Quadrupole Time Of Flight Mass Spectrometer Research Articles

Proteomics analysis on aortic smooth muscle cells reveals new potential targets for the treatment of Marfan syndrome-associated thoracic aortic aneurysm

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health Background Thoracic aortic aneurysm (TAA) is characterized by the abnormal enlargement of the initial segment of the aorta. Patients with genetic Marfan syndrome (MFS) develop TAA in young age, since mutations of fibrillin-1 contribute to thoracic aortic wall detrimental weakening. Presently, effective treatment options for this life-threatening condition are lacking, and existing pharmacological approaches are merely palliative, by postponing the need for surgical aortic replacement. To identify new treatments or MFS-related TAA (MFS-TAA), current research is concentrated on pinpointing specific biological targets and mechanisms underlying this aortic disorder. Purpose This study is aimed to unveil potential therapeutic targets that could be exploited for treating MFS-TAA by adopting an advanced proteomics technique. Material and Methods A label-free quantitative mass spectrometry technique was employed, utilizing a hybrid quadrupole-time of flight mass spectrometer coupled with a UPLC Mclass system and a nano-source, to analyze and compare the protein expression levels in vascular smooth muscle cells (VSMC) isolated from the aortas of MFS patients (MFS-VSMC) and healthy subjects (HC-VSMC). The proteomics findings were subsequently validated through qRT-PCR and Western blot assays. Results The proteomics investigation yielded 16 proteins displaying statistically significant differences. Among these, five proteins were notably more abundant in MFS-VSMC compared to HC-VSMC: nestin (NES, p<0.01), filamin B (FLNB, p<0.05), A-kinase anchor protein 12 (AKAP12, p<0.05), catenin delta-1 (CTNND1, p<0.05), and heparan sulfate proteoglycan core protein (HSPG2, p<0.05). The Gene Ontology (GO) analysis performed on cellular components of these 5 items using the clusterProfiler R package highlighted the enrichment of GO terms generally related to transmembrane proteins and anchoring junctions. Specifically, enriched GO terms included cell cortex (p<0.002), focal adhesion (p<0.002), cell-substrate junction (p<0.002), and intermediate filament binding (p<0.03). To verify these findings, two out of the five proteins with increased expression in MFS-VSMC (i.e., nestin and filamin B) were subjected to validation experiments. Results confirmed the elevated gene expression and protein levels of both nestin (p<0.05) and filamin B (p<0.05) in MFS-VSMC samples when compared with HC-VSMC. Conclusions Taken together, these results suggest that proteins with increased expression in MFS-VSMC may represent valuable biological target of MFS-TAA. This may encompass their potential both as diagnostic tools and/or mechanistic mediators of TAA in MFS subjects. In details, the pharmacological targeting of nestin and filamin B may represent a novel and exploitable therapeutic option for limiting/inhibiting TAA onset or progression in MFS pathological scenario.

Human metabolism of the semi-synthetic cannabinoids hexahydrocannabinol, hexahydrocannabiphorol and their acetates using hepatocytes and urine samples.

Hexahydrocannabinol (HHC), hexahydrocannabiphorol (HHCP) and their acetates, HHC-O and HHCP-O, respectively, are emerging in Europe as alternatives to tetrahydrocannabinol (THC). This study aimed to elucidate the metabolic pathways of the semi-synthetic cannabinoids HHC, HHCP, HHC-O and HHCP-O from incubation with human hepatocytes. The metabolites of HHC were also identified in authentic urine samples. HHC, HHCP, HHC-O and HHCP-O were incubated with primary human hepatocytes for 1, 3 and 5 h. Authentic urine samples from cases screened positive for cannabis in blood using ELISA but confirmed negative were analysed both non-hydrolysed and hydrolysed for HHC metabolites. Potential metabolites were identified using ultra-high performance liquid chromatography (UHPLC) coupled to a quadrupole time-of-flight mass spectrometer (QToF-MS). HHC and HHCP were primarily metabolised through monohydroxylation (monoOH), followed by oxidation to a carboxylic acid metabolite. HHC-O and HHCP-O were rapidly metabolised to HHC and HHCP, respectively. In authentic urine samples, 18 different metabolites were identified, and 99.3% of hydroxylated metabolites were glucuronidated. 11-OH-HHC, 5'OH-HHC and another metabolite with a monoOH on the side chain were the only metabolites present in all 16 urine samples. The metabolism of HHC and HHCP were similar, although the longer alkyl side chain of HHCP (heptyl) led to greater hydroxylation on the side chain than HHC (pentyl). The use of HHC and HHCP can be differentiated from the use of THC and other phytocannabinoids, but the use of the acetate analogues may not be differentiable from their non-acetate analogues.

