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1.
Environ Pollut ; 328: 121639, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37062400

RESUMO

With variable atomic ratios, Ce-Al bimetallic oxides were fabricated using the sol-gel combustion method and utilized for efficient fluoride removal. The synthesized bimetallic oxides were extensively studied using advanced characterization techniques, including TGA, XRD, FTIR, BET surface area analysis, EDX-assisted FESEM, XPS and impedance analysis. These techniques facilitate the interpretation of the chemical and physical properties of the synthesized material. The Ce-Al (1:1) bimetallic oxide was selected as an adsorbent for the defluoridation. The Ce-Al (1:1) oxide demonstrates a moderately high surface area of 108.67 m2/g. The sorption behaviour of fluoride on Ce-Al (1:1) was thoroughly investigated using batch and column modes. The maximum fluoride removal efficiency (99.4%) was achieved at a temperature of 45 °C and pH of 7.0 using an adsorbent dose of 0.18 g/L for 35 min. Pseudo-second-order kinetic model appropriately describes the sorption process. Freundlich's adsorption isotherm was more pertinent in representing fluoride adsorption behaviour. The maximum fluoride adsorption capacity is 146.73 mg/g at 45 °C. Thermodynamics study indicates fluoride adsorption on Ce-Al (1:1) bimetallic oxide is spontaneous and feasible. The adsorption mechanism was interpreted through XPS spectra, indicating that the physisorption process is mainly responsible for fluoride adsorption. An in-depth investigation of the adsorption dynamics was carried out using mass transfer models and found that the external diffusion process limits the overall adsorption rate. An electrochemical investigation was performed to understand the effect of fluoride adsorption on the electrochemical behaviour of bimetallic oxide. The fixed-bed column adsorption study suggested that the lower flow rate and increased bed height favourably impacted the overall defluoridation process, and column adsorption results were suitably interpreted through both the Adam-Bohart model and Yoon-Nelson dynamics model. The sustainable aspect of the defluoridation process was elucidated in terms of carbon footprint measurement using life cycle assessment analysis. The carbon footprint of the entire treatment process was calculated as 0.094 tons/year.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Óxidos/química , Água , Fluoretos/análise , Adsorção , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise , Cinética
2.
Org Lett ; 17(11): 2656-9, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-25954832

RESUMO

A metal-free room temperature decarboxylative cross-coupling between cinnamic acids and arylsulfonyl hydrazides has been realized for the first time for the synthesis of (E)-vinyl sulfones. The scope and versatility of the reaction has been demonstrated by the regio- and stereoselective synthesis of 22 derivatives with diverse structural features.

3.
Anticancer Agents Med Chem ; 15(8): 1066-77, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25642980

RESUMO

Phospholipase A2 (PLA2), Cyclooxygenase (COX) and 5-Lipoxygenase (5-LOX) are arachidonic acid metabolizing enzymes and their inhibitors have been developed as therapeutic molecules for cancer and inflammation related disorders. In the present study, PLA2, COX 1&2 and 5-LOX inhibitory studies of Borassus flabellifer seed coat extract were carried out and substantial 5-LOX inhibitory activity was found. Dammarane triterpenoid 1 (Dammara-20,23-diene-3,25-diol) was isolated according to 5-LOX activity guided isolation, and screened for COX (1 & 2) inhibitory activities. Dammarane triterpenoid 1 inhibited carrageenan-induced rat paw edema and TNF-α secretion levels in lipopolysaccharide (LPS)-induced THP-1 human monocytes. Anticancer activity studies demonstrated the antiproliferative effect of dammarane triterpenoid 1 on various cancer cell lines including MIA PaCa-2 pancreatic, DU145 prostate, HL-60 leukemia and Caco-2 colon cancers. Dammarane triterpenoid 1 showed good antiproliferative activity on MIA PaCa-2 pancreatic cancer cell line with IC50 of 12.36±0.33 µM, among other tested cell lines. Apoptosis inducing activity of dammarane triterpenoid 1 was confirmed based on increased sub-G0 phase cell population in cell cycle analysis, loss of mitochondrian membrane potential, elevated levels of cytochrome c, nuclear morphological changes and DNA fragmentation in MIA PaCa-2 pancreatic cancer cells. Therefore, dammarane triterpenoid skeleton may raise the hope of developing novel anti-inflammatory and anticancer drugs in the future.


Assuntos
Apoptose/efeitos dos fármacos , Arecaceae/química , Monócitos/efeitos dos fármacos , Neoplasias Pancreáticas/patologia , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Células CACO-2 , Linhagem Celular Tumoral , Inibidores de Ciclo-Oxigenase/isolamento & purificação , Inibidores de Ciclo-Oxigenase/farmacologia , Regulação para Baixo/efeitos dos fármacos , Edema/induzido quimicamente , Edema/imunologia , Edema/patologia , Células HL-60 , Humanos , Lipopolissacarídeos , Inibidores de Lipoxigenase/isolamento & purificação , Inibidores de Lipoxigenase/farmacologia , Masculino , Monócitos/imunologia , Monócitos/metabolismo , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Ratos , Ratos Wistar , Sementes/química , Damaranos
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