-fluoro-2-deoxyglucose (2FDG), to determine insulin-stimulated tissue-specific glucose clearance in conscious, unrestrained mice. MethodsInjections of saline or insulin with 2FDG were coupled with LC-Q Exactive Hybrid Quadrupole-Orbitrap (LC) MS-based measures of plasma 2FDG and tissue (2-fluoro-2-deoxyglucose-6-phosphate) 2FDGP to determine glucose clearance in mice under several different conditions. ResultsThe newly developed method was first applied to a dose response experiment in mice. Next, the ability of this method to quantify changes in glucose clearance in response to an insulin stimulus was assessed, and glucose clearance was compared between chow and high fat fed mice. Results from these studies showed that insulin-stimulated skeletal muscle and heart glucose clearance can be estimated following a bolus injection of tracer, and these fluxes are blunted in diet-induced obese mice. The broad applicability of this approach was then demonstrated by assessing glucose clearance in a mouse model with anticipated changes in insulin-stimulated skeletal muscle glucose metabolism. ConclusionsThe results validated a new LC-MS method to quantify insulin-stimulated tissue-specific glucose clearance in vivo without the use of catheters or radiolabeled tracers. The method offers great potential because it is designed for application to pre-clinical studies seeking high throughput tests and/or assays that can be coupled with discovery technologies such as genomics, proteomics and metabolomics. HIGHLIGHTSO_LIIn vivo glucose clearance can be estimated by a new non-radiolabeled method. C_LIO_LIThe plasma tracer to tracee ratio is required to determine tissue tracer phosphorylation. C_LIO_LIMeasures of plasma glucose and tracer kinetics are critical for data interpretation. C_LIO_LIThe new method can be combined with omics technologies such as metabolomics. C_LI
Kopel, B.; Prado, F. M.; de Moura, R. D.; Guimaraes-Ramos, S. L.; di Mascio, P.; Hoch, N. C.; de Medeiros, M. H. G.; de Souza-Pinto, N. C.
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Adenine nucleotides, including ATP, ADP, ADP-ribose, AMP, NAD+ and NADH, play central roles in cellular homeostasis and involved in multiple metabolic and signaling pathways. Owing to their broad functional relevance in cell biology, the accurate quantification of these metabolites is essential for diverse research areas such as bioenergetics, cell signaling and cancer biology. Several analytical methods have been described for the measurement of adenine nucleotides, ranging from enzymatic assays to mass spectrometry-based approaches. In this study, we developed a reverse-phase high-performance liquid chromatography (RP-HPLC) method with UV-Vis detection that enables the simultaneous quantification of ATP, ADP, ADP-ribose, AMP, NAD+ and NADH. This method is simple, sensitive within the physiological concentration range of all analytes, and capable of detecting biologically relevant changes in ATP, AMP and NAD+ levels induced by pharmacological treatments. Therefore, it presents an accessible and reliable alternative for quantification of these nucleotides in biological samples.
Thakker, A.; Spickett, C.; Pitt, A.
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1Phospholipid oxidation (OxPL) generates a wide variety of products with potentially novel biological activities that may be associated with disease pathogenesis. To understand their role in disease requires precise information about their abundance in biological samples. Liquid chromatography-mass spectrometry (LCMS) is a sensitive technique that can provide detailed information about the oxidative lipidome, but challenges remain. Furthermore, variation in charge of the polar head groups and the extreme diversity of oxidised species make analysis of several classes of OxPLs within one analytical run challenging.\n\nThe work in this study aims to develop improved methods for detection of OxPLs by improvement of chromatographic separation through the serial coupling of polystyrene-divinylbenzene based monolithic, and mixed-mode hydrophilic interaction (HILIC) with use of semi-targeted mass spectrometry approaches. The results suggests that by serially coupling two columns, HILIC and monolith, provided the better coverage of OxPL species in a single analytical run. We tested in-vitro generated oxidized species for phosphatidylcholine (PC) and phosphatidylethanolamine (PE) class and the combination of orthogonal chromatographic separation allowed separation of oxdised species from both the classes, which otherwise coeluted.
