LC-QTOF MS Research Articles

High-Throughput Determination of Major Mycotoxins with Human Health Concerns in Urine by LC-Q TOF MS and Its Application to an Exposure Study.

Human biomonitoring constitutes a suitable tool to assess exposure to toxins overcoming the disadvantages of traditional methods. Urine constitutes an accessible biological matrix in biomonitoring studies. Mycotoxins are secondary metabolites produced naturally by filamentous fungi that produce a wide range of adverse health effects. Thus, the determination of urinary mycotoxin levels is a useful tool for assessing the individual exposure to these food contaminants. In this study, a suitable methodology has been developed to evaluate the presence of aflatoxin B2 (AFB2), aflatoxin (AFG2), ochratoxin A (OTA), ochratoxin B (OTB), zearalenone (ZEA), and α-zearalenol (α-ZOL) in urine samples as exposure biomarkers. For this purpose, different extraction procedures, namely, the Solid Phase Extraction (SPE); Dispersive Liquid–Liquid Microextraction (DLLME); and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods were assessed, followed by Liquid Chromatography coupled to Quadrupole Time of Flight Mass Spectrometry with Electrospray Ionization (LC-ESI-QTOF-MS) determination. Then, the proposed methodology was applied to determine mycotoxin concentrations in 56 human urine samples from volunteers and to estimate the potential risk of exposure. The results obtained revealed that 55% of human urine samples analyzed resulted positive for at least one mycotoxin. Among all studied mycotoxins, only AFB2, AFG2, and OTB were detected with incidences of 32, 41, and 9%, respectively, and levels in the range from <LOQ to 69.42 µg/L. Risk assessment revealed a potential health risk, obtaining MoE values < 10,000. However, it should be highlighted that few samples were contaminated, and that more data about mycotoxin excretion rates and their BMDL10 values are needed for a more accurate risk assessment.

A NIR, 1H-NMR, LC-MS and chemometrics pilot study on the origin of carvedilol drug substances: a tool for discovering falsified active pharmaceutical ingredients

The study explores the profile of carvedilol active ingredients by NIR, 1H-NMR and LC-MS Q-TOF and data were analysed by PCA, cluster analysis and PLSDA. Two different groups of manufacturers based on the geographical area are classified.

Cyclotide-rich fractions containing nanofibers by electrospinning: preparation, characterization and examination of antimicrobial activity.

In this study, antimicrobial nanofibers were produced with the mixtures of polyvinyl alcohol (PVA) and cyclotide-rich fractions by electrospinning method. After extraction, the first separation was carried out with C18 flash chromatography and then fractioned into five separate parts by reversed-phase high-pressure liquid chromatography (RP-HPLC). The molecular weights of cyclotides in each fraction were determined by quadrupole time-of-flight liquid chromatography-mass spectrometry (Q-TOF LC-MS). Cyclotide-rich fractions were mixed with 10% of PVA solution and nanofibers were produced from this biocomposite mixture by electrospinning method. The nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), and it was observed that 100% peptide-containing nanofibers (cyclotide-rich fraction/10% PVA, w/v) had more regular fiber textures. The presence of the peptides in the nanofiber was also confirmed by analytical RP-HPLC, as the peptides in both peptide fractions and nanofiber solutions have the same retention times. The nanofibers produced with the fourth cyclotide-rich fraction showed activity against gram-positive bacteria (Bacillus cereus) in antimicrobial susceptibility test. As a result of these findings, cyclotide-containing nanofibers with antimicrobial activity can be produced for pharmaceutical research and development studies.

Recovery of antioxidant from Decapterus Macarellus waste using wet rendering method

In Malaysia, Decapterus Maruadsi is widely used as the main ingredient in food products such as ‘keropok lekor’ and fish cracker. The wastes generated from the fish snack industry are underutilized and most are discarded into the sea, generating considerable environmental pollution. The recovery of antioxidants in the fish wastes could lead to the development of a very exciting and promising alternative source of commercial antioxidant compounds. The objective of the present work is to investigate the effect of temperature, type of solvent, extraction time, and ratio of sample to solvent loading in the extraction of antioxidants from Decapterus Maruadsi waste using the wet rendering method. The collected fish waste of Decapterus Maruadsi was pre-treated and then subjected to a wet rendering treatment at 0–60 °C for 30–150 min with ratio of sample to solvent loading of between 1:10 and 9:10 (w/v). The presence of antioxidant in the extract was analyzed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Total Phenolic Compound (TPC) assays. Based on the results of this study, wet rendering treatment performed for 90 min at 30 °C with a ratio of sample to solvent loading of 3:10 produced an extract with the highest concentration of active antioxidant compounds. Besides, only N-Acetyl-glutamic acid was identified with LCMS QTOF analysis. These results suggest that the fish waste of Decapterus Maruadsi can be exploited to become a source of antioxidants for food and pharmaceutical applications.

