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1.
Top Curr Chem (Cham) ; 378(1): 11, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31903506

RESUMO

The dramatic increase in atmospheric carbon dioxide (CO2) concentrations has attracted human attention and many strategies about converting CO2 into high-value chemicals have been put forward. Metal-organic frameworks (MOFs), as a class of versatile materials, have been widely used in CO2 capture and chemical conversion, due to their unique porosity, multiple active centers and good stability and recyclability. Herein, we focused on the processes of chemical conversion of CO2 by MOFs-based catalysts, including the coupling reactions of epoxides, aziridines or alkyne molecules, CO2 hydrogenation, and other CO2 conversion reactions. The synthesized methods and high catalytic activity of MOFs-based materials were also analyzed systematically. Finally, a brief perspective on feasible strategies is presented to improve the catalytic activity of novel MOFs-based materials and explore the new CO2 conversion reactions.


Assuntos
Dióxido de Carbono/química , Estruturas Metalorgânicas/química , Alcenos/química , Aminas/química , Aziridinas/química , Catálise , Compostos de Epóxi/química , Hidrogenação , Líquidos Iônicos/química
2.
Phys Chem Chem Phys ; 22(5): 2878-2886, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31950118

RESUMO

Keggin-type polyoxometalate derived ionic liquids (POM-ILs) have recently been presented as effective solvent systems for biomass delignification. To investigate the mechanism of lignin dissolution in POM-ILs, the system involving POM-IL ([C4C1Im]3[PW12O40]) and guaiacyl glycerol-ß-guaiacyl ether (GGE), which contains a ß-O-4 bond (the most dominant bond moiety in lignin), was studied using quantum mechanical calculations and molecular dynamics simulations. These studies show that more stable POM-IL structures are formed when [C4C1Im]+ is anchored in the connecting four terminal oxygen region of the [PW12O40]3- surface. The cations in POM-ILs appear to stabilize the geometry by offering strong and positively charged sites, and the POM anion is a good H-bond acceptor. Calculations of POM-IL interacting with GGE show the POM anion interacts strongly with GGE through many H-bonds and π-π interactions which are the main interactions between the POM-IL anion and GGE and are strong enough to force GGE into highly bent conformations. These simulations provide fundamental models of the dissolution mechanism of lignin by POM-IL, which is promoted by strong interactions of the POM-IL anion with lignin.


Assuntos
Líquidos Iônicos/química , Lignina/química , Simulação de Dinâmica Molecular , Teoria Quântica , Compostos de Tungstênio/química , Guaifenesina/análogos & derivados , Guaifenesina/química , Ligações de Hidrogênio , Lignina/metabolismo , Solubilidade , Eletricidade Estática
3.
Phys Chem Chem Phys ; 22(6): 3490-3498, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-31990285

RESUMO

The liquid structures of six choline carboxylate/amino acid ionic liquids (bio-ILs) and their mixtures with water and various n-alkanols have been investigated by small-angle X-ray scattering (SAXS). The ILs exhibit long-range amphiphilic nanostructure comprised of polar and apolar domains that can be controlled by choice of anion, and which is tolerant to water dilution. Mixtures with n-alkanols can lead to marked changes in domain size and ordering. Utilising the Teubner-Strey model, we find amphiphilicity factors in many of these mixtures are comparable to those observed in conventional microemulsions, and that cooperative assembly in bio-IL/alkanol mixtures can enhance amphiphilicity, with potential to improve performance in a range of applications.


Assuntos
Aminoácidos/química , Ácidos Carboxílicos/química , Colina/química , Líquidos Iônicos/química , Nanoestruturas/química , Tensoativos/química
4.
J Photochem Photobiol B ; 202: 111706, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31775112

RESUMO

The noble metal such as Ag and Au doped CeO2 nanoparticles was successfully prepared by ionic liquid assisted hydrothermal method in the presence of Justicia adhatoda leaves extract and were used as an antibacterial and anticancer agent. The FT-IR and Raman spectrum exhibit the peaks at 460 and 464 cm-1 assigned to CeO stretching vibrations of NPs. The electron microscopic micrographs confirmed the spherical shaped morphology of prepared NPs. The insertion of Ag and Au ions into the CeO2 surface creates lattice defects the leads to reduce the band gap energy of Ag-Au/CeO2 at 3.15 eV. The XRD results suggested the average crystalline size of the silver­gold loaded CeO2 was 28 nm. From the elemental mapping images, we have visualized that existence and uniform distribution of Ag, Au, Ce, and O in the prepared nanomaterials. The antibacterial activity of unloaded and bimetal loaded CeO2 NPs was evaluated with Gram-positive and Gram-negative bacteria using disc diffusion assay. The AgAu loaded CeO2 NPs exhibited the highest zone of inhibition against E. coli and S. aureus strains when compared with pristine CeO2, Ag loaded CeO2, and Au loaded CeO2 NPs. In addition, the 100 µg mL-1 of CeO2, Ag/CeO2, Au/CeO2 and Ag-Au/CeO2 NPs exposed the 50, 51, 52 and 56% of anticancer activity against the HeLa cells respectively. Overall, this study concludes that the ionic liquid functionalized green synthesized bimetal loaded cerium oxide NPs showed potent antibacterial and anticancer activities.


