Journal of the Brazilian Chemical Society最新文献_第4页

Formation of α,β-Unsaturated Imines in Apolar Aprotic Solvent: Effect of Hidden Acid Catalysts Analyzed by Theoretical Calculations 极性非质子溶剂中α，β-不饱和亚胺的形成:隐含酸催化剂的理论计算分析

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-10-06 DOI: 10.21577/0103-5053.20230063

Virginia C. Rufino, Josefredo Pliego Jr.

引用次数: 0

Chemical Characterization of Aspartic Protease from Artichoke Flower (Cynara cardunculus L. var scolymus) Using MIR Spectroscopy and Analytical Measurements 朝鲜蓟花(Cynara cardunculus L. var scolymus)中天冬氨酸蛋白酶的化学性质及分析方法

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-10-06 DOI: 10.21577/0103-5053.20230065

Josane Cardim de Jesus, Lucas Reis, M. Santos, Leandro Santos, S. Ferrão

{"title":"Chemical Characterization of Aspartic Protease from Artichoke Flower (Cynara cardunculus L. var scolymus) Using MIR Spectroscopy and Analytical Measurements","authors":"Josane Cardim de Jesus, Lucas Reis, M. Santos, Leandro Santos, S. Ferrão","doi":"10.21577/0103-5053.20230065","DOIUrl":"https://doi.org/10.21577/0103-5053.20230065","url":null,"abstract":"Vegetable proteases have been studied as milk coagulants, and artichoke flower (Cynara cardunculus L. var scolymus) has potential coagulant action as a substitute for microbial chymosin. The objective was to perform chemical characterization of aspartic proteases from artichoke flower (Cynara cardunculus L. var scolymus) by mid-infrared spectroscopy (MIR) and analytical measurements. Artichoke flower extracts were obtained and crude thistle flower extract and microbial chymosin were used as a reference. Plant extracts and microbial chymosin were analyzed for protein concentration, proteolytic activity (PA), milk clotting activity (MCA), specificity ratio (SR), effects of pH, temperature, NaCl and CaCl2 concentration on MCA and PA and characterized by electrophoretic, spectroscopic, chromatographic and storage stability. The results indicated that the crude extract of artichoke flower showed high MCA (510.08 SU mL-1 ), low PA (10.50 µg mg-1), SR (48.57) and storage stability for up to 90 days under frozen. The electrophoretic profile of artichoke flower resulted in a protein band with an apparent molecular weight of 32 kDa, associated with cardosin A. Artichoke flower may be a new alternative for commercial plant proteases with active enzymes for milk coagulation.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68339131","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}

引用次数: 0

Featured Properties of the Adsorption of Tebuconazole on Ag Surface Characterized through SERS Spectroscopy 用SERS光谱法表征戊康唑在银表面的吸附特性

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230042

R. de Oliveira, A. C. Sant’Ana

{"title":"Featured Properties of the Adsorption of Tebuconazole on Ag Surface Characterized through SERS Spectroscopy","authors":"R. de Oliveira, A. C. Sant’Ana","doi":"10.21577/0103-5053.20230042","DOIUrl":"https://doi.org/10.21577/0103-5053.20230042","url":null,"abstract":"Pesticides present utmost importance in modern agriculture and are extensively used in countries with strong agricultural activity, such as Brazil. However, these substances are considered a significant part of environmental contamination by organic compounds. In the present work, Raman spectroscopy was employed in the vibrational characterization of the fungicide tebuconazole and surface-enhanced Raman scattering spectroscopy to the study of the adsorption of this compound on the surface of Ag nanoparticles. The proposed chemical interaction between tebuconazole and the metallic surface was inferred by relating experimental results and vibrational assignment supported by density functional theory calculations. The vibrational assignments of surface-enhanced Raman scattering spectra, by considering surface selection rules, suggest that the adsorption of the tebuconazole with Ag surface occurs by interactions of phenyl and triazole groups simultaneously. For the case of the interaction with the phenyl group, a modification of the charge distribution in the ring after adsorption was hypothesized, which was supported through the analysis of the frontier molecular orbitals of the Ag-tebuconazole complex calculated by density functional theory.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333265","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}

引用次数: 2

Photocatalytic Degradation of Bentazon Pesticide by a Fe2O3-TiO2 Composite Catalyst Irradiated by UVA, UVB, and Natural Light UVA、UVB和自然光照射下Fe2O3-TiO2复合催化剂光催化降解苯达松农药

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230039

Cristian Braga, G. Bessegato, K. Maestre, F. Quiñones, H. Alves, Leandro Santana Da Silva, Renato Eising, R. Bariccatti

{"title":"Photocatalytic Degradation of Bentazon Pesticide by a Fe2O3-TiO2 Composite Catalyst Irradiated by UVA, UVB, and Natural Light","authors":"Cristian Braga, G. Bessegato, K. Maestre, F. Quiñones, H. Alves, Leandro Santana Da Silva, Renato Eising, R. Bariccatti","doi":"10.21577/0103-5053.20230039","DOIUrl":"https://doi.org/10.21577/0103-5053.20230039","url":null,"abstract":"Environmental pollution by contaminants of emerging concern, among these various pesticides, has been a concern of environmentalists and scientists around the world. Thus, efforts to mitigate the impacts of these substances have been carried out, and the use of advanced oxidation processes, such as photocatalysis, is an alternative. This work sought to synthesize a composite photocatalyst based on iron oxides and titanium dioxide to assess its applicability in degrading the herbicide bentazon (BTZ) by a lamp that simulates the solar spectrum (visible, ultraviolet A and ultraviolet B) and sunlight. Photocatalytic degradation reached 51% in 120 min with a rate constant k = 0.0058 min−1 when a UV-Vis lamp of 300 W was used. The applicability was demonstrated under sunlight radiation, reaching 38% degradation of a bentazon solution (4.1 × 10−4 mol L−1) after 320 min. TiO2 and Fe2O3 were synthesized similarly but showed no degradation under the same conditions. Thus, Fe2O3-TiO2 is an inexpensive and non-toxic material capable of efficiently conducting the photocatalytic degradation of organic compounds, such as the bentazon herbicide.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333439","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}

引用次数: 0

Theoretical Study of 2,6-Dichloro-3-methyl-1,4-benzoquinone Interacting with Graphene 2,6-二氯-3-甲基-1,4-苯醌与石墨烯相互作用的理论研究

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230041

Leandro Sobrinho, S. Guerini

引用次数: 0

Ursolic Acid Derivatives Down Regulate Inflammatory Mediators 熊果酸衍生物下调炎症介质

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230036

Elaine C Scherrer, Ydia M. Valadares, C. Alves, A. Carli, Bárbara Fernandes, P. Carvalho, Karla Ramos, M. Salvador, J. D. da Silva, Fernando Silva, Â. Denadai, S. Castro

{"title":"Ursolic Acid Derivatives Down Regulate Inflammatory Mediators","authors":"Elaine C Scherrer, Ydia M. Valadares, C. Alves, A. Carli, Bárbara Fernandes, P. Carvalho, Karla Ramos, M. Salvador, J. D. da Silva, Fernando Silva, Â. Denadai, S. Castro","doi":"10.21577/0103-5053.20230036","DOIUrl":"https://doi.org/10.21577/0103-5053.20230036","url":null,"abstract":"Ursolic acid (UA) is being investigated due to its anti-inflammatory potential, and structural modifications can enhance its biological activities. The aim of this study was to evaluate the immunomodulatory effect of the ursolic acid derivatives (UAD) in macrophages and in the carrageenan-induced paw edema model. RAW264.7 cells were cultured in the presence or absence of UA or UAD (1-18). Nitric oxide (NO), nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF), and cellular viability were measured. 30 min before the carrageenan-induced paw edema, the UAD1 and UAD2 (200 mg kg-1) were administered intraperitoneally. The results showed that UAD2-4, UAD7, UAD9-11 had half maximal inhibitory concentration (IC50) greater than 90 µM and were able to reduce NO, NF-κB and TNF production. Moreover, UAD1 and UAD2 reduced paw edema and IL-6 production. In conclusion, the results obtained demonstrated a variation in the response between the derivatives due to the chemical modifications, showing potential to reduce the inflammatory mediators, deserving further investigations.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332702","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}

引用次数: 0

Silver Nanocatalyst Supported on Waste-Based Polystyrene Foam for Thermal and Plasmonic Reduction of p-Nitrophenol 废基聚苯乙烯泡沫载银纳米催化剂对硝基苯酚的热等离子体还原

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230044

Wélida Tamires Alves da Silva, Geovânia C de Assis, Roberta Anjos de Jesus, R. Motta, Luiz Fernando Ferreira, Yolice Patricia Ruiz, A. Galembeck, R. Schneider, R. D. de Oliveira

{"title":"Silver Nanocatalyst Supported on Waste-Based Polystyrene Foam for Thermal and Plasmonic Reduction of p-Nitrophenol","authors":"Wélida Tamires Alves da Silva, Geovânia C de Assis, Roberta Anjos de Jesus, R. Motta, Luiz Fernando Ferreira, Yolice Patricia Ruiz, A. Galembeck, R. Schneider, R. D. de Oliveira","doi":"10.21577/0103-5053.20230044","DOIUrl":"https://doi.org/10.21577/0103-5053.20230044","url":null,"abstract":"Disposal of plastics into the environment has been one of the major problems for the environment. The accumulation of polystyrene (PS) occurs in an accelerated way and, therefore, its reuse is challenging. Polystyrene nanocomposites impregnated with Ag nanoparticles (PS/AgNP) are generated from polystyrene residues and can be applied in the catalytic and plasmonic photo-catalytic reduction of phenolic compounds such as p-nitrophenol (PNP) to p-aminophenol (PAP). The AgNP were synthesized by a reverse micelle method resulting in nanoparticles with sizes in a range of 31.1-34.0 nm. The organocolloid was characterized by UV-Vis and dynamic light scattering (DLS), demonstrating the preparation of spherical nanoparticles. The preparation of the PS/AgNP, obtained using a thermally induced phase separation method (TIPS), was confirmed by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), laser-induced breakdown spectroscopy (LIBS), and Fourier transform visible infrared spectroscopy (FTIR). Nanocomposites showed impressive performance in the catalytic and plasmonic photocatalytic reduction under blue light irradiation, reaching up to 98% conversion, being a promising material for wastewater treatment as well as other various environmental issues. We used blue light to observe the plasmonic effect of silver nanoparticles, and no previous reports of this composite for PNP reduction using blue light photocatalysis were found.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333306","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}

引用次数: 0

Voltammetric Study on the Electrowinning of Cobalt in the Presence of Additives 添加剂存在下钴电积的伏安法研究

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230048

引用次数: 2

Stable and Thermo-Responsive Dextran Sulfate-Graft-PNIPAm Amphiphilic Nanoparticles for Potential Target Methotrexate Delivery 稳定和热响应性的硫酸葡聚糖接枝PNIPAm两亲性纳米粒子用于潜在的靶向甲氨蝶呤递送

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230037

A. D. dos Santos, E. D. da Silva, Raquel Montenegro, Jeanlex de Sousa, R. D. de Paula, J. Feitosa

{"title":"Stable and Thermo-Responsive Dextran Sulfate-Graft-PNIPAm Amphiphilic Nanoparticles for Potential Target Methotrexate Delivery","authors":"A. D. dos Santos, E. D. da Silva, Raquel Montenegro, Jeanlex de Sousa, R. D. de Paula, J. Feitosa","doi":"10.21577/0103-5053.20230037","DOIUrl":"https://doi.org/10.21577/0103-5053.20230037","url":null,"abstract":"Thermo-responsive copolymers grafted with N-isopropylacrylamide (NIPAm) are excellent candidates for drug release. Dextran sulfate (DS) acts as a specific ligand in inflamed regions, turning it highly useful as a target for drug delivery. DS was associated with NIPAm to produce amphiphilic graft copolymers prepared via free radicals. The molar ratio of feed reagents NIPAm/DS varied from 1 (DS-g-PNIPAm) to 4 (DS-g-4PNIPAm). The synthesis was confirmed by spectroscopic techniques (Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR)). All copolymers showed self-organization capacity in an aqueous medium in temperatures higher than 34 °C, and sizes less than 300 nm. DS-g-3PNIPAm exhibited stability in water and in phosphate buffer at pH 7.4. Scanning electron microscopy confirmed their spherical shape. This copolymer showed specificity to leukemic cells, and normal cells’ proliferation. Methotrexate (MTX) is a very low water-soluble drug used for rheumatoid arthritis and cancer. Unfortunately, MTX have severe collateral effects. MTX-loaded nanoparticles can overcome such issues as well as enhance bioactivity and stability. The MTX was encapsulated and delivered from the DS-g-3PNIPAm with potential target delivery due to the presence of DS. Comparison with MTX encapsulated in other nanoparticles reveals that the DS-g-PNIPam presents the best performance among the thermoresponsive and the second among the target MTX nanocarriers.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68332881","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}

引用次数: 0

Synthesis and Anticancer Activity of Homodimeric Morita-Baylis-Hillman Adducts Based on 3-Hydroxyindolin-2-one Core 基于3-羟基吲哚啉-2-酮核的同二聚莫里塔-贝利斯-希尔曼加合物的合成及其抗癌活性

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-08-25 DOI: 10.21577/0103-5053.20230038

Maísa Coelho, Aleff Castro, Tayná Olegário, Rodrigo Cristiano, B. Vaz, Gabriel dos Santos, Lucas Machado, Gardenia C G Militão, Paulo da Silva, M. Vasconcellos, C. Lima‐Junior

{"title":"Synthesis and Anticancer Activity of Homodimeric Morita-Baylis-Hillman Adducts Based on 3-Hydroxyindolin-2-one Core","authors":"Maísa Coelho, Aleff Castro, Tayná Olegário, Rodrigo Cristiano, B. Vaz, Gabriel dos Santos, Lucas Machado, Gardenia C G Militão, Paulo da Silva, M. Vasconcellos, C. Lima‐Junior","doi":"10.21577/0103-5053.20230038","DOIUrl":"https://doi.org/10.21577/0103-5053.20230038","url":null,"abstract":"Cancer treatment represents one of the main scientific study targets today, mainly due to the pronounced side effects arising from chemotherapy. This study reports the synthesis, characterization, and anticancer activity of ten compounds from the Morita-Baylis-Hillman reaction. Ethylene glycol diacrylate was used as a double Michael acceptor in reactions with isatin derivatives to give homodimers of 3-hydroxyindolin-2-one core, recognized in the literature for its extensive pharmacological profile. The use of 1,4-diazabicyclo[2,2,2]octane (DABCO) as a catalyst and room temperature were the optimal conditions for the study reaction. The isolated yields were up to 63%, with most reaction times inferior to 24 h, some as fast as 15 min. The anticancer potential of the synthesized dimers was evaluated in vitro against three cancer strains, resulting in average inhibitory concentrations up to 0.72 μM. It was also found that the best performing homodimers are more active than their monomeric counterparts. Considering the promising selectivity indices observed, the preliminary results obtained here act as a basis for broader tests regarding the effectiveness of homodimeric adducts against cancer cells.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333181","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}

引用次数: 0