Isolation of amygdalin epimer at high diastereomeric purity and its structural characterization by spectroscopic and Q-TOF LC-MS methods

Isolation of amygdalin epimer at high diastereomeric purity and its structural characterization by spectroscopic and Q-TOF LC-MS methods

Multiplexed Analysis of Endogenous Guanidino Compounds via Isotope-Coded Doubly Charged Labeling: Application to Lung Cancer Tissues as a Case.

Endogenous guanidino compounds (GCs), nitrogen-containing metabolites, have very important physiological activities and participate in biochemical processes. Therefore, accurately characterizing the distribution of endogenous GCs and monitoring their concentration variations are of great significance. In this work, a new derivatization reagent, 4,4'-bis[3-(dimethylamino)propyl]benzyl (BDMAPB), with isotope-coded reagents was designed and synthesized for doubly charged labeling of GCs. BDMAPB-derivatized GCs not only promote the MS signal but also form multicharged quasimolecular ions and abundant fragment ions. With this reagent, an isotope-coded doubly charged labeling (ICDCL) strategy was developed for endogenous GCs with high-resolution liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF MS). The core of this methodology is a 4-fold multiplexed set of [d0]-/[d4]-/[d8]-/[d12]-BDMAPB that yields isotope-coded derivatized GCs. Following a methodological assessment, good linear responses in the range of 25 nM to 1 μM with correlation coefficients over 0.99 were achieved. The limit of detection and the limit of quantitation were below 5 and 25 nM, respectively. The intra- and interday precisions were less than 18%, and the accuracy was in the range of 77.3-122.0%. The percentage recovery in tissues was in the range of 85.1-113.7%. The results indicate that the developed method facilitates long-term testing and ensures accuracy and reliability. Finally, the method was applied for the simultaneous analysis of endogenous GCs in four types of lung tissues (solid adenocarcinoma, solid squamous-cell carcinoma, ground-glass carcinoma, and paracancerous tissues) for absolute quantification, nontargeted screening, and metabolic difference analysis. It is strongly believed that ICDCL combined with isotope-coded BDMAPB will benefit the analysis and study of endogenous GCs.

Preparation, Characterization and Antibacterial Activity of Malva Sylvestris L. Seed Extract Containing Novel Electrospun PVA Nanofibers

Medicinal plants have been a great source for pharmaceutical agents. However, prossessing these raw sources to turn into therapeutic drugs requires highly complex technologies and expensive methods. Malva sylvestris L. is a commonly used vegetable in traditional and ethnoveterinary medicine because of its antimicrobial and anti-inflammatory properties. Therefore, in this study we used PVA/M. sylvestris L. seed (MSs) extract biocomposites to produce nanofibers with electrospun technique. M. sylvestris L. seed extracts were prepared and divided into fractions with 20% ACN. The metabolites in MSs extract characterized by Q-TOF LC-MS. Biocomposites with different ratios of both polymer and extract were prepared for nanofiber production. Bionanofibers have been produced from these biocomposites with optimized electrospinning conditions and their morphological analysis has been performed using SEM and FTIR techniques. Nanofibers had average diameters within the range of ∼180–244 nm. They were also found to have antibacterial activity against several microorganisms including Gram-negative (P.aeruginosa and E.coli) and Gram-positive (S.aureus and E.faecalis) bacteria. These newly generated bionanofibers with antibacterial properties hold great potential to be used in medical applications and food packaging.

Urine Drug Screening in the Era of Designer Benzodiazepines: Comparison of Three Immunoassay Platforms, LC-QTOF-MS and LC-MS-MS.

