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Journal of the Brazilian Chemical Society, Volume: 35, Número: 1, Publicado: 2024
  • Anaerobically Treated Leachate from a Composting Plant: Characterization and Evaluation as a Biofertilizer Article

    Freire, Rita de Cássia M.; Aguiar, Adalin Cezar M. de; Nascimento, Mayra Aparecida; Cruz, Felipe S. O.; Mounteer, Ann H.; Silva, Antônio Alberto; Lopes, Renata P.

    Resumo em Inglês:

    Leachate from a composting plant was characterized and applied as a biofertilizer in lettuce crops. Characteristics of untreated (UE) and anaerobically treated (TE) leachate samples were compared. The pH of TE (8.2) increased in relation to the UE (5.2) due to an increase in ammonia nitrogen in TE (1197 mg L-1) compared to UE (859 mg L-1). Anaerobic treatment was efficient in the removal of organic matter from the leachate, evaluated by the decrease of dissolved organic carbon, biochemical oxygen demand, total organic carbon and total solids. K presented the highest concentration (1743 mg L-1) in TE, followed by Mg (135 mg L-1). Cd, Pb and Cr were present at low concentrations in the samples, 0.047, 0.206 and 0.081 mg L-1, respectively. Salmonella, thermotolerant coliforms and viable helminth eggs were not present in TE, which was applied as a biofertilizer in a lettuce crop and compared to mineral fertilization based on fresh matter and dry matter production. Lettuce production using TE was statistically equivalent to mineral fertilization. Toxic metals were not detected in the lettuce shoots. It was concluded that the anaerobically treated leachate from the composting company has the potential to be used as a biofertilizer.
  • Corrosion Behavior of NdFeB Magnets in Different Aqueous Solutions Article

    Popescu, Ana-Maria; Calderon-Moreno, Jose M.; Yanushkevish, Kazimir; Aplevich, Alexei; Demidenko, Olga; Neacsu, Elena Ionela; Constantin, Virgil

    Resumo em Inglês:

    Sintered NdFeB magnets possess excellent magnetic properties, but behave passively in alkaline and saline media and are susceptible to corrosion in acidic environments. The corrosion behavior of NdFeB magnets in industrial environments: potassium hydroxide (KOH), perchloric acid (HClO4) and sodium chloride (NaCl), was investigated by immersion and electrochemical tests. The immersion test concluded that the most corrosive electrolyte of the three studied was HClO4. Electrochemical tests showed that the NdFeB sample without magnetic order had better corrosion resistance. Metallographic microscopy and scanning electron microscopy support the obtained corrosion data. X-ray photoelectron spectroscopy indicates that the main elements on the surface of the analyzed sample (Nd, Fe, B) are in the oxidized state after corrosion.
  • In silico and Experimental Assessments Applied to Preliminary Identification of New Illicit Substances Structures Article

    Lopes, Karen P. S.; Lucena, Maria C. C.; Lopes, Thiago Inacio B.; Silva, Ámison R. L. da; Silva, Leonardo P. da; Monteiro, Norberto K. V.; Lima-Neto, Pedro de; Ricardo, Nágila M. P. S.

    Resumo em Inglês:

    This is an initial study using infrared (IR) in silico data as a standard database in preliminary method for new synthetic seized drugs. For this purpose, ten of the most common synthetic illicit seized substances on the Brazilian market were compared and computational chemistry was used as a tool for theoretical standard database. Infrared data from standard electronic library, experimental data from seized samples and data simulated by Density Functional Theory (DFT) were evaluated. The feasibility of the method was based on the degree of correlation of evaluated data. The results suggest that the computational methodology can be a viable way to analyze the structures of new synthetic drugs and obtain preliminary infrared profiles. Correlations data indicated a presumptive identification of the analyzed samples and it was also possible to observe a preliminary identification of drugs in five classes. However, it was observed that some synthetic cathinones and phenylethylamines were confused with amphetamines. Therefore, new studies must be developed to optimize the use of these data, because the simulated IR spectra can be advantageous to evaluate the profile of possible substances that may be synthesized in the future.
  • Microstructural, Morphological, and Optical Study of Synthesis of ZnO and Pt ZnO Nanoparticles by a Simple Method Using Different Precipitating Agents Article

    Gines-Palestino, Ruby S.; Montalvo-Romero, Carlos; Solano, Guadalupe Luna; Amador-Gómez, Luis P.; Cantú-Lozano, Denis

    Resumo em Inglês:

    Due to its multiple applications, zinc oxide (ZnO) is one of the most used materials in science and technology. Therefore, this research carried out the synthesis of ZnO and Pt-ZnO nanoparticles (NPs) by the direct precipitation method, which is characterized by being simple and reproducible, using two different precipitating agents, potassium hydroxide (KOH) and sodium hydroxide (NaOH); for the doping of Pt-ZnO NPs was used platinum acetylacetone. To evaluate the effect of the precipitating agent on the properties of each doped material, they were characterized by Fourier transform infrared spectroscopy, where the Zn-O vibrations were more pronounced using KOH. X-ray diffraction analysis shows a hexagonal structure (wurtzite) formation for ZnO with NaOH, obtaining a smaller crystal size than the other synthesized materials. Scanning electron microscopy analysis showed hexagonal and hemispherical shapes for ZnO (with NaOH and KOH) and Pt-ZnO (with NaOH), respectively; also, cylindrical shapes were obtained for Pt-ZnO (with KOH). The highest band gap obtained was for the Pt-ZnO material synthesized with KOH.
  • Synthesis, in vitro Toxicity, and Antitrypanosomal Activity of Arylated and Diarylated Thiazoles Article

    Figueira, Kelly L.; Girão, Roberson D.; Costa, Krislayne N. da; Barreto, Ana C. R.; Soeiro, Maria de Nazaré C.; Limberger, Jones

    Resumo em Inglês:

    Chagas disease is a relevant public health threat that affects over 6 million people worldwide, resulting in devastating social and economic consequences. Moreover, the therapeutic options are limited, highlighting the urgency in searching for novel active antitrypanosomal molecules. Compounds with either thiazole or biaryl units have been described as possessing anti Trypanosoma cruzi activities. Therefore, here, we describe the synthesis of nine arylated and diarylated thiazole derivatives and the evaluation of their in vitro toxicity on mammalian cells as well as their anti T. cruzi activity. The compounds were prepared in straightforward synthetic routes, using Hantzsch thiazole synthesis and cross-coupling reactions as key steps. A pyridyl-phenyl-thiazole (PPT) derivative (4c) presented 76% of T. cruzi growth inhibition in preliminary tests using a fixed concentration of 20 µM. This compound was used as a scaffold for the synthesis of two novel PPT analogs (4g and 4h). Dose-response assays on intracellular forms of T. cruzi demonstrated that these three compounds presented high antiparasitic potency (half maximal effective concentration (EC50) values ranging from 1.15 to 2.38 μM) and low toxic profile against L929 cell lines. Hence, these findings highlight the pyridyl-phenyl-thiazole backbone as a novel privileged scaffold in the search for active molecules against T. cruzi.
  • Revisiting the Synthesis of Gibbsite, a Precursor for Li/Al LDH Synthesis and Its Use as a Support for Porphyrin Immobilization Article

    Bosa, Gabriela; Silva, Caroline G.; Brito, Bianca R.; Terzi, Carolina M.; Wypych, Fernando; Nakagaki, Shirley

    Resumo em Inglês:

    In this work, some of the synthesis methods already reported for aluminum(III) hydroxide polymorphs with layered structure like gibbsite are revisited. Gibbsite was synthesized with high purity and yield by a simple route developed from modifications of a heating method proposed in the literature, making it possible to prepare gibbsite in regular glassware, avoiding the use of hydrothermal reactor and oven, as described in the literature. The proposed synthesis was conducted with a heating system under reflux conditions in a glass heating flask, using an oil bath, without the need for more sophisticated equipment. This is an accessible alternative method for crystalline gibbsite synthesis, with yield (76 wt.%). The obtained gibbsite was used as a precursor for the synthesis of a lithium/aluminum layered double hydroxide (LDH) from the intercalation method of Al(OH)3 in aqueous solution of lithium chloride. Gibbsite and the obtained LDH Li/Al were used for the immobilization of an anionic porphyrin with a loading on the order of 10-5 mol g-1 of solid, thus being alternative solid supports for catalytic species such as porphyrins.
  • Gas-Phase Fragmentation Reactions of Protonated Pumiliotoxin (+)-251D and Allopumiliotoxin (+)-267A in ESI-MS/MS Short Report

    Minder, Basil; Mendonça, Jacqueline N.; Grant, Taran; Lopes, Norberto P.

    Resumo em Inglês:

    In recent years, there has been great interest in understanding the chemistry of natural products from different organisms and their role in ecological processes. Some species of frogs sequester and metabolize dietary alkaloids obtained primarily from mites and ants as chemical defense. Most of these studies have employed gas chromatography techniques coupled with mass spectrometry, which restricts the possibility of observing more polar metabolites. In the case of pumiliotoxin (+)-251D and allopumiliotoxin (+)-267A, the fragmentation mechanisms in electrospray ionization systems with collision-induced fragmentation are undescribed. The present study aims to elucidate the fragmentation pathways of these two toxins. For this purpose, we used direct infusion of toxins in a time-of-flight hyphenated quadrupole electrospray ionization tandem mass spectrometry (ESI-MS/MS) system. Different collision energies were applied, and the data rationalized from the concepts of reaction mechanisms. The joint analysis allowed to present a robust map of fragmentation opening perspectives for their application in studies of the occurrence of new polar analogues.
  • Evaluation of Free- and Bound-Carbonyl Compounds in Craft Beers Article

    Acácio, Marinice S. S.; Alves, Eliete C.; Andrade, Jailson B. de; Anjos, Jeancarlo P. dos

    Resumo em Inglês:

    Carbonyl compounds (CC) can be formed during the craft beer production process, which influence the sensory properties, in addition to their toxicity. The formation of bound CC, in craft beers, is favored by the high reactivity of these substances. This work aimed to quantify 15 carbonyl compounds, in free and bound forms, in craft beers using hydrolysis (bound CC only) and derivatization reactions. Acetaldehyde concentrations ranged from 8.83 to 466.1 µg L-1 (free fraction) and 22.47 to 1665 µg L-1 (bound fraction). Other compounds found were acrolein (free + boundmax.: 2897 µg L-1), benzaldehyde (free + boundmax.: 1326 µg L-1), heptanal (free + boundmax.: 1140 µg L-1) and formaldehyde (free + boundmax.: 97.73 µg L-1). Craft beers showed a proportion of up to 76% for CC in the bound form, which can be related to undesirable flavors in beverages. The consumption of craft beers containing freeand bound-CC (especially acrolein) could pose a risk to the health of frequent consumers.
  • Mucuna cinerea Seeds: Levodopa Extraction Using Deep Eutectic Solvent and Its Mammalian Cell Activity Article

    Silva, Bruna T.; Demuner, Antonio J.; Blank, Daiane E.; Campos, Mateus G.; Mendes, Tiago A. O.

    Resumo em Inglês:

    A new class of deep eutectic solvents (DES) was used in the extraction of levodopa (L-dopa) present in Mucuna cinerea, which has been termed “green” or “designer” solvents, with notable productive and economic/environmental benefits. The seeds of Mucuna cinerea were prepared and submitted to extraction with heating and agitation in a solvent mixture of DES with citric acid, urea, or glycerol. The extracts were analyzed by high performance liquid chromatography (HPLC) which confirmed the efficiency of DES in extracting L-dopa. These extractions were carried out to determine the L-dopa extracts in DES with regard to the induction of cellular response activity, demonstrating the synergy between L-dopa and DES. The DES-glycerol extract exhibited a higher proliferative activity than commercial L-dopa after 24 h of treatment. The human glandular kallikrein-1 gene (hGK3) demonstrated higher expression in the treatment with the DES-urea, while the G protein-coupled receptor kinase-6 gene (GRK6) showed higher expression for all extracts compared to commercial L-dopa, with a higher value obtained for DES glycerol, followed by DES urea extract. The DES extraction method is therefore promising and unprecedented, confirming its possible use in the replacement of expensive solvents, supporting the use of ecologically viable DES in the extractions of other plant species.
  • Impact of Conservation Processes on the Lipid Profile and Immunological Factors IL-10 and TGF-β1 in Whey Separated from Discarded Human Milk Article

    Alves, Eloize S.; Castro, Matheus C.; Saqueti, Bruno H. F.; Manin, Luciana P.; Alencar, Josiane B.; Zacarias, Joana M. V.; Bruni, Andressa R. S.; Madrona, Grasiele S.; Visentainer, Jeane E. L.; Cristianini, Marcelo; Santos, Oscar O.; Visentainer, Jesui V.

    Resumo em Inglês:

    Reuse made by the separation of whey can reduce the waste of human milk. However, the authors are not aware of the literature on treatments in human whey, made available by pasteurization holder, freeze-drying, spray drying, and high hydrostatic pressure. In this context, the present study applied treatments to human whey and evaluated their lipid and immunological quality. Among the results, a different formation in the triacylglycerol profile was evidenced after the application of spray drying and high hydrostatic pressure, while pasteurization and freeze-drying presented ion intensity close to the control human whey. In addition, pasteurization proved to be adequate for lipid nutritional quality and transformation factor-β1 (TGF-β1) concentration, while an increase in interleukin-10 (IL-10) levels was promoted, between 73 and 80%, after freeze-drying, spray drying, and high hydrostatic pressure. Through the principal component analysis, it is noteworthy that the processes presented divergences in terms of the effects caused, with similarity only between pasteurization and freeze-drying in the composition of fatty acids. However, it was observed that all processes were able to maintain the nutrients. Nevertheless, it is relevant to consider individual characteristics presented and the interest in the desired quality, which can be promising as a complementary product to infant feeding.
  • Polymer-Supported Dibutylstannyl Azide: An Efficient and Recoverable Reagent in the One-Pot Synthesis of Aryl Azides and 5-Aryl 1H-tetrazoles Article

    Prieto, Leonela Godoy; Lockhart, María T.; Fiego, Marcos J. Lo

    Resumo em Inglês:

    Herein, a very stable and highly reactive insoluble polymer-supported organotin azide was prepared from a Merrifield resin and its azide loading was determined by elemental analysis. This immobilized azide was employed in one-pot diazotization-azidodediazoniation of aromatic amines to provide a wide range of aryl azides in very good yields under mild conditions. On the other hand, this supported reagent was successfully applied in the 1,3-dipolar cycloaddition reaction with aromatic nitriles to provide 5-aryl 1H-tetrazoles in good yields. In addition, the recyclability of tin azide from the supported dibutyltin sulfonate recovered in the synthesis processes was reported. The developed methods allow the recycling and reuse of the supported tin azide, without significant loss of reactivity after four cycles in our reaction scale and less than 20 ppm of residual tin concentration in final products without additional purification.
  • Investigating the Expression of Genes Involved in Apoptosis and Mutation in Ovarian Cancer Cell Line and Possible Hepatotoxicity in Rats Induced by New Green Synthesized Ag-NPs Article

    Fang, Fang; Zhang, Xiaoyan; Bai, Rongrong; Wang, Bing; Majd, Mostafa Heidari

    Resumo em Inglês:

    Silver nanoparticles (Ag-NPs) can enter tumor cells through endocytosis and transfer to mitochondria, then disrupt mitochondrial function, damage deoxyribonucleic acid (DNA), and finally lead to cell death and apoptosis. As the Ag-NPs synthesized by Moringa peregrina leaf extract contain biomolecules such as flavonoids and terpenoids, they may suppress cancer by disrupting the flow of autophagy and inhibiting the differentiation of cancer cells, especially in apoptosis-resistant cancer cells. Accordingly, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromid (MTT) assay proved that Ag-NPs could inhibit the OVCAR-3 cell line in a timeand concentration-dependent manner. Real-time polymerase chain reaction (PCR) results showed that the ratio of the pro-apoptotic Bak1 gene to the anti-apoptotic Bclx gene increased about 10 times compared to the control. Also, the expression of the caspase-3 gene has increased about 18 times compared to the control. In addition, it was found that Ag-NPs can inhibit the progression of ovarian cancer cell lines and decrease the expression of the AKT1 gene by 0.08. And the more important point was the safety of Ag-NPs, which was checked by the lipid peroxidation method and it was confirmed that the treated hepatocytes did not have any significant difference in the production of malondialdehyde with the control and probably do not cause hepatotoxicity.
  • Supramolecular Assembly between Cationic Pyridinium-Pillararene and Aminosalicylate Drug Article

    Demos, Willian; Micke, Lizandra C. B.; Lacerda, Luis H. S.; Souza, Bruno S.; Gerola, Adriana P.; Affeldt, Ricardo F.

    Resumo em Inglês:

    The preparation and characterization of a novel pillar[5]arene based supramolecular system with mesalazine, a prescribed aminosalicylate drug was successfully achieved. Pyridinium-pillar[5]arene was efficiently prepared in three steps from hydroquinone bis(2-hydroxyethyl) ether derivative in high yield. It was demonstrated that the association between the compounds is pH dependent with an association constant of 3.4 × 103 L mol-1 near physiological conditions, leading to quenching of the fluorescence emission of mesalazine in the presence of the cationic macrocycle. Theoretical calculations indicate that the association between both molecules is of electrostatic nature. Formation of aggregates was also demonstrated in low concentrations of pillar[5]arene that is related to the non-linear behavior of the Stern-Volmer plot for quenching of mesalazine fluorescence emission.
  • The Art of Scientific Writing and Ethical Use of Artificial Intelligence Account

    D. Neto, Brenno Amaro; Eberlin, Marcos N.

    Resumo em Inglês:

    We share our consolidated views, long-term experiences, and best tips for effective scientific writing. After writing hundreds of manuscripts and thus having battled and succeeded in this “mine-field”, and knowing the importance of guidance for successful science communication, particularly for beginners, we have tried to introduce readers to the art of scientific writing, from A to Ω. To help less experienced scientific writers to learn quickly and overcome some initial barriers, avoiding common mistakes that we ourselves have also made, we discuss the most important techniques we have used in trying to write clear, comprehensible, and concise manuscripts that are as attractive and impacting as possible. This guide therefore offers crucial tips and concepts - from the very first words, initial draft, and on to submission, “battles” with reviewers and finally to acceptance and publication. The ethical use of artificial intelligence tools, along with some best practice suggestions for their application, is also presented and discussed. In the end, readers should have a comprehensive picture to help them understand basic manuscript structures and major features, habits and tips that help ensure excellence in scientific writing.
  • Advances in Breast Cancer Drug Discovery: A Review of Therapeutic Strategies and Studies Involving Photosensitizers, Caged Xanthones and Thiosemicarbazones Derivatives Review

    Oliveira, Douglas D. S.; Lapierre, Thibault J. W. Jacques Dit; Silva, Fernanda C.; Cunha, Ieda V.; Souza, Rafael A. C.; Matos, Patrícia A.; Almeida, Gustavo M.; Oliveira, Carolina G.; Araújo, Thaise G.; Tsubone, Tayana M.; Rezende Jr., Celso O.

    Resumo em Inglês:

    Cancer is one of the major causes of death worldwide, and breast cancer is the most prevalent and deadly type among women. Despite the side effects and the phenomena of chemoresistance associated with the drugs involved, chemotherapy remains the main therapeutic strategy to combat and control breast cancer. Therefore, several new classes of compounds against breast cancer have been explored, in an effort to identify new drug candidates with alternative mechanisms of action. The principal results of such exploration, focusing on caged xanthones, thiosemicarbazones and photosensitizers, are presented in this review, along with the main aspects of the drug discovery process against breast cancer. More specifically, the design, structure-activity relationship investigations and anti-breast cancer properties of these three classes are described and discussed in this work.
  • Biochar and Hydrochar in the Development and Application of Electrochemical Devices in the Sensing and Degradation of Target Compounds: A Mini-Review of the Recent Contributions of 2020-2023 Review

    Silva, Jonatas O. S.; Granja, Honnara S.; Santos, José F. dos; Freitas, Lisiane S.; Sussuchi, Eliana M.

    Resumo em Inglês:

    In this review, we present the versatility of biomass and its derivatives obtained through thermal conversion processes (biochar and hydrochar) for applications in the development of electrochemical devices. This work highlights the generation of carbonaceous materials through pyrolysis and hydrothermal carbonization, in addition to proposing strategies to modify their physicochemical properties through activation methodologies to enhance their application as electrode materials. The processes of monitoring and degrading chemical species are discussed based on the diversity of electrodes that can be obtained with these bioderived coals, according to recent contributions available in the literature (2020-2023), which show the wide applicability of these materials in the field of electrochemistry.
  • The World of Cave Microbiomes: Biodiversity, Ecological Interactions, Chemistry, and the Multi-Omics Integration Review

    Kato, Natália N.; Arini, Gabriel S.; Silva, Ricardo Roberto; Bichuette, Maria Elina; Bitencourt, José Augusto P.; Lopes, Norberto P.

    Resumo em Inglês:

    Caves are ecosystems and natural heritage sites with magnificent biological diversity, from microorganisms to animals, despite their selective environment for development and survival. Until now, studies on cave microbiomes have included taxonomic classification through metagenomics analysis, demonstrating microbiological heterogeneity mainly composed of prokaryotic organisms or bacteria species. The generally oligotrophic environment, with limited energy input and dark zone, is the main feature differentiating the cave microorganisms from the other microbiomes and resulting in a unique habitat, which has unexplored regard to biology and chemical diversity. Multi-omics integration is a key strategy for scanning and integrating the macro and micromolecular universe, providing a better comprehension of processes and answers of the microbiome in natural cavities. Here, we highlight the strategies employed to study the cave microbiome, from the microbial genomes to their ability to secondary metabolites production, and also the multi-omics integration to explore the chemical and biological diversity in caves.
  • Welcome to 2024 Editorial

    Vieira, Paulo Cezar
Sociedade Brasileira de Química Instituto de Química - UNICAMP, Caixa Postal 6154, 13083-970 Campinas SP - Brazil, Tel./FAX.: +55 19 3521-3151 - São Paulo - SP - Brazil
E-mail: office@jbcs.sbq.org.br