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In aquatic environments the concurrent exposure of molluscs to microplastics (MPs) and estrogens is common, as these pollutants are frequently released by wastewater treatment plants into estuaries. Therefore, this study aimed to evaluate the independent and co-exposure impacts of polyethylene microplastics (PE-MPs) and estrogenic endocrine-disrupting chemicals (EEDCs) at environmentally relevant concentrations on polar metabolites and morphological parameters of the Sydney rock oyster. A seven-day acute exposure revealed no discernible differences in morphology; however, significant variations in polar metabolites were observed across oyster tissues. The altered metabolites were mostly amino acids, carbohydrates and intermediates of the Kreb's cycle. The perturbation of metabolites were tissue and sex-specific. All treatments generally showed an increase of metabolites relative to controls – a possible stimulatory and/or a potential hormetic response. The presence of MPs impeded the exposure of adsorbed and free EEDCs potentially due to the selective feeding behaviour of oysters to microplastics, favouring algae over similar-sized PE-MPs, and the formation of an eco/bio-corona involving faeces, pseudo-faeces, natural organic matter, and algae. [Display omitted] • Effects of microplastics and estrogens are sex and tissue specific. • Single and mixed exposure similarly affect overall metabolic status. • At environmentally realistic concentrations, contaminants exerted a stimulatory effect. • Exposure to low concentrations of both contaminants may present a hormetic response. [ABSTRACT FROM AUTHOR]

Rapid diagnosis of diseases is one of the challenging areas in clinical research. From the analytical chemist's perspective, the main challenges are isolating the compounds from the bio-specimen and lengthy analysis times. In this regard, solid phase microextraction offers a platform to address the abovementioned challenges. Moreover, its sharp tip-thin film geometry, known as coated blade spray (CBS), can enhance the extraction and act as an ionization source in direct mass spectrometric analysis. In this study, a new CBS device specifically designed for polar analytes was prepared and optimized to determine urinary metabolites. For this purpose, polyacrylonitrile (PAN) was selected as a base polymer as it can be electrospun to form a nanofibrous structure, and it can be modified with weak ion exchange moieties to interact with polar analytes. Following the electrospinning of PAN, hydrolysis was optimized, and conditions leading to sufficient extraction enhancement without dissolving the polymer were obtained when probes were treated with 5.0 M of NaOH for 2.5 h. Using the coated blades prepared as explained, the evaluation of various extraction conditions showed that 5 min is sufficient for equilibrium extraction. In addition, the solution's ionic strength and pH significantly affect the extraction. Optimum sorption was obtained at no salt added and pH 7.0 conditions. The CBS-MS optimization showed that 10.0 µL of ACN/MeOH/H 2 O (40:40:20, v/v/v) with formic acid kept for 15 seconds on the blade before voltage application leads to the highest signal. The limits of quantification of the analytes are between 50 and 100 ng/mL. [Display omitted] • Hydrolyzed electrospun PAN can be used for extraction of polar metabolites. • New electrospun based extractive phase provides fast extraction kinetics. • The CBS-MS method is only 6 min and can be used as a fast diagnostic tool. [ABSTRACT FROM AUTHOR]

• The metabolic phenotyping of the polar metabolites excreted in urine is challenging. • Urinalysis using HILIC is currently the method of choice for polar metabolites. • Ion mobility-enabled analysis (HILIC-IM-MS) significantly increased peak detection. • A cyclic IM-MS instrument gave enhanced peak detection compared to a linear IM-MS configuration. • HILIC-IM-MS improved both coverage of the polar urinary metabolome and MS data. 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 -t R 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. [ABSTRACT FROM AUTHOR]