This study investigated the presence of designer benzodiazepines in 35 urine specimens obtained from emergency department patients undergoing urine drug screening. All specimens showed apparent false-positive benzodiazepine screening results (i.e., confirmatory testing using a 19-component liquid chromatography-tandem mass spectrometry (LC-MS-MS) panel showed no prescribed benzodiazepines at detectable levels). The primary aims were to identify the possible presence of designer benzodiazepines, characterize the reactivity of commercially available screening immunoassays with designer benzodiazepines and evaluate the risk of inappropriately ruling out designer benzodiazepine use when utilizing common urine drug screening and confirmatory tests. Specimens were obtained from emergency departments of a single US Health system. Following clinically ordered drug screening using Abbott ARCHITECT c assays and laboratory-developed LC-MS-MS confirmatory testing, additional characterization was performed for investigative purposes. Specifically, urine specimens were screened using two additional assays (Roche cobas c502 and Siemens Dimension Vista) and LC-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) to identify presumptively positive species, including benzodiazepines and non-benzodiazepines. Finally, targeted, qualitative LC-MS-MS was performed to confirm the presence of 12 designer benzodiazepines. Following benzodiazepine detection using the Abbott ARCHITECT, benzodiazepines were subsequently detected in 28/35 and 35/35 urine specimens using Siemens and Roche assays, respectively. LC-QTOF-MS showed the presumptive presence of at least one non-Food and Drug Administration (FDA)-approved benzodiazepine in 30/35 specimens: flubromazolam (12/35), flualprazolam (11/35), flubromazepam (2/35), clonazolam (4/35), etizolam (9/35), metizolam (5/35), nitrazepam (1/35) and pyrazolam (1/35). Two or three designer benzodiazepines were detected concurrently in 13/35 specimens. Qualitative LC-MS-MS confirmed the presence of at least one designer benzodiazepine or metabolite in 23/35 specimens, with three specimens unavailable for confirmatory testing. Urine benzodiazepine screening assays from three manufacturers were cross-reactive with multiple non-US FDA-approved benzodiazepines. Clinical and forensic toxicology laboratories using traditionally designed LC-MS-MS panels may fail to confirm the presence of non-US FDA-approved benzodiazepines detected by screening assays, risking inappropriate interpretation of screening results as false positives.

Effect of Selected Trichoderma Strains and Metabolites on Olive Drupes

Beneficial fungal strains of the genus Trichoderma are used as biofungicides and plant growth promoters. Trichoderma strains promote the activation of plant defense mechanisms of action, including the production of phenolic metabolites. In this work, we analyzed the effects of selected Trichoderma strains (T. asperellum KV906, T. virens GV41, and T. harzianum strains TH1, M10, and T22) and their metabolites (harzianic acid and 6-pentyl-α-pyrone) on drupes of young olive trees (4-year-old) cv. Carolea. This study used the untargeted analysis of drupe metabolome, carried out by LC–MS Q-TOF, to evaluate the phenolics profiles and target metabolomics approach to detect oleuropein and luteolin. The untargeted approach showed significant differences in the number and type of phenolic compounds in olive drupes after Trichoderma applications (by root dipping and drench soil irrigation method) compared to control. The levels of oleuropein (secoiridoid) and luteolin (flavonoid) varied according to the strain or metabolite applied, and in some cases, were less abundant in treated plants than in the control. In general, flavonoids’ levels were influenced more than secoiridoid production. The dissimilar aptitudes of the biological treatments could depend on the selective competence to cooperate with the enzymes involved in producing the secondary metabolites to defend plants by environmental stresses. Our results suggest that using selected fungi of the genus Trichoderma and their metabolites could contribute to selecting the nutraceutical properties of the olive drupe. The use of the metabolites would bring further advantages linked to the dosage in culture and storage.

