cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14278844.v1
title: EVALUATION OF MOBILE PHASE ADDITIVES AND TEMPERATURE ON COLUMN LIFETIME FOR HIGHPERFORMANCE LIQUID CHROMATOGRAPHY

description: Buffered solutions, additives, and column temperature are widely used in high-performance liquid chromatography to promote adequate retention of compounds and to improve the chromatographic separation. However, these factors can dramatically reduce the column lifetime. In this work, the effect of column temperature, pH and the salt type and concentration in buffered mobile phases were evaluated on the stability of a typical commercial C18 stationary phase. A method for rapid evaluation of stationary phase degradation caused by these variables was employed to avoid the generation of large volumes of organic waste. By monitoring the performance of stationary phase in the separation of a standard test mixture, it was possible to verify that the pH of the mobile phase is the most drastic condition to reduce the column lifetime. Buffer solutions of inorganic salts as well as the use of temperatures above 40 °C also significantly reduce the column lifetime. However, a column can have its use extended working with low concentrations of organic additives in the mobile phase, under moderated temperature, and adjusting the pH to the safety range of silica-based materials.
DOI: 10.6084/m9.figshare.14278824
title: METHOD DEVELOPMENT AND VALIDATION FOR THE FLUOROQUINOLONES DETERMINATION BY STABILIZED SILVER NANOPARTICLES

description: Silver nanoparticles (AgNPs) stabilized with glutathione (GSH) were used as nanosensors for the determination of fluoroquinolones such as ciprofloxacin (CIP), norfloxacin (NOR) and enrofloxacin (ENRO) in aqueous systems. The AgNPs were stabilized with GSH (Ag-GSH NPs), whereas the decrease of the surface plasmon resonance (SPR) band at 400 nm and the bathochromic shift of the absorption band were monitored. The method was validated and the analytical performance was verified. The results were satisfactory, with recoveries between 83.7 and 110% in almost all the experimental conditions and the repeatability and intermediate accuracy of less than 20%. The limits of detection were 0.397, 0.437 and 0.398 µmol L-1, and the limits of quantification were 1.203, 1.323 and 1.205 µmol L-1 for ciprofloxacin, norfloxacin and enrofloxacin, respectively. The method was selective in a group of drugs and applied in the determination of fluoroquinolones in potable water samples.
DOI: 10.6084/m9.figshare.14278847
title: EVALUATION OF THE METABOLIC PRODUCTION OF THE ENDOPHYTIC FUNGUS Phomopsis sp.

description: Endophytic microorganisms have been shown to be an important source of bioactive compounds, and much has been studied about their metabolites. For example, compounds with different biological activities have been isolated from Phomopsis sp. The metabolic study of this genus may lead to a better understanding of the routes of production of metabolites of interest. The aim of this study was to map the metabolic profile of Phomopsis sp., isolated as an endophyte of Syzygium jambolanum DC, using culture filtrate. The fungus was cultivated for six weeks in potato dextrose medium under hypoxia and at room temperature. The filtrate was collected weekly, and the analyses were performed using proton nuclear magnetic resonance (1H NMR) spectroscopy by applying NOESY1D with suppression of the water signal. The occurrence of reductive routes was verified: alcoholic fermentation throughout cultivation and reductive tricarboxylic acid cycle in the cytosol until the third week of cultivation were observed.
DOI: 10.6084/m9.figshare.14278847.v1
title: EVALUATION OF THE METABOLIC PRODUCTION OF THE ENDOPHYTIC FUNGUS Phomopsis sp.

description: Endophytic microorganisms have been shown to be an important source of bioactive compounds, and much has been studied about their metabolites. For example, compounds with different biological activities have been isolated from Phomopsis sp. The metabolic study of this genus may lead to a better understanding of the routes of production of metabolites of interest. The aim of this study was to map the metabolic profile of Phomopsis sp., isolated as an endophyte of Syzygium jambolanum DC, using culture filtrate. The fungus was cultivated for six weeks in potato dextrose medium under hypoxia and at room temperature. The filtrate was collected weekly, and the analyses were performed using proton nuclear magnetic resonance (1H NMR) spectroscopy by applying NOESY1D with suppression of the water signal. The occurrence of reductive routes was verified: alcoholic fermentation throughout cultivation and reductive tricarboxylic acid cycle in the cytosol until the third week of cultivation were observed.
DOI: 10.6084/m9.figshare.14278849
title: DETERMINATION OF PESTICIDE MULTIRESIDUES IN HONEY PRODUCED IN THE TRIÂNGULO MINEIRO REGION OF BRAZIL BY UHPLC-MS/MS

description: Excessive use of pesticides can lead to the accumulation of residues in different parts of plants, endangering various species and contaminating foods. Honey can be used as an indicator of agricultural contamination and pre-mature bee mortality by pesticides. However, to quantify pesticide residues in honey, high sensitivity analytical methodologies are required. In this work, a new method was proposed for the determination of seven pesticides, widely used in Triângulo Mineiro, in honey samples based on QuEChERS method and quantification by UHPLC-MS/MS. The method was optimized and validated according to the protocol recommended by the European Community. The method presented LOQ in the range of 0.6-4.0 µg kg-1, lower than the MRLs established for the pesticides studied. Also, the methodology showed high accuracy, with recoveries ranging from 89-107%, and good accuracy, RSD &lt;14%. Honey samples obtained in the Triângulo Mineiro region and subjected to the determination of pesticide residues were analyzed by the analytical methodology, indicating the presence of methomyl and imidacloprid residues in all samples. These results indicate that beehives close to the grain and sugarcane crops are being affected by the application of pesticides in the Triângulo Mineiro Region, Brazil.
DOI: 10.6084/m9.figshare.14278849.v1
title: DETERMINATION OF PESTICIDE MULTIRESIDUES IN HONEY PRODUCED IN THE TRIÂNGULO MINEIRO REGION OF BRAZIL BY UHPLC-MS/MS

description: Excessive use of pesticides can lead to the accumulation of residues in different parts of plants, endangering various species and contaminating foods. Honey can be used as an indicator of agricultural contamination and pre-mature bee mortality by pesticides. However, to quantify pesticide residues in honey, high sensitivity analytical methodologies are required. In this work, a new method was proposed for the determination of seven pesticides, widely used in Triângulo Mineiro, in honey samples based on QuEChERS method and quantification by UHPLC-MS/MS. The method was optimized and validated according to the protocol recommended by the European Community. The method presented LOQ in the range of 0.6-4.0 µg kg-1, lower than the MRLs established for the pesticides studied. Also, the methodology showed high accuracy, with recoveries ranging from 89-107%, and good accuracy, RSD &lt;14%. Honey samples obtained in the Triângulo Mineiro region and subjected to the determination of pesticide residues were analyzed by the analytical methodology, indicating the presence of methomyl and imidacloprid residues in all samples. These results indicate that beehives close to the grain and sugarcane crops are being affected by the application of pesticides in the Triângulo Mineiro Region, Brazil.
DOI: 10.6084/m9.figshare.14278832.v1
title: Extracts of Lilium sp., Agapanthus sp. and Hydrangea sp.: behavior as natural indicators in different pH range

description: This experimental activity proposes the use of lily (Lilium sp.), agapanthus (Agapanthus sp.) and hydrangea (Hydrangea sp.) extracts to investigate the colorimetric profile of each extract between pH 1-14. Water, ethanol and ethanol/HCl 1% (w/w) were used as extractive solvents. Among the flowers tested, the extracts of orange lily and burnt yellow lily were the ones that presented the greatest color variation with the solution pH change. In addition, the total content of anthocyanins in relation to cyanidin-3-glycosidic was determined and in ascending order we have: yellow lily (LAM: 0,07 ± 0,03) &lt; agapanthus white (AGB: 0,21 ± 0,03) &lt; agapanthus violet (AGV: 1,72 ± 0,13) &lt; blue hydrangea (HAZ: 1,83 ± 0,47) &lt; orange lily (LAL: 2,87 ± 0,52) &lt; burnt yellow lily (LAQ: 9,55 ± 0,46). For this determination methanol/HCl 1% (w/w) was used as the solvent. Using UV-Vis spectroscopy, it is suggested that the behaviors are due to the presence of cyanidin in AGB, AGV, LAL and LAQ, delphinidin in HAZ and apigeninidine in LAM. This activity can be applied in courses that have Chemistry in their curricular matrix and in General Chemistry subjects when the acid-base theme is approached.
DOI: 10.6084/m9.figshare.14278851
title: PLANT METABOLOMICS: METHODS AND CHALLENGES

description: Metabolomics has played a central role in various areas of plant sciences, offering new perspectives for the advancement of agriculture, drug discovery, chemical ecology and taxonomy. Plant metabolomics (identification and quantification) aims to understand the relationship between biological systems and genetic, pathological and or environmental stimuli in terms of differential expression of the metabolism. Owing to the unique challenges, such studies require multidisciplinary skills involving biology, chemistry, statistics, and computer science for the extraction and complete understanding of information. In this sense, this review summarizes the main procedures that involve the steps of plant metabolomic study (design of experiments, sample preparation, analytical methods and data analysis), providing a comprehensive overview, showing the main challenges and limitations and possible solutions for the different approaches used.
DOI: 10.6084/m9.figshare.14278853.v1
title: THE SHORT ALTERNATE REALITY GAME (SHORT ARG) AS A STRAGEGY FOR DISCUSSING CHEMICAL CONCEPTS AT COLLEGE EDUCATION

description: This paper presents the application of a Short ARG built to be applied in a single class, instead of a longer interval, as it is common in strategies such as ARG. ARGs are games based on role-playing experiences that involve role playing using a particular place, in this case, two classrooms and an education lab. Whereas ARG’s characters are the participants/players themselves, in this study, they were the Chemistry undergraduate students. The students/players were aimed of various clues and moments involving chemical concepts to find a lost student. We could notice ARG can be a teaching strategy, we mean, an alternative for conceptual discussion in the classroom as well as a diagnostic and formative assessment tool, characteristic of the use of games and recreational activities in teaching scientific concepts.
DOI: 10.6084/m9.figshare.14278851.v1
title: PLANT METABOLOMICS: METHODS AND CHALLENGES

description: Metabolomics has played a central role in various areas of plant sciences, offering new perspectives for the advancement of agriculture, drug discovery, chemical ecology and taxonomy. Plant metabolomics (identification and quantification) aims to understand the relationship between biological systems and genetic, pathological and or environmental stimuli in terms of differential expression of the metabolism. Owing to the unique challenges, such studies require multidisciplinary skills involving biology, chemistry, statistics, and computer science for the extraction and complete understanding of information. In this sense, this review summarizes the main procedures that involve the steps of plant metabolomic study (design of experiments, sample preparation, analytical methods and data analysis), providing a comprehensive overview, showing the main challenges and limitations and possible solutions for the different approaches used.
DOI: 10.6084/m9.figshare.14278855
title: CONSTRUCTION OF MINI OVEN FOR THERMAL FUNCTIONALIZATION OF MONOLITHIC STATIONARY PHASES

description: The present work describes a mini oven built to be applied in the preparation of monolithic stationary phase through the thermal polymerization approach. The developed device was successfully tested for functionalization of monolithic stationary phase in the internal surface of the silica capillary column fused with gold nanoparticles.
DOI: 10.6084/m9.figshare.14278856
title: THE CONSTRUCTION OF CONCEPTS ON THE MANAGEMENT AND TREATMENT OF CHEMICAL WASTE: A TRAINING EXPERIENCE OF CHEMISTRY STUDENTS

description: This work aims to analyze the contribution of a training action to the awareness and improvement of the knowledge of students of Chemistry and Chemical Engineering of Universidade Federal do Rio Grande do Sul (UFRGS) courses, regarding the processes of management and treatment of chemical wastes and wastewater generated in the experimental course. The research was performed with 66 students enrolled in the Experimental General Chemistry subject in the second semester of 2017. For that purpose, a two-hour lesson action training course was offered. As data collecting tools, an Initial Questionnaire was applied before the training stage and a Final Questionnaire was applied after the training stage. In order to do the analyses of the questionnaire answers, were elaborated also images about the frequency of the words by using NVivo 12(®) software. The data set indicates a scientific inculturation/alphabetization of concepts by students in terms of the main treatment types used to mitigate residues that are generated in teaching labs, as Coprocessing, Incineration and Sanitary Landfill. It can also be inferred that the activity offered to the students contributed to the formation of values necessary for the formation of professionals more aware of their performance in society.
DOI: 10.6084/m9.figshare.14278856.v1
title: THE CONSTRUCTION OF CONCEPTS ON THE MANAGEMENT AND TREATMENT OF CHEMICAL WASTE: A TRAINING EXPERIENCE OF CHEMISTRY STUDENTS

description: This work aims to analyze the contribution of a training action to the awareness and improvement of the knowledge of students of Chemistry and Chemical Engineering of Universidade Federal do Rio Grande do Sul (UFRGS) courses, regarding the processes of management and treatment of chemical wastes and wastewater generated in the experimental course. The research was performed with 66 students enrolled in the Experimental General Chemistry subject in the second semester of 2017. For that purpose, a two-hour lesson action training course was offered. As data collecting tools, an Initial Questionnaire was applied before the training stage and a Final Questionnaire was applied after the training stage. In order to do the analyses of the questionnaire answers, were elaborated also images about the frequency of the words by using NVivo 12(®) software. The data set indicates a scientific inculturation/alphabetization of concepts by students in terms of the main treatment types used to mitigate residues that are generated in teaching labs, as Coprocessing, Incineration and Sanitary Landfill. It can also be inferred that the activity offered to the students contributed to the formation of values necessary for the formation of professionals more aware of their performance in society.
DOI: 10.6084/m9.figshare.14278853
title: THE SHORT ALTERNATE REALITY GAME (SHORT ARG) AS A STRAGEGY FOR DISCUSSING CHEMICAL CONCEPTS AT COLLEGE EDUCATION

description: This paper presents the application of a Short ARG built to be applied in a single class, instead of a longer interval, as it is common in strategies such as ARG. ARGs are games based on role-playing experiences that involve role playing using a particular place, in this case, two classrooms and an education lab. Whereas ARG’s characters are the participants/players themselves, in this study, they were the Chemistry undergraduate students. The students/players were aimed of various clues and moments involving chemical concepts to find a lost student. We could notice ARG can be a teaching strategy, we mean, an alternative for conceptual discussion in the classroom as well as a diagnostic and formative assessment tool, characteristic of the use of games and recreational activities in teaching scientific concepts.
DOI: 10.6084/m9.figshare.14278858
title: Quantification of bergenin, antioxidant activity and nitric oxide inhibition from bark, leaf and twig of Endopleura uchi

description: Phytochemical investigation of Endopleura uchi led to the isolation of a gallic acid derivate, known as bergenin (2) and friedelin (1), a pentacyclic triterpene. The present work also reports the bergenin quantification in different Endopleura uchi bark, twig and leaves extracts. Our findings showed the highest bergenin concentration in bark methanol extracts (4.75%) and the lowest concentration in twig aqueous extracts (1.89%). Phenolics quantification by Folin-Ciocalteu, revealed phenolic compounds level values from 16.69 to 43.02 mg GAE g-1 dry extract. The ferric reducing antioxidant activity ranged from 230.43 to 567.89 mmol Fe+2 g-1 dry extract. DPPH IC50 free radicals showed to range from 12.04 to 24.20 μg mL-1. Leaves’ chloroform fraction exhibited the highest nitric oxide inhibiting activity bearing IC50= 3.2 μg mL-1. Results show this species to hold significant bergenin concentrations as well as phenolic and anti-inflammatory compounds in all extracts suggesting it bear therapeutic potential.
DOI: 10.6084/m9.figshare.14278858.v1
title: Quantification of bergenin, antioxidant activity and nitric oxide inhibition from bark, leaf and twig of Endopleura uchi

description: Phytochemical investigation of Endopleura uchi led to the isolation of a gallic acid derivate, known as bergenin (2) and friedelin (1), a pentacyclic triterpene. The present work also reports the bergenin quantification in different Endopleura uchi bark, twig and leaves extracts. Our findings showed the highest bergenin concentration in bark methanol extracts (4.75%) and the lowest concentration in twig aqueous extracts (1.89%). Phenolics quantification by Folin-Ciocalteu, revealed phenolic compounds level values from 16.69 to 43.02 mg GAE g-1 dry extract. The ferric reducing antioxidant activity ranged from 230.43 to 567.89 mmol Fe+2 g-1 dry extract. DPPH IC50 free radicals showed to range from 12.04 to 24.20 μg mL-1. Leaves’ chloroform fraction exhibited the highest nitric oxide inhibiting activity bearing IC50= 3.2 μg mL-1. Results show this species to hold significant bergenin concentrations as well as phenolic and anti-inflammatory compounds in all extracts suggesting it bear therapeutic potential.
DOI: 10.6084/m9.figshare.14278860
title: Iridoids, triterpenes and other constituents from the trunk bark and flowers of the Tabebuia caraiba

description: The trunk bark of Tabebuia caraiba Bignoniaceae was found to contain four novel iridoids, 6-O-E-p-coumaroyljioglutin D (2), 6-O-E-p-coumaroyl-3-demethyl-3-O-ethyljioglutin D (3), 6-O-E-p-coumaroyl-1-demethyl-1-O-ethyljioglutin D (4), 7-O-E-p-coumaroyljiofuranaldehyde (5), three known iridoids, including one iridoid glucoside, jioglutin D (1), rehmaglutin D (6), 6-O-E-p-coumaroylcatalpol (7). From the flowers were obtained six triterpenes, betulinic acid (8), olean-12-en-3-one (9), β-amyrin (10), oleanolic acid (11), ursolic acid (12), 3-O-E-p-coumaroylursolic acid (13), 2α-hydroxyursolic acid (14), 6β,19α-dihydroxyursolic acid (15), and one phenylethanoid, tyrosol (16), in addition to β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside and β-sitosterol-3-O-β-D-(6´-O-acyl)-glucopyranoside and E-p-coumaric acid. The structures of the isolated compounds were established on the basis of 1D and 2D NMR spectroscopic techniques. The chemical profile of the trunk bark of the plant was determined by HPLC/DAD/HRESIMS and did not present a good correlation with the phytochemical study. It did not detect most of the isolated substances and allowed to propose the presence of some non-isolated compounds.
DOI: 10.6084/m9.figshare.14278860.v1
title: Iridoids, triterpenes and other constituents from the trunk bark and flowers of the Tabebuia caraiba

description: The trunk bark of Tabebuia caraiba Bignoniaceae was found to contain four novel iridoids, 6-O-E-p-coumaroyljioglutin D (2), 6-O-E-p-coumaroyl-3-demethyl-3-O-ethyljioglutin D (3), 6-O-E-p-coumaroyl-1-demethyl-1-O-ethyljioglutin D (4), 7-O-E-p-coumaroyljiofuranaldehyde (5), three known iridoids, including one iridoid glucoside, jioglutin D (1), rehmaglutin D (6), 6-O-E-p-coumaroylcatalpol (7). From the flowers were obtained six triterpenes, betulinic acid (8), olean-12-en-3-one (9), β-amyrin (10), oleanolic acid (11), ursolic acid (12), 3-O-E-p-coumaroylursolic acid (13), 2α-hydroxyursolic acid (14), 6β,19α-dihydroxyursolic acid (15), and one phenylethanoid, tyrosol (16), in addition to β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside and β-sitosterol-3-O-β-D-(6´-O-acyl)-glucopyranoside and E-p-coumaric acid. The structures of the isolated compounds were established on the basis of 1D and 2D NMR spectroscopic techniques. The chemical profile of the trunk bark of the plant was determined by HPLC/DAD/HRESIMS and did not present a good correlation with the phytochemical study. It did not detect most of the isolated substances and allowed to propose the presence of some non-isolated compounds.
DOI: 10.6084/m9.figshare.14278865
title: A survey of parabens in commercial baby wipes from Brazil and estimation of daily exposure

description: Several studies have shown endocrine-disrupting effects of parabens. Parabens are a group of antimicrobials used as preservatives in a wide variety of products, mainly in personal care products. However, little information is available regarding the occurrence of parabens in baby products. In this study, the concentrations of five commonly used parabens, methyl-, ethyl-, propyl-, butyl- and, benzyl-paraben in 50 Brazilian baby wet wipes were analyzed by liquid chromatography coupled to mass spectrometry. All samples contained parabens, and the total concentrations ranged from 16 to 332,470 ng g-1 (geometric mean: 5344 ng g-1). Methyl-paraben, ethyl-paraben, propyl-paraben, and butyl-paraben were found in &gt;65% of the samples. 24 out of 50 samples exceed the permitted value of 0.4 % for methyl-paraben for their use in personal care products. Although, propyl-paraben and butyl-paraben are forbidden in cosmetic products designed for application on the nappy area of children under three years of age, the detection rate of them were 94 and 70 %, respectively. Based on the measured concentrations and use frequency of baby wipes the estimated daily intake of parabens was calculated. The median estimated daily intake values of total concentrations of parabens for babies of one year old was 391 ng kg-1 bw day-1. In conclusion, babies and children may be exposed to high levels of parabens through use of baby wipes. It is also worth to mention that two forbidden parabens were frequently detected.