Currently, there is a growing demand by our society, authorities and science to increase the knowledge about the quality of food and its relationship with health and disease. Untargeted metabolomics ...approaches are emerging as powerful tools for exploring metabolic changes in biological systems under different conditions with great potential in the food field. To this aim, it is necessary to apply advanced analytical techniques, such as chromatography hyphenated to high resolution mass spectrometry, which provides enough sensitivity and selectivity to cover a wide range of metabolites in complex samples, as food and biological samples. The objective of this work is to provide an overview of the most widely adopted strategies based on the use of high resolution mass spectrometry-based techniques for the identification of food (bio)markers through the untargeted metabolomics workflow. Detailed information is provided about the trends in each stage of the metabolomics process from updated literature with the objective to help researchers to select the most appropriate metabolic approaches.
•Updated review (2017–2020) of untargeted metabolomics strategies applied on food field.•Advances in LC, GC and HRMS greatly contributed to food (bio)markers research.•Trends and future of HRMS-based untargeted metabolomics strategies are discussed.•Applications on food processing, food intake and food health effects are reviewed.
Recently, the high analytical power provided by the new HRMS instruments (working in the MS or MS/MS mode, stand alone or hyphenated with separation techniques) is making more feasible the ...characterization of plant secondary metabolites. In this regard, HRMS-based techniques are becoming the technique of choice, since they are capable of answering many questions regarding the analytical characterization of secondary metabolites, usually found in very complex matrices, including their structural elucidation and quantification in a very fast and sensitive way. In this manuscript we will provide a critical and updated revision of this topic covering the works published in the last 4 years (2015–2018), including the different configurations in which HRMS may be used (stand alone or hyphenated), the data treatment, the strategies for the identification of unknown metabolites, the current software for structure elucidation, as well as the last trends and future outlooks in this hot area of research.
•Recent HRMS-based applications for plant secondary metabolites are reviewed.•Stand alone or hyphenated HRMS configurations are discussed and compared.•A broad variety of databases and HRMS-data mining strategies are presented.•Future challenges in dereplication and metabolite profiling are emphasized.
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•New system of IPs taking full advantage of the capabilities of HRMS instruments.•Novel comprehensive HRMS quantitative target method to analyze 2316 micropollutants.•Decision limit ...(CCα) and detection capability (CCβ) introduced in the validation.•398 pollutants were detected and quantified in real wastewater.
This study presents the development and validation of a comprehensive quantitative target methodology for the analysis of 2316 emerging pollutants in water based on Ultra-Performance Liquid Chromatography Quadrupole-Time-Of-Flight Mass Spectrometry (UPLC-Q-ToF-HRMS/MS). Target compounds include pesticides, pharmaceuticals, drugs of abuse, industrial chemicals, doping compounds, surfactants and transformation products, among others. The method was validated for 195 analytes, chosen to be representative of the chemical space of the target list, enabling the assessment of the performance of the method. The method involves a generic sample preparation based on mixed mode solid phase extraction, a UPLC-QTOF-MS/MS screening method using Data Independent Acquisition (DIA) mode, which provides MS and MS/MS spectra simultaneously and an elaborate strong post-acquisition evaluation of the data. The processing method was optimized to provide a successful identification rate >95 % and to minimize the number of false positive results (< 5 %). Decision limit (CCα) and detection capability (CCβ) were also introduced in the validation scheme to provide more realistic metrics on the performance of a HRMS-based wide-scope screening method. A new system of identification points (IPs) based on the one described in the Commission Decision 2002/657/EC was applied to communicate the confidence level in the identification of the analytes. This system considers retention time, mass accuracy, isotopic fit and fragmentation; taking full advantage of the capacities of the HRMS instruments. Finally, 398 contaminants were detected and quantified in real wastewater.
Highlights • Snapshot of approaches of illicit chemists to synthesis of new cannabinoids. • Analysis of reasons of popularity of smoke mixtures. • The structures of five new synthetic cannabinoids ...are determined. • New group of cannabinoids, indazole-3-carboxylates, is classified. • MS, HRMS, HRMS/MS, NMR and FT-IR spectra of new cannabinoids are presented.