Degradation of imatinib mesylate by manganese peroxidase (MnP): Optimization, identification of transformation products, pathway proposal and in silico predictions

Imatinib (IMB) is an antineoplastic agent used as kinase inhibitor in the treatment of chronic myeloid leukemia. IMB can introduce endocrine and mutagenic disrupting effects, which could adversely impact the environmental due to its commercialization and expanded use in recent years. The fungal ligninolytic enzyme manganese peroxidase (MnP) is a powerful oxidant agent that oxidizes Mn2+ to Mn3+ and promotes degradation of organic pollutants as pharmaceuticals. In this work, the efficiency of MnP for degradation of IMB in distilled water (DW) and simulated wastewater (SW) was evaluated. As a first stage, the experimental condition was optimized using the Doehlert design, response surface methodology, and the desirability profile. The results demonstrated that 1.12 U L-1 of MnP, 1.87 mmol L-1 of hydrogen peroxide, and 0.755 mmol L-1 of Mn2+ created optimal conditions within 4 h of enzymatic treatment in both aqueous matrices. The IMB degradation in both study matrices was observed within a reaction time of 8 h, achieving degradation percentages of 68% ± 4 in DW and 47% ± 7 in SW by the end of the experiment. Control experiments were also conducted to verify the synergy between MnP, Mn ions, and H2O2 on degradation experiments. Sixteen new transformation products (TPs) were elucidated by LC-QTOF MS using two diverse and complementary chromatographic methods. According to (Q)SAR tools, most of the TPs showed the development of toxicity and no biodegradability characteristics; however, the mutagenicity potential decreased compared to the parental IMB, which is an encouraging result considering the mutagenic characteristic of IMB.

Detection of Serotonin, Melatonin, and Their Metabolites in Honey.

Melatonin and serotonin, products of tryptophan metabolism, are endogenous neurotransmitters and hormones. We have identified and quantified these metabolites in natural honey from Australia, USA, and Poland using a Xevo G2 XS qTof LC-MS. To help ensure correct product identification, some samples were prepurified by RP-HPLC based on the retention times of standards, prior to LC-MS. The concentrations of the metabolites of interest depended on the source of the honey. For Australian honey, levels for melatonin and 2-hydroxymelatonin were 0.91 and 0.68 ng/g, respectively. Melatonin was detected in one brand of US commercial honey at 0.48 ng/g, while a second brand contained serotonin at 88.2 ng/g. In Polish natural honey, 20.6 ng/g of serotonin and 40.8 ng/g of N-acetylserotonin (NAS) were detected, while in Polish commercial honey 25.9 ng/g of serotonin and 7.30 ng/g of NAS were present. We suggest that addictive and health-related properties of honey may be in part dependent on the presence of serotonin, melatonin, and their metabolites, and that these compounds may play a role in the colony activities of bees.

Multi-criteria decision-making techniques associated with (Q)SAR risk assessment for ranking surface water microcontaminants identified using LC-QTOF MS

Contaminants of emerging concern (CECs) have been a focus of study for years, with investigations revealing the contamination of different environmental matrices (surface water, soil, air, and sediment) by diverse classes of microcontaminants. Understanding the contamination profiles requires identification and risk assessment of the microcontaminants. In the present work, analysis was made of the presence of 3250 compounds in 27 samples from the Conceição River (Rio Grande do Sul State, Brazil), using an SPE-LC-QTOF MS method. In total, 150 microcontaminants (confirmed and suspected) of different classes, especially pesticides and pharmaceuticals, were identified by an initial qualitative analysis. Subsequently, in silico predictions of eight endpoints, using quantitative structure-activity relationship ((Q)SAR) models, were employed to determine the risk of each previously screened microcontaminant. This large amount of (Q)SAR data, frequently with conflicting information in relation to the responses of the different endpoints, makes it difficult to define which microcontaminants should be prioritized for analysis. Therefore, in order to rank the identified microcontaminants by risk assessment, two multi-criteria decision-making (MCDM) ranking techniques (ToxPi and TOPSIS), associated with a weighting method, were performed to establish the order of priority for further quantitative analysis of the most hazardous microcontaminants. The two rankings were statistically similar, especially for the 20 highest priority microcontaminants. Nonetheless, sensitivity tests carried out for the ToxPi and TOPSIS outputs showed higher performance robustness of TOPSIS, compared to ToxPi. This is the first time that such an approach (screening/(Q)SAR/MCDM methods) has been performed in the context of microcontaminant environmental risk evaluation and demonstrated to be an available strategy to help rank the most concern microcontaminants identified in aqueous environment samples.

Bioformulations with Beneficial Microbial Consortia, a Bioactive Compound and Plant Biopolymers Modulate Sweet Basil Productivity, Photosynthetic Activity and Metabolites.

