O Programa de Mestrado Profissional em Química em Rede Nacional, PROFQUI, completa 7 anos de atividade em 2024, tendo concedido o título de mestre para mais de 400 professores de química da educação básica em nível nacional. É uma marca significativa e que mostra o potencial do programa em contribuir para a formação continuada de professores e para a melhoria da educação básica brasileira. Esse artigo traz um breve histórico da formação continuada de professores no Brasil e como se deu a criação do PROFQUI nesse contexto. As discussões e tomadas de decisão em torno da construção do projeto do programa também estão aqui registradas. Além dessa contextualização histórica, o artigo faz uma breve apresentação da organização acadêmica e administrativa do programa, das suas linhas de pesquisa e disciplinas oferecidas. Um panorama da oferta de vagas, do número de matriculados e de evadidos das turmas é apresentado, assim como uma análise do perfil do corpo docente e da variedade de recursos educacionais desenvolvidos pelos mestrandos até 2023. Por fim, são mencionados os principais desafios a serem superados pelo PROFQUI nos próximos anos.
The pathogen S. agalactiae, categorized as Lancefield group B streptococci (GBS), is a Gram-positive bacterium, encapsulated, anaerobic facultative bacillus, which occurs in pairs or short chains. It was responsible for more than 319,000 cases of infections in neonates. Early and late streptococci, in the course of an illness or medical condition, are infections that have high mortality and morbidity rates, with an incidence of 2.0 to 5.0 per 1000 live births in North America, Europe, and Australia. The infection of newborns usually happens through transmission from infected mothers during and after childbirth, with GBS being among the critical bacterial infections in the Brazilian epidemiological picture. S. agalactiae strains isolated from different regions of Brazil, indicate a great diversity among the isolated serotypes but with a higher incidence of serotype Ia. Publications report that, in pregnant women in Brazil, the prevalence of serotype Ia has been constant between 2002 and 2018, followed by serotypes II and IV. Serotypes Ib, III, and V also appear, but with some fluctuations in different regions of the country. The pathogen which causes invasive disease are usually surrounded by a polysaccharide capsule and is its major virulence factor, being that the key antigen in protective response triggered by polysaccharides and, more recently, protein-polysaccharide conjugate vaccines. The development of antibiotic resistance by these microorganisms to different antibiotics has been the guideline in leading therapeutic options against these infections including the use of prophylactic vaccines in pregnant women, immunosuppressed or older people. Such prophylactic alternatives can be constructed from capsular polysaccharides.Based on the experience in the production and purification of Neisseria meningitidis polysaccharides for vaccines, Bio-Manguinhos developed a process for the production, purification and characterization of S. agalactiae Ia polysaccharides. In the present study, the capsular polysaccharide from the strain isolated in clinical material of a public hospital, in Rio de Janeiro – Brazil, was obtained from simple batch cultures, with purification process achieving about 20 mg∙g−1 in yield for cell dry weight (CDW) and ca. of 100% of purity. Hence, to prove that the CPS of GBS Ia can be consistently produced, purified, and characterized by NMR, HRGC-MS, and SEC-MALS – from such strain – to be used in vaccine productions against S. agalactiae.
COVID-19, an airborne disease caused by a betacoronavirus named SARS-- CoV-2, was officially declared a pandemic in early 2020, resulting in more than 770 million confirmed cases and over 6.9 million deaths by September 2023. Although the introduction of vaccines in late 2020 helped reduce the number of deaths, the global effort to fight COVID-19 is far from over. While significant progress has been made in a short period, the fight against SARS-CoV-2/COVID-19 and other potential pandemic threats continues. Like AIDS and hepatitis C epidemics, controlling the spread of COVID-19 will require the development of multiple drugs to weaken the virus's resistance to different drug treatments. Therefore, it is essential to continue developing new drug candidates derived from natural or synthetic small molecules. Coumarins are a promising drug design and development scaffold due to their synthetic versatility and unique physicochemical properties. Numerous examples reported in scientific literature, mainly by in silico prospection, demonstrate their potential contribution to the rapid development of drugs against SARS-CoV-2/COVID-19 and other emergent and reemergent viruses.