Genetic improvement for drought tolerance in chickpea requires a solid understanding of biochemical processes involved with different physiological mechanisms. The objective of this study is to ...demonstrate genetic variations in altered metabolic levels in chickpea varieties (tolerant and sensitive) grown under contrasting water regimes through ultrahigh‐performance liquid chromatography/high‐resolution mass spectrometry‐based untargeted metabolomic profiling. Chickpea plants were exposed to drought stress at the 3‐leaf stage for 25 days, and the leaves were harvested at 14 and 25 days after the imposition of drought stress. Stress produced significant reduction in chlorophyll content, Fv/Fm, relative water content, and shoot and root dry weight. Twenty known metabolites were identified as most important by 2 different methods including significant analysis of metabolites and partial least squares discriminant analysis. The most pronounced increase in accumulation due to drought stress was demonstrated for allantoin, l‐proline, l‐arginine, l‐histidine, l‐isoleucine, and tryptophan. Metabolites that showed a decreased level of accumulation under drought conditions were choline, phenylalanine, gamma‐aminobutyric acid, alanine, phenylalanine, tyrosine, glucosamine, guanine, and aspartic acid. Aminoacyl‐tRNA and plant secondary metabolite biosynthesis and amino acid metabolism or synthesis pathways were involved in producing genetic variation under drought conditions. Metabolic changes in light of drought conditions highlighted pools of metabolites that affect the metabolic and physiological adjustment in chickpea that reduced drought impacts.
Drought stress is one of the major problems in chickpea‐growing areas. Though drought stress changes biochemical mechanisms in plants, however, little is known about the complex metabolic regulation for genetic improvement in chickpea under drought stress environments. This study was conducted to identify changes at different metabolites in two chickpea varieties contrasting for drought tolerance under drought and control conditions. This study also demonstrates the metabolic pathways potentially involved in drought tolerance mechanisms in chickpea.
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•An UHPLC-Q-Orbitrap HRMS method was developed for the analysis of DATNBI and its raw material.•Evolution of impurities during the synthesis route of DATNBI was revealed.•The origin ...of impurities in DATNBI was deduced.
1,1′-diamino-4,4′,5,5′-tetranitro-2,2′-biimidazole (DATNBI) is an attractive insensitive highly energetic explosive. Even though DATNBI can be easily produced through deprotonation and ammoniation of 4,4′,5,5′-tetranitro-2,2′-biimidazole (TNBI), the type and source of impurities in DATNBI are still unclear. In present study, ultrahigh performance liquid chromatography coupled to a quadrupole-orbitrap mass spectrometry (UHPLC-Q-Orbitrap MS) was employed to analyze the chemical structures and origin of the impurities in DATNBI. A chromatographic method has been developed to separate the impurities of DATNBI and its raw material TNBI. The chemical structures of all impurities were tentatively identified by the analysis of retention time, UV–vis spectrum, elemental composition and MS/MS fragmentation patterns. In DATNBI, four impurities have been detected, including TNBI, mono-ammoniated TNBI, a dimer of DATNBI and the mono-ammoniated product of an impurity in TNBI. Interestingly, all compounds in the DATNBI sample produced fragment ions identical to the fragment ions of TNBI or its impurity, indicating TNBI and its impurity are the source of the impurities in DATNBI. This study gives an insight in the origin of impurities in DATNBI and provide the basis for quality improvement in future work.
Little is known about the impact of emissions of micropollutants from small and large-scale sewage treatment plants (STPs) on drinking water source areas. We investigated a populated catchment that ...drains into Lake Mälaren, which is the drinking water source for around 2 million people including the inhabitants of Stockholm, Sweden. To assess the persistence, mobility, bioavailability and bioaccumulation of 32 structurally diverse emerging organic contaminants, sediment, integrated passive and grab water samples were collected along the catchment of the River Fyris, Sweden. The samples were complemented with STP effluent and fish samples from one sampling event. Contaminants identified as persistent, mobile, and bioavailable were 4,6,6,7,8,8-hexamethyl-1,3,4,7-tetrahydrocyclopentagisochromene (galaxolide), 2,4,7,9-tetramethyl-5-decyn-4,7-diol, tris(2-chloro-ethyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, and tris(1-chloro-2-propyl) phosphate. Galaxolide and 2,4,7,9-tetramethyl-5-decyn-4,7-diol were additionally found to be bioaccumulative, whereas n-butylbenzenesulfonamide was found to be only persistent and mobile. The total median mass flux of the persistent and mobile target analytes from Lake Ekoln into the drinking water source area of Lake Mälaren was estimated to be 27kg per year. Additionally, 10 contaminants were tentatively identified by non-target screening using NIST library searches and manual review. Two of those were confirmed by reference standards and further two contaminants, propylene glycol and rose acetate, were discharged from STPs and travelled far from the source. Attenuation of mass fluxes was highest in the summer and autumn seasons, suggesting the importance of biological degradation and photodegradation for the persistence of the studied compounds.
