Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230030
N. Falcão, Gilvan P. Pires, Paloma Abrantes, Poliana Abrantes, João Batista M. Resende Filho, Claudio Lima Junior, E. Teotonio, J. Vale
This work describes the route to prepare a novel core-shell catalyst based on 1,4-diazabicyclo[2,2,2]octane (DABCO) supported magnetic nanoparticles (MNPs). The morphology and composition of the obtained catalysts were characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), quantum design vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). These nanomaterials presented high performance as a basic catalyst for Knoevenagel condensation between malononitrile and aldehydes, leading to products with excellent yields (84-99%) and short reaction times (5-60 min). Furthermore, it was also efficient in the condensation of isatins with 4-phenylthiosemicarbazide, resulting in isatin-β-thiosemicarbazones with high yields (81-94%) and short times (60-180 min). It is worth mentioning that the catalyst was recovered and reused in these two kinds of reactions after six cycles without significant yield loss.
{"title":"Magnetic Nanoparticles Based on DABCO as Catalysts in the Knoevenagel Reaction and Synthesis of Isatin-β-thiosemicarbazones","authors":"N. Falcão, Gilvan P. Pires, Paloma Abrantes, Poliana Abrantes, João Batista M. Resende Filho, Claudio Lima Junior, E. Teotonio, J. Vale","doi":"10.21577/0103-5053.20230030","DOIUrl":"https://doi.org/10.21577/0103-5053.20230030","url":null,"abstract":"This work describes the route to prepare a novel core-shell catalyst based on 1,4-diazabicyclo[2,2,2]octane (DABCO) supported magnetic nanoparticles (MNPs). The morphology and composition of the obtained catalysts were characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), quantum design vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). These nanomaterials presented high performance as a basic catalyst for Knoevenagel condensation between malononitrile and aldehydes, leading to products with excellent yields (84-99%) and short reaction times (5-60 min). Furthermore, it was also efficient in the condensation of isatins with 4-phenylthiosemicarbazide, resulting in isatin-β-thiosemicarbazones with high yields (81-94%) and short times (60-180 min). It is worth mentioning that the catalyst was recovered and reused in these two kinds of reactions after six cycles without significant yield loss.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230027
E. Peres, Mayane P. Souza, T. Sousa, C. da Silva, A. Barros, F. D. da Silva, E. Costa, L. D. de Medeiros, M. Forim, A. D. de Souza, Weider H. P. Paz, G. D. da Silva, A. D. de Souza, H. Koolen
Penicillium meliponae, a recently described and rare species, was isolated as an endophytic fungus from the Amazonian plant Duguetia sthelechantha, and has been proven to be a pigment producer. Considering the high productivity of this species and the lack of data on its chemical composition, the present study aimed to characterize the chemical profile of P. meliponae and evaluate the influence of agitation and the use of different culture media. For this purpose, liquid chromatography coupled with mass spectrometry (LC-MS/MS) and molecular networking were used, allowing the identification of 17 azaphilone molecules with sclerotiorin-like skeletons, becoming the first chemical report of this species. In addition, the different production patterns in the tested culture media were indicative that this species is sensitive to changes in the composition of the carbon source and to the presence of agitation. Furthermore, this work contributes to the fragmentation mechanisms of the different possible structural arrangements for azaphilones of the sclerotiorin type and serves as a repository of information on the gas-phase behavior of this type of metabolite in mass spectrometry experiments and will assist future studies aimed at the discovery of azaphilones.