Mechanism of aroma enhancement methods in accelerating Congou black tea acidification subjected to room temperature storage

Acidification of aroma-enhanced black tea during storage was studied. UPLC-Q-TOF/MS (Ultra Performance Liquid Chromatography and Quadrupole-Time of Flight Mass Spectrometer) and HPLC (High-Performance Liquid Chromatography) analysis of non-volatile substances and organic acids revealed a decrease of soluble sugars and amino acids in aroma-enhanced black tea, while an increase in organic acids such as oxalic acid, malic acid and quinic acid. Further in vitro experiments indicated that the acidification of aroma-enhanced tea during storage can be attributed to decomposition of sugars and amino acids by heating, oxidation of aromatic aldehydes. Meanwhile, the amino acids, catechins, soluble sugars and flavonoids that constitute the taste of black tea are further reduced, changing the taste composition of tea infusion and further increasing its acidity. This study revealed the reasons for black tea acidification during aroma enhancement and storage and provided a theoretical basis for improving black tea quality.

First insights into herbivore–plant interaction of the spurge hawkmoth and Euphorbia cyparissias

The spurge hawkmoth Hyles euphorbiae (Lepidoptera, Sphingidae) is an insect herbivore feeding exclusively on spurges (Euphorbia). These are toxic due to their secondary metabolites including diterpene esters with numerous harmful biological activities, preventing their use by most herbivores. Extracts of frass from H. euphorbiae and of its main larval food plant in Central Europe, the cypress spurge (Euphorbia cyparissias L.), were analyzed via liquid chromatography using a triple-quadrupole (MS/MS) and a high-resolution–quadrupole time-of-flight mass spectrometer (QTOF-MS). We report for the first time the finding of the tigliane (phorbol ester) phorbol-13-acetate and two 12-O-tetradecanoylphorbol-13-acetate (TPA) isomers of unknown structure (compounds 2 and 3) in E. cyparissias. Our data support the assignment of these two compounds as tiglianes and are therefore referred to by us as “putative tiglianes”. Additionally, the distribution of the three reported compounds within the plant parts (leaves, stem and root) was analyzed to gain first insights into the metabolite conditions H. euphorbiae copes with in nature. Phorbol-13-acetate was detected in the plant’s root only, while the other compounds were observed in all three plant parts, although in different distributions. Moreover, our results indicate that the occurrence of compound 3 rises upon larval feeding. Finally, the presence of the plant-derived putative tiglianes in frass from E. cyparissias leaves feeding larvae is confirmed, corroborating the close plant–herbivore interaction.

Optimization of an Ultrasound-Assisted Extraction Method for the Extraction of Gingerols and Shogaols from Ginger (Zingiber officinale)

The goal of this study is to optimize a UAE method for the extraction of the main bioactive compounds present in the ginger rhizome (gingerols and shogaols). Ginger rhizome (Zingiber officinale) has a considerable content of bioactive compounds, in particular gingerols and shogaols, with interesting pharmacological activities such as anti-inflammatory, antioxidant, anti-cancer, and antimicrobial properties, among others. The isolation of these compounds requires an efficient extraction process with short extraction times and the employment of specific non-toxic solvents for humans. In this work, the optimization of an ultrasound-assisted extraction (UAE) method for the extraction of the main pungent compounds in the ginger rhizome, i.e., gingerols and shogaols, has been carried out. For this purpose, a Box–Behnken design (BBD) has been used to optimize the experimental design through a response surface methodology (RSM). The percentage of ethanol in the extraction solvent, the temperature, the amplitude, and the cycle of the ultrasounds, as well as the sample-to-solvent ratio, were the variables to be studied. Thus, the percentage of ethanol in the extraction solvent was identified as the most influential factor. Once the compounds were extracted, the identification of gingerols and shogaols was performed by ultra-high-performance liquid chromatography (UHPLC) coupled to a quadrupole-time-of-flight mass spectrometer (Q-ToF-MS), and the quantification by UHPLC coupled to a diode array detector (DAD) detector. Finally, the optimized UAE method required only 10 min of extraction time, presenting good repeatability and intermediate precision levels (<5%). The method was applied to extract gingerols and shogaols from diverse sources, thereby demonstrating its applicability and highlighting the potential variations in compound concentrations across different samples based on factors such as origin, and growing conditions, among others.