Li, L.; Chu, Z.; Ning, K.; Zhu, M.; Zhai, R.; Xu, P.
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Phytohemagglutinin (PHA), a natural tetramer comprising PHA-E and PHA-L subunits that preferentially bind to red and white blood cells, respectively, constitutes a significant antinutritional and allergenic factor in common bean seeds. The accurate measurement of PHA content is a prerequisite for ensuring food safety inspections and facilitating genetic improvements in common bean cultivars with reduced PHA levels. Currently, mainstream methods for PHA quantification involve hemagglutination assays and immunodetection, but these methods often require fresh animal blood and lack specificity and accuracy. In this study, we present a novel LC-MS/MS-based method for PHA quantification, leveraging the advantages of isotope dilution mass spectrometry (IDMS). Two signature peptides each for PHA-E and PHA-L, along with a common signature peptide, were identified and employed for quantification, allowing differentiation between PHA-E and PHA-L subunits. The incorporation of amino acid analysis-isotope dilution mass spectrometry (AAA-IDMS) enabled precise determination of the synthetic signature peptides purity during measurement, enhancing metrological accuracy. In addition, the TCA-acetone protocol was established as the optimized method for total protein extraction from dry bean seeds. Quantitative analysis of PHA-E and PHA-L subunits in six common bean varieties using the developed method demonstrated excellent linearity (r > 0.999), sensitivity (limit of detection and quantitation as low as 2.32 ng/mg and 7.73 ng/mg, respectively), recovery (94.18-104.47%), and repeatability (relative standard deviation < 3.45%). This method has the potential to serve as a standard for measuring PHA contents in common beans and other agricultural products containing PHA.
Mohamad Ishak, N. S.; Ikemoto, K.
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Pyrroloquinoline quinone (PQQ) is a redox-active compound with physiological functions, widely used in functional foods and supplements. However, quantifying the reduced form, PQQred, is difficult due to its low solubility and susceptibility to oxidation. This study presents a robust HPLC method for direct quantification of PQQred in complex matrices. By changing to a strongly acidic eluent, the oxidation of PQQred was suppress, and the optimized method successfully separated PQQred from its oxidized counterpart (PQQox)and matrix interferences, enabling accurate quantification. A pretreatment using ascorbic acid and {gamma}-CD effectively reduced and solubilized PQQred, and total PQQ can be analyzed as PQQred. The method achieved excellent linearity (R2 = 1), low detection limits (LOD: 0.20 mg/L, LOQ: 0.50 mg/L), and high precision (RSD < 3%). Application to commercial beverages showed consistent recovery (99-101%) with minimal interference. Moreover, the method suctandem mass spectrometry.cessfully detected biologically generated PQQred in yeast cultures, demonstrating its utility in physiological systems. This redox-specific and practical approach enables routine analysis and quality control of PQQ-enriched products, especially where accurate assessment of redox state is essential.
Ahonen, L.; Jantti, S.; Suvitaival, T.; Thelaide, S.; Risz, C.; Kostiainen, R.; Rossing, P.; Oresic, M.; Hyotylainen, T.
