cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14304182
title: Protein Removal from Natural Rubber Latex with Fe3O4@Al2O3 Nanoparticle

description: The presence of protein in the natural rubber latex for the medical device manufacture seems to be the most considered compound due to its allergic effect. Magnetic coated alumina (Fe3O4@Al2O3) has been known as an adsorbent for organic substrates due to its performance through physical and/or chemical interaction. In the current study, we tried to figure out the potential of Fe3O4@Al2O3 to prepare low protein’s natural rubber latex with and without the presence of surfactant through a continuous batch system. The dry rubber content, surfactant amount, and time during the incubation were investigated to determine the effective protein removal natural rubber. The highly deproteinized natural rubber was confirmed using Kjeldahl method, proven that the utilization of Fe3O4@Al2O3 could reduce the protein content from 0.38 to 0.016% in an optimum condition (dry rubber content of 10.00%; surfactant of 0.25%; Fe3O4@Al2O3 of 1.00 wt.%; and 15 min of incubation time). These results showed that Fe3O4@Al2O3 is a very good material to remove protein from natural rubber latex and this method can be performed using a continuous batch system.
DOI: 10.6084/m9.figshare.14304165
title: A Green Procedure Using Disposable Pipette Extraction to Determine Polycyclic Aromatic Sulfur Heterocycles in Water Samples and Solid Petrochemical Residues

description: A simple and efficient method using reduced amounts of solvents for the determination of polycyclic aromatic sulfur heterocycles (PASHs) in aqueous matrices from a lagoon and leachate solid waste from a petrochemical industry is proposed. The target analytes were previously concentrated using the disposable pipette extraction (DPX) technique applying gas chromatography-mass spectrometry (GC-MS) for analysis. In this innovative approach, the DPX was modified with 8-hydroxyquinoline silica gel immobilized with PdII for the pre-concentration of 4-methyldibenzothiophene, 4,6-dimethyldibenzothiophene, 1,2-naphtobenzothiophene, 2-methylbenzothiophene and 3-methylbenzothiophene. To improve the extraction efficiency, parameters such as desorption solvent, ionic strength, extraction and desorption cycles were optimized. The values obtained for the limits of detection (LOD) and quantification (LOQ) are adequate for the determination of PASHs in aqueous and leachate solid waste samples. Precision and accuracy parameters showed satisfactory results, providing relative recoveries of 74.6-131.2% for PASHs from lagoon water samples and 72.7-118.0% for leachate of solid waste samples. In the lagoon samples the relative standard deviation (RSD) values for the five PASHs ranged from 0.3 to 9.2% and 3.8 to 19.4% for the leachate of the solid waste. These results demonstrate that the proposed method represents a promising alternative for the determination of PASHs in aqueous and leachate solid waste samples.
DOI: 10.6084/m9.figshare.14304162
title: Determining Methamphetamine in Urine by Molecularly Imprinted Polymer Assisted Paper Spray Ionization Mass Spectrometry

description: The usefulness of molecularly imprinted polymer assisted paper spray ionization mass spectrometry (MIP-PSI-MS) for the determination of methamphetamine in urine has been demonstrated. MIP-PSI-MS is a method in which a MIP is synthesized on the surface of a paper, producing a chemically selective paper surface with molecular recognition sites for a target analyte. The analyte is extracted by the MIP substrate, which is posteriorly used for conventional PSI-MS analysis. As methamphetamine is one of the most widely used drugs of abuse in the world, it was selected to be studied in synthetic urine by the MIP-PSI-MS method. Methamphetamine was detected at higher ion signals compared to other different drugs, such as lysergic acid diethylamide (LSD) and cocaine, suggesting that MIP-PSI-MS has a chemical affinity for methamphetamine. In experiments to validate the method, a linear calibration curve was achieved with R-squared (R2) &gt; 0.99. Limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.8 and 2.8 µg L-1, respectively. Precision (relative standard deviation) and accuracy (relative error) were less than 10%, and the recoveries were close to 100%. The matrix effect was below 10%. These data demonstrate the possibility of using MIP-PSI-MS as an analytical tool for a specific/selective analysis of methamphetamine in forensic sciences.
DOI: 10.6084/m9.figshare.14304159
title: Rapid and Inexpensive Colorimetric Detection of Total Serum Protein Using Microzone Plates Wax-Printed on Polyester Films