Enhancing the efficacy of radiotherapy with Kalanchoe daigremontiana: A nanotechnological approach

Radiotherapy is widely utilized in the treatment of cancer, but this method is associated with dose-dependent limitation. Herbal compounds contain various secondary metabolites that increase the effectiveness of radiotherapy. However, a significant challenge associated with the use of herbal preparations is their poor biocompatibility. To address this limitation, the active ingredients of the leaves of Kalanchoe daigremontiana were extracted subsequently, phytoniosomes were prepared from the extract. The phytoniosomes were characterized through various analyses, Content analysis was performed with Quadrupole time-of-flight mass spectrometer (QTOF-MS) and encapsulation efficiency was evaluated with High-performance liquid chromatography (HPLC). Then, the cytotoxic effects of the phytoniosomes were evaluated on the Human Breast Epithelial Adenocarcinoma Cell Line (MCF-7), and Human Cervix epithelial Adenocarcinoma Cell Line (HeLa), using the MTT assay over multi-periods. Then radiotherapy studies have been carried out to increase this effect via Linear Accelerator (LINAC). Finally, to further understand the interactions between the phytoniosomes and cells, the niosomes were labelled with Fluorescein isothiocyanate (FITC) and fluorescence images were obtained. The results confirmed that the size of plain niosomes and phytoniosomes were 95.9 ± 0.52 and 126.0 ± 5.14 nm, respectively and localized around cytoplasm. Phytoniosomes combined with radiotherapy on cell lines are more effective than radiotherapy or phytoniosomes alone. The cell viability decreased significantly to 7.102 ± 3.51 for the MCF-7 cell line and to 8.183 ± 4.117 for the HeLa cell line). In conclusion, the combined use of these niosomal preparations with radiotherapy has the potential to be used as a tool for overcoming dose-dependent limitation in radiotherapy.

Target and untargeted screening of perfluoroalkyl substances in biota using liquid chromatography coupled to quadrupole time of flight mass spectrometry

Perfluoroalkyl substances (PFAS) are known to bioaccumulate and trigger adverse effects in marine birds. This study develops an extraction and analytical methodology for the target/untargeted analysis of PFAS in eggs of Yellow-legged gull (Larus michahellis) and Audouin's gull (Larus audouinii) and blood of Greater flamingo (Phoenicopterus roseus), which are used as bioindicators of organic chemical pollution. Samples were extracted by ultrasonication with acetonitrile and cleaned-up with activated carbon, and analysis was performed by ultra-high-performance liquid chromatography coupled to a quadrupole-time of flight mass spectrometer (UHPLC-Q-TOF) with negative electrospray ionization. Data-independent acquisition (DIA) was performed through full-scan acquisition to obtain MS1 at 6 eV and MS2 at 30 eV. In a first step, quantitative analysis of 25 PFAS was performed using 9 mass-labelled internal standard PFAS and quality parameters of the method developed are provided. Then, an untargeted screening workflow is proposed using the high-resolution PFAS library database from NORMAN to identify new chemicals through accurate mass measurement of MS1 and MS2 signals. The method permitted to detect several PFAS at concentrations ranging from 0.45 to 55.2 ng/g wet weight in gull eggs and from 0.75 to 125 ng/mL wet weight in flamingos’ blood, with PFOS, PFOA, PFNA, PFUdA, PFTrDA, PFDoA, PFHxS and PFHpA the main compounds detected. In addition, perfluoro-p-ethylcyclohexylsulfonic acid (PFECHS, CAS number 646-83-3) and 2-(perfluorohexyl)ethanol (6:2 FTOH, CAS number 647-42-7) were tentatively identified. The developed UHPLC-Q-TOF target/untargeted analytical approach increases the scope of PFAS analysis, enabling a better assessment on contaminant exposure and promoting the use of bird species as bioindicators of chemical pollution.