In this work, the combined use of p-sulfonic acid-calix[n]arene and microwave energy to hydrolyze the 1,3-dioxolane ketal of isatin was evaluated with excellent results. This is the first time that p-sulfonic acid-calix[n]arene has been used as the catalyst in a ketal hydrolysis reaction and the deprotection of the ketone carbonyl of isatin is reported. The presence of 2.5 mol% of p-sulfonic acid-calix[4,6]arene at 160 ºC resulted in over 96% conversion of this ketal in 10 min, with the additional advantage of using water as a solvent. This catalytic system (aqueous phase containing p-sulfonic acid-calix[4]arene) was reused for five consecutive cycles, with a conversion above 96% maintained. This reusable system is not practicable using p-toluenesulfonic acid and p-hydroxybenzenesulfonic acid as catalysts since both are extracted to the organic phase with the reaction product. The hydrolysis of 1,3-dioxolane ketal of isatins with different substituents (CH3, I, Br, Cl, F, NO2) in the aromatic ring was also evaluated. The protecting group of 5-methyl-isatin was removed with 73% conversion using 2.5 mol% of p-sulfonic acid-calix[4]arene at 160 ºC for 5 min. In contrast, the ketal of 5-nitro-isatin reached 80% conversion using the same conditions after 40 min.
In this paper, pyrrole compounds were synthesized based on the Knorr method consisting of a cyclocondensation reaction between alpha-amino-beta-ketoester with beta-ketoesters and beta-diketone. Different pyrrole derivatives were obtained by varying the composition of the ester group into beta-ketoesters through transesterification reactions. Furthermore, after the synthesis of pyrrole nuclei, acid hydrolysis reactions, decarboxylation of the tert-butyl group, electrophilic aromatic substitution using N-bromosuccinimide or reaction with thiosemicarbazide were explored to vary the composition of the alpha group in relation to the nitrogen heteroatom of the pyrrole nuclei. Regarding the anti-Trypanosoma cruzi activity of pyrrole derivatives, 4 compounds synthesized were active, with IC50 ranging between 14.1 and >50 mu M.
Advancements in digital information and communication technology has promoted transformations in several sectors of our society, including the educational area.For this reason, teaching methodologies need to be increasingly related to technology.In addition, emergency crisis situations (such as the current COVID-19 pandemic) have brought about drastic changes in the way we act, live, and teach-learn.In this sense, new educational approaches are being researched, developed and implemented, in an attempt to adapt education to incessant advances and global changes.Thus, in order to make a brief review, and at the same time to indicate paths for research or use of technological resources in teaching, this article reports, even in a modest way, some of the tools that can be used for teaching chemistry -at the different levels and educational modalities of this science.
The isonitrosoacetanilide, 2-bromoisonitrosoacetanilide and 2-methoxyisonitrosoacetanilide were synthesized and investigated as mild steel corrosion inhibitors in 1 mol L-1 HCl solution by potentiodynamic polarization curves, electrochemical impedance, weight loss measurements, scanning electron microscopy analysis and theoretical calculations. The weight loss measurements varying temperature show that the isonitrosoacetanilides are adsorbed on the mild steel surface by physisorption. The adsorption of inhibitor obeys the Langmuir's adsorption isotherm and the adsorption is an exothermic process with a decrease in entropy. The Tafel polarization method reveals that the inhibitors act as mixed type inhibitor. The obtained experimental results suggested that the maximum inhibition efficiency of isonitrosoacetanilide derivatives were over 90% at 5 x 10(-3) mol L-1 at 25 degrees C. The weight loss measurements and electrochemical results were confirmed with scanning electron microscopy (SEM). Quantum chemical calculation was applied to correlate electronic structure parameters of isonitrosoacetanilides molecules with their corrosion inhibition performances and showed that possibly the adsorption process is of the physical type. The 2-bromoisonitrosoacetanilide and 2-methoxyisonitrosoacetanilide results were slightly superior to those obtained in the presence of isonitrosoacetanilide, showing that the bromo atom and methoxy group enhances the inhibitory properties. (C) 2021 Elsevier B.V. All rights reserved.
The crescent number of scientific articles published per year shows that research on biodiesel continues to play an important role to support the growing demand for this biofuel. The second edition of Biodiesel: An Overview presents the worldwide research in the last 15 years. Microalgae biomass is the most studied raw material alternative in this period and several studies have been carried out to develop basic heterogeneous catalysts for biodiesel production. Concerning to production technologies, supercritical conditions and intensification process have been extensively investigated. The development of new antioxidants additives has focused mainly on biomass-derived formulations and there are few studies on biocide candidates. In terms of pollutant emissions, in general, the studies showed that the addition of biodiesel generates lower concentrations of polycyclic aromatic hydrocarbons (PAH), CO and n-alkanes pollutants, but carbonyl compounds, major ions and NOx are emitted in a higher concentration compared to pure diesel.