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BackgroundSeveral small molecule biomarkers have been reported in the literature for prediction and diagnosis of (pre)diabetes, its co-morbidities and complications. Here, we report the development and validation of a novel, quantitative, analytical method for use in the diabetes clinic. This method enables the determination of a selected panel of 36 metabolite biomarkers from human plasma.\n\nMethodsBased on a review of the literature and our own data, we selected a panel of metabolites indicative of various clinically-relevant pathogenic stages of diabetes. We combined these candidate biomarkers into a single ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method and optimized it, prioritizing simplicity of sample preparation and time needed for analysis, enabling high-throughput analysis in clinical laboratory settings.\n\nResultsWe validated the method in terms of limit of (a) detection (LOD), (b) limit of quantitation (LOQ), (c) linearity (R2), (d) linear range, and (e) intra- and inter-day repeatability of each metabolite. The methods performance was demonstrated in the analysis of selected samples from a diabetes cohort study. Metabolite levels were associated with clinical measurements and kidney complications in type 1 diabetes (T1D) patients. Specifically, both amino acids and amino acid-related analytes were associated with macro-albuminuria. Additionally, specific bile acids were associated with kidney function, anti-hypertensive medication, statin medication and clinical lipid measurements.\n\nConclusionsThe developed analytical method is suitable for robust determination of selected plasma metabolites in the diabetes clinic.
Adams, C. A.; Bever, C. S.; Blake-Hedges, J. M.; Brown, S.; Thompson, M. G.; Behie, S.; Keasling, J. D.; Shih, P.
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1.1.The death cap mushroom, Amanita phalloides, is well known for containing amatoxins such as alpha- and beta-amanitin, which inhibit eukaryotic RNA polymerase II. While these toxins have been used in research for almost a century, they have recently garnered attention for their role in drug-antibody conjugates. The amatoxins are still largely extracted from wild mushrooms, which cannot be made to fruit in the lab. We propose simplified extraction methods that could reduce hazardous exposures to dust and expedite sample analysis without sacrificing accuracy. We recently developed a Lateral Flow Immunoassay (LFIA), for which we identified that sample maceration was not needed to extract the amatoxins and that the incubation time for extraction could be accomplished in 1 minute. In this current work, we hypothesized that these same extraction adjustments-minimal tissue maceration and reduced incubation time-could be transferable to instrumental detection methods. To test the need for sample maceration, we utilized three different techniques: 1) traditional mortar and pestle, 2) a similarly disruptive method of bead beating, and 3) no grinding, but rather hand shaking dried mushroom tissue in extraction buffer. In addition, we performed the solvent extraction step at varying times to observe if more time allows for more toxin to be removed from the tissue. Lastly, we utilized two comparable solvent evaporation methods (rotovap or speedvac) to establish if multiple samples could be processed simultaneously, thus improving sample throughput. We adjusted aspects of the typical extraction protocol, which resulted in a rapid (1 min) incubation step, along with minimal sample handling (no grinding) of the dried mushroom tissue. We present an extraction protocol that saves time, reduces equipment contamination, and minimizes risk to the researcher. The impact of this faster, safer method may help produce these important toxins faster, for both research and medical use.
Nakatani, K.; Izumi, Y.; Umakoshi, H.; Yokomoto-Umakoshi, M.; Nakaji, T.; Kaneko, H.; Nakao, H.; Ogawa, Y.; Ikeda, K.; Bamba, T.
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Quantitative information on blood metabolites has the potential to be utilized in medical strategies such as early disease detection and prevention. Monitoring of bioactive lipids, such as steroids, bile acids, and polyunsaturated fatty acid (PUFA) metabolites, could be a valuable indicator for health status. However, a method for simultaneous measurement of these bioactive lipids has not been reported at present. Here, we report a liquid chromatography tandem mass spectrometry (LC/MS/MS) method that can simultaneously measure more than 140 bioactive lipids, including steroids, bile acids, and PUFA metabolites, from human plasma, and a sample preparation method for these targets. Protein removal in methanol precipitation and purification operations of bioactive lipids by solid-phase extraction improved the recovery of targeted compounds in human plasma samples, demonstrating the importance of sample preparation methods in a wide range of bioactive lipid analyses. Using the developed method, we measured plasma from healthy human volunteers and confirmed the presence of bioactive lipid molecules associated with sex differences and circadian rhythms. The practical bioactive lipid analysis method developed is expected to be applied to health monitoring and disease biomarker discovery for precision medicine.