{"title":"Dereplication of Sclerotiorin-Like Azaphilones Produced by Penicillium meliponae Using LC-MS/MS Analysis and Molecular Networking","authors":"E. Peres, Mayane P. Souza, T. Sousa, C. da Silva, A. Barros, F. D. da Silva, E. Costa, L. D. de Medeiros, M. Forim, A. D. de Souza, Weider H. P. Paz, G. D. da Silva, A. D. de Souza, H. Koolen","doi":"10.21577/0103-5053.20230027","DOIUrl":"https://doi.org/10.21577/0103-5053.20230027","url":null,"abstract":"Penicillium meliponae, a recently described and rare species, was isolated as an endophytic fungus from the Amazonian plant Duguetia sthelechantha, and has been proven to be a pigment producer. Considering the high productivity of this species and the lack of data on its chemical composition, the present study aimed to characterize the chemical profile of P. meliponae and evaluate the influence of agitation and the use of different culture media. For this purpose, liquid chromatography coupled with mass spectrometry (LC-MS/MS) and molecular networking were used, allowing the identification of 17 azaphilone molecules with sclerotiorin-like skeletons, becoming the first chemical report of this species. In addition, the different production patterns in the tested culture media were indicative that this species is sensitive to changes in the composition of the carbon source and to the presence of agitation. Furthermore, this work contributes to the fragmentation mechanisms of the different possible structural arrangements for azaphilones of the sclerotiorin type and serves as a repository of information on the gas-phase behavior of this type of metabolite in mass spectrometry experiments and will assist future studies aimed at the discovery of azaphilones.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230026
Bruno Carvalho, Patrícia dos Santos, Geovane da Silva, C. Senes, J. Visentainer, O. Santos
This study describes the validation of a headspace gas chromatography with flame ionization (HS-GC-FID) method for the determination of propanal, pentanal, hexanal, octanal, and trans-2-nonenal originated by lipid oxidation from cat food samples, as well as the evaluation of the matrix effect in the results. This method was applied to the analysis of commercial cat food and proved to be suitable for the determination of these volatile compounds in different samples. Mean recoveries between 88 and 109% were obtained and repeatability expressed as relative standard deviation was always lower than 6.95%. The intra- and inter-assay precisions ranged from 0.44 to 20.88% and from 0.45 to 20.52%, respectively. In addition, the matrix effect of cat food samples was determined by comparing the slopes of the standard addition method, and the external calibration curve and its influences were verified. These results highlight the high potential of this method, which allows the determination of lipid oxidation products in cat food samples directly, without requiring prior sample preparation techniques.
{"title":"Validation of an Analytical Method by Headspace Gas Chromatography with Flame Ionization and Evaluation of Matrix Effect of Volatile Compounds in Cat Food","authors":"Bruno Carvalho, Patrícia dos Santos, Geovane da Silva, C. Senes, J. Visentainer, O. Santos","doi":"10.21577/0103-5053.20230026","DOIUrl":"https://doi.org/10.21577/0103-5053.20230026","url":null,"abstract":"This study describes the validation of a headspace gas chromatography with flame ionization (HS-GC-FID) method for the determination of propanal, pentanal, hexanal, octanal, and trans-2-nonenal originated by lipid oxidation from cat food samples, as well as the evaluation of the matrix effect in the results. This method was applied to the analysis of commercial cat food and proved to be suitable for the determination of these volatile compounds in different samples. Mean recoveries between 88 and 109% were obtained and repeatability expressed as relative standard deviation was always lower than 6.95%. The intra- and inter-assay precisions ranged from 0.44 to 20.88% and from 0.45 to 20.52%, respectively. In addition, the matrix effect of cat food samples was determined by comparing the slopes of the standard addition method, and the external calibration curve and its influences were verified. These results highlight the high potential of this method, which allows the determination of lipid oxidation products in cat food samples directly, without requiring prior sample preparation techniques.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230082
Marcelo H R Carvalho, G. Amarante, P. D. de Castro
Multicomponent reactions (MCRs) are important transformations, which allow the attainment of structurally complex derivatives in a single step, starting from three or more compounds with relatively simple structures. These reactions are generally associated with the principles of green chemistry, allowing the incorporation of most (or all) atoms of the starting materials in the products (atom economy) and reducing purification steps (and, consequently, the need for solvents and waste production). For a long time, asymmetric methodologies (in special enantioselective protocols) for most multicomponent transformations remained a gap in the literature, limiting the use of these reactions to produce derivatives only as racemates or in low diastereoselectivities. Over the last two decades, a better comprehension of the mechanisms associated with these transformations allowed the development of efficient enantio- and diastereoselective procedures, attracting the interest of both academia and industry. In this review, selected examples of four important multicomponent reactions (Strecker, Mannich, Passerini and Ugi) will be discussed, presenting a general overview of the development of this field and pointing out possible advantages and limitations of the above mentioned methodologies. In some cases, discussions around mechanisms, proposed transition states and activation modes will be detailed disclosed.