Increasing attention is being given to the development of innovative formulations to substitute the use of synthetic chemicals to improve agricultural production and resource use efficiency. Alternatives can include biological products containing beneficial microorganisms and bioactive metabolites able to inhibit plant pathogens, induce systemic resistance and promote plant growth. The efficacy of such bioformulations can be increased by the addition of polymers as adjuvants or carriers. Trichoderma afroharzianum T22, Azotobacter chroococcum 76A and 6-pentyl-α-pyrone (6PP; a Trichoderma secondary metabolite) were administrated singularly or in a consortium, with or without a carboxymethyl cellulose-based biopolymer (BP), and tested on sweet basil (Ocimum basilicum L.) grown in a protected greenhouse. The effect of the treatments on basil yield, photosynthetic activity and secondary metabolites production was assessed. Photosynthetic efficiency was augmented by the applications of the bioformulations. The applications to the rhizosphere with BP + 6PP and BP + T22 + 76A increased the total fresh weight of basil by 26.3% and 23.6%, respectively. Untargeted LC-MS qTOF analysis demonstrated that the plant metabolome was significantly modified by the treatments. Quantification of the profiles for the major phenolic acids indicated that the treatment with the T22 + 76A consortium increased rosmarinic acid content by 110%. The use of innovative bioformulations containing microbes, their metabolites and a biopolymer was found to modulate the cultivation of fresh basil by improving yield and quality, thus providing the opportunity to develop farming systems with minimal impact on the environmental footprint from the agricultural production process.

Cross platform solutions to improve the zebrafish polar metabolome coverage using LC-QTOF MS: Optimization of separation mechanisms, solvent additives, and resuspension solvents

Untargeted metabolomics has been widely used for studies with zebrafish embryos. Until now, the number of analytical approaches to determine metabolites in zebrafish is limited, and there is a lack of consensus on the best platforms for comprehensive metabolomics analysis of zebrafish embryos. In addition, the capacity of these methods to detect metabolites is unsatisfactory and the confidence level for identifying compounds is relatively low. To improve the metabolome coverage, we mainly focused on the optimization of separation mechanisms, mobile phase additives, and resuspension solvents based on liquid chromatography (LC) coupling to high-resolution mass spectrometry (HRMS) techniques. Moreover, the procedures for optimizing methods were assessed when taking metabolite profiles in both positive and negative ionization modes into account. Four LC columns were studied: C18, T3, PFP, and HILIC. In positive ionization mode, it was strongly recommended to employ the HILIC approach operated at the neutral condition, which led to the presence of more than 4700 features and the annotation of 151 metabolites, mainly zwitterionic and basic compounds, in comparison to reverse phase (RP)-based methods with less than 1000 features. In negative ionization mode, the PFP column operated at 0.02% acetic acid showed the best performance in terms of metabolite coverage: 3100 metabolic features were detected and 218 metabolites were annotated in zebrafish embryos. Metabolite profiles mainly contained acidic and zwitterionic compounds. HILIC-based platforms were complementary to RP columns when analyzing highly polar metabolites. Additionally, it was preferable to reconstitute zebrafish extracts in 100% water for analysis of metabolites on RP columns, with a 20–30% increase in the number of identified metabolites compared to a 50% water in methanol solution. However, water/methanol (1:9, v/v), as resuspension solution, was advantageous over water/methanol (1:1, v/v) for HILIC analysis showing an 8–15% increase in detected metabolites. In total 336 polar metabolites were annotated by the combination of the optimized HILIC (positive) and PFP (negative) approaches. The largest metabolome coverage of polar metabolites in zebrafish embryos was obtained when three approaches were combined (negative PFP and HILIC, and HILIC positive) resulting in more than 420 annotated compounds.

Chemical and Biological Profiles of Dendrobium in Two Different Species, Their Hybrid, and Gamma-Irradiated Mutant Lines of the Hybrid Based on LC-QToF MS and Cytotoxicity Analysis.