description: This report describes a rapid and inexpensive colorimetric method based on biuret assay for total serum protein analysis using wax printed microzone plates and a desktop scanner. The colorimetric assay was performed in 96-microzone plates fabricated on polyester films through a wax printing protocol. The image scanning mode and the concentration of the biuret reagents were optimized to achieve the highest detectability levels. The best analytical response was obtained using the slide scanning mode as well as 4% CuSO4 and 150 mmol L-1 potassium sodium tartrate solutions. The proposed method offered linear relationship for the bovine serum albumin concentration range between 25 and 200 µmol L-1 with a limit of detection of 9.7 µmol L-1. The colorimetric approach revealed satisfactory precision (relative standard deviation values between 0.6 and 4.4%). The bioanalytical feasibility was demonstrated through the total protein analysis in serum samples collected from dogs previously diagnosed with kidney disease. The total serum protein concentrations varied from 960 ± 19 to 1661 ± 38 µmol L-1 and the achieved values revealed good accordance with those obtained through a reference method. Based on the reported results, wax printed microzone plates have demonstrated simplicity and potential to be adopted as alternative platforms for bioassays.
DOI: 10.6084/m9.figshare.14304158
title: Arsenic and Other Elements Determination in Seawater Using Coprecipitation and Standard Mode Inductively Coupled Plasma Mass Spectrometry

description: The present work aims the determination of As, Co, Cr, Cu, Mn and Pb in seawater samples using coprecipitation extraction procedure before standard mode inductively coupled plasma mass spectrometry (ICP-MS) (no collision/reaction cell). The coprecipitation procedure is based on the precipitation of Mg(OH)2 from the reaction of the Mg2+ ions (present into the seawater) with ammonia added to the sample. Central composite design, desirability function, and response surface methodology were used to optimize the coprecipitation procedure. The optimum values obtained were 1200 µL of aqueous ammonia, 30 min of centrifugation time and 400 µL of nitric acid. The procedure obtained showed low limits of detection since good preconcentration factors were obtained. Good accuracy was also obtained when the reference material Trace Metals 1 in seawater was evaluated. Thus, the proposed procedure can be considered a good strategy for the determination of As, Co, Cr, Cu, Mn and Pb in seawater by ICP-MS, due to its simplicity, low cost, high analytical frequency, besides the good sensitivity and accuracy achieved.
DOI: 10.6084/m9.figshare.14304155
title: Reusable Heterogeneous SnO2/ZnO Catalyst for Biodiesel Production from Acidified/Acid Oils

description: A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, catalyst concentration of 5%, and methanol:oil molar ratio of 15:1. The catalyst achieved 92% of total fatty acid methyl esters (FAME) content and was used five times without the necessity of catalyst washing from one reaction to the other. Then, such conditions were applied to produce biodiesel from the oil extracted from Scenedesmus sp. microalgae; the system reached 72% of FAME content, without any previous refining or degumming process of the oil. Rietveld refinement, X-ray diffraction, elemental mapping in scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and pyridine-desorption Fourier-transform infrared spectroscopy were used to characterize the material.
DOI: 10.6084/m9.figshare.14304150
title: A Facile Synthesized Polyaniline Coated Zerovalent Iron-Silica as an Efficient Sorbent for Magnetic Solid Phase Extraction of Phenolic Pollutants in Water Samples

description: A magnetic material based on polyaniline coated zerovalent iron-silica (Fe@SiO2@PANI) was simply synthesized using a facile manner under low energy consumption and applied for magnetic solid phase extraction of phenolic pollutants prior to analysis by high performance liquid chromatography-photodiode array detection (HPLC-PDA). The parameters which affected the extraction efficiency, i.e., sorbent amount, extraction time, sample volume and pH, desorption solvent and its volume, were optimized. Wide linear dynamic range of 0.012-10.000 μg mL-1 and the coefficients of determination better than 0.9926 were achieved. The limits of detection and the limits of quantitation were found in the ranges of 0.001-0.030 and 0.012-0.090 μg mL-1, respectively. The precision, expressed as relative standard deviation (RSD), was better than 11%. The synthesized sorbent exhibits good adsorption affinity and reusability up to 16 cycles. Applicability of the proposed methodology for analysis of phenolic residues in environmental and wastewater samples showed the recoveries in the range of 83.4-118.9%.
DOI: 10.6084/m9.figshare.14304149
title: Synthesis, Characterization and Exchange Reactions of Layered Double Hydroxides of Copper and Aluminum, Intercalated with Sulfate