Nuclear fission energy is an important part of the energy matrix of several countries, including Brazil. The use of this energy source has advantages, but it also causes wide discussion and concern regarding the risks of accidents. The knowledge of the concepts that involve the nuclear reaction, the behavior of the particles and their particularities is a first opportunity to understand the relevance of the topic. This work reports some recent data on world production and consumption of nuclear energy, gives a brief historical-conceptual approach of nuclear chemistry and also presents the basic scheme of a nuclear fission plant operation, to chemistry professionals, undergraduate and high school students.
BACKGROUND:Chagas disease, also known as American trypanosomiasis, is classified as one of the 17 most important neglected diseases by the World Health Organization. The only drugs with proven efficacy against Chagas disease are benznidazole and nifurtimox, however both show adverse effects, poor clinical efficacy, and development of resistance. For these reasons, the search for new effective chemical entities is a challenge to research groups and the pharmaceutical industry.OBJECTIVE:Synthesis and evaluation of antitrypanosomal activities of a series of thiosemicarbazones and semicarbazones containing 1,2,3-1H triazole isatin scaffold.METHOD:5'-(4-alkyl/aryl)-1H-1,2,3-triazole-isatins were prepared by Huisgen 1,3-dipolar cycloaddition and the thiosemicarbazones and semicarbazones were obtained by the 1:1 reactions of the carbonylated derivatives with thiosemicarbazide and semicarbazide hydrochloride, respectively, in methanol, using conventional reflux or microwave heating. The compounds were assayed for in vitro trypanocidal activity against Trypanosoma cruzi, the aetiological agent of Chagas disease. Beyond the thio/semicarbazone derivatives, isatin and triazole synthetic intermediates were also evaluated for comparison.RESULTS:A series of compounds were prepared in good yields. Among the 37 compounds evaluated, 18 were found to be active, in particular thiosemicarbazones containing a non-polar saturated alkyl chain (IC50 = 24.1, 38.6, and 83.2 µM; SI = 11.6, 11.8, and 14.0, respectively). To further elucidate the mechanism of action of these new compounds, the redox behaviour of some active and inactive derivatives was studied by cyclic voltammetry. Molecular docking studies were also performed in two validated protein targets of Trypanosoma cruzi, i.e., cruzipain (CRZ) and phosphodiesterase C (TcrPDEC).CONCLUSION:A class of thio/semicarbazones structurally simple and easily accessible was synthesized. Compounds containing thiosemicarbazone moieties showed the best results in the series, being more active than the corresponding semicarbazones. Our results indicated that the activity of these compounds does not originate from an oxidation-reduction pathway but probably from the interactions with trypanosomal enzymes.
Novel isatinspirooxazine derivatives were designed and synthesized as potential anti-proliferative agents. The new compounds were obtained from aldol condensation reactions between isatin and 3-(hydroxyimino)butan-2-one in the presence of an organic base in order to generate an aldol adduct, followed by cyclization in trifluoroacetic acid, providing the desired isatinspirooxazines in 30 to 80% yield. All the synthesized compounds, including the starting material and the synthetic intermediates, were tested for in vitro anti-proliferative activity against cell lines MCF-7 and MDA-MB231 (breast cancer) and A549 (lung cancer), highlighting the compound 4-methyl,5’-methyl-spiro[(5-aza-4-eno-3-one-cyclohexane)-1,3’-(1H-indol-one)] with an IC50 (half maximal inhibitory concentration) = 0.34 μM, more potent than the reference drug, doxorubicin (IC50 = 1.88 μM), in breast cancer line MDA-MB231.