The Dendrobium species (Orchidaceae) has been cultivated as an ornamental plant as well as used in traditional medicines. In this study, the chemical profiles of Dendrobii Herba, used as herbal medicine, Dendrobium in two different species, their hybrid, and the gamma-irradiated mutant lines of the hybrid, were systematically investigated via ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QToF MS). Among the numerous peaks detected, 17 peaks were unambiguously identified. Gigantol (1), (1R,2R)-1,7-hydroxy-2,8-methoxy-2,3-dihydrophenanthrene-4(1H)-one (2), tristin (3), (−)-syringaresinol (4), lusianthridin (5), 2,7-dihydroxy-phenanthrene-1,4-dione (6), densiflorol B (7), denthyrsinin (8), moscatilin (9), lusianthridin dimer (10), batatasin III (11), ephemeranthol A (12), thunalbene (13), dehydroorchinol (14), dendrobine (15), shihunine (16), and 1,5,7-trimethoxy-2-phenanthrenol (17), were detected in Dendrobii Herba, while 1, 2, and 16 were detected in D. candidum, 1, 11, and 16 in D. nobile, and 1, 2, and 16 in the hybrid, D. nobile × candidum. The methanol extract taken of them was also examined for cytotoxicity against FaDu human hypopharynx squamous carcinoma cells, where Dendrobii Herba showed the greatest cytotoxicity. In the untargeted metabolite analysis of 436 mutant lines of the hybrid, using UPLC-QToF MS and cytotoxicity measurements combined with multivariate analysis, two tentative flavonoids (M1 and M2) were evaluated as key markers among the analyzed metabolites, contributing to the distinction between active and inactive mutant lines.

Optimized Preparation of Urine Samples from Acute Melioidosis Patients for In-Solution Proteomic Studies using LCMS QTOF or MALDI TOF MS

Introduction: Investigation of urine proteome in patients with acute melioidosis may reveal potential disease markers, from either bacterial or human proteins. We used an in-solution gel-free method instead of 2-DE to detect human and Burkholderia pseudomallei proteins in urine of patients with acute melioidosis. Here, we propose a simpler, economical method for preparing urine samples directly from melioidosis patients, for in-solution proteomic analysis using LCMS-QTOF MS/MS or MALDI-TOF MS/MS. Material and Methods: We adapted an acetone-TCA based protein precipitation method with LCMS-QTOF MS to detect the B. pseudomallei proteins directly from urine of acute melioidosis patients (culture positive and negative). This process involves protein precipitation, desalting, trypsin digestion, and optimization for the mass spectrometry. Results: A total of 3,866 human peptides were detected across 11 urine samples from clinically suspected acute melioidosis patients. Among them were three Burkholderia specific proteins detected in 75% of culture positive samples. Large amounts of acute phase proteins, cell mediated immunity proteins, complement pathway proteins and inflammatory mediators were seen upon gene ontology (GO) annotation and GO enrichment analysis. Conclusions: This simple in-solution sample preparation method can be replicated easily for LCMS/MS-QTOF and MALDI-TOF proteomic analyses, avoiding tedious optimization steps in 2-DE. This method is cost effective and can be done in centres without specialized 2-DE or MS equipment and elutes can be easily transported for analysis and bioinformatics. This is the first study to analyse urine samples directly for B. pseudomallei proteins. Discovery of the entire proteome as a whole is important in leading to biomarker discovery.

Burkholderia Pseudomallei Short-Chain Dehydrogenase/ Oxidoreductase: Potential Urine Biomarker Candidate for Acute Melioidosis

INTRODUCTION: In the current climate of urgency in identifying biomarkers for the development of rapid diagnostic kits, the use of urine samples to diagnose acute melioidosis was evaluated, comparing urine samples from Burkholderia pseudomallei culture-positive and culture-negative patients, and comparing pneumonic and septicemic melioidosis. MATERIAL AND METHODS: Eleven urine samples from clinically suspected melioidosis patients from a tertiary referral center, Hospital Tengku Ampuan Afzan, Pahang was used. An in-solution method for the detection of bacterial proteins using liquid chromatography-mass spectrometry quadrupole time-of-flight (LCMS QTOF) was used. RESULTS: Three bacterial proteins were consistently detected among all the culture[1]positive and PCR-positive cases tested, namely SDR family NAD(P)-dependent oxidoreductase protein (32kDa), 3-hydroxyacyl-CoA dehydrogenase Burkholderia sp. (32kDa), and NAD(P)-dependent dehydrogenase (short-subunit alcohol dehydrogenase family) Burkholderia sp. (33kDa). CONCLUSIONS: Short-chain dehydrogenase (SDO) proteins could potentially be a urine biomarker candidate as these have shown to aid in the ability of Burkholderia spp. to invade host cells as this action is important for the initial intracellular survival of the organism.

