cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14303896.v1
title: Pyrimidine Derivatives: QSAR Studies of Larvicidal Activity against Aedes aegypti

description: The present study investigated the activity of pyrimidine derivatives against Aedes aegypti. Two compounds, 3c and 3d showed excellent larvicide activity. Additionally, quantitative structure-activity relationship (QSAR) models were built using multiple-linear regression and partial least squares with descriptors generated from Dragon and VolSurf+ software, respectively. The best model is obtained with multiple linear regression (MLR), leading to a robust model. Moreover, the QSAR model is validated by means of some internal validation techniques in order to check its reliability, quality and robustness for predicting the larvicidal activity against A. aegypti. The models confirmed that the three-dimensional structure of molecules, steric properties, hydrophobic polar surface area, log partition (logP) and a simple pattern of substituent groups as methyl, methoxy, and succinimide in the pyrimidine derivatives are responsible for the larvicidal activity of the pyrimidine derivatives. Even more, the activity decreases by an electron-withdrawing group in R1 and increases when it is replaced by an aromatic ring activator group. These findings will aid in further studies of new pyrimidine derivatives active against Aedes aegypti.
DOI: 10.6084/m9.figshare.14303894.v1
title: Combined Analytical Py-GC/MS, SEM, FTIR and 13C NMR for Investigating the Removal of Trace Metals from Aqueous Solutions by Biochar

description: In this study, the efficiency of biochar (BC) produced from sugarcane bagasse at different pyrolysis temperatures (300, 400, 500 and 600 ºC) for simultaneous removal of CdII, PbII, CuII, CrIII, NiII and ZnII ions from aqueous solutions was assessed. All BC were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), 13C nuclear magnetic resonance (13C NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The effects of pyrolysis temperature, initial adsorbate concentration and adsorbent dosage on adorption capacity of BC were examined through batch experiments. The BC efficiency was also evaluated after a desorption cycle. The maximal adsorptions (CdII: 51.50%, CrIII: 74.35%, CuII: 91.18%, NiII: 47.05%, PbII: 96.17% and ZnII: 40.50%) were observed for BC produced at 500 ºC, probably because of its higher porosity and presence of functional groups detected by SEM and FTIR. The maximum adsorption capacity for CdII, CrIII, CuII, NiII and ZnII (ions fitted to Langmuir model) were 175, 303, 455, 156 and 128 µg g-1, respectively. The predominance of phenolic groups observed in Py-GC-MS data may explain the high percentage of multi-element removal. Experimental data were best fitted to pseudo-second order, Sips and Freundlich models. The BC presented good removal results after a desorption cycle.
DOI: 10.6084/m9.figshare.14303891.v1
title: Synthesis, Characterization and in vitro, in vivo and in silico Anti-Inflammatory Studies of the Novel Hybrid Based on Ibuprofen and 3-Hydroxy-Copalic Acid Isolated from Copaiba Oil (Copaifera multijuga)

description: A novel anti-inflammatory hybrid 3-ibuprofenyl-copalic acid (3-IbuCA) was synthesized from 3-hydroxy-copalic acid isolated from Amazonian copaiba oil (Copaifera multijuga Hayne), and the anti-inflammatory ibuprofen. After full characterization, several assays to verify its anti-inflammatory effects were performed in vitro, in vivo and in silico (molecular docking). Induced fit docking was performed to observe the interactions with the enzymes cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). In vitro tests of cytotoxicity and tumor necrosis factor (TNF)-α inhibition, and in vivo tests of pleurisy, protein expression and gastrocytotoxicity were performed. Molecular docking studies with COX-1 and 2 showed binding free energies (ΔG) of -2.2 and -7.8 kcal mol-1, respectively, while for mofezolac and indomethacin, the binding free energies ΔG presented values of -8.5 and -10.1 kcal mol-1, which makes 3-IbuCA selective for COX-2 inhibition. This hybrid showed no toxicity against human macrophage at concentrations up to 2 µM, and inhibited TNF-α production in lipopolysaccharide (LPS)-stimulated macrophages. In the pleurisy assays, 3-IbuCA reduced the total leukocytes and mononuclear cells, which was followed by reduction of p-IKBα (phosphorylated nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha) protein expression. Compared with ibuprofen alone, the hybrid caused less gastric damage. Thus, the docking, together with in vitro and in vivo studies suggest that this novel hybrid has potential as a new anti-inflammatory agent.
DOI: 10.6084/m9.figshare.14303890.v1
title: Simultaneous Quantification of Plasma Catecholamines and Metanephrines by LC-MS/MS