{"title":"Recent Synthetic Developments of Asymmetric Multicomponent Transformations: Strecker, Mannich, Passerini and Ugi Reactions","authors":"Marcelo H R Carvalho, G. Amarante, P. D. de Castro","doi":"10.21577/0103-5053.20230082","DOIUrl":"https://doi.org/10.21577/0103-5053.20230082","url":null,"abstract":"Multicomponent reactions (MCRs) are important transformations, which allow the attainment of structurally complex derivatives in a single step, starting from three or more compounds with relatively simple structures. These reactions are generally associated with the principles of green chemistry, allowing the incorporation of most (or all) atoms of the starting materials in the products (atom economy) and reducing purification steps (and, consequently, the need for solvents and waste production). For a long time, asymmetric methodologies (in special enantioselective protocols) for most multicomponent transformations remained a gap in the literature, limiting the use of these reactions to produce derivatives only as racemates or in low diastereoselectivities. Over the last two decades, a better comprehension of the mechanisms associated with these transformations allowed the development of efficient enantio- and diastereoselective procedures, attracting the interest of both academia and industry. In this review, selected examples of four important multicomponent reactions (Strecker, Mannich, Passerini and Ugi) will be discussed, presenting a general overview of the development of this field and pointing out possible advantages and limitations of the above mentioned methodologies. In some cases, discussions around mechanisms, proposed transition states and activation modes will be detailed disclosed.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68338807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230021
Diogo M. Betiolo, Heloisa R. Cadorim, E. Carasek, Tatiane Maranhão
The use of extraction technique with disposable tips (DPX) was applied for the first time for the extraction and preconcentration of Yb in samples of liquid waste from the petrochemical industry and environmental water using bioabsorbent cork. The use of cork as an extracting phase in the determination of Yb by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) was evaluated. The pyrolysis and atomization temperatures were optimized at 1400 and 2400 ºC, respectively. H2SO4, HNO3 and HCl acids were compared in the steps of cleaning the extraction phase and desorption of the analyte by DPX. The best extraction in the selected conditions was obtained with pH 8.0 and 5% v/v HCl. The recoveries were close to 100% for residual water and drinking water, 33 to 77% for produced water and 64 to 93% for river water. Tests with interfering ions in different concentrations were performed. The relative limit of quantification (LOQ) and limit of detection (LOD) were estimated at 0.03 and 0.01 µg L-1, respectively. The total time for the preparation of the samples by DPX was close to 1 min per sample. Extraction and pre-concentration were observed using DPX with a preenrichment factor of approximately 4 times.