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•The fate of organic wastewater contaminants was tracked along a river transect.•Five persistent, mobile and bioavailable contaminants were identified.•Two persistent and mobile contaminants were additionally found in fish.•All five contaminants were found in a lake used as a drinking water reservoir.•The majority of contaminants originated from sewage treatment plant effluent.
Ciguatera poisoning occurs throughout subtropical and tropical regions globally. The Virgin Islands in the Caribbean Sea is a known hyperendemic region for ciguatera and has been associated with ...Caribbean ciguatoxin (C-CTX) contamination in fish. An algal C-CTX (C-CTX5) was identified in Gambierdiscus silvae and G. caribeaus isolated from benthic algal samples collected in waters south of St. Thomas, US Virgin Islands. The highest CTX-producing isolate, G. silvae 1602 SH-6, was grown at large-scale to isolate sufficient C-CTX5 for structural confirmation by NMR spectroscopy. A series of orthogonal extraction and fractionation procedures resulted in purification of approximately 40 μg of C-CTX5, as estimated by quantitative NMR. A suite of 1D and 2D NMR experiments were acquired that verified the structure originally proposed for C-CTX5. The structural confirmation and successful isolation of C-CTX5 opens the way for work on the stability, toxicology and biotransformation of C-CTXs, as well as for the production of quantitative reference materials for analytical method development and validation. The strategies developed for purification of C-CTX5 may also apply to isolation and purification of CTXs from the Pacific Ocean and other regions.
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•Gambierdiscus silvae bulk cultured for isolation of C-CTX5.•1-D and 2-D NMR spectra acquired with ∼40 μg of C-CTX5.•HSQC and HMBC spectra acquired with non-uniform sampling for structure elucidation.•C-CTX5 structure confirmed as 3-oxo C-CTX analogue.
Estrogens, which are extensive in the eco-environments, are a category of high-toxic emerging contaminants that induce metabolic disorders and even carcinogenic risks in wildlife and humans. Here we ...investigate whether fungus-secreted laccase can be used as a green catalyst to eliminate a representative estrogen, 17β-estradiol (E2). A white-rot fungus Trametes hirsuta La-7 with high laccase-productivity, was isolated from pig manure-contaminated soil. Extracellular laccase activity expressed by strain La-7 was 65.4 U·mL−1 for a 3 d inoculation under the optimal fermentation parameters. The concentrated-crude laccase from Trametes hirsuta La-7 (CC-ThLac) was capable of effectively metabolizing E2 at pH 4–6, and the apparent pseudo first-order reaction rate constant and half-life values were respectively 0.027–0.055 min−1 and 25.86–12.67 min (R2 > 0.98). The mass measurement of high-resolution mass spectrometry in combination with 13C-isotope labeling identified that the main by-products of E2 metabolism were dimers, trimers, and tetramers, which are consistent with radical-driven C–C and/or C–O–C covalent coupling pathway, involving the initial enzymatic production of phenoxy radical intermediates and then the successive oxidative-oligomerization of radical intermediates. The formation of oligomers dramatically reduced the estrogenic activity of E2. Additionally, CC-ThLac also exhibited high-efficiency metabolism capability toward E2 in the natural water and pig manure, with more than 94.4% and 91.0% of E2 having been metabolized, respectively. These findings provide a broad prospect for the clean biotechnological applications of Trametes hirsuta La-7 in estrogen-contaminated ecosystems.
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•A Trametes hirsuta La-7 was isolated from contaminated soil to yield laccase.•Activity of laccase reached 65.4 U·mL−1 under the optimal fermentation conditions.•E2 metabolites were identified by HRMS combined with 13C-isotope labeling.•E2 was step-polymerized to produce various oligomers via radical coupling mechanism.•CC-ThLac was capable of effectively metabolizing E2 in environmental matrices.
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