The aim of this study was to compare two methods for determining the fatty acid methyl ester content of biodiesel by applying high-performance liquid chromatography (HPLC-UV) and the reference method based on gas chromatography (GC). The samples of biodiesel were also analyzed by H-1 NMR. External standards were used for the quantification of fatty acid methyl esters by HPLC-UV. The analytical curves of the methyl oleate, methyl linoleate, and methyl linolenate standards showed good linearity (coefficient of determination >= 0.995). Cochran's test was used to assess the homoscedasticity of the analytical curves. The limits of detection and quantitation were found: 0.0018% mass and 0.0054% mass for methyl oleate, 0.0002% mass and 0.0007% mass for methyl linoleate, and 0.0001% mass and 0.0004% mass for methyl linolenate. The accuracy of the HPLC-UV method was assessed by determining recovery (%), which resulted on values between 81.7 +/- 0.2 and 110.9 +/- 0.1. Precision was assessed by determining repeatability (%), which was found to be between 0.2 and 1.3. The proposed HPLC-UV method proved efficient in determining the fatty acid methyl ester content of biodiesel and the paired t-test showed it to correlate well with the reference method (GC).
BACKGROUNDTrypanosomiasis and leishmaniasis cause severe infections in humans and domestic animals in the tropics. Although typical diseases in Latin America, globalization and the migration of infected people has spread these diseases to countries in North America, Asia and Europe. Currently available drugs are not effective in the chronic phase, as well as cause side effects and develop resistance.RESULTSAmong the chemical groups studied as potential anti-T. cruzi and anti-Leishmania are the thio-and semicarbazones, which are easy to obtain, possess structural versatility and can sequester metal. In this article, we present an overview of thio-and semicarbazones associated with heterocycles, indanones, and styryl and aryl skeletons, including their metal complexes with antimony, platinum, palladium, copper, ruthenium, rhenium, manganese and vanadium.CONCLUSIONBecause of the efficiency and selectivity that some of these derivatives have shown, it can be concluded that thio-and semicarbazones constitute promising chemical scaffolds in the search for new anti-parasitic agents.
Isatin methyl derivatives have several pharmacotherapeutic applications, such as antibacterial, antifungal, antiviral, anticonvulsants and anticancer activities. The electrochemical behaviours of thirteen isatin-substituted derivatives with different functional groups, such as isatin 1-morpholinomethyl, isatin 1-hydroxymethyl, and isatin 1-, 5- or 7-methyl, and their halogenated derivatives, in phosphate buffer pH = 7.2, at a glassy carbon electrode, by cyclic, differential pulse and square wave voltammetry, were investigated. The oxidation mechanism of all isatin derivatives occurred in two consecutive irreversible charge transfer pH-dependent reactions. The first anodic reaction was on the benzene ring, with the generation of one hydroxyl group attached to the ring, which was oxidized in the second step to para- and/or ortho-quinone derivatives, and/or polymeric products. The reduction mechanism of all isatin derivatives, was an irreversible cathodic process, dependent on pH and the presence/absence of attached halogenated groups. The isatin derivatives reduction, in the absence of halogens, caused the irreversible cleavage of the carbonyl group, at the position C3, in the heterocyclic ring, and, in the presence of halogens, the cathodic peak corresponded to the carbon-halogen bond reduction. The functional groups attached to the isatin ring at the 1-position, morpholinomethyl-, hydroxymethyl- and methylare not electroactive, and do not affect considerably the isatin derivatives redox mechanism, since the oxidation occurs at the benzene ring, and the reduction at the carbonyl C3-position.
5'-4-Alkyl/aryl-1H-1,2,3-triazole derivatives PILAB 1-12 were synthesized and a pharmacological screening of these derivatives was performed to identify a possible effect on the Central Nervous System (CNS) and to explore the associated mechanisms of action. The mice received a peritoneal injection (100 µmol/kg) of each of the 12 PILAB derivatives 10 min prior to the injection of pentobarbital and the mean hypnosis times were recorded. The mean hypnosis time increased for the mice treated with PILAB 8, which was prevented when mice were administered CTOP, a µ-opioid antagonist. Locomotor and motor activities were not affected by PILAB 8. The anxiolytic effect of PILAB 8 was evaluated next in an elevated-plus maze apparatus. PILAB 8 and midazolam increased a percentage of entries and spent time in the open arms of the apparatus compared with the control group. Conversely, a decrease in the percentages of entries and time spent in the closed arms were observed. Pretreatment with naloxone, a non-specific opioid antagonist, prior to administration of PILAB 8 exhibited a reverted anxiolytic effect. PILAB 8 exhibited antinociceptive activity in the hot plate test, and reduced reactivity to formalin in the neurogenic and the inflammatory phases. These data suggest that PILAB 8 can activate µ-opioid receptors to provoke antinociceptive and anti-inflammatory effects in mice.