Hydrocarbon polar metabolites are gaining interest from industry and the remediation community due to their ubiquity and uncertainty around their toxicity. In this study, we used headspace-gas chromatography/mass spectrometry (HS-GC/MS) to characterize polar metabolites present in elutriates derived from uncontaminated, freshly hydrocarbon contaminated and partially remediated Antarctic soils. Elutriates represent the bioavailable fraction and may be used as a proxy for leachate runoff in environmental risk assessments. Control and contaminated soil elutriates were analysed for the presence of 12 aldehydes and two ketones, which cover a broad spectrum of metabolites, ranging from nC 2 – nC 12 carbon chain length. A total of nine aldehydes were detected in the soil elutriates. Types of aldehydes present in uncontaminated and hydrocarbon contaminated elutriates were similar. Among the polar metabolites measured in elutriates, acetaldehyde was most abundant in partially remediated soils. Microtox assays were used to determine the potential toxicity of elutriates. In addition, three aldehydes that were present at the highest concentrations in the contaminated and partially remediated soil elutriates (acetaldehyde, octanal and undecanal) were tested as single compounds. Contaminated soil elutriates tested were found to be toxic, with partially remediated elutriates less toxic than freshly contaminated elutriates. None of the three aldehydes tested separately were toxic at levels at which they were measured in elutriates. We infer that high levels of acetaldehyde in partially remediated soil due to hydrocarbon degradation highlight the potential of this metabolite as a useful chemical marker for hydrocarbon degradation under certain conditions. Microtox was sensitive to metabolites and provided a useful initial screening tool for elutriates. Unlabelled Image • Polar metabolites have a higher solubility than their parent hydrocarbons and are potentially bioavailable. • Nine aldehydes ranging from nC 2 -nC 12 were found in hydrocarbon contaminated soil elutriates. • Aldehydes could be potential chemical markers for hydrocarbon degradation. [ABSTRACT FROM AUTHOR]

Extraction of polar endogenous compounds remains an important issue in bioanalysis although different techniques have been evaluated. Among them, electromembrane extraction (EME) is a relevant approach but supported liquid membranes (SLMs) dedicated to polar molecules are still lacking. In this study 22 organic solvents were evaluated as SLMs on a set of 45 polar basic metabolites (log P from −5.7 to 1.5) from various biochemical families. To investigate a large variety of organic solvents, a parallel electromembrane extraction device was used and a constant current approach was applied to circumvent the heterogeneous conductivities of the different SLMs. Among the tested organic solvents, 2-nitrophenyl pentyl ether (NPPE) appeared the most efficient SLM with the extraction of a large variety of polar cationic metabolites, high extraction yields, and low extraction variabilities. The applied current and the composition of the acceptor and donor solutions were also evaluated and 300 μA per well and acetic acid 1% (v/v), both as acceptor and donor compartments, were the most efficient conditions. The new SLM and the optimized experimental parameters were successfully applied to the extraction of precipitated plasma samples. Although the extraction recovery decreased for most compounds in the biological matrix, process efficiency (PE) up to 90% and low extraction variability (RSD between 2 and 18%) were obtained for several very polar compounds such as choline or acetylcholine, emphasizing the potential of EME for polar compounds. [ABSTRACT FROM AUTHOR]

A simple and effective method was developed for analyzing dinotefuran and its three metabolites (MNG, UF, and DN) in plum using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Due to the polarity and high water miscibility, dinotefuran and some of its metabolites (especially DN) have some limitations to be extracted with acetonitrile and salt following the “QuEChERS” sample preparation methodology. Alternatively, the samples were extracted with methanol, and purified with dispersive-solid phase extraction procedure (d-SPE) using primary secondary amine (PSA) and C 18 sorbents after filtration, and mass up. Due to the suppression effect originated from plum matrix, matrix-matched calibration curves, which provided good linearity with coefficient of determination ( R 2 ) ≥ 0.998, were used for quantification of all analytes. Blank plum samples fortified with 2 spiking levels (10 × LOQ and 50 × LOQ) yielded satisfactory recoveries for all tested analytes in the range of 83.01 to 110.18% with relative standard deviation (RSD) ≤ 8.91. The method was successfully applied to field-incurred plum samples and dinotefuran and all metabolites were positively detected and quantified. In conclusion, we suggest that the method can be expanded to polar compounds having solvent and partitioning problems in any of the versions of QuEChERS. [ABSTRACT FROM AUTHOR]