Stepwise photoassisted decomposition of carbohydrates to H2

Stepwise photoassisted decomposition of carbohydrates to H2

Decomposition of N, N-diethyl-m-toluamide by water plasma with mist generation

The study presents the decomposition of a high concentration of N, N-diethyl-m-toluamide (DEET) by water plasma with mist generation at atmosphere pressure. The water mist generated from the DEET solution was used for the plasma. The relationship between operational arc currents and DEET decomposition was discussed in detail. The results showed that the decomposition rate of the DEET was improved as an increase of arc current at torch powers of 1.07–1.39 kW. Major effluent gases were H2, CO2, CO, and N2. The total organic carbon (TOC) for the effluent liquid was reduced up to 98%. The H, O, and OH as reactive species generated by the dissociation of water molecules were verified, and the plasma temperatures were estimated at over 8000 K. A possible decomposition pathway was deduced based on the identification of intermediate products by optical emission spectroscopy (OES), UV–visible (UV–vis) spectroscopy, and quadrupole time of flight mass spectrometer (QTOF-MS). Electron dissociation and hydroxylation were found to play important roles in ring opening and initial cleavage of the alkyl chains at the beginning of decomposition. The water plasma shows a robust driving force for processing organic wastes as an alternative green technology.

Microwave-assisted extraction of antioxidant compounds from Russian olive leaves and flowers: Optimization, HPLC characterization and comparison with other methods

Russian olive is a medicinal plant containing phytochemicals with antioxidant activities, which are of great interest due to their beneficial health effects. Our preliminary studies produced extracts from Russian olive leaves and flowers and determined their potential antioxidant activity and their most abundant phenolic compounds were detected. However, the maximum retention of these antioxidant compounds during microwave-assisted extraction (MAE) requires optimized process conditions. Therefore, two-level fractional factorial designs in preliminary tests were used for assessing the magnitude of microwave extraction factors' effects on the extraction of bioactive compounds from Russian olive samples and the experimental domains were determined. Subsequently, Response surface methodology (RSM) was conducted to determine the optimized MAE process variables including citric acid’s molarity (X1: 1–5 M), extraction temperature (X2: 60–110 °C), ethanol concentration (X3: 0–100%) and solid to solvent ratio (X4: 5–15) for maximum recovery of total phenolic content, total flavonoid content and total antioxidant compounds in the extracts. Based on the results, the optimal extraction conditions were as follows: solid to solvent ratio of 7.5 (w/v), citric acid molarity of 2 M, ethanol concentration of 59.8% and 66.4%, and temperature of 97.4 °C and 97.5 °C for Russian olive leaves and flowers, respectively. In addition, the influence of extraction parameters on the responses was modeled using a second-order regression equation and a good agreement between the predicted values and the experimentally obtained values was indicated. Finally, among phenolic compounds which were previously identified through Quadrupole Time of Flight Mass Spectrometer (QTOF-MS) analysis, three abundant flavonoids of the extracts with therapeutic properties including isorhamnetin, luteolin and rutin contained in the optimized extract from MAE were compared with that of ultrasonic extraction and conventional extraction using high-performance liquid chromatography (HPLC) analysis. Results confirmed MAE as an efficient method for extraction of bioactive phytochemicals from Russian olive.

A reversed phase ultra-high-performance liquid chromatography-data independent mass spectrometry method for the rapid identification of mycobacterial lipids

A rapid reversed-phase ultra-high-performance liquid chromatography-high resolution mass spectrometry based mycobacterial lipidomics approach is described. This method enables the separation of various lipid classes including lipids specific to mycobacterial, such as methoxy mycolic acid and α-mycolic acid. Lipid separation occurs during a relatively short runtime of 14 min on a charged surface hybrid C18 column. A high-resolution quadrupole-time of flight mass spectrometer and a data independent acquisition mode allowed for the simultaneous acquisition of the full scan and collision induced dissociation fragmentation. The proposed method provides lipid detection results equivalent to or better than existing methods, but with a faster throughput and an overall higher sensitivity. The reversed-phase ultra-high-performance liquid chromatography-high resolution mass spectrometry method was shown to obtain structural information for lipids extracted from Mycobacterium smegmatis, but the method is applicable to the analysis of lipids from various bacterial and mammalian cell lines.

The migration of NIAS from ethylene-vinyl acetate corks and their identification using gas chromatography mass spectrometry and liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry

An exhaustive migration study of eight corks, made of ethylene–vinyl acetate, was carried out to identify any non-volatile and volatile compounds using an untargeted approach. The challenge associated with the structural elucidation of unknowns was undertaken using both ultra-high-performance liquid chromatography coupled to an ion-mobility separation quadrupole-time of flight mass spectrometer and gas chromatography mass spectrometry. A total of fifty compounds were observed to migrate from the corks, and among these additives such as antioxidants (Butyl 4-hydroxybenzoate, Irganox 1010, Irganox 1075, Irgafos 168 and BHT) or lubricants (EBO and octadecanamide, N,N'-1,2-ethanediylbis-) were identified. A high proportion (84%) of the detected compounds was non-intentionally added substances (NIAS), and included several cyclic oligomers with different chain sequences. NIAS, such as 2,6-bis(1,1-dimethylethyl)-4-ethyl and 7,9-ditert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione, break-down products, including hexa-, hepta- and nonadecanamide, N,N'-1,2-ethanediylbis-, and oxidation products were also identified. One cork was found to be unsuitable for use as a food contact material.

Degradation and chlorination mechanism of fumaric acid based on SO4•-: an experimental and theoretical study.

It is well known that chloride ions could affect the oxidation kinetics and mechanism of contaminant based on SO4•- in the wastewater. Here, the degradation of an organic acid, fumaric acid (FA), was investigated in the presence of chloride (0-300 mM) by the Fe(II)/peroxymonosulfate (Fe(II)/PMS) system. A negative impact of chloride was observed on the rates of FA degradation. The degree of inhibitory effect was higher in Fe(II)/PMS addition order. Some chlorinated byproducts were identified during the FA oxidation process in the presence of Cl- by the ultraperformance liquid chromatography and quadrupole-time of flight mass spectrometer (UPLC-QTOF-MS). With the increasing content of Cl-, an accumulation of adsorbable organic halogen (AOX), an increase in acute toxicity, and an inhibition of mineralization were observed. According to the results of kinetic modeling, the production and transformation of oxidative species were dependent on Cl- dosage and reaction time. SO4•- was supposed to be the main radical for FA degradation with Cl- concentration below 5 mM, whereas Cl2•- was primarily responsible for the depletion of FA at [Cl-] > 5 mM. A possible degradation pathway of FA was discussed. This study reveals the potential environmental risk of organic acid and is necessary to explore useful strategies for ameliorating the treatment of chloride-rich wastewater.

Improving Resolution of Isomeric Flavonoids and Their Glycosides Using Two-Dimensional Liquid Chromatography Coupled With High-Resolution Mass Spectrometry

The separation of isomers is one of the key issues in analysing complex natural matrices, thus commanding a higher separating power from the applied analytical system. In this study, 42 common flavonoid glycosides from three key subclasses (flavanones, flavones, flavonols) were analysed in three steps to maximise chromatographic and spectrometric resolution via: (1) C18 liquid chromatography (LC) coupled to a quadrupole time-of-flight mass spectrometer (QTOF/MS), (2) tandem mass spectrometry (MS/MS), and (3) two-dimensional LC with heart-cutting for specific regions of co-elution. While the LC-QTOF/MS step was found to separate the majority of flavonoid glycoside isomers, some isomers with identical accurate mass were not resolved. Following this, increased spectrometric resolution was achieved with MS/MS; however, this technique was not suitable for particularly challenging isomers that were also identical in aglycone and saccharide structure. Furthermore, a heart-cutting method was developed using a three-level full-factorial design to separate such challenging isomers, and satisfactory resolution was obtained for the targeted isomers (R > 2.00) with reasonable efficiency (total run time < 25 min) and repeatability (RSD < 2%). In conclusion, the developed strategy highlights the significance of combining high-resolution mass spectrometry with chromatographic separation for added confidence in the identification of isomers.

Isolation of Burkholderia sp. HQB-1, A Promising Biocontrol Bacteria to Protect Banana Against Fusarium Wilt Through Phenazine-1-Carboxylic Acid Secretion.

Fusarium wilt is a devastating soil-borne fungal disease caused by Fusarium oxysporum f.sp. cubense (Foc). In recent years, some antifungal bacteria have been applied for the prevention and biocontrol of pathogenic fungi. In our study, a bacterial strain HQB-1, isolated from banana rhizosphere soil, was cultured for investigation. It showed broad-spectrum antifungal activities against representative phytopathogenic fungi including Fusarium oxysporum, Colletotrichum gloeosporioides, Botrytis cinerea, and Curvularia fallax. The strain HQB-1 was identified as Burkholderia sp. by morphological, physiological, and biochemical examinations, confirmed by 16S rRNA gene sequence analysis. Among the metabolites produced by the strain, we identified an antifungal compound which was identified phenazine-1-carboxylic acid (PCA) (C13H8N2O2) through ultraviolet, liquid chromatography quadrupole-time of flight mass spectrometer, and nuclear magnetic response. Furthermore, PCA exhibited the lowest minimum inhibitory concentration (MIC) against F. oxysporum (1.56 μg/ml) and yielded the highest MIC against C. gloeosporioides. Pot experiments showed that application of 5 μg/ml or more of PCA efficiently controlled banana wilt and promoted the growth of banana plants. These results suggested that Burkholderia sp. HQB-1, as an important microbial resource of PCA, could be a promising biological agent against wilt diseases and promoting banana growth.

Characterizing changes of dissolved organic matter composition with the use of distinct feeds in recirculating aquaculture systems via high-resolution mass spectrometry

Recirculating aquaculture systems (RAS) are a new alternative to traditional aquaculture approaches, allowing full control over the fish production conditions, while reducing the water demand. The reduction of water exchange leads to an accumulation of dissolved organic matter (DOM) that can have potential effects on water quality, fish welfare and system performance. Despite the growing awareness of DOM in aquaculture, scarce scientific information exists for understanding the composition and transformation of DOM in RAS. In this study, a non-targeted approach using ultra-performance liquid chromatography coupled to a hybrid quadrupole-time of flight mass spectrometer (UPLC-QTOF-MS) was used to characterize compositional changes of low molecular weight (LMW) DOM in RAS, when operated under two different feed types. A total of 1823 chemicals were identified and the majority of those contained a CHON chemical group in their structure. Changes in the composition of LMW-DOM in RAS waters were observed when the standard feed was switched to RAS feed. The DOM with the use of standard feed, consisted mainly of lignin/CRAM-like, CHO and CHOS chemical groups, while the DOM that used RAS feed, was mainly composed by unsaturated hydrocarbon, CHNO and CHNOS chemical groups. The Bray-Curtis dissimilarity cluster demonstrated differences in the composition of DOM from RAS and was associated to the type of feed used. When the RAS feed was used, the Kendrick mass defect plots of –CH2- homologous units in the pump-sump (after the water treatment) showed a high removal capacity for CHNO, CHNOS and halogenated chemicals with high Kendrick mass defect, KMD > 0.7. To our knowledge, this is the first report of LMW-DOM characterization of RAS by high-resolution mass spectrometry (HRMS).

Bioanalysis and Quadrupole-Time of Flight-Mass Spectrometry Driven In Vitro Metabolite Profiling of a New Boronic Acid-Based Anticancer Molecule

(E/Z)-(4-(3-(2-((4-chlorophenyl)amino)-4-(dimethylamino)thiazol-5-yl)-2-(ethoxy carbonyl)-3-oxoprop-1-en-1-yl)phenyl) boronic acid, a newly developed molecule having anticancer activity serves as a potential candidate for the further drug development process. In this study, to ascertain the anticancer potential of the molecule, we screened it against different cell lines and compared the activity against the standard drug doxorubicin. The molecule showed promising activity at a low concentration against almost all cell lines used in the study. Apart from that, the molecule was characterized for its pKa and a precise reverse phase high-performance liquid chromatography bioanalytical method has been developed. The method was validated according to the United States of Food and Drug Administration bioanalytical guideline and was found to produce linear response over the calibration range of 0.8-25μg/mL. Inter- and intra-day accuracy were found to be in the range of 93.44-99.74%, whereas precision [% coefficient of variation (CV)] for inter- and intra-day was ranged between 1.63 and 5.79%, and 0.87 and 6.96%, respectively. The bioanalytical stability testing was carried out in different conditions including 8h benchtop, 12h autosampler and three freeze-thaw cycles. The analyte was stable in all the tested stability conditions. Finally, an in vitro metabolite identification study was conducted using quadrupole-time of flight-mass spectrometer, and two metabolites have been identified.

Effect of Temperature, Water Activity and Carbon Dioxide on Fungal Growth and Mycotoxin Production of Acclimatised Isolates of Fusarium verticillioides and F. graminearum.

Climate change is primarily manifested by elevated temperature and carbon dioxide (CO2) levels and is projected to provide suitable cultivation grounds for pests and pathogens in the otherwise unsuitable regions. The impacts of climate change have been predicted in many parts of the world, which could threaten global food safety and food security. The aim of the present work was therefore to examine the interacting effects of water activity (aw) (0.92, 0.95, 0.98 aw), CO2 (400, 800, 1200 ppm) and temperature (30, 35 °C and 30, 33 °C for Fusarium verticillioides and F. graminearum, respectively) on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum isolated from maize. To determine fungal growth, the colony diameters were measured on days 1, 3, 5, and 7. The mycotoxins produced were quantified using a quadrupole-time-of-flight mass spectrometer (QTOF-MS) combined with ultra-high-performance liquid chromatography (UHPLC) system. For F. verticillioides, the optimum conditions for growth of fumonisin B1 (FB1), and fumonisin B2 (FB2) were 30 °C + 0.98 aw + 400 ppm CO2. These conditions were also optimum for F. graminearum growth, and zearalenone (ZEA) and deoxynivalenol (DON) production. Since 30 °C and 400 ppm CO2 were the baseline treatments, it was hence concluded that the elevated temperature and CO2 levels tested did not seem to significantly impact fungal growth and mycotoxin production of acclimatised Fusarium isolates. To the best of our knowledge thus far, the present work described for the first time the effects of simulated climate change conditions on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum.

Degradation of a mixture of pharmaceuticals in hospital wastewater by a zero-valent scrap iron (ZVSI) combined reduction-oxidation process

Zero-valent scrap iron (ZVSI) combined with Fenton-based oxidation reaction (reduction-oxidation process) was studied under natural sunlight conditions to degrade a mixture of six pharmaceuticals. ZVSI is a waste product from metalworking industries, which present excellent reactivity. The morphological and structural properties of ZVSI were evaluated using different techniques. The parent compounds and their transformation products (TPs) were monitored using Liquid Chromatographic coupled with Quadrupole-Time of Flight mass spectrometer (LC-QTOF MS). The in silico (quantitative) structure-activity relationship ((Q)SAR) predictions of toxicity and biodegradability were predicted for each TP by using different freely available models. According the characterization ZVSI consisted mainly of carbon (48.5 %) and iron (43.6 %) with 0.6922 m2/g of surface area. Hematite and magnetite were the main crystalline phases ZVSI. Doehlert design and desirability profile were used to select the experimental conditions. Higher degradation rates were achieved at pH 3.0, 32.5 mg L−1 H2O2 and 2 g L−1 ZVSI. Under the optimal conditions, pharmaceuticals removal was as high as 87 % in all matrixes evaluated, following a pseudo-first order kinetic model behavior. Three reuse cycles were performed using real hospital wastewater (RHWW) achieving degradation percentages >70% and no substantial variation in the crystalline phases of the ZVSI was observed. Twenty-three TPs were detected. According to in silico (Q)SAR predictions, the integrated system decreased the toxicity of TPs. Moreover, most of TPs were predicted as persistent compounds. The results indicated that ZVSI combined with solar Fenton-based oxidation is an interesting alternative for the degradation of pharmaceuticals in RHWW allowing the reuse of catalyst.

Optimization of extraction for Anemarrhena asphodeloides Bge. using silica gel-based vortex-homogenized matrix solid-phase dispersion and rapid identification of antioxidant substances.

A novel and simple method was established for the extraction and determination of seven compounds in Anemarrhena asphodeloides Bge. using silica gel-based vortex-homogenized matrix solid-phase dispersion and ultra-high performance liquid chromatography quadrupole-time of-flight mass spectrometer. The conditions for the extraction were optimized. Silica gel was used as the dispersant, 50% methanol-water was selected as an elution solvent and the grinding time was 3min. Compared with the traditional ultrasonic-assisted extraction, the developed method was rapid and efficient. In order to screen potential antioxidants, extract dealing with the optimized method was applied to a polyamide chromatography column and a D-101 macroporous resin column. Fr.2.2 showed the highest antioxidant activities with the most content of flavonoid. A total of 25 peaks were identified from the active fraction. A 2,2'-diphenyl-1-picrylhydrazyl ultra-high performance liquid chromatography coupled with mass spectrometry approach was adopted for the rapid and exact screening and identification of antioxidant compounds. It indicated that flavonoids exhibited potential antioxidant activities. The antioxidant activities of nine monomeric compounds in vivo were tested. Structure-activity relationships were discussed. Five flavonoids with the concentration of 500 µg/mL would reduce the oxidative stress of PC12 cells that were induced with 2,2'-azobis[2-methylpropionamidine] dihydrochloride.