description: Layered double hydroxides (LDHs) of Cu:Al in the molar ratio of 2:1, intercalated with sulfate, sulfate/(Li+, Na+, K+ or NH4+), NO3- and CO32-, were synthesized by co-precipitation with increasing pH. The materials were submitted to exchange reactions using B2SO4 (B = Li+, Na+, K+, NH4+) solutions in an attempt to replace previously intercalated cations or incorporated cations without removing intercalated sulfate. X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra were consistent with the expected intercalated species and scanning electron microscopy (SEM) images indicated submicrometric platelet-like particles, typical of LDHs. The chemical compositions of all phases were confirmed by inductively coupled plasma optical emission spectrometry (ICP OES) and thermogravimetric analyses (TGA). In the exchange reactions, only in [Cu6Al3(OH)18][Na(H2O)6(SO4)2]·6H2O the sodium cations were almost totally replaced with lithium, potassium and ammonium, without removing the intercalated sulfate.
DOI: 10.6084/m9.figshare.14304146
title: Spatial Distribution and Pollution Assessment of Trace Elements Pb, Cu, Ni, Fe and As in the Surficial Water of Staring Bay, Indonesia

description: Staring Bay has long been used by the local community for fisheries and fishing activities; however, the rapid population growth and industrial activities around the bay in recent years are predicted to contribute significantly to the increase of waste entering the bay. This particular study was aimed to provide baseline levels of trace elements Pb, Cu, Ni, Fe, and As in this bay. Concentration and spatial distribution of trace elements were analyzed to determine the pollution status of the bay. An inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify elements content. The concentrations of trace elements varied from 0.049-0.685 µg L-1 (average: 0.261 ± 0.163 µg L-1) for Pb, 0.170-1.278 µg L-1 (0.475 ± 0.252 µg L-1) for Cu, 0.375-1.469 µg L-1 (0.754 ± 0.258 µg L-1) for Ni, 0.544-69.290 µg L-1 (8.036 ± 13.779 µg L-1) for Fe, and 0.952-1.721 µg L-1 (1.366 ± 0.168 µg L-1) for As. The present study suggests that Staring Bay has been highly contaminated by trace elements Pb and Fe relative to their normal oceanic levels. The contaminated areas were found in the estuaries due to terrestrial anthropogenic inputs from industrial and agricultural activities, residential areas and brackish ponds.
DOI: 10.6084/m9.figshare.14304144
title: Molecularly Imprinted Polypyrrole on Glassy Carbon Electrode Modified with Reduced Graphene Oxide and Gold Nanoparticles for Isoamyl Alcohol Analysis in Fusel Oil

description: A molecularly imprinted electrochemical sensor for determination of isoamyl alcohol was successfully constructed by modifying the glassy carbon electrode (GCE) with gold nanoparticles (AuNPs) and reduced graphene oxide (RGO). The modification of the GCE increased the electron transfer rate and the electrode surface area, which, consequently, made more room available for the formation of the molecularly imprinted polymer (MIP). The development of the MIP on the modified surface was carried out via electropolymerization of the pyrrole in acetate buffer solution in the presence of the target molecule. The MIP-AuNPs-RGO/GCE showed low limit of detection (8.4 × 10-8 mol L-1), satisfactory quantification range, amperometric sensitivity of 1.1 A L mol-1, excellent reproducibility and stability. Even when in the presence of analogous molecules, the sensor exhibited excellent selectivity. These results suggest that the proposed sensor is suitable for the detection of isoamyl alcohol in fusel oil samples.
DOI: 10.6084/m9.figshare.14304141
title: Identification of Two Additional Behaviorally Active Gland Constituents of Female Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