A HILIC-UHPLC–MS/MS untargeted urinary metabonomic method combined with quantitative analysis of five potential polar biomarkers in rat urine was developed and validated, to further understand the anti-osteoporosis effect of Gushudan(GSD) and its mechanism on prednisolone-induced osteoporosis(OP) rats in this study. The metabolites were separated and identified on Waters BEH HILIC (2.1 mm × 100 mm, 1.7 μm) column using the Waters ACQUITY™ ultra performance liquid chromatography system (Waters Corporation, Milford, USA) coupled with a Micromass Quattro Micro™ API mass spectrometer (Waters Corp, Milford, MA, USA). Principal component analysis (PCA) was used to identify potential biomarkers. Primary potential polar biomarkers including creatinine, taurine, betaine, hypoxanthine and cytosine, which were related to energy metabolism, lipid metabolism and amino acid metabolism, were found in the untargeted metabonomic research. Moreover, these targeted biomarkers were further separated and quantified in multiple-reaction monitoring (MRM) with positive ionization mode, using tinidazole as internal standard (I.S.). Good linearities (r > 0.99) were obtained for all the analytes with the low limit of quantification from 1.00 to 12.8 μg/mL. The relative standard deviation (RSD) of the intra-day and inter-day precisions were within 15.0% and the accuracy ranged from −14.3% to 13.5%. The recovery was more than 85.0%. And the validated method was successfully applied to investigate the urine samples of the control group, prednisolone-induced osteoporosis model group and Gushudan-treatment group in rats. Compared to the control group, the level of creatinine, taurine, betaine, hypoxanthine and cytosine in the model group revealed a significant decrease trend (p < 0.05), while the Gushudan-treatment group showed no statistically differences by an independent sample t -test. This paper provided a better understanding of the therapeutic effect and mechanism of GSD on prednisolone-induced osteoporosis rats. [ABSTRACT FROM AUTHOR]

• A HILIC-MS/MS method was developed for direct determination of polar metabolites in cancer metabolic reprogramming. • Nineteen polar metabolites with different chemical properties, including isomers, were determined with high selectivity and sensitivity. • The metabolic profile of patients with prostate cancer is specific compared with the healthy group. Metabolic reprogramming of cancer cells is a hallmark of cancer, in which the polar metabolites involving aerobic glycolysis, pentose phosphate pathway (PPP), tricarboxylic acid (TCA) cycle, and glutaminolysis play a crucial role in the occurrence and development of cancer. Therefore, targeted analysis of the polar metabolites in these pathways is of great value for understanding cancers, finding diagnostic biomarkers, and identifying therapeutic targets. However, it is still challenging to directly determine polar metabolites in these pathways without derivatization due to their diverse chemical properties, isomers, and strong polarity. Herein, a highly selective and sensitive HILIC-MS/MS method was developed for direct determination of the polar metabolites in aerobic glycolysis, PPP, TCA cycle, and glutaminolysis pathways. Without derivatization, 19 polar metabolites and their isomers with carbonyl, carboxyl, or phosphoryl groups in human plasma and cell extracts of prostate cancer (PC) were determined with strong retention and high resolution. This method has been widely verified by measuring linearity, precision, sensitivity, repeatability, matrix effect, and accuracy. The analysis of plasma samples by HILIC-MS/MS revealed distinct PC-specific metabolic signatures compared to a healthy control. In addition, this method could also be used to screen the targets of metabolic inhibitors at the cellular level. We conclude that the developed HILIC-MS/MS method provides a valuable means to study the cancer metabolic reprogramming or energy metabolism in living organisms. [ABSTRACT FROM AUTHOR]

Dynamic metabolic flux analysis requires efficient and effective methods for extraction, purification and analysis of a plethora of naturally-occurring compounds. One area of metabolism that would be highly informative to study using metabolic flux analysis is the tricarboxylic acid (TCA) cycle, which consists of short-chain carboxylic acids. Here, we describe a newly-developed method for extraction, purification, derivatization and analysis of short-chain carboxylic acids involved in the TCA cycle. The method consists of snap-freezing the plant material, followed by maceration and a 12–15 h extraction at −80 °C. The extracts are then subject to reduction (to stabilize β-keto acids), purified by strong anion exchange solid phase extraction and methylated with methanolic HCl. This method could also be readily adapted to quantify many other short-chain carboxylic acids. [ABSTRACT FROM AUTHOR]

• Hard and soft phenotypes showed differential firmness between the inner and the outer mesocarp tissues. • Cell wall analysis indicated changes in galacturonic acid content in both phenotypes. • A differential carbohydrate metabolism was detected between mesocarp tissues. Tissue texture influences the grape berry consumers acceptance. We studied the biological differences between the inner and outer mesocarp tissues in hard and soft berries of table grapes cv NN107. Texture analysis revealed lower levels of firmness in the inner mesocarp as compared with the outer tissue. HPAEC-PAD analysis showed an increased abundance of cell wall monosaccharides in the inner mesocarp of harder berries at harvest. Immunohistochemical analysis displayed differences in homogalacturonan methylesterification and cell wall calcium between soft and hard berries. This last finding correlated with a differential abundance of calcium measured in the alcohol-insoluble residues (AIR) of the inner tissue of the hard berries. Analysis of abundance of polar metabolites suggested changes in cell wall carbon supply precursors, providing new clues in the identification of the biochemical factors that define the texture of the mesocarp of grape berries. [ABSTRACT FROM AUTHOR]