首次将一次性尖端提取技术(DPX)应用于生物吸附软木对石油化工废液和环境用水样品中Yb的提取和富集。研究了高分辨率连续源石墨炉原子吸收光谱法(HR-CS GF AAS)中以软木为萃取相测定Yb的方法。优化的热解温度为1400℃，雾化温度为2400℃。比较了H2SO4、HNO3和HCl酸对分析物萃取相的清洗和DPX解吸的影响。在所选条件下，pH为8.0,HCl为5%，提取效果最佳。剩余水和饮用水的回收率接近100%，采出水的回收率为33 ~ 77%，河水的回收率为64 ~ 93%。用不同浓度的干扰离子进行了试验。相对定量限(LOQ)和检出限(LOD)分别为0.03和0.01µg L-1。DPX制备样品的总时间接近1 min /个样品。用预富集因子约为4倍的DPX进行提取和预富集。
{"title":"Application of Disposable Pipette Extraction for Determination of Yb by High‑Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry Using Lanthanum as a Chemical Modifier","authors":"Diogo M. Betiolo, Heloisa R. Cadorim, E. Carasek, Tatiane Maranhão","doi":"10.21577/0103-5053.20230021","DOIUrl":"https://doi.org/10.21577/0103-5053.20230021","url":null,"abstract":"The use of extraction technique with disposable tips (DPX) was applied for the first time for the extraction and preconcentration of Yb in samples of liquid waste from the petrochemical industry and environmental water using bioabsorbent cork. The use of cork as an extracting phase in the determination of Yb by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) was evaluated. The pyrolysis and atomization temperatures were optimized at 1400 and 2400 ºC, respectively. H2SO4, HNO3 and HCl acids were compared in the steps of cleaning the extraction phase and desorption of the analyte by DPX. The best extraction in the selected conditions was obtained with pH 8.0 and 5% v/v HCl. The recoveries were close to 100% for residual water and drinking water, 33 to 77% for produced water and 64 to 93% for river water. Tests with interfering ions in different concentrations were performed. The relative limit of quantification (LOQ) and limit of detection (LOD) were estimated at 0.03 and 0.01 µg L-1, respectively. The total time for the preparation of the samples by DPX was close to 1 min per sample. Extraction and pre-concentration were observed using DPX with a preenrichment factor of approximately 4 times.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68329849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230019
C. Cunha, Paulo Vinícius de Antonio, Maria do Carmo Gomes Lustosa, Á. Cruz, J. Holzbach, D. Pereira, Isabele R. Nascimento
The genus Aristolochia stands out as the most representative of the Aristolochiaceae plant family, with approximately 550 species distributed around the world, many of which have little or no studies reported in the literature. Investigation of the acetone extract from leaves of Aristolochia warmingii Mast. resulted in the isolation and identification of twenty-three compounds, mostly lignans and neolignans, including the new furofuran lignans warmingin A (1), warmingin B (2) and warmingin C (3). The structures of the compounds were established by comprehensive spectroscopic and spectrometric analyses. A large amount of (−)-epieudesmin (4) was isolated from the extract, which suggests that A. warmingii could be a potential source of this compound. The hexane, acetone, ethanol, and ethanol Soxhlet extracts, in addition to fourteen of the isolated compounds, were evaluated for their ability to inhibit the formation of advanced glycation end products (AGEs), but they did not show significant activities.
{"title":"Warmingins A, B and C, Three New Furofuran Lignans from Aristolochia warmingii Mast. (Aristolochiaceae)","authors":"C. Cunha, Paulo Vinícius de Antonio, Maria do Carmo Gomes Lustosa, Á. Cruz, J. Holzbach, D. Pereira, Isabele R. Nascimento","doi":"10.21577/0103-5053.20230019","DOIUrl":"https://doi.org/10.21577/0103-5053.20230019","url":null,"abstract":"The genus Aristolochia stands out as the most representative of the Aristolochiaceae plant family, with approximately 550 species distributed around the world, many of which have little or no studies reported in the literature. Investigation of the acetone extract from leaves of Aristolochia warmingii Mast. resulted in the isolation and identification of twenty-three compounds, mostly lignans and neolignans, including the new furofuran lignans warmingin A (1), warmingin B (2) and warmingin C (3). The structures of the compounds were established by comprehensive spectroscopic and spectrometric analyses. A large amount of (−)-epieudesmin (4) was isolated from the extract, which suggests that A. warmingii could be a potential source of this compound. The hexane, acetone, ethanol, and ethanol Soxhlet extracts, in addition to fourteen of the isolated compounds, were evaluated for their ability to inhibit the formation of advanced glycation end products (AGEs), but they did not show significant activities.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68330120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230024
Lin Xiuzhou, Zhuo Wei, Yang Feng, Yang Han, P. Qiang, Mei Yongjun, Wang Yuhao, Dou Baojie
The low-temperature electrochemical corrosion behavior of aircraft 2024 aluminum alloy was investigated in different concentrations of potassium-acetate-type fluid, and the results showed that the corrosion medium initially impacted some corrosiveness on the 2024 aluminum alloy. However, the corrosion rate of the alloy decreased with prolonged immersion in the corrosion medium, and this was attributed to the protective effect of the corrosion products layer, which impeded the attack by the aggressive solution. Time-domain analysis of electrochemical noise measurements at -5 °C revealed the occurrence of uniform corrosion on the alloy at the initial stages of immersion, general corrosion at the middle stages of immersion, and a pitting-dominated corrosion type from the middle to late stages of immersion.
{"title":"Corrosion Electrochemical Behavior of 2024 Aluminum Alloy in Potassium Acetate Deicing Fluid","authors":"Lin Xiuzhou, Zhuo Wei, Yang Feng, Yang Han, P. Qiang, Mei Yongjun, Wang Yuhao, Dou Baojie","doi":"10.21577/0103-5053.20230024","DOIUrl":"https://doi.org/10.21577/0103-5053.20230024","url":null,"abstract":"The low-temperature electrochemical corrosion behavior of aircraft 2024 aluminum alloy was investigated in different concentrations of potassium-acetate-type fluid, and the results showed that the corrosion medium initially impacted some corrosiveness on the 2024 aluminum alloy. However, the corrosion rate of the alloy decreased with prolonged immersion in the corrosion medium, and this was attributed to the protective effect of the corrosion products layer, which impeded the attack by the aggressive solution. Time-domain analysis of electrochemical noise measurements at -5 °C revealed the occurrence of uniform corrosion on the alloy at the initial stages of immersion, general corrosion at the middle stages of immersion, and a pitting-dominated corrosion type from the middle to late stages of immersion.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68331060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230029
D. Conde, L. Mendes, Guilherme Ramos, Rafael G. Silva, Á. Teixeira, R. Teixeira, Gustavo Martins, C. Cerceau, R. Lopes
Essential oils (EO) have diverse applications, such as antibacterial and antifungal activity. However, they are susceptible to oxidation in the presence of air, light, and moisture. In addition, they are thermally unstable. In this sense, it is necessary to develop techniques to increase the lifespan of EO. In this work, EO was obtained from cloves and characterized by different techniques. The major compounds found were eugenol (83%), eugenol acetate (9%), and β-caryophyllene (8%). The EO was encapsulated by extrusion using a microfluidic device. The sodium alginate was used as wall material, and the CaCl2 solution was used as a crosslinking agent. The microcapsule presented sizes of 164.7 ± 0.3 µm, with an encapsulation yield of 64 ± 14%. Functional characteristic groups of EO were observed in the microcapsule by infrared and Raman spectroscopies. The microcapsule increased the thermal decomposition of the EO from 162 to 230 °C. Release kinetics of the capsule was performed, with an equilibrium time of 72 h and release of 54% of the EO. Finally, the pure EO and encapsulated EO-microcapsules were applied in the Aedes aegypti larvae control, showing mean lethal concentration necessary to eliminate 50% (LC50) values of 74.4 and 96.9 µg mL-1 and lethal concentration necessary to eliminate 90% (LC90) of 106.2 and 133.3 µg mL-1 for pure EO and encapsulated EO, respectively. Therefore, it was concluded that these microcapsules have the potential for application in the Aedes aegypti larvae control.
{"title":"Larvicidal Activity of Calcium Alginate Microcapsules Containing Clove Essential Oil Obtained by Microfluidics","authors":"D. Conde, L. Mendes, Guilherme Ramos, Rafael G. Silva, Á. Teixeira, R. Teixeira, Gustavo Martins, C. Cerceau, R. Lopes","doi":"10.21577/0103-5053.20230029","DOIUrl":"https://doi.org/10.21577/0103-5053.20230029","url":null,"abstract":"Essential oils (EO) have diverse applications, such as antibacterial and antifungal activity. However, they are susceptible to oxidation in the presence of air, light, and moisture. In addition, they are thermally unstable. In this sense, it is necessary to develop techniques to increase the lifespan of EO. In this work, EO was obtained from cloves and characterized by different techniques. The major compounds found were eugenol (83%), eugenol acetate (9%), and β-caryophyllene (8%). The EO was encapsulated by extrusion using a microfluidic device. The sodium alginate was used as wall material, and the CaCl2 solution was used as a crosslinking agent. The microcapsule presented sizes of 164.7 ± 0.3 µm, with an encapsulation yield of 64 ± 14%. Functional characteristic groups of EO were observed in the microcapsule by infrared and Raman spectroscopies. The microcapsule increased the thermal decomposition of the EO from 162 to 230 °C. Release kinetics of the capsule was performed, with an equilibrium time of 72 h and release of 54% of the EO. Finally, the pure EO and encapsulated EO-microcapsules were applied in the Aedes aegypti larvae control, showing mean lethal concentration necessary to eliminate 50% (LC50) values of 74.4 and 96.9 µg mL-1 and lethal concentration necessary to eliminate 90% (LC90) of 106.2 and 133.3 µg mL-1 for pure EO and encapsulated EO, respectively. Therefore, it was concluded that these microcapsules have the potential for application in the Aedes aegypti larvae control.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230031
Marcos V. S. Sales, E. Tanabe, T. Maciel, M. Tavares, Juliana Leal, L. Pinto, Keyla S. N. Pires, Jorge Coelho, E. Silva, Samuel Souza, E. Fonseca, Thiago Fragoso, Thiago Aquino, A. Borbely, U. Rocha, Josué Santos, A. C. Leite
Hematological problems are associated with Coronavirus disease 2019 (COVID-19). Respiratory impairment is the higher point studied, although without experimental studies related to the oxygen transport performed by erythrocytes. Therefore, we decided to investigate if erythrocytes from COVID-19 patients have their functionality changed. The case-control study included hospitalized patients with a positive real-time polymerase chain reaction (RT-PCR) result admitted to University Hospital. Volunteers (negative RT-PCR results) were recruited as a control group. Thus, we assessed different erythrocytes parameters, oxidative stress markers, and biophysical studies using whole blood and isolated hemoglobin. We found a decrease of 51% in oxygen uptake and reduced antioxidant enzyme activity in COVID-19 patients compared to controls. Raman spectrometry showed structural changes in the hemoglobin and lipids of the erythrocytes from COVID-19 patients; thus, these results were consolidated with an increase in Young’s modulus in erythrocytes followed by morphology changes. Besides, isolated hemoglobin from COVID-19 patients has a distinct interaction profile using a ligand model compared to the control. COVID-19 leads to structural, functional, and morphological damage to human erythrocytes. Our data showed structural and molecular changes and induction of oxidative stress in erythrocytes by COVID-19, a new perspective on the contribution of erythrocytes to a respiratory commitment in COVID-19.
{"title":"COVID-19 Infection Changes the Functions and Morphology of Erythrocytes: A Multidisciplinary Study","authors":"Marcos V. S. Sales, E. Tanabe, T. Maciel, M. Tavares, Juliana Leal, L. Pinto, Keyla S. N. Pires, Jorge Coelho, E. Silva, Samuel Souza, E. Fonseca, Thiago Fragoso, Thiago Aquino, A. Borbely, U. Rocha, Josué Santos, A. C. Leite","doi":"10.21577/0103-5053.20230031","DOIUrl":"https://doi.org/10.21577/0103-5053.20230031","url":null,"abstract":"Hematological problems are associated with Coronavirus disease 2019 (COVID-19). Respiratory impairment is the higher point studied, although without experimental studies related to the oxygen transport performed by erythrocytes. Therefore, we decided to investigate if erythrocytes from COVID-19 patients have their functionality changed. The case-control study included hospitalized patients with a positive real-time polymerase chain reaction (RT-PCR) result admitted to University Hospital. Volunteers (negative RT-PCR results) were recruited as a control group. Thus, we assessed different erythrocytes parameters, oxidative stress markers, and biophysical studies using whole blood and isolated hemoglobin. We found a decrease of 51% in oxygen uptake and reduced antioxidant enzyme activity in COVID-19 patients compared to controls. Raman spectrometry showed structural changes in the hemoglobin and lipids of the erythrocytes from COVID-19 patients; thus, these results were consolidated with an increase in Young’s modulus in erythrocytes followed by morphology changes. Besides, isolated hemoglobin from COVID-19 patients has a distinct interaction profile using a ligand model compared to the control. COVID-19 leads to structural, functional, and morphological damage to human erythrocytes. Our data showed structural and molecular changes and induction of oxidative stress in erythrocytes by COVID-19, a new perspective on the contribution of erythrocytes to a respiratory commitment in COVID-19.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.21577/0103-5053.20230032
Rafaela Gomes, Marina Tonucci, M. Prete, C. Tarley, B. Baeta, R. Afonso
A hybrid molecular imprinted polymer (HMIP) obtained by the organic monomer 4-vinylpyridine (4-VP) and the inorganic precursor tetraethyl orthosilicate (TEOS) was synthesized for the selective extraction of urinary S-phenylmercapturic acid (u-SPMA), a biomarker of benzene exposure. The chemical and structural characterization of the synthetic adsorbent was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and textural analysis employing N2 adsorption-desorption isotherms. Selective and adsorptive performance of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic, and selectivity studies. The kinetic data were well adjusted to pseudo-second order and intraparticle diffusion models, leading to selectivity coefficient (K) value of 0.03 g mg-1 min-1 for HMIP. In addition, the adsorption isotherms were better described by the Sip model achieving a maximum adsorption capacity of 284.81 μg g-1 (at 288.15 K).
以有机单体4-乙烯基吡啶(4-VP)和无机前体正硅酸四乙酯(TEOS)为原料合成了一种杂化分子印迹聚合物(HMIP)，用于选择性提取尿中苯暴露的生物标志物s -苯基巯基酸(u-SPMA)。通过傅里叶红外光谱(FTIR)、热重分析(TGA)和N2吸附-脱附等温线的结构分析对合成吸附剂进行了化学和结构表征。印迹聚合物的选择性和吸附性能通过动力学、等温、热力学和选择性研究进行了评价。动力学数据调整为准二级和颗粒内扩散模型，使得HMIP的选择系数(K)值为0.03 g mg-1 min-1。在288.15 K条件下，其吸附量最大可达284.81 μg -1。
{"title":"A Hybrid Molecularly Imprinted Polymer for Selective Adsorption of Urinary S-Phenylmercapturic Acid","authors":"Rafaela Gomes, Marina Tonucci, M. Prete, C. Tarley, B. Baeta, R. Afonso","doi":"10.21577/0103-5053.20230032","DOIUrl":"https://doi.org/10.21577/0103-5053.20230032","url":null,"abstract":"A hybrid molecular imprinted polymer (HMIP) obtained by the organic monomer 4-vinylpyridine (4-VP) and the inorganic precursor tetraethyl orthosilicate (TEOS) was synthesized for the selective extraction of urinary S-phenylmercapturic acid (u-SPMA), a biomarker of benzene exposure. The chemical and structural characterization of the synthetic adsorbent was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and textural analysis employing N2 adsorption-desorption isotherms. Selective and adsorptive performance of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic, and selectivity studies. The kinetic data were well adjusted to pseudo-second order and intraparticle diffusion models, leading to selectivity coefficient (K) value of 0.03 g mg-1 min-1 for HMIP. In addition, the adsorption isotherms were better described by the Sip model achieving a maximum adsorption capacity of 284.81 μg g-1 (at 288.15 K).","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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