Assuntos
Antibacterianos/química , Antineoplásicos/química , Líquidos Iônicos/química , Adhatoda/química , Nanopartículas Metálicas/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cério/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Ouro/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Células HeLa , Humanos , Adhatoda/metabolismo , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Prata/química
5.
J Environ Sci (China) ; 87: 341-348, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31791507

RESUMO

Ionic liquids (ILs) are a class of solvents increasingly used as "green chemicals." Widespread applications of ILs have led to concerns about their accidental entry to the environment. ILs have been assessed for some environmental impacts; however, little has been done to characterize their potential impacts on drinking water if ILs accidentally enter surface water. IL cations are often aromatic or alkyl quaternary amines that resemble structures of previously confirmed N-nitrosamine (NA) precursors. Therefore, this study has evaluated two common ILs, 1-ethyl-3-methylimidazolium bromide (EMImBr) and 1-ethyl-1-methylpyrrolidinium bromide (EMPyrBr), for their NA formation potential. Each IL species was reacted with pre-formed monochloramine under various laboratory conditions. The reaction mixtures were extracted using liquid-liquid extraction and analyzed for NAs using high performance liquid chromatography tandem mass spectrometry. At low concentration of IL (250 µmol/L), the yields of NAs (NMEA or NPyr) increased with increasing doses of monochloramine from both IL species. The total NA yield was as high as 2.5 ±â€¯0.3 ng/mg from EMImBr, and as high as 8.6 ±â€¯0.8 ng/mg from EMPyrBr. At high concentration of IL (5 mmol/L), the NA yield reached a maximum at 2.5 mmol/L NH2Cl, and then decreased with subsequent increases in the reactant concentrations, demonstrating ILs' solvent effects. This study re-emphasizes the importance of preventing discharge of ILs to water bodies to prevent secondary impacts on drinking water.


Assuntos
Líquidos Iônicos/química , Poluentes Químicos da Água/química , Imidazóis , Modelos Químicos , Nitrosaminas , Solventes/química
6.
Ecotoxicol Environ Saf ; 187: 109836, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31675504

RESUMO

Toxicity of 13 ionic liquids (ILs) corresponding to different families were studied by inhibition respiration assays (15 min) using activated sludge. Toxicity increased as increasing the number of carbons in the alkyl-chain of imidazolium-based ILs, with EC50 values from 4.19 to 0.17 for 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]) and 1-octyl-3-methylimidazolium chloride ([Omim][Cl]), respectively. An increase in toxicity was observed for aromatic-based ILs (pyridinium- and imidazolium-based ILs) due to the hydrophobic character of the head groups in comparison with linear structures as phosphonium and ammonium cations. Among to the anions studied fixing [Emim]+ as cation, [HSO4]- and [NTf2]- presented low EC50 values (0.34 mM and 1.69 mM, respectively) while [Cl]- and [EtSO4]- were considered harmless anions due to the hydrophilic character of chloride and the organic nature of [EtSO4]-. ILs toxicity/inhibition was determined by adding a biodegradable compound and measuring the sludge response after being in contact with the ILs for at least 15 h. The exposure of sewage sludge to ILs for more than 15 min used in short inhibition assays caused more toxic effect on microorganisms, even for [Choline][NTf2], previously defined as practically harmless (EC50 = 2.79 mM). Biodegradability assays confirmed the biodegradable nature of choline cation, related with TOC conversion of 40%, only due to cation consumption. No oxygen consumption or even lysis of microbial cells was observed for Tetrabutylammonium bis(trifluoromethylsulfonyl)imide and for 1-Ethyl-3-methylimidazolium hydrogensulphate due to the presence of anions previously defined as hazardous ([NTf2]- and [HSO4]-), maintaining their recalcitrant character to sewage systems.