• The properties of a new 1.7 μ m zwitterionic HILIC phase were investigated. • Conditions for the targeted LC-MS/MS of 88 hydrophilic metabolites were optimized. • Untargeted LC-TOF/MS metabolic profiling was also studied using this methodology. • Metabolomic analysis using the BEH Z-HILIC phase was performed on mouse liver extracts. Metabolic phenotyping studies using mouse liver extracts as a model, performed on a novel zwitterionic HILIC UHPLC column, which is based on ethylene-bridged hybrid organic/inorganic particles bonded with sulfobetaine groups and packed into column hardware modified with hybrid surface technology are reported. Initially the chromatographic performance was evaluated under different mobile phase conditions using selected metabolite standards. Following optimization of the chromatographic conditions for 88 hydrophilic metabolites both targeted and untargeted profiling analyses were performed on tissue extracts using LC-MS/MS and LC-TOF/MS, respectively. Chromatographic efficiency parameters such as peak resolution, peak shapes, selectivity and precision in retention and peak areas as well as characteristics that are critical for metabolic profiling analysis such as metabolite coverage and retention time distribution were assessed. The hybrid zwitterionic column exhibited efficient chromatographic separations providing analysis of ca 80 hydrophilic metabolites from different chemical classes and polarities. Utilizing a one-dimensional separation both targeted and untargeted profiling provided comprehensive metabolic signatures that enabled the acquisition of the metabolic phenotypes of the tissue extracts. [ABSTRACT FROM AUTHOR]

Highlights: [•] We developed a novel IP-LC–MS protocol for the identification and quantification of polar metabolites. [•] The IP method resolves biologically interesting molecules with good linearity and repeatability. [•] We demonstrate the versatility of method by determining the metabolomic signature of 3 biological systems. [ABSTRACT FROM AUTHOR]

Abstract: At a mononitrotoluene-contaminated waste disposal site, the groundwater was screened for polar transformation products of mononitrotoluenes, by means of HPLC–MS, HPLC–NMR and further off-line NMR and MS techniques. Besides expected metabolites such as aminotoluenes (ATs) and nitrobenzoic acids (NBAs), three unknowns (di- and tetrahydro-derivatives of (2-oxo-quinolin-3-yl) acetic acid) could be identified which, in the context of explosives and related compounds, are new metabolites. Evidence could be provided by microcosm experiments with 2-nitrotoluene (2-NT) that these metabolites are microbial transformation products of 2-NT under anaerobic conditions. The NMR and MS data are presented and the possible pathway for the formation of these metabolites after addition of 2-NT to fumarate is discussed. [Copyright &y& Elsevier]

Abstract: The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), is widely used to control pre- and post-emergence of grass and broad-leaved weeds in cereal crops. Its degradation in soils is a key process for assessing its leaching risk to groundwater resources. The degradation properties of various samples from surface and subsurface soil (down to 1m depth) of a heterogeneous agricultural field were studied using 14C-IPU. Laboratory incubations were carried out at 22 and 10°C and at water contents 90% and 50% of the estimated water holding capacity (eWHC) corresponding to water potentials between −56kPa and −660MPa. Degradation was found to be more sensitive to water content variations than to temperature variations in the ranges that we used. For surface layers, at 10 and 22°C, the degradation half-life increased by a factor 10 and 15, respectively, when water content decreased from 90% to 50% eWHC. Under optimal degradation conditions (i.e. 22°C and 90% eWHC), 3-(4-isopropylphenyl)-1-methylurea (MDIPU) was the main metabolite in surface samples. At subsurface depths, IPU half-lives were larger than 100d, IPU was the main compound after 92d of incubation and the main metabolite was an unidentified polar metabolite. These results suggest a metabolic pathway involving hydroxylations for subsurface materials. IPU degradation was largely affected by water availability in both surface and subsurface horizons. Clay content seemed to play a major role in degradation processes in subsurface soil by determining through sorption IPU availability in soil solution and/or by limiting water availability for microorganisms. [Copyright &y& Elsevier]

