RESUMO
Herein, four silver(I) complexes bearing acetylated d-galactopyranoside-based N-heterocyclic carbene ligands were synthesized and fully characterized by elemental analysis, NMR, and X-ray photoelectron spectroscopy. All complexes were obtained with an anomeric ß-configuration and as monocarbene species. In this study, we investigated the biological effects of the silver(I) complexes 2a-d on the human rhabdomyosarcoma cell line, RD. Our results show concentration-dependent effects on cell density, growth inhibition, and activation of key signaling pathways such as Akt 1/2, ERK 1/2, and p38-MAPK, indicating their potential as anticancer agents. Notably, at 35.5 µM, the complexes induced mitochondrial network disruption, as observed with 2b and 2c, whereas with 2a, this disruption was accompanied by nuclear content release. These results provide insight into the utility of carbohydrate incorporated NHC complexes of silver(I) as new agents in cancer therapy.
Assuntos
Antineoplásicos , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Rabdomiossarcoma , Prata , Humanos , Acetilação , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Relação Dose-Resposta a Droga , Galactose/química , Galactose/farmacologia , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Metano/química , Metano/análogos & derivados , Metano/farmacologia , Metano/síntese química , Estrutura Molecular , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/patologia , Prata/química , Prata/farmacologia , Relação Estrutura-AtividadeRESUMO
This work presents a comparison between an environmental impact assessment (EIA) and a life cycle assessment (LCA) using a case study: upgrading of biogas. The upgrading of biogas is studied using three solvents: water, physical solvent and amine. The EIA follows the requirements of the legislation of Santa Fe Province (Argentina), and the LCA follows ISO 14040. The LCA results showed that water produces a minor impact in most of the considered categories whereas the high impact in the process with amines is the result of its high energy consumptions. The positive results obtained in the EIA (mainly associated with the cultural and socioeconomic components) make the project feasible and all the negative impacts can be mitigated by preventive and remedial measures. From the strengths and weaknesses of each tool, it is inferred that the EIA is a procedure that can complement the LCA.
Assuntos
Biocombustíveis , Dióxido de Carbono/isolamento & purificação , Meio Ambiente , Metano/síntese química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Argentina , Dióxido de Carbono/química , Simulação por Computador , Monitoramento Ambiental/métodos , Modelos Teóricos , Solventes/química , Poluentes Químicos da Água/químicaRESUMO
Eight different grasses collected from pastures of the Kermanshah province (Kermanshah, Iran), at mid-vegetative stage were used to study the relationships between their chemical compositions, kinetic parameters of in vitro gas production and rumen methane production. There was a positive correlation (r = 0.62, p 0.05) between crude protein (CP) content of grasses and total gas production (A) at 96h incubation. Negative correlations were also observed between acid detergent fiber (ADF) content and total gas production (r = -0.60, p 0.05). Amongst the nutrients, neutral detergent fiber (NDF) and ADF were positively correlated with methane concentration, (r = 0.75 and 0.77, p 0.01). The methane reduction potential (MRP) was negative for Trachyspermum copticum indicating higher methane production than the control hay for this grass. The MRP of Chamaemelum nobile was more than 25%, indicating plants that reduce methane production more than 20 percent methane in comparison with control actually have ingredients to reduce methane.(AU)
Oito tipos diferentes de capim tirados de pastagens na província de Kermanshah (Kermanshah, Iran), em estágio meio vegetativo, foram analisados para ver sua relação entre as composições químicas, parâmetros cinéticos de produção de gás e produção de metano no rúmen in vivo. Houve uma correlação positiva (r = 0,62; p 0,05) entre a proteína bruta (PB), conteúdo do capim e a produção total de gás (A) após 96h de incubação. Foram observadas correlações negativas entre a fibra de detergente ácido (FDA) e a produção total de gás (r = -0,60; p 0,05). Entre os nutrientes, a fibra de detergente neutro (FDN) e a FDA foram positivamente correlacionados com concentração de metano (r = 0,75 e 0,77; p 0,01). O potencial reducional de metano (PRM) era negative para Trachyspermum copticum e indicava uma produção maior de metano do que o controle feno nesse capim. O PRM de Chamaemelum nobile chegou a mais de 25% e indicava plantas que reduzem a produção de metano em mais de 20% quando comparadas ao controle que tem ingredientes para diminuir o metano.(AU)
Assuntos
Pastagens/análise , Pastagens/métodos , Fermentação , Metano/análise , Metano/síntese químicaRESUMO
Eight different grasses collected from pastures of the Kermanshah province (Kermanshah, Iran), at mid-vegetative stage were used to study the relationships between their chemical compositions, kinetic parameters of in vitro gas production and rumen methane production. There was a positive correlation (r = 0.62, p 0.05) between crude protein (CP) content of grasses and total gas production (A) at 96h incubation. Negative correlations were also observed between acid detergent fiber (ADF) content and total gas production (r = -0.60, p 0.05). Amongst the nutrients, neutral detergent fiber (NDF) and ADF were positively correlated with methane concentration, (r = 0.75 and 0.77, p 0.01). The methane reduction potential (MRP) was negative for Trachyspermum copticum indicating higher methane production than the control hay for this grass. The MRP of Chamaemelum nobile was more than 25%, indicating plants that reduce methane production more than 20 percent methane in comparison with control actually have ingredients to reduce methane.
Oito tipos diferentes de capim tirados de pastagens na província de Kermanshah (Kermanshah, Iran), em estágio meio vegetativo, foram analisados para ver sua relação entre as composições químicas, parâmetros cinéticos de produção de gás e produção de metano no rúmen in vivo. Houve uma correlação positiva (r = 0,62; p 0,05) entre a proteína bruta (PB), conteúdo do capim e a produção total de gás (A) após 96h de incubação. Foram observadas correlações negativas entre a fibra de detergente ácido (FDA) e a produção total de gás (r = -0,60; p 0,05). Entre os nutrientes, a fibra de detergente neutro (FDN) e a FDA foram positivamente correlacionados com concentração de metano (r = 0,75 e 0,77; p 0,01). O potencial reducional de metano (PRM) era negative para Trachyspermum copticum e indicava uma produção maior de metano do que o controle feno nesse capim. O PRM de Chamaemelum nobile chegou a mais de 25% e indicava plantas que reduzem a produção de metano em mais de 20% quando comparadas ao controle que tem ingredientes para diminuir o metano.
Assuntos
Fermentação , Metano/análise , Metano/síntese química , Pastagens/análise , Pastagens/métodosRESUMO
Triarylmethane and thiazine dyes have attracted attention as anticancer and antimicrobial agents, due to their structural features and selective localizations. Although these dyes have been initially explored in the context of photodynamic therapy, some of these such as New Fuchsin and Azure B have still not been extensively investigated. For this reason, we evaluated the chemical stability, aggregation effect, and lipophilicity, as well as the photodynamic activity against LM-2 murine mammary carcinoma cells of five new brominated dyes of triarylmethane and thiazine. These cationic compounds were obtained at high purities and unequivocally characterized by conventional techniques. The introduction of bromine atoms into the chromophoric system of New Fuchsin and Azure B dyes gave rise to a moderate bathochromic shift and increased the lipophilicity, thereby improving their photophysical and photochemical properties for biomedical applications. Moreover, the in vitro photodynamic activity demonstrated that, as the degree of bromination increased, the phototoxicity remained unchanged or decreased. The lower efficiency to inactivate cultured tumor cells may be attributed to the formation of the colorless carbinol pseudobase and aggregation effects for triarylmethane and thiazine dyes, respectively. A promising strategy to reverse the biological activity decrease observed might be the design of third-generation photosensitizers.
Assuntos
Metano/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Tiazinas/farmacologia , Animais , Linhagem Celular Tumoral , Estabilidade de Medicamentos , Feminino , Interações Hidrofóbicas e Hidrofílicas , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias Mamárias Animais/patologia , Metano/síntese química , Metano/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Relação Estrutura-Atividade , Tiazinas/síntese química , Tiazinas/químicaRESUMO
Here we present the preparation of a variety of diarylmethanes obtained via ultrasound Stille coupling under palladium catalysis between some substituted aryl compounds and benzyltributyltin compounds generated through sonicated Barbier reaction in a very short time reaction and excellent yield. The study reported below compares different methods to optimize the synthesis of usually unstable benzyltin derivatives and is another contribution to the investigation of Csp(3)-Csp(2) coupling process involving benzyl-aryl reagents. Substituted carboxylated benzophenones were easily prepared in a very good yield by oxidation of some diarylmethanes.
Assuntos
Antibacterianos/química , Antibacterianos/síntese química , Benzofenonas/química , Benzofenonas/síntese química , Metano/química , Metano/síntese química , Ultrassom , Técnicas de Química SintéticaRESUMO
Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N(2) and CH(4) and includes traces of many simple organic compounds. This atmosphere also partly consists of haze and aerosol particles which during the last 4.5 gigayears have been processed by electric discharges, ions, and ionizing photons, being slowly deposited over the Titan surface. In this work, we investigate the possible effects produced by soft X-rays (and secondary electrons) on Titan aerosol analogs in an attempt to simulate some prebiotic photochemistry. The experiments have been performed inside a high vacuum chamber coupled to the soft X-ray spectroscopy beamline at the Brazilian Synchrotron Light Source, Campinas, Brazil. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The infrared spectra have presented several organic molecules, including nitriles and aromatic CN compounds. After the irradiation, the brownish-orange organic residue (tholin) was analyzed ex-situ by gas chromatographic (GC/MS) and nuclear magnetic resonance ((1)H NMR) techniques, revealing the presence of adenine (C(5)H(5)N(5)), one of the constituents of the DNA molecule. This confirms previous results which showed that the organic chemistry on the Titan surface can be very complex and extremely rich in prebiotic compounds. Molecules like these on the early Earth have found a place to allow life (as we know) to flourish.
Assuntos
Adenina/síntese química , Adenina/efeitos da radiação , Meio Ambiente Extraterreno/química , Saturno , Adenina/química , Atmosfera/química , Dióxido de Carbono/síntese química , Dióxido de Carbono/química , Monóxido de Carbono/síntese química , Monóxido de Carbono/química , Cianatos/síntese química , Cianatos/química , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Aromáticos/síntese química , Hidrocarbonetos Aromáticos/química , Espectroscopia de Ressonância Magnética , Metano/síntese química , Metano/química , Nitrilas/síntese química , Nitrilas/química , Nitrogênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Raios XRESUMO
Rate constants for the hydrolysis of Fischer carbenes (CO)5Cr=C(OR)Ph (R = n-propyl, neopentyl, isopropyl, and menthyl) in 50% MeCN-50% water (v/v) at 25 degrees C are reported. The rate constants for the addition of -OH to the carbene carbon are 5.3, 3.7, 0.84, and 0.01 M(-1) s(-1), respectively. These rate constants give linear correlations with the corresponding rate constants for the hydrolysis of esters such as acetate, benzoate, and formiate. The slopes of the plots of the observed rate constants for the carbenes vs the rate constants for the esters are 1.4 and 1.2 for acetate and benzoate, respectively, indicating that the factors that decrease the reactivity of the two types of compounds are similar, but the carbenes show higher sensitivity. The rate constants are well correlated with several steric parameters giving a value of -3.84 for the Charton's psi parameter. The results show that the steric bulkiness of the R group is the main factor determining the reactivity differences for these carbene complexes.