Identification of unknown disinfection byproducts in drinking water produced from Taihu Lake source water

Although disinfection byproducts (DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry (LC-QTOF MS) to identify the unknown disinfection byproducts (DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surrounding regions. In total, 91 formulas of DBPs were discovered through LC-QTOF MS nontarget screen, 81 of which have not yet been reported. Among the 91 molecules, 56 only contain bromine, 15 only contain chlorine and 20 DBPs have both bromine and chlorine atoms. Finally, five DBPs including 2,4,6-tribromophenol, 2,6-dibromo-4-chlorophenol, 2,6-dichloro-4-bromophenol, 4-bromo-2,6-di-tert-butylphenol and 3,6-dibromocarbazole were confirmed using standards. The former three compounds mainly formed in the predisinfection step (maximum concentration, 0.2-2.6 µg/L), while the latter two formed in the disinfection step (maximum concentration, 18.2-33.6 ng/L). In addition, 19 possible precursors of the discovered DBPs were detected, with the aromatic compounds being a major group. 2,6-di-tert-butylphenol as the precursor of 4-bromo-2,6-di-tert-butylphenol was confirmed with standard, with a concentration of 20.3 µg/L in raw water. The results of this study show that brominated DBPs which are possibly formed from industrial pollutants are relevant DBP species in drinking water produced form Taihu source water, suggesting protection of Taihu Lake source water is important to control the DBP risks.

Pesticides in surface water from Brazil and Paraguay cross-border region: Screening using LC-QTOF MS and correlation with land use and occupation through multivariate analysis

In this study, the presence of pesticides in surface water from Brazil and Paraguay cross-border region was investigated by application of screening method based on Liquid Chromatography coupled to Quadrupole-Time of Flight mass spectrometry (LC-QTOF MS). The main results indicated screening of 43 pesticides from different classes, being herbicide, fungicide, and insecticide the most tentatively identified classes. From these 43 compounds, 36 were tentatively identified in rivers located in Brazil and 28 in rivers located in Paraguay. The most frequently detected compounds were atrazine and its metabolites (desethylatrazine (DEA), 2-hydroxy-atrazine and desisopropylatrazine (DIA)) and, also dinoterb and 8-hydroxyquinoline. Screening data and land use were subjected to cluster analysis (CA) and the 24 monitoring sites were classified from relatively low pollution to high pollution. Principal Component Analysis (PCA) was carried out a multivariate exploratory investigation of pesticides data and their relationship with land use. Open access software was used to predict in silico persistence and toxicity of the compounds, being fipronil TPs and difeconazole present the highest persistence time.

Understanding the effects of Moringa oleifera in chronic unpredictable stressed zebrafish using metabolomics analysis

Ethnopharmacological relevanceMoringa leaves have been used for thousands of years to maintain skin health and mental fitness. People also use it to relieves pain and stress. Aim of the studyTo determine the effects of Moringa oleifera leaves ethanol-aqueous (ratio 7:3) extract (MOLE) on the chronically stressed zebrafish. MethodThe changes in the stress-related behaviour and the metabolic pathways in response to MOLE treatment in zebrafish were studied. A chronic unpredictable stress model was adopted in which zebrafish were induced with different stressors for 14 days. Stress-related behaviour was assessed using a depth-preference test and a light and dark test. Three doses of MOLE (500, 1000, and 2000 mg/L) were administered to the zebrafish. Upon sacrifice, the brains were harvested and processed for LC-MS QTOF based, global metabolomics analysis. ResultsWe observed significant changes in the behavioural parameters, where the swimming time at the light phase and upper phase of the tank were increased in the chronically stressed zebrafish treated with MOLE compared to those zebrafish which were not treated. Further, distinctive metabolite profiles were observed in zebrafish with different treatments. Several pathways that shed light on effects of MOLE were identified. MOLE is believed to relieve stress by regulating pathways that are involved in the metabolism of purine, glutathione, arginine and proline, D-glutamine, and D-glutamate. ConclusionMOLE is potentially an effective stress reliever. However, its effects in human needs to be confirmed with a systematic randomised control trial.