• Key research gaps on the current scenario of antineoplastics have been discussed. • Fate profile of cytostatic compounds depends primarily on physico-chemical nature. • Resistance to chemotherapy correlates with the cellular toxicity of antineoplastics. • The polar and solubility nature of pyrimidine analogues renders water contamination. • Oxidative degradation cost-effectively removes mutagenicity of Anthracyclines. Antineoplastics (anticancer agents) i.e. alkylating and non-alkylating agents, topoisomerase inhibitors etc. are classified as the contaminants of emerging concern due to growing concern about environmental health degradation. Such cytostatic agents contain a suit of functional groups (i.e. folic acid/purine/pyrimidine/nitrogen analogues), which render their complex chemistry and determine partitioning in the aquatic systems. A systematic review of the recent literature published between 2009 and 2020 has been presented to validate the hypothesis that the environmental fate, distribution, and removal aspects of chemotherapeutic agents depend largely on the structural orientation, environmental (and genetic) factors, and degree of ionization. The key knowledge gaps on the current challenges and opportunities of research trends of cytostatic drugs (and their derivatives) in the environment have been identified and critically discussed. This review provides an overview of risk assessment of pyrimidine antimetabolites and topoisomerase inhibitors, which is need of the hour considering their increasing consumption and state-of-the-art analytical detection. The main focus of the review is that a cocktail mixture of tamoxifen, 5-fluorouracil and other active metabolites of polar, water soluble antineoplastic agents may have the accumulation effect on the aquatic species. They can spread drug resistance via their interaction with some kinases. [ABSTRACT FROM AUTHOR]

• Six HILIC and one RPLC columns are tested for polar metabolites. • A decision tree-based univariate approach is used to optimize HILIC-MS methods. • 99% of analytical panel standards can successfully be separated and detected. • Human urine, plasma and liver cells show thousands of features with mRSD < 25%. • Hundreds of metabolites were annotated in biological samples with L1 or L2 confirmation. The analysis of polar metabolites based on liquid chromatography-mass spectrometry (LC-MS) methods should take into consideration the complexity of interactions in LC columns to be able to cover a broad range of metabolites of key biological pathways. Therefore, in this study, different chromatographic columns were tested for polar metabolites including reversed-phase and hydrophilic interaction liquid chromatography (HILIC) columns. Based on a column screening, two new generations of zwitterionic HILIC columns were selected for further evaluation. A tree-based method optimization was applied to investigate the chromatographic factors affecting the retention mechanisms of polar metabolites with zwitterionic stationary phases. The results were evaluated based on a scoring system which was applied for more than 80 polar metabolites with a high coverage of key human metabolic pathways. The final optimized methods showed high complementarity to analyze a wide range of metabolic classes including amino acids, small peptides, sugars, amino sugars, phosphorylated sugars, organic acids, nucleobases, nucleosides, nucleotides and acylcarnitines. Optimized methods were applied to analyze different biological matrices, including human urine, plasma and liver cell extracts using an untargeted approach. The number of high-quality features (< 30% median relative standard deviation) ranged from 3,755 for urine to 5,402 for the intracellular metabolome of liver cells, showing the potential of the methods for untargeted purposes. [ABSTRACT FROM AUTHOR]

This study determined the effects of low-pulsed electric field (LPEF-2.5 kV, 50 Hz, 20 μs) and high-PEF (HPEF-10 kV, 50 Hz, 20 μs) on the quality attributes and metabolite profiles of wet and dry aged venison M Longissimus dorsi (LD) muscles. Twelve loins from six red deer at 24 h postmortem were randomly assigned to seven treatments: No-PEF control (WAC), heated control (HC), dry aged No-PEF control (DAC), wet aged LPEF (WALPEF), dry aged LPEF (DALPEF), wet aged HPEF (WAHPEF), and dry aged HPEF (DAHPEF). Samples were aged 21d at 4 °C at 80% relative humidity. HPEF treatment improved meat tenderness by 9%. Metabolite profiles were unaffected by all PEF treatment groups with key differences found due to ageing method. These observations demonstrate the viability of HPEF in improving drying rate (by 6%) and tenderisation of venison LD muscle during the dry ageing process, which will improve product quality and production efficiency. The study shows that the use of PEF can improve mass transfer and enhance drying kinetics leading to reduced processing time and improved control over weight loss in the dry ageing of venison. Application of high PEF treatment (HPEF - 10 kV, 50 Hz, 20 μs) offers improved meat tenderness and no detrimental effect to product metabolomics, thereby increasing the product quality and value of the aged venison. • Meat tenderness was improved by high PEF (10 kV, 50 Hz, 20 μs) treatment. • The observed tenderization was mainly the result of myofibril disruption. • Wet and dry ageing processes achieved similar meat tenderness. • NMR-based metabolomics showed no effect due to PEF treatment. • Glucose and mannose flavour precursors were higher in dry aged venison. [ABSTRACT FROM AUTHOR]