description: The sugarcane borer, Diatraea saccharalis (Fabricius), is the major pest insect attacking sugarcane crops in Brazil. Population control by insecticide treatment is not efficient due to simultaneous presence of all developmental stages of the insect throughout the year, and alternative control methods are needed. Two female-produced sex pheromone components, (Z,E)-hexadeca-9,11-dienal and (Z)-hexadec-11-enal, have previously been reported to elicit antennal activity and behavioral response of males in flight tunnel experiments. However, the attractiveness of these compounds in field tests has been very low. In this study, two additional female-produced compounds in D. saccharalis eliciting consistent antennal response in males were identified as (Z)-hexadec-9-enal and hexadecanal. In flight tunnel assays, the behavioral response to a quaternary blend was significantly higher when compared with the previously identified binary blend. Subtracting (Z)-hexadec-9-enal or hexadecanal from the full blend did not reduce attraction, indicating redundancy in the communication channel. We conclude that additional compounds are part of the sex pheromone of D. saccharalis, which may improve the efficiency of trap lures for monitoring of this pest.
DOI: 10.6084/m9.figshare.14304140
title: Mapping Biochemical Pathways in Maytenus ilicifolia (Celastraceae) through Integrated Proteomics and Histochemistry

description: Maytenus ilicifolia (Celastraceae) is a medicinal plant that is native to southern Brazil and is popularly known as “espinheira-santa”. From a biosynthesis perspective, this species accumulates quinonemethide triterpenes and sesquiterpene pyridine alkaloids as major secondary metabolites that exhibit interesting biological properties, with antitumoral and antiprotozoal activities, respectively, being the most frequently reported. Additionally, the restricted accumulation of such compounds in the roots raises questions about the expression of proteins involved in such compartmentalization and their possible biological and/or ecological role in M. ilicifolia. Thus, this article describes the use of shotgun proteomics and histochemical studies for the characterization of the main biosynthetic pathways involved in the regulation of the metabolism in M. ilicifolia roots. This combined approaches also resulted in the identification of a series of proteins involved in the quinonemethide triterpenes and sesquiterpene pyridine alkaloids, providing evidences of their differential compartmentalization.
DOI: 10.6084/m9.figshare.14304134
title: Blue Glow Sticks: Cinnamic Acids and Arylacrylonitriles with Liquid-Crystalline Properties and Highly Fluorescent

description: Five new π-conjugated chromophores derived from acrylic acid and acrylonitrile were synthesized and their thermal and photophysical behaviors were analyzed. They were designed and synthesized through Knoevenagel condensations between arylacetylenebenzaldehydes and a methylene group activated from cyanoacetic and malonic acids. The characterization of the target compounds was performed by Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (NMR), 13C NMR, thermogravimetric analysis (TGA), absorption and emission spectroscopy techniques. Arylcinnamic acids were obtained as pure E-isomers. On the other hand, arylacrylonitrile was obtained as a mixture of E/Z-isomers and the pure E-isomer was isolated in chromatographic columns. The liquid crystal properties were investigated through differential scanning calorimetry and polarized optical microscopy. All chromophores displayed smectic and nematic mesophases. These materials displayed intense fluorescence under UV-Vis light excitation. The maximum absorption peaks were observed between 342-356 nm while emission varied from 428 to 460 nm in chloroform solution. Higher values for the quantum fluorescence yield were associated with acrylic acids compared to arylacrylonitriles. The solvatochromism studies of the materials showed a significant increase in the red-shift of the fluorescence spectra as the polarity of the solvent increased. In some cases, a variation in the emission wavelength from the blue to the green region of the spectrum was observed.
DOI: 10.6084/m9.figshare.14304129
title: Assessment of the Physicochemical Quality Indicators and Microbiological Effects of Brazilian Ozonized Vegetable Oils