Assuntos
Imidazóis/toxicidade , Líquidos Iônicos/toxicidade , Esgotos/microbiologia , Ânions , Biodegradação Ambiental , Cátions , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Líquidos Iônicos/química , Estrutura Molecular
7.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1130-1131: 121833, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31670105

RESUMO

In this work, a novel type of mesoporous magnetic nanocomposite (Fe3O4@PDA@TiO2@Cu3(BTC)2) was prepared by one-step method with ionic liquid (ILs) as solvent. ILs was used as templates for fabrication the porous material as well as green solvent. The material showed good sensitivity (1 fmol), excellent selectivity (molar ratio of phosphopeptides/non-phosphopeptides up to1:1000) and good repeatability (5 cycles) towards phosphopeptides. Furthermore, it has been applied to the enrichment of phosphopeptides in human saliva and human serum, 29 and 4 endogenous phosphopeptides were detected, respectively.


Assuntos
Óxido Ferroso-Férrico/química , Nanocompostos/química , Fosfopeptídeos/análise , Fosfopeptídeos/isolamento & purificação , Química Verde , Humanos , Líquidos Iônicos/química , Espectrometria de Massas , Saliva/química
8.
Org Biomol Chem ; 17(45): 9778-9791, 2019 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-31701105

RESUMO

This study investigates the synthesis of ß-branched amines and ß-branched quaternary ammonium chloride ionic liquids as novel extractants. The synthesis methodology was tailored to facilitate the reaction scale-up and the use of biorenewable starting materials. The developed process is an overall green, easy and straightforward synthesis of ß-branched amines, and ammonium salts, starting from linear aldehydes. In order to evaluate the potential of the synthesised materials in applications, the rheology, density, thermal stability, chemical stability, phase transitions, and mutual solubility with water of the novel extractants was studied.


Assuntos
Líquidos Iônicos/síntese química , Compostos de Amônio Quaternário/síntese química , Aminas/síntese química , Aminas/química , Interações Hidrofóbicas e Hidrofílicas , Líquidos Iônicos/química , Estrutura Molecular , Compostos de Amônio Quaternário/química , Solubilidade , Água/química
9.
Anal Bioanal Chem ; 411(28): 7461-7472, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31616968

RESUMO

Five commercial ionic liquid (IL) columns have been evaluated for the first time for the gas chromatography-mass spectrometry (GC-MS) analysis of low molecular weight carbohydrate (LMWC) standards (mono-, di-, and trisaccharides, inositols, and iminosugars). A previous derivatization step was necessary to convert the LMWCs into their volatile and stable derivatives. Compared with conventional GC stationary phases, such as HP-1 and Supelcowax® 10, IL columns have shown a different selectivity in the separation of target compounds. Among the IL columns, only SLB™-IL82 allowed the elution of all the LMWCs studied. Its performance in terms of peak width and asymmetry, evaluated under different oven temperature conditions, was shown to be dependent on the carbohydrate class considered. As an example of application, a SLB™-IL82 column was successfully used to separate the complex mixtures of LMWCs in hyacinth and mulberry extracts. This column is an interesting alternative to the conventional stationary phases used in the GC analysis of LMWCs in real-world samples. Graphical abstract.


Assuntos
Carboidratos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Líquidos Iônicos/química , Extratos Vegetais/química , Temperatura Ambiente
10.
Ecotoxicol Environ Saf ; 186: 109784, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31634657

RESUMO

Surface-active ionic liquids (SAILs) belonging to the series of N-alkylmethylimidazolium halides [C8mimX] (X = Br, Cl, and BF4) and [CnmimBr] (n = 10, 12, 14, and 16) were employed to understand the influence of hydrophobicity of alkyl chain length and the chaotropicity of counter-ions of SAILs on the micellization, antimicrobial action and cytotoxicity properties. The micellization phenomenon of SAILs in an aqueous environment was examined employing tensiometry and steady-state fluorescence spectrophotometry. The corresponding interfacial parameters viz., critical micelle concentration (CMC), effectiveness (γCMC), surface pressure (ПCMC), maximum surface excess concentration (Гmax), and the minimum area engaged per molecule (Amin) at the air-water interface were evaluated at 303.15 K. These experimental findings were monitored and geometrically optimized theoretically using Gaussian software to highlight the recent advances in this field of theoretical calculations for putative structure. The simulation descriptors correlated the micellization behavior as a function of hydrophobicity which may contribute to obtaining awareness on their ecological behavior and fate. In addition, the biological screening of all the examined SAILs was undertaken with a combined experimental and theoretical (optimized) method against bacteria and fungus. Results revealed that SAILs with the alkyl chain-length greater than C8- act as a fair antimicrobial agent against the selected microbial strain which is attributed to the enhanced degree of SAILs hydrophobicity. The cytotoxicity of these imidazolium-based SAILs was also assessed on the cervical human cell line (HeLa) using the MTT cell viability assay and the data thus obtained were subjected to statistical analysis.


Assuntos
Líquidos Iônicos/química , Tensoativos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Líquidos Iônicos/farmacologia , Micelas , Tensoativos/farmacologia , Água/química
11.
AAPS PharmSciTech ; 20(8): 322, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31650263

RESUMO

The objectives of this work were to prepare a 5 wt% lidocaine-diclofenac ionic liquid drug-loaded gelatin/poly(vinyl alcohol) transdermal patch using a freeze/thaw method and to evaluate its physicochemical properties, in vitro release of lidocaine and diclofenac, and stability test. The lidocaine-diclofenac ionic liquid drug was produced by the ion pair reaction between the hydrochloride salts of lidocaine and the sodium salts of diclofenac. The thermal properties of the final drug product were significantly changed from the primary drugs. The ionic liquid drug could be dissolved in water and mixed in a polymer solution. The resulting transdermal patch was then exposed to 10 cycles of freezing and thawing preparation at - 20°C for 8 h and at 25°C for 4 h, respectively. As a result, it was found that the lidocaine-diclofenac ionic liquid drug-loaded transdermal patch showed good physicochemical properties and could feasibly be used in pharmaceutical applications. The lidocaine-diclofenac ionic liquid drug was not affected by the properties of the transdermal patch due to the lack of chemical interaction between polymer base and drug. The high drug release values of both lidocaine and diclofenac were controlled by the gelatin/poly(vinyl alcohol) transdermal patch. The patch showed good stability over the study period of 3 months when kept at 4°C or under ambient temperature.


Assuntos
Diclofenaco/farmacocinética , Gelatina/farmacocinética , Líquidos Iônicos/farmacocinética , Lidocaína/farmacocinética , Álcool de Polivinil/farmacocinética , Adesivo Transdérmico , Administração Cutânea , Anestésicos Locais/química , Anestésicos Locais/farmacocinética , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacocinética , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Diclofenaco/química , Combinação de Medicamentos , Liberação Controlada de Fármacos , Congelamento , Gelatina/química , Líquidos Iônicos/química , Lidocaína/química , Álcool de Polivinil/química
12.
Top Curr Chem (Cham) ; 377(6): 30, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31628623

RESUMO

Ionic liquids (ILs) are considered as highly useful materials for potential diverse uses such as greener and more convenient alternatives to volatile organic solvents, reagents, additives, ligands and co-solvents. Thermal stability, negligible vapor pressure and high polarity with ionic environments have possibly conferred some unique physico-chemical properties and a wider electrochemical window on ILs. More importantly, these properties are tuneable, depending on variations in alkyl chains and counter-anions. On the other hand, various transition-metal-catalyzed cross-coupling reactions constitute an important backbone of contemporary organic synthesis. A vast number of C-C and C-heteroatom cross-coupling reactions are reported in the presence of ILs, often showing better performance. The influence of IL on the action of a given catalyst or on the course of a reaction can be relatively complex, and is not understood well enough to be able to draw succinct conclusions. However, there are a few reports in the literature that help understand the role of actual and active catalytic species stabilized in an IL environment. Stabilization, which can be either helpful or detrimental to catalysis depends on specific circumstances. This review article is aimed primarily at summarizing the various applications of ILs during the past decade, focusing as far as possible on the task-specific properties of ILs in transition-metal-catalyzed C-C and C-heteroatom cross-coupling reactions. Several successful achievements and noteworthy progress in this field of research leads to the sensible conclusion that future prospects in this field of research are not only bright but promise new horizons.


Assuntos
Líquidos Iônicos/química , Catálise , Compostos Heterocíclicos/química , Ligantes , Metano/análogos & derivados , Metano/química , Solventes/química , Elementos de Transição/química
13.
Phys Chem Chem Phys ; 21(42): 23269-23282, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31621726

RESUMO

Ionic liquids (ILs) present a vast number of solvents capable of replacing toxic organic solvents in chemical, biotechnology and biomedical applications. ILs are inexpensive and environmentally friendly as the materials can be recycled conveniently. Chemists use a variety of cation and anion combinations to produce an IL that fits the requirements of the sustainable future through the pursuit of greener chemical processes. As such, the development of various types of ILs has been recognized as the emergence of environmentally friendly solvents to attain enhanced protein stability in vitro. The literature survey reveals that there exist a large number of scholarly articles as well as elegant reviews on protein stability in ILs. Biomolecules have adapted to antagonistic environmental stresses that normally denature proteins, and the mechanism of adaptation that protects the cellular components against denaturation involves the intracellular concentration of co-solvents. In this regard, recent experimental results distinctly demonstrated that ILs are stabilizing proteins against denaturing stresses, and their presence in the cells does not alter protein functional activities. However, a review focusing particularly on the refolding and counteracting effects of the ILs against denatured proteins by multiple stresses is still missing. This perspective unveils the studies that have been conducted to improve protein stabilities with ILs as well as the refolding and counteracting abilities of these ILs against the denatured proteins under the influence of multiple stresses. We believe that ILs can provide significant environmental and economic advantages for biochemical processes in the near future. Essentially, numerous investigations are required to allow us to further explore the stabilizing properties of ILs over proteins.


Assuntos
Líquidos Iônicos/química , Proteínas/química , Solventes/química , Cristalização , Muramidase/química , Muramidase/metabolismo , Mioglobina/química , Mioglobina/metabolismo , Redobramento de Proteína , Estabilidade Proteica , Proteínas/metabolismo , Temperatura de Transição
14.
Anal Bioanal Chem ; 411(28): 7375-7385, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31655857

RESUMO

A new class of magnetic ionic liquids (MILs) with metal-containing cations was applied in in situ dispersive liquid-liquid microextraction (DLLME) for the extraction of long and short double-stranded DNA. For developing the method, MILs comprised of N-substituted imidazole ligands (with butyl-, benzyl-, or octyl-groups as substituents) coordinated to different metal centers (Ni2+, Mn2+, or Co2+) as cations, and chloride anions were investigated. These water-soluble MILs were reacted with the bis[(trifluoromethyl)sulfonyl]imide anion during the extraction to generate a water-immiscible MIL capable of preconcentrating DNA. The feasibility of combining the extraction methodology with anion-exchange high-performance liquid chromatography with diode array detection (HPLC-DAD) or fluorescence spectroscopy was studied. The method with the Ni2+- and Co2+-based MILs was easily combined with fluorescence spectroscopy and provided a faster and more sensitive method than HPLC-DAD for the determination of DNA. In addition, the method was compared to conventional DLLME using analogous water-immiscible MILs. The developed in situ MIL-DLLME method required only 3 min for DNA extraction and yielded 1.1-1.5 times higher extraction efficiency (EFs) than the conventional MIL-DLLME method. The in situ MIL-DLLME method was also compared to the trihexyl(tetradecyl)phosphonium tris(hexafluorocetylaceto)nickelate(II) MIL, which has been used in previous DNA extraction studies. EFs of 42-99% were obtained using the new generation of MILs, whereas EFs of only 20-38% were achieved with the phosphonium MIL. This new class of MILs is simple and inexpensive to prepare. In addition, the MILs present operational advantages such as easier manipulation in comparison to hydrophobic MILs, which can have high viscosities. These MILs are a promising new class of DNA extraction solvents that can be manipulated using an external magnetic field. Graphical abstract Magnetic ionic liquids with metal-containing cations are applied in in situ dispersive liquid-liquid microextraction for the extraction of long and short double-stranded DNA.


Assuntos
DNA/isolamento & purificação , Líquidos Iônicos/química , Microextração em Fase Líquida/métodos , Magnetismo , Metais/análise , Água/química
15.
Environ Sci Pollut Res Int ; 26(32): 33260-33268, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31520374

RESUMO

Waste printed circuit boards (WPCBs) are usually dismantled, crushed, and sorted to WPCB metal-enriched scraps, still containing an amount of non-metallic materials. This research used slurry electrolysis to refine these WPCB metal-enriched scraps and to examine if a standard ionic liquid, [MIm]HSO4, can replace H2SO4 in the system. The impact of the refinement process on metal migration and transformation is discussed in detail. The results demonstrated that metals in WPCB metal-enriched scraps could be successfully refined using slurry electrolysis, and [MIm]HSO4 can be used to replace H2SO4 in the system. When 80% of H2SO4 was replaced by [MIm]HSO4 (electrolyte of 200 mL, 30 g/L CuSO4·5H2O, 60 g/L NaCl, 130 g/L H2SO4, and 1.624 A for 4 h), the total metal recovery rate is 85%, and the purity, current efficiency, and particle size of cathode metal powder were 89%, 52%, and 3.77 µm, respectively. Moreover, the microstructure of the cathode metal powder was dendritic in the H2SO4-CuSO4-NaCl slurry electrolysis system, whereas at an 80% [MIm]HSO4 substitution rate slurry electrolysis system, the cathode metal powder was irregular and accumulated as small-sized spherical particles. Thus, replacing inorganic leaching solvents with ionic liquids may provide a potential choice for the resources in WPCB metal-enriched scraps.


Assuntos
Resíduo Eletrônico/análise , Líquidos Iônicos/química , Metais/análise , Cobre/química , Eletrólise , Eletrólitos , Íons , Tamanho da Partícula , Solventes
16.
J Agric Food Chem ; 67(40): 11018-11024, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31512873

RESUMO

In this study, nine pyrimethanil ionic liquids (PILs) were synthesized through an acid-base reaction with nine naturally derived organic acid anions to improve the physicochemical properties and reduce the environmental adverse impacts. The PILs presented lower volatilization, higher photostability, better soil adsorption capacity, and improved fungicidal activity relative to pyrimethanil. When the length of the carbon chains in the anions was increased, the PILs showed better properties in terms of melting point, water solubility, volatility, and surface tension. The photostabilities and fungicidal activities of the PILs were significantly improved when cyclic compounds were used as the paired anion ions. With enhanced physicochemical properties and better fungicidal activity, PIL7 was selected as the best alternative to pyrimethanil. The intrinsic disadvantages of pyrimethanil could be surmounted using the system developed in the study; thus, ILs could have immense potential in the development of eco-friendly and efficient fungicides in the future.


Assuntos
Fungicidas Industriais/química , Líquidos Iônicos/química , Compostos Orgânicos/química , Pirimidinas/química , Adsorção , Ânions/química , Ânions/farmacologia , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Fungicidas Industriais/síntese química , Fungicidas Industriais/farmacologia , Líquidos Iônicos/farmacologia , Cinética , Compostos Orgânicos/farmacologia , Pirimidinas/farmacologia , Solo/química , Solubilidade , Volatilização
17.
Top Curr Chem (Cham) ; 377(5): 26, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529210

RESUMO

Lignin, one of the main components of lignocellulosic biomass, is the largest renewable source of aromatics on the planet and presents an extraordinary opportunity for being used in the production of bio-based products. It can be transformed for the substitution of aromatic chemical-derived petrol as BTXs. The wide range of applications that it can be obtained from BTXs building blocks makes the selective depolymerization of lignin a great scientific challenge. This review emphasizes the different strategies for the fragmentation of lignin to monomers or aromatics hydrocarbons. Thus, a by-product traditionally discarded or used for energy generation, it could be valorized into high added-value products.


Assuntos
Benzeno/química , Lignina/química , Tolueno/química , Xilenos/química , Líquidos Iônicos/química , Estrutura Molecular , Polimerização
18.
Molecules ; 24(18)2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487951

RESUMO

To obtain highly selective toxic derivatives of fipronil, a series of Schiff bases with an alkynyl group (3a-3k) were designed and synthesized from 4-ethynylbenzaldehyde (2) and 4-substituted 5-amino-N-arylpyrazole (1a-1k) via a nucleophilic addition elimination reaction in ionic liquids. Utilization of ionic liquids was demonstrated to endow the yield of each compound beyond 50%, which was enhanced over 1.5 times of the synthetic productive rates comparing the conventional method by which longer reactive time was consumed. The derivatives were characterized via nuclear magnetic resonance hydrogen spectroscopy (1H-NMR), carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR), and electrospray ionization high resolution mass spectrometry (ESI-HRMS). The cytotoxicity of these derivatives on Trichoplusia ni (Hi-5) cell and Spodoptera litura cell (SL cell) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) bioassays. The results indicated that several compounds had potential cytotoxicity on Hi-5 cell, especially a 4-ethyl substituted alkynyl Schiff base derivative (3f) that was demonstrated to possess high selective toxicity to the Hi-5 cell than the SL cell. In addition, 3f exhibited comparable toxic activity to commercial fipronil on a Hi-5 cell while a little toxic effect on the SL cell, which satisfied the expectation for selective toxicity screening.


Assuntos
Líquidos Iônicos/química , Pirazóis/síntese química , Pirazóis/farmacologia , Bases de Schiff/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética , Humanos , Estrutura Molecular , