Chromatography Coupled With Mass Spectrometry Research Articles

A new strategy for constructing ZIF-67@PBA core-shell 3D cross-heterostructures for improving fire safety of TPU at ultra-low addition amount

Thermoplastic polyurethane (TPU) has an extensive application in many different industries. However, serious fire hazards and smoke toxicity have been the main reason limiting its wide application. Therefore, it is necessary and urgent to perform flame retardant and smoke suppression treatment for TPU. In recent years, metal-organic framework compounds (MOFs) have very promising application prospects in the fields of flame-retardant polymer composites. However, there is a problem of low flame-retardant efficiency for the original MOFs alone in polymer composites. It is reported the multi-level and multi-structured flame-retardant system has better flame-retardant efficiency than the traditional structures. So, the dual MOF core-shell heterostructure may have more effective heat reduction and smoke suppression than any single component. In this paper, a core-shell 3D cross-heterostructures nanohybrid (ZIF-67H@PBA) was prepared using ZIF-67H as the host MOF and Prussian blue nanocubes (PBA) as the guest MOF. It has been found that TPU/ZIF-67H@PBA composites with ultra-low additions have excellent fire safety. Compared with those of pure TPU, the peak heat release rate (PHRR), total smoke release (TSP), and smoke factor (SF) of the samples with 0.5wt% ZIF-67H@PBA were reduced by 33.6 %, 47 %, and 61 %, respectively. At the same time, a cone calorimeter (CCT), a homemade soot sampling device and a gas chromatography-mass spectrometry (GC–MS) coupling with each other were constructed and used to demonstrate the most realistic effects of flame retardants in terms of smoke suppression and toxicity reduction. This work provides a new strategy to design TPU flame retardants.

Biodiesel photoelectrocatalytic synthesis employing α-Fe2O3 film decorated with Pt nanoparticles as photoanode

In this work, photoelectrochemical route for biodiesel production using an electrochemical cell configured with platinum and α-Fe2O3 modified with Pt nanoparticles as electrodes was investigated. XRD patterns registered for film prepared by modified hydrothermal method revealed a trigonal structure of the hematite (α-Fe2O3) phase. The α-Fe2O3 film surface was decorated by metallic Pt nanoparticles (PtNP) in order to reduce the charge recombination and improve the photocatalytic efficiency. The band gap energy (EBG) of the α-Fe2O3 and PtNP/α-Fe2O3 films was estimated by UV-Vis spectroscopy at approximately 2.1 eV. Electrochemical measurements showed that the oxide is an n-type semiconductor adequate to be used as a photoanode in biodiesel synthesis. Under polarization conditions, the electrochemical cell changed the pH from 7 to 14 when the system was polarized at 5.0 V. In the synthesis of biodiesel by esterification reaction, oleic acid, 300 µL of 0.1 mol L−1 aqueous KCl solution and methanol were used as precursor reagents. The reaction was carried out free of strong base, such as KOH or NaOH, as a supporting electrolyte. In this route, the reduction of the water molecule occurred on the cathode, with the formation of hydroxyl (OH-) species, methoxy, and consequently fatty acid methyl esters (FAMEs). Thermogravimetric analysis (TGA) and Gas chromatography coupled to mass spectrometry (CG-MS) were performed to evaluate the catalysis products. GC-MS analyzes show that the reaction has a yield of about 7 % with the formation of FAMEs, such as methyl 9-octadecenoate, methyl hexadecanoate and methyl hexadecanoate.

The severity of COVID-19 upon hospital admission is associated with plasma omega-3 fatty acids

Fatty acids are precursors of inflammatory oxylipins. In the context of COVID-19, an excessive production of pro-inflammatory cytokines is associated with disease severity. The objective was to investigate whether the baseline omega 3/omega 6 fatty acids ratio and the oxylipins were associated with inflammation and oxidative stress in unvaccinated patients with COVID-19, classified according to the severity of the disease during hospitalization. This Prospective population-based cohort study included 180 hospitalized patients with COVID-19. The patients were classified into five groups according to the severity of their disease. Group 1 was the least severe and Group 5 was the most severe. Three specific types of fatty acids—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA)—as well as their enzymatic and non-enzymatic oxylipins were determined using chromatography coupled mass spectrometry. There was no difference in the ratio of omega-3 to omega-6 fatty acids between the groups (p = 0.276). However, the EPA/AA ratio was lower in Group 4 compared to Group 1 (p = 0.015). This finding was associated with an increase in both C-Reactive Protein (p < 0.001) and Interleukin-6 (p = 0.002). Furthermore, the concentration of F2-Isoprostanes was higher in Group 4 than in Group 1 (p = 0.009), while no significant changes were observed for other oxylipins among groups. Multivariate analysis did not present any standard of biomarkers, suggesting the high complexity of factors involved in the disease severity. Our hypothesis was confirmed in terms of EPA/AA ratio. A higher EPA/AA ratio upon hospital admission was found to be associated with lower concentration of C-Reactive Protein and Interleukin-6, leading to a better prognosis of hospitalized SARS-CoV-2 patients. Importantly, this beneficial outcome was achieved without any form of supplementation. The trial also provides important information that can be further applied to reduce the severity of infections associated with an uncontrolled synthesis of pro-inflammatory cytokines.Trial registration: https://clinicaltrials.gov/study/NCT04449718—01/06/2020. ClinicalTrials.gov Identifier: NCT04449718.

UafR: An R package that automates mass spectrometry data processing.

Chemical information has become increasingly ubiquitous and has outstripped the pace of analysis and interpretation. We have developed an R package, uafR, that automates a grueling retrieval process for gas -chromatography coupled mass spectrometry (GC -MS) data and allows anyone interested in chemical comparisons to quickly perform advanced structural similarity matches. Our streamlined cheminformatics workflows allow anyone with basic experience in R to pull out component areas for tentative compound identifications using the best published understanding of molecules across samples (pubchem.gov). Interpretations can now be done at a fraction of the time, cost, and effort it would typically take using a standard chemical ecology data analysis pipeline. The package was tested in two experimental contexts: (1) A dataset of purified internal standards, which showed our algorithms correctly identified the known compounds with R2 values ranging from 0.827-0.999 along concentrations ranging from 1 × 10-5 to 1 × 103 ng/μl, (2) A large, previously published dataset, where the number and types of compounds identified were comparable (or identical) to those identified with the traditional manual peak annotation process, and NMDS analysis of the compounds produced the same pattern of significance as in the original study. Both the speed and accuracy of GC -MS data processing are drastically improved with uafR because it allows users to fluidly interact with their experiment following tentative library identifications [i.e. after the m/z spectra have been matched against an installed chemical fragmentation database (e.g. NIST)]. Use of uafR will allow larger datasets to be collected and systematically interpreted quickly. Furthermore, the functions of uafR could allow backlogs of previously collected and annotated data to be processed by new personnel or students as they are being trained. This is critical as we enter the era of exposomics, metabolomics, volatilomes, and landscape level, high-throughput chemotyping. This package was developed to advance collective understanding of chemical data and is applicable to any research that benefits from GC -MS analysis. It can be downloaded for free along with sample datasets from Github at github.org/castratton/uafR or installed directly from R or RStudio using the developer tools: 'devtools::install_github("castratton/uafR")'.

Emodin ameliorates doxorubicin-induced cardiotoxicity by inhibiting ferroptosis through the remodeling of gut microbiota composition.

The relationship between gut microbiota and doxorubicin-induced cardiotoxicity (DIC) is becoming increasingly clear. Emodin (EMO), a naturally occurring anthraquinone, exerts cardioprotective effects and plays a protective role by regulating gut microbiota composition. Therefore, the protective effect of EMO against DIC injury and its underlying mechanisms are worth investigating. In this study, we analyzed the differences in the gut microbiota in recipient mice transplanted with different flora using 16S-rDNA sequencing, analyzed the differences in serum metabolites among groups of mice using a nontargeted gas chromatography-mass spectrometry coupling system, and assessed cardiac function based on cardiac morphological staining, cardiac injury markers, and ferroptosis indicator assays. We found EMO ameliorated DIC and ferroptosis, as evidenced by decreased myocardial fibrosis, cardiomyocyte hypertrophy, and myocardial disorganization; improved ferroptosis indicators; and the maintenance of normal mitochondrial morphology. The protective effect of EMO was eliminated by the scavenging effect of antibiotics on the gut microbiota. Through fecal microbiota transplantation (FMT), we found that EMO restored the gut microbiota disrupted by doxorubicin (DOX) to near-normal levels. This was evidenced by an increased proportion of Bacteroidota and a decreased proportion of Verrucomicrobiota. FMT resulted in changes in the composition of serum metabolites. Mice transplanted with EMO-improved gut microbiota showed better cardiac function and ferroptosis indices; however, these beneficial effects were not observed in Nrf2 (Nfe2l2)-/- mice. Overall, EMO exerted a protective effect against DIC by attenuating ferroptosis, and the above effects occurred by remodeling the composition of gut microbiota perturbed by DOX and required Nrf2 mediation.NEW & NOTEWORTHY This study demonstrated for the first time the protective effect of emodin against DIC and verified by FMT that its cardioprotective effect was achieved by remodeling gut microbiota composition, resulting in attenuation of ferroptosis. Furthermore, we demonstrated that these effects were mediated by the redox-related gene Nrf2.

Amazonia Phytotherapy Reduces Ischemia and Reperfusion Injury in the Kidneys.

Acute kidney injury (AKI) is defined as a sudden decrease in kidney function. Phytomedicines have shown positive effects in the treatment of AKI worldwide. The aim of this study was to evaluate the effect of Abuta grandifolia on the renal function of rats submitted to AKI. A phytochemical study of the plant was performed through liquid chromatography coupled with mass spectrometry (CL-EM) and DPPH and ABTS antioxidant tests. Renal function tests were performed in 20 male adult Wistar rats weighing from 250 to 300 g distributed in the following groups: SHAM (submitted to laparotomy with simulation of renal ischemia); ABUTA (animals that received 400 mg/kg of AG, orally-VO, once a day, for 5 days, with simulation of renal ischemia); I/N (animals submitted to laparotomy for clamping of bilateral renal pedicles for 30 min, followed by reperfusion); ABUTA + I/R (animals that received AG-400 mg/kg, 1× per day, VO, for 5 days, submitted to renal ischemia after treatment with herbal medicine). The results suggest that the consumption of Abuta grandifolia promoted renoprotection, preventing the reduction of renal function induced by ischemia, oxidizing activity, and deleterious effects on the renal tissue, confirmed by the decrease of oxidative metabolites and increase of antioxidants in the animals' organisms.

Comparative study of UV/H2O2 and UV/PMS processes for treating pulp and paper wastewater.

Pulp and paper wastewater (PPWW) contains numerous refractory and harmful contaminants that require advanced treatment to meet the discharge criteria. This study compared the efficacy of two PPWW treatments: ultraviolet/peroxymonosulfate (UV/PMS) and ultraviolet/H2O2 (UV/H2O2) working under similar circumstances. The initial pH value, oxidant dosage, UV radiation intensity, and pseudo-first-order constant kobs were systematically studied in both systems. Optimally, the UV/PMS process produced an effluent of higher quality than the UV/H2O2, as measured by the removal efficiencies of chemical oxygen demand (COD) in 60 min, which were 48.2 and 64.3% for the respective UV/H2O2 and UV/PMS processes and corresponding kobs values of 0.0102 and 0.0159 min-1, respectively. Radical scavenging experiments demonstrated that •OH was the primary reactive oxygen species in UV/H2O2 process, and •OH and SO4-• in the UV/PMS process. Moreover, ultraviolet-visible spectroscopy and gas chromatography coupled mass spectroscopy analyses showed that deep treatment of petroleum hydrocarbons with carbon chain lengths greater than 18 and macromolecular semi-volatile organic compounds in paper wastewater is difficult, whereas the UV/PMS process can significantly improve the removal of amides, esters, phenols, and other aromatic compounds.

PH regulated rapid photocatalytic degradation of methylene blue dye via niobium-nitrogen co-doped titanium dioxide nanostructures under sunlight

Niobium and nitrogen co-doped titanium dioxide (Nb-N-TiO2) semiconductor nanostructures were synthesized through a facile sol-gel protocol using titanium tetra iso-propoxide (TTIP), urea and niobium pentoxide as precursors followed by calcination at 450 °C for 4 h. The synthesized nanomaterial (Nb-N-TiO2) was characterized via Fourier Transform Infrared (FTIR) and Raman spectroscopy, UV-Visible (UV-Vis) Spectroscopy, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) technique, Dynamic Light Scattering (DLS) technique and ZETA Potential analysis. The band gap of Nb-N-TiO2 was reduced as compared to TiO2 due to reduced space between valance and conduction band which also reduced the electron-hole (e-, h+) recombination and led to better photocatalytic activity of the Nb-N-TiO2 as confirmed by TAUC plot. Photocatalytic activity of Nb-N-TiO2 was investigated for degradation of methylene blue (MB) dye under sunlight as cheaper light source. Factors like dye concentration, dosage of catalyst, volume of solution time and pH were studied and optimized for MB degradation. Under finally optimized conditions, 97% of 25 ppm MB was degraded just in one minute using 45 mg of photocatalyst. The co-doped nanocatalyst, was re-used for MB degradation upto 4th cycle with its efficiency reduced to 75% which shows a better catalytic role by the catalyst. Degradation products of MB were recognized through electrospray ionization coupled mass spectroscopy (ESI-MS) and liquid chromatography coupled mass spectroscopy (LC-MS) techniques. The catalyst was also applied for MB degradation in tap water sample.

Lure design for Drosophila suzukii based on liquid culture of fruit epiphytic yeasts: Comparing the attractivity of fermentation volatiles for seasonal morphs

AbstractThe spotted‐wing vinegar fly (Drosophila suzukii) is currently one of the most serious, invasive pest of berry crops worldwide. Most drosophilids are known to be attracted to fermentation volatiles produced by fruit epiphytic yeasts. Therefore, vinegar and wine baits are widely used in field trapping. However, these traps are not selective for spotted‐wing drosophila. We wished to exploit the previously discovered tight‐knit relationship between this vinegar fly and a fruit‐colonizing yeast, Hanseniaspora uvarum, and utilize this in the design of a selective lure. Field trapping experiments were carried out in a commercial cherry orchard to evaluate the attractiveness of bottle traps baited with liquid culture of four epiphytic yeast species on stone fruits and soft‐skinned fruits: H. uvarum, Metschnikowia pulcherrima, Pichia terricola and Saccharomyces cerevisiae as well as the mixed culture of the first two species. We also completed experiments using apple juice inoculated with H. uvarum. We compared the attractivity of yeast culture baits for D. suzukii and other drosophilids with that of apple cider vinegar. To explore the relationship between lure volatile emission and trap efficiency, solid‐phase microextraction (SPME) was used to measure the headspace of the freshly prepared and 3‐day‐old lures collected from the field. Headspace samples were analysed for their volatilome with gas chromatography coupled mass spectroscopy. The H. uvarum‐containing lures were more specific for D. suzukii than other yeast tested, and the attractivity was significantly higher if it was inoculated in apple juice. H. uvarum‐fermented apple juice lures were more specific for female D. suzukii than the traditional apple cider vinegar lures. Winter‐morph females showed an altered preference for yeast volatiles in the absence of fruit substrate.

Volatile Organic Compounds Released During the Fast Pyrolysis of Peanut Shells and Environmental Implications

The biomass conversion technologies, especially different types of pyrolysis, have been intensively studied to improve biomass energy transformation suggesting a low impact on the environment. In particular, fast pyrolysis of biomass is considered to be a thermal process in which the starting material is converted to bio-oil, char and gas products. In this work, volatile organic compounds (VOCs) of the gaseous fraction of peanut shells fast pyrolysis were collected and identified at atmospheric pressure. Aromatic compounds, hydrocarbons, furans and other oxygenated compounds were identified using solid phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (CG-MS) as a detection system. The composition of volatiles was analyzed and compared with the constituents of liquid fraction for comparative purposes. Atmospheric implications of the main compounds identified in the gases fraction were assessed by determining tropospheric lifetimes of the VOCs identified and its impact on environment at the local, regional or global scale.

Flagellin lysine methyltransferase FliB catalyzes a [4Fe-4S] mediated methyl transfer reaction.

The methyltransferase FliB posttranslationally modifies surface-exposed ɛ-N-lysine residues of flagellin, the protomer of the flagellar filament in Salmonella enterica (S. enterica). Flagellin methylation, reported originally in 1959, was recently shown to enhance host cell adhesion and invasion by increasing the flagellar hydrophobicity. The role of FliB in this process, however, remained enigmatic. In this study, we investigated the properties and mechanisms of FliB from S. enterica in vivo and in vitro. We show that FliB is an S-adenosylmethionine (SAM) dependent methyltransferase, forming a membrane associated oligomer that modifies flagellin in the bacterial cytosol. Using X-band electron paramagnetic resonance (EPR) spectroscopy, zero-field 57Fe Mössbauer spectroscopy, methylation assays and chromatography coupled mass spectrometry (MS) analysis, we further found that FliB contains an oxygen sensitive [4Fe-4S] cluster that is essential for the methyl transfer reaction and might mediate a radical mechanism. Our data indicate that the [4Fe-4S] cluster is coordinated by a cysteine rich motif in FliB that is highly conserved among multiple genera of the Enterobacteriaceae family.

Comparative study of the chemical composition, larvicidal, antimicrobial and cytotoxic activities of volatile oils from E. punicifolia leaves from Minas Gerais and Goiás

Eugenia punicifolia (Kunth) D.C., Myrtaceae, known as “pedra-ume-caá”, is popularly used in the treatment of inflammation, infections, fever, flu, diabetes, and diarrhea. This study aimed to carry out a comparative study of the chemical composition of volatile oil from E. punicifolia leaves collected in Goiás and Minas Gerais, as well as to evaluate the larvicidal activity against Aedes aegypti L3 larvae, the antimicrobial activity against bacteria, pathogenic fungi, and environmental, and cytotoxic activity to Balb 3T3 cells (murine fibroblasts). Volatile oils were obtained by hydrodistillation in a Clevenger apparatus and analyzed by Gas Chromatography Coupled to Mass Spectrometry (CG/MS). A total of 60 compounds were identified, the main components found in the leaves of Goiás being Germacrene D, bicyclogermacrene and β-longipenene and in the leaves collected in Minas Gerais they were (Z)-caryophyllene, γ-cadinene, spathulenol, caryophyllene oxide, and α-cadinol. The larvicidal effect was moderate against Ae. aegypti, with LC50 of 85.53 µg / mL for samples from Goiás and LC50 of 91.52 µg / mL for samples from Minas Gerais. Both oils showed moderate bactericidal activity against K. rhiziphyla (ATCC 9341), M. luteus (ATCC 10240), and S. aureus (ATCC 29737). The oils from Goiás (IC50 706.7 µg / mL) and Minas Gerais (IC50 160.7 µg / mL) had a lower cytotoxic concentration than the toxic action for larvae and bacteria, evidencing a safety profile and an interesting therapeutic potential, mainly concerning to volatile oil from Goiás. Therefore, the volatile oils from E. punicifolia leaves collected in Goiás and Minas Gerais that presented moderate larvicidal activity for Ae. aegypti also presented a bactericide activity and less cytotoxicity against murine fibroblasts. This is the first study of the larvicidal, antimicrobial and cytotoxic activity of volatile oils from E. punicifolia leaves.

Piper regnellii (Miq.) C. DC.: Chemical composition, antimicrobial effects, and modulation of antimicrobial resistance

Plant-derived essential oils are volatile hydrophobic compounds with significant antimicrobial activities. Considering the rise of antimicrobial resistance, these natural products have been highlighted as efficient weapons against multidrug-resistant microorganisms. This work aimed to investigate the phytochemical composition and antimicrobial activity of Piper regnellii essential oil against strains of Escherichia coli, Staphylococcus aureus, Candida albicans, and Candida tropicalis. Phytochemical analysis was performed through gas chromatography coupled with mass spectrometry (CG/MS). The intrinsic antimicrobial activity and the ability of the essential oil to modulate antimicrobial resistance were assessed using the broth microdilution method. Fungal virulence inhibition was analyzed by measuring the growth of hyphae in microculture chambers. Phytochemical characterization revealed a predominance of phenylpropanoids, including apiol (70.79%) and dilapiol (15.05%) as major constituents. While presenting clinically ineffective antibacterial effects (MIC ≥ 1.024 µg/mL for all strains), the essential oil potentiated the activity of gentamicin against E. coli at concentrations above 20 µg/mL. Piper regnellii essential oil showed clinically ineffective antifungal activity with IC50 values above 500 µg/mL. However, it was found to potentiate the activity of fluconazole against C. tropicalis at concentrations ranging from 32 μg/mL to 1024 μg/mL. Furthermore, the morphological transition was inhibited by culturing C. albicans and C. tropicalis with different concentrations of the essential oil. Together, our results indicate that P. regnellii essential oil presents promising antifungal effects. However, the mechanisms underlying its interference on Candida virulence remain to be further investigated.

GUIA PARA PROCESSAMENTO DE DADOS DE CROMATOGRAFIA ACOPLADA A ESPECTROMETRIA DE MASSAS

GUIDE FOR CHROMATOGRAPHY COUPLED TO MASS SPECTROMETRY DATA PROCESSING. In this work, a discussed and step-wise tutorial for LC-MS and GC-MS data processing using the open-access software MZMine2 is presented and discussed. The rationale behind each step was demonstrated to enable the readers to go through their own data and process it accordingly. The main lesson to be learned is that each parameter must be chosen in light of the raw data and no guidelines should suggest a predetermined value. Still, it is worth mentioning that ideal values for each parameter do not exist, and that the user might end up investing too much time futilely optimizing values. Our suggestion is to process your data in light of the raw data (and the study design) following the preview figure result and the resulting feature list generated in each processing step, interpret your data, and go back to process it again to tune the detection of important features.

Challenges and future directions in LC-MS-based multiclass method development for the quantification of food contaminants

Monitoring of food contaminants and residues has undergone a significant improvement in recent years and is now performed in an intensive manner. Achievements in the area of chromatography-mass spectrometry coupling techniques enabled the development of quantitative multi-target approaches covering several hundred analytes. Although the majority of methods are focusing on the analysis of one specific group of substances, such as pesticides, mycotoxins, or veterinary drugs, current trends are going towards the simultaneous determination of multiclass compounds from several families of contaminants and residues. This work provides an overview of relevant multiclass concepts based on LC-MS/MS and LC-HRMS instruments. Merits and shortcomings will be critically discussed based on current performance characteristics of the EU legislation system. In addition, the discussion of a recently developed multiclass approach covering >1000 substances is presented as a case study to illustrate the current developments in this area.

Determinación de la composición fenólica en granos ancestrales de uso alimentario. Comparación de métodos analíticos y de actividad antioxidante

El objetivo de este estudio fue cuantificar los compuestos fenólicos totales de diferentes granos ancestrales: dos variedades de tef (Eragrostis tef), trigo sarraceno (Fagopyrum esculentum) y trigo espelta (Triticum spelta) por diferentes métodos espectrofotométricos (Folin-Ciocalteu y Fast Blue BB) y comparar con los resultados obtenidos de estudiar la composición fenólica individualizada mediante cromatografía líquida de alta resolución acoplada a un sistema de detección de fotodiodos y espectrometría de masas (HPLC-DAD-MS). También se determinó la actividad antioxidante in vitro de los extractos de los granos ancestrales estudiados por el método TEAC (capacidad antioxidante equivalente de Trolox) y FRAP (poder antioxidante reductor del hierro). El uso de HPLC-DAD-MS permitió identificar un gran número de compuestos fenólicos: compuestos hidroxibenzoicos, hidroxicinámicos, flavonoles, flavonas y flavanoles. Las flavonas fueron la familia de compuestos fenólicos más abundante detectada en las muestras de espelta, teff, blanco y marrón. Sin embargo, en el trigo sarraceno son los flavanoles (64 %). La cuantificación de los compuestos fenólicos por HPLC-DAD-MS parece más oportuna que por los métodos espectrofotométricos. Con respecto a la actividad antioxidante, el trigo sarraceno mostró los valores más altos frente a su capacidad de captar radicales libres y poder reductor en relación a las otras muestras estudiadas, pudiéndose relacionar con su alto contenido en compuestos fenólicos.

Eremanthus arboreus (Gardner) MacLeish (Candeeiro): natural source of α-Bisabolol

There is a growing search in the chemical composition of essential oils, as they have biological and pharmacological activities. Among the plants with homogeneous composition in essential oils stands out the species Eremanthus arboreus (Gardner) MacLeish, (Asteraceae) popularly known as the “candeeiro”. This plant species is native to Chapada of Araripe - Ceará, Brazil. The objective was to characterize chemically the constituents of the essential oil (OE) of E. arboreus by means of Gas Chromatography and perform a review of its biological and pharmacological activities. The botanical material was collected in Chapada of Araripe, Barbalha - CE, Brazil, in April 2014, the extraction and collection of OE was done in Clevenger apparatus. The chemical composition of the OE was performed by Gas Chromatography coupled to Mass Spectrometry (CG/MS). As for the review, specialized scientific bases (Scopus, Scielo and Web of Science) were consulted. According to the results, 8 constituents were identified, where α-Bisabolol is mentioned as being the main component of the essential oil of this species. As for the biological and pharmacological activities of the OE, it was demonstrated that the species has the following activities: antimicrobial, larvicide, anti-inflammatory and antinociceptive. Eremanthus arboreus is a species with great pharmaceutical potential and also an alternative for industries that target products based on the constituent α-Bisabolol.

Óleo essencial das cascas descartadas do fruto de Hymenaea courbaril L. como larvicida frente Aedes aegypti

Este estudo objetivou avaliar a atividade larvicida do óleo essencial (OE) extraído das cascas do fruto comumente descartadas de Hymenaea coubaril L. Para extração do OE foi utilizada a técnica de hidrodestilação em um sistema extrator de Clevenger modificado. Os constituintes químicos foram obtidos por Cromatografia Gasosa acoplada a espectrometria de massas (CG/EM). Para atividade larvicida submeteu-se larvas de Aedes aegypti a soluções do OE em concentrações de 10-100 mg L-1, onde avaliou-se a mortalidade das larvas e determinou-se a CL50. O β-ocimeno foi quantificado como majoritário no OE. Observou-se ação do OE como larvicida onde foi determinada a CL50 de 16,6 mg L-1. Os resultados obtidos permitiram concluir que o OE estudado apresentou atividade larvicida eficiente contra as larvas de Aedes aegypti, sendo importante e incentivado seu uso e aplicação.

Chemical composition and larvicidal activity of Citrus limonia Osbeck bark essential oil

Aedes aegypti mosquito arouses the interest of public authorities, as it is a vector for four diseases (dengue, zika, chikungunya, and yellow fever) and one of the ways to combat it is through insecticides. In this study, the main constituent, the predominant class of essential oil extracted from the husks of Citrus limonia Osbeck was identified and evaluated to know if it has biological activity against larvae in the third stage of Ae.aegypti. gas chromatography coupled with mass spectrometry (CG-MS); larvicidal activity as described by the World Health Organization (WHO) was evaluated and the lethal concentration (LC50) from the Probit model was calculated. The results show that the oil consists mainly of limonene, beta-Pinene, meta-Cymene, beta.-Phellandrene and alpha-Pinene, in which the predominant class was monoterpenes and the lethal concentration, CL50, was 67.18 µg.mL-1. Therefore, the oil has potential larvicidal activity. Key words: Volatile compounds, monoterpenes, aedes aegypti, limonene, natural insecticide.

2,4-Thiazolidinedione as Precursor to the Synthesis of Compounds with Anti-glioma Activities in C6 and GL261 Cells.

Thiazolidinediones (TZDs) represent an important class of heterocyclic compounds that have versatile biological activities, including anticancer activity. Glioma is one of the most common primary brain tumors, and it is responsible for most of the deaths caused by primary brain tumors. In the present work, 2,4-thiazolidinediones were synthesized via a multicomponent microwave one-pot procedure. The cytotoxicity of compounds was analyzed in vitro using rat (C6) and mouse (GL261) glioblastoma cell lines and primary cultures of astrocytes. This study aims to synthesize and characterize 2,4-thiazolidinediones and evaluate their antitumor activity. TZDs were synthesized from three components: 2,4-thiazolidinedione, arene-aldehydes, and aryl chlorides. The reactions were carried out inside a microwave and monitored using thinlayer chromatography (TLC). Compounds were identified and characterized using gas chromatography coupled to mass spectrometry (CG-MS) and hydrogen (1H-NMR) and carbon nuclear magnetic resonance spectroscopy (13C-NMR). The antitumor activity was analyzed using the 3-(4,5- dimethyl)-2,5-diphenyltetrazolium bromide (MTT) reduction test, in which cell viability was verified in the primary cultures of astrocytes and in rat and mouse glioblastoma cells exposed to the synthesized compounds. The cytotoxicity of all derivatives was analyzed at the 100 μM concentration, both in astrocytes and in the mouse and rat glioblastoma cell lines. The compounds that showed the best results, 4CI and 4DI, were also tested at concentrations 25, 50, 100, 175, and 250 μM to obtain the IC50. Seventeen TZD derivatives were easily obtained through one-pot reactions in 40 minutes with yields ranging from 12% to 49%. All compounds were cytotoxic to both glioblastoma cell lines without being toxic to the astrocyte primary cell line at 100 μM, thus demonstrating a selective activity. Compounds 4CI and 4DI showed the best results in the C6 cells: IC50 of 28.51 μM and 54.26 μM, respectively. The compounds were not cytotoxic in astrocyte culture, demonstrating selectivity for malignant cells. Changes in both rings are important for anti-glioma activity in the cell lines tested. TZD 4CI had the best anti-glioma activity.