description: The study of quality indicators in the process of obtaining ozonized vegetable oils is useful for monitoring the ozonation reaction. The Brazilian oils “dendê”, soy, corn, rice and sunflower were studied, all of them were ozonated applying different doses of ozone. Ozonized oils were evaluated by determining the physicochemical indexes of peroxide, acidity, iodine and density in addition viscosity, fatty acid composition and microbiological activity were determined. The results showed that of the five ozonized oils evaluated, “dendê” oil exhibited a higher peroxide index, approximately 1746 mmol-equiv kg-1, using an applied ozone dose of 97 mg g-1, during an hour and a half of the ozonation reaction. This result could be explained by its chemical composition, rich in oleic acid that facilitates the reaction with ozone due to its spatial conformation. It was also demonstrated that “dendê” oil exhibits a greater antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 1.9 to 4.75 mg mL-1 against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. It is suggested that the ozonated “dendê” oil presents greater possibilities to be used in the preparation of pharmaceutical or cosmetic formulations.
DOI: 10.6084/m9.figshare.14304126
title: o-DGT Devices for the Determination of Emerging Contaminants in Aqueous Matrices

description: Samplers based on the diffusive gradients in thin films for organics (o-DGT) were developed and applied in Brazilian aqueous matrices for the determination of four emerging contaminants (EC): 4-octylphenol, 4-nonylphenol, triclosan, and bisphenol A. The OASIS HLB resin used as the binding phase presented a high sorption capacity and the extraction associated with sonication, using a mixture of acetonitrile and methanol (2:1, v v-1) as the solvent, provided a higher desorbed mass of the compounds. The diffusion coefficients determined experimentally were in the range of the values found in the literature and the pH and ionic strength influenced the sorption of some compounds by the binding phase. The substances were detected and quantified in tap and river water samples after 7 days of deployment using gas chromatography tandem mass spectrometry (GC-MS/MS). Finally, the results indicate deficiencies in the current wastewater, as well as water treatment systems, and could contribute in the future to the improvement of public policies on basic sanitation in Brazil.
DOI: 10.6084/m9.figshare.14304125
title: Automated Framework for Developing Predictive Machine Learning Models for Data-Driven Drug Discovery

description: The increasing availability of extensive collections of chemical compounds associated with experimental data provides an opportunity to build predictive quantitative structure-activity relationship (QSAR) models using machine learning (ML) algorithms. These models can promote data-driven decisions and have the potential to speed up the drug discovery process and reduce their failure rates. However, many essential aspects of data preparation and modeling are not available in any standalone program. Here, we developed an automated framework for the curation of chemogenomics data and to develop QSAR models for virtual screening using the open-source KoNstanz Information MinEr (KNIME) program. The workflow includes four modules: (i) dataset preparation and curation; (ii) chemical space analysis and structure-activity relationships (SAR) rules; (iii) modeling; and (iv) virtual screening (VS). As case studies, we applied these workflows to four datasets associated with different endpoints. The implemented protocol can efficiently curate chemical and biological data in public databases and generates robust QSAR models. We provide scientists a simple and guided cheminformatics workbench following the best practices widely accepted by the community, in which scientists can adapt to solve their research problems. The workflows are freely available for download at GitHub and LabMol web portals.
DOI: 10.6084/m9.figshare.14304119
title: Evaluation of Lignins of Trunk and Roots from Citrus sinensis L. Osbeck: A Large Available Brazilian Biomass

description: Citrus biomass is a source of biobased products and presents extensive chemical diversity. Among the structural macromolecules, lignins have been used in resins, bioplastics, and nanoencapsulation. Brazil has a large source of lignins, which are orange trees removed from groves that need to be renewed. However, the knowledge about these lignins is limited and little explored. Thus, this work aimed to evaluate the lignins from Citrus sinensis and to provide information on the interesting use of orange trees as a source of macromolecules. The lignins were isolated from the trunk, central and secondary roots from the orange tree by Technical Association of the Pulp and Paper Industry (TAPPI)-methods. The lignin contents for the extractive-free samples were 19.8 ± 0.19, 21.9 ± 0.36, and 19.5 ± 0.41% (m/m) in the trunk, central and secondary roots, respectively. Infrared (IR) and 13C nuclear magnetic resonance (NMR) analyses confirmed typical bands and chemical shifts to syringyl and guaiacyl units. These results are consistent with the features of lignins previously reported for orange tree branches and hardwood roots. The greatest amount of lignin in the orange tree was found in the central root. The lignins extractive-free by TAPPI-T264 cm-97 presented low solubility in organic solvents, due to their compaction and folding, which was confirmed by 13C NMR in the solid-state, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).