description: The quantification of the low levels of catecholamines and metanephrines in biological fluids is important for clinical screening of pheochromocytoma/paraganglioma and diagnosis of overtraining syndrome in athletes. We introduce a novel, accurate and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of these biogenic amines in human plasma. Simple protein precipitation combined with rapid 2-aminoethyl diphenylborinate-assisted liquid-liquid extraction allow us to quantify catecholamines and metanephrines over broad concentration ranges. Target analytes were monitored in positive electrospray ionization mode by multiple reaction monitoring. Method performance was validated for linearity, lower limit of quantification, limit of detection, intra-day and inter-assay precision, carry-over, recovery, and matrix effect. The assay was linear within analytical range 25-1000 pg mL-1 for epinephrine, 30-2500 pg mL-1 for norepinephrine, 15-1000 pg mL-1 for dopamine, 25-2000 pg mL-1 for metanephrine and 50-10000 pg mL-1 for normetanephrine, with lower limits of quantification of 15, 20, 10, 15 and 30 pg mL-1, respectively. The intra- and inter-day precisions for all compounds ranged from 0.4 to 6.9% and from 0.9 to 6.6%, respectively. The efficiency of novel method was confirmed by assaying external quality control samples which demonstrated consistent and accurate results.
DOI: 10.6084/m9.figshare.14303889.v1
title: Nanostructured Lipid Carriers Loaded with 17-α-Estradiol Accumulate into Hair Follicles

description: To improve 17-α-estradiol targeting in alopecia treatment, a formulation of nanostructured lipid carrier (NLC) prepared by the sonication method was developed. The physicochemical characterization showed an average diameter of 96 ± 15 nm and the average zeta potential of -17 ± 6 mV. In addition, the encapsulation efficiency (EE) of 17-α-estradiol, assessed by ultra-performance liquid chromatography (UPLC) fluorescence, was 99.6 ± 0.3%. Physical stability of NLC stored at room temperature was followed for 42 days through several physicochemical parameters, such as diameter, zeta potential, pH and EE. No changes were observed in the physicochemical parameters during this period, demonstrating the potential of NLC as a delivery system of 17-α-estradiol. NLC dermal penetration, investigated by Franz diffusion cell and confocal microscopy using rhodamine-labeled NLCs, showed an accumulation of NLC in the outer portions of the epidermis, precisely in the hair follicle. The NLCs distribution in the skin suggests that 17-α-estradiol targeting was improved.
DOI: 10.6084/m9.figshare.14303887.v1
title: Application of a Chemometric Method to Interpret Spectrophotometric Data Obtained for Degradation of an Organic Dye in Water Using Manganese Oxide

description: Birnessite type manganese oxide (δ-MnO2) was synthesized for use in degradation of the cationic dye methylene blue in aqueous solution. The material was characterized using infrared spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller (BET) surface area calculations. The removal of the dye from aqueous solutions was evaluated considering the effects of the following variables: pH, manganese oxide concentration, contact time, and temperature. UV-Vis spectroscopy analyses indicated achievement of 99 and 95% removal of methylene blue (7 mg L-1) at pH 2.0 and 4.0, respectively, after 120 min of contact with the birnessite (100 mg L-1). At higher pH of 6.0 and 8.0, removals of around 99 and 80%, respectively, were obtained after a longer time of 1860 min. Analyses of total organic carbon (TOC) revealed that 80% reduction of organic matter was obtained at pH 4.0. The method of multivariate curve resolution-alternating least squares (MCR-ALS) was used together with UV-Vis spectroscopy to evaluate the removal process, confirming the degradation of methylene blue. Thionine (λmax = 601 nm) was identified as one of the byproducts of N-demethylation of methylene blue. The results indicated that the degradation process started with N-demethylations of the methylene blue molecule.
DOI: 10.6084/m9.figshare.14303885.v1
title: Two Years Monitoring of Ethyl Carbamate in Sugar Cane Spirit from Brazilian Distilleries

description: This paper describes the monitoring of ethyl carbamate concentration in sugar cane spirit from industrial distilleries in Brazil. In total, 18 distilleries from Minas Gerais and São Paulo states were evaluated, with, a total of 336 samples from August 2017 to August 2019. The ethyl carbamate was analyzed using a previously validated mass spectrometric method. Analytical curves presented coefficient of determination (R2) values higher than 0.99, and quality control samples showed a relative standard deviation (RSD) below 9%. Concentrations of ethyl carbamate ranged from not detected to 1608 µg L-1, with mean values of 294.2, 280.7 and 230.0 µg L-1 in 2017, 2018, and 2019, respectively. On average, 46, 44 and 69% of samples presented levels of ethyl carbamate below 210 µg L-1. A variety of factors may have led to distillery A having a low level (ca. 115 µg L-1) of ethyl carbamate, including controlled temperature, yeast strain, post-harvesting quality, sugar cane variety choice, and the treatment process on the sugar cane juice, which goes towards the addition of Ca(OH)2, heating and freezing. These results showed the importance of internal quality control, and that sugar cane juice treatment may be a way to decrease ethyl carbamate in the distilleries.
DOI: 10.6084/m9.figshare.14303883.v1
title: Synthesis, Characterization, and Synergic Photocatalytic Activity of Amorphous TiO2/Chitosan Carbon Microspheres

description: In this work, we report the synthesis and characterization of new amorphous graphene-like TiO2/chitosan carbon microspheres and its performance as photocatalyst. Four different carbon chitosan microspheres materials were obtained based on the distinctive procedure to incorporate TiO2 and TiOSO4 to chitosan structure by pyrolysis at 600 °C. Detailed characterizations were carried out using many different techniques, as thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), scanning electron miscroscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, and the obtained materials show an amorphous and a graphene-like structure, which improve the photocatalytic activity. The synthesized materials promoted a fast degradation of three micropollutants under UV-A radiation and, in all cases the degradation rate was approximately 98% at 30 min of reaction, being superior to the P-25 TiO2 efficiency. Due to the amorphous graphene-like structure, all the materials present low adsorption capacity, the high photocatalytic efficiency can be attributed to the material structure that promotes the effective charge separation which reduces the recombination electron/hole, enhancing the photocatalytic efficiency.
DOI: 10.6084/m9.figshare.14303882.v1
title: Production of Furanic Compounds and Organic Acids from Brazilian Pequi (Caryocar brasiliensis Camb.) Residues Using Green Chemistry

description: In the current search for renewable energy sources, residual biomass has gained ground in the concept of biorefinery. Furanic compounds such as 5-hydroxymethylfurfural (HMF), furfural (FF) and derivatives such as levulinic acid (LA), obtained from biomass, have emerged as important industrial chemical platforms. In this sense, this work aimed to use pequi bark, typical biomass and abundant in the Brazilian cerrado, in the production of HMF, FF and LA using the ionic liquid 1-n-butyl-3-methyl-imidazole bromide ([BMIM][Br]). The analysis of chemical composition of pequi bark showed that it has potential for use in the production of bioproducts, FF, HMF and LA, with yields of 65, 3 and 23.7%, respectively. High glucose conversion rates were found (&gt; 90%). The analysis of variance (ANOVA) was applied to obtain the mathematical model with α = 0.05, verifying the significance of the second order model established for HMF (F = 0.00167) and FF (0.004494). The model fit is satisfactory, obtaining the coefficient of determination (R2) for the HMF and for the FF of 0.9599 and 0.08422, respectively. From the results obtained, it can be concluded that pequi bark has good precursor capacity for use in biorefinery processes.
DOI: 10.6084/m9.figshare.14303879.v1
title: Effect of Growth Parameters on the Photocatalytic Performance of TiO2 Films Prepared by MOCVD

description: The present study evaluated the main factors that influence the photocatalytic activity of titanium dioxide (TiO2) films grown by metalorganic chemical vapor deposition (MOCVD) at 400 and 500 °C, in different growth times. The photocatalytic behavior was analyzed by measuring the methyl orange dye degradation at different pH values. Structural and morphological characteristics, and the recyclability of the catalysts for several cycles were also investigated. Anatase phase was identified in all films. The higher photodegradation performances were obtained at acidic pH. The results demonstrated that the photocatalyst thickness is an important parameter in heterogenous photocatalysis. The best photocatalytic result occurred for the 395 nm-thick TiO2 film grown at 400 °C, which presented 65.3% of the dye degradation under UV light. The recyclability experiments demonstrated that the TiO2 films grown by MOCVD present a great stability after several photocatalytic cycles, which allows their practical application for water treatment with high efficiency.
DOI: 10.6084/m9.figshare.14303876.v1
title: Occurrence of Pesticides Associated to Atmospheric Aerosols: Hazard and Cancer Risk Assessments

description: Since the 1950s, pesticides have been used in agriculture. The increase in their consumption has been observed in recent years. In this work, it was determined the concentration of pesticides in the atmosphere of São Paulo and Piracicaba cities (sugarcane plantation site) and the hazard quotients and cancer risk caused by inhalation of these compounds were calculated. Twenty-three samples were analyzed and 34 pesticides associated to atmospheric particulate matter (with diameter equal to or less than 2.5 (PM2.5) and 10 µm (PM10)) were investigated by gas chromatograpy-mass spectrometry (GC-MS). Fourteen compounds including organochlorines, organophosphorus, and pyrethroids pesticides, were determined in these samples. The concentrations in the particulate matter ranged from 17 pg m−3 (tebuconazole) in Piracicaba, to 166 pg m−3 (endrin aldehyde) in São Paulo. The highest values of daily inhalation exposure for heptachlor were 9.0 × 10−5mg kg−1 day−1 at Piracicaba, and 6.5 × 10−5 mg kg−1 day−1 at São Paulo, in both cases registered in infants. The values of the hazard quotients are lower than 1.0, indicating that there is no danger to the exposed population, it is health protective. On the other hand, the cancer risk calculations for heptachlor resulted in values above those recommended by US Environmental Protection Agecy (EPA).
DOI: 10.6084/m9.figshare.14303873.v1
title: Microwave Assisted Synthesis of Thiocarbamoylpyrazoles and Application as an Alternative Latent Fingermark Developers

description: Fingerprints are unique to each individual, contributing to human identification in forensic cases. The powder technique being widely used is considered one of the most important in latent fingermarks analysis. In this sense, the present work aimed to synthesize 1-thiocarbamoyl-4,5-dihydro-1H-pyrazoles and apply them as powder agents to develop latent fingermarks. The compounds were prepared from an effective and green synthesis via the condensation of chalcones with thiosemicarbazide in ethanol under microwave irradiation. Pyrazoles were tested and compared with a standard white powder (Sirchie®) on glass surfaces using sebaceous and natural fingermarks so that molecule 2c has been shown to be more promising providing image clarity. The derivatives of pyrazoles were promising as an alternative latent fingermark, presenting high quality images for fingermarks, proving to be a great tool for forensic sciences.
DOI: 10.6084/m9.figshare.14303870.v1
title: New α-Hydroxy-1,2,3-triazoles and 9H-Fluorenes-1,2,3-triazoles: Synthesis and Evaluation as Glycine Transporter 1 Inhibitors

description: Two series of new compounds containing 1,2,3-triazole moiety were designed as putative GlyT1 inhibitors aiming the discovery of new hits with activity in cognitive disorders. 1,4-Disubstituted α-hydroxy-1,2,3-triazoles were obtained as racemates in moderate to good yields by the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction (click chemistry) as the key step between propargyl alcohols and aryl azides, previously prepared from anilines or boronic acids. Benzo[c]chromene-triazoles were planned to be obtained by palladium-catalyzed C−H activation using [bis(trifluoroacetoxy)iodobenzene] (PhI(TFA)2) of some α-hydroxy-1,2,3-triazoles, since benzo[c]chromenes are also privileged groups with several biological activities, including to the central nervous system. Unexpectedly, 9H-fluorenes-1,2,3-triazoles, instead of benzo[c]chromene-triazoles, were obtained by Friedel-Crafts alkylation reaction. The two series of compounds were tested for inhibition of the glycine transporter (rat GlyT1 isoform) but only the α-hydroxy-1,2,3-triazole 9b was active (half maximal inhibitory concentration (IC50) = 8.0 µM).
DOI: 10.6084/m9.figshare.14303866.v1
title: Quantification of Arsenic, Cadmium, Mercury and Lead in Pineapple: Method Development, Validation and Evaluation of In-House Reference Materials

description: A method for quantification of arsenic, cadmium, mercury, and lead in pineapple using inductively coupled plasma-mass spectrometry (ICP-MS) was developed, validated, and used to test the homogeneity and stability of in-house reference materials. The method was tested at the regulation levels given by the Food and Agriculture Organization of the United Nations (FAO, 100 µg kg−1). The mineralization conditions of the samples, in a microwave oven, were improved throughout the study of HNO3 and H2O2 concentrations, sample weight, time, and temperatures. The calibration was made by a gravimetric standard addition method with internal standard correction. The validation parameters were accuracy (trueness as recovery, between 97-112%, and precision as repeatability, below 12%), limits of detection (As 14.2, Cd 1.5, Hg 21.9, and Pb 5.4 µg kg−1 measured in pineapple), linearity and selectivity. The in-house material was lyophilized or dried in an oven. The best way to dry it was by the oven process because it has the lowest uncertainty.
DOI: 10.6084/m9.figshare.14303865.v1
title: Aqueous Extracts of the Castor Beans as a Corrosion Inhibitor of Mild Steel in HCl Media

description: The present work studied aqueous extracts of castor beans as a natural inhibitor of the corrosion of mild steel in 1 M HCl using gravimetric tests, potentiodynamic polarization curves, linear polarization method, electrochemical impedance measurements, surface analysis by scanning electron microscopy (SEM) and chemical characterization by Fourier transform infrared spectroscopy (FTIR). Gravimetric tests showed that inhibition efficiency (IE) increased with immersion time and concentration of the extract, reaching 97.8% in the presence of 800 mg L−1 inhibitor after 24 h immersion time. For the gravimetric tests varying the temperature, a decrease of the activation energy (Ea) was observed, suggesting chemical adsorption of extract components on the metal surface. The extracts from the castor beans acted as a good corrosion inhibitor, and the macromolecules present in the high molecular weight fraction (HMWF) have a fundamental participation in this process since it presented 93.7% of IE for 200 mg L−1.
DOI: 10.6084/m9.figshare.14303864.v1
title: Diethyl Selenodiglycolate: An Eco-Friendly Synthetic Antioxidant with Potential Application to Inflammatory Disorders

description: This study describes a single step, high yield and purity, ecofriendly and scalable procedure to prepare a selenium derivative (diethyl selenodiglycolate). Diethyl selenodiglycolate rapidly reduces hypochlorous acid (HOCl, second-order rate constant of 7 × 107 M−1 s−1) to generate its corresponding selenoxide. In activated HL-60 cells, diethyl selenodiglycolate selectively reacted with HOCl (half maximal inhibitory concentration (IC50) = 23.07 µM) but not with superoxide anion radical or hydrogen peroxide without any cytotoxicity. These results show that this synthetically simple selenide reacts in a very efficient and specific way with the harmful pro-oxidant HOCl being a promising compound to be applied in oxidative inflammatory-related conditions.
DOI: 10.6084/m9.figshare.14303861.v1
title: Stability Indicating Method for Determination of Benznidazole and Its Degradation Products in Active Pharmaceutical Ingredient

description: Currently, treatment of Chagas disease is restricted to the use of benznidazole and nifurtimox; however, nifurtimox was temporarily suspended in some countries. Based on the limitations in pharmacological treatments, it is essential to guarantee the quality of benznidazole. Therefore, this work aimed to identify the degradation products of benznidazole and to validate a stability indicating method. The stability test was performed through a forced degradation study, exposing benznidazole under a range of conditions. Benznidazole proved to be unstable under acidic and alkaline conditions, and three products were identified by liquid chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer (UPLC-QTOF-MS). Furthermore, a stability indicating method by high performance liquid chromatography with a diode array detector (HPLC-DAD) for benznidazole was developed and validated according to ICH (International Conference on Harmonisation) and ANVISA (Agência Nacional de Vigilância Sanitária) guidelines. The method was linear (180-420 µg mL-1 range), selective in the presence of degradation products, precise (relative standard deviation (RSD) &lt; 0.6%), accurate (recovery &gt; 99.2%), robust, and free of matrix effects. The method was successfully able to quantify the benznidazole in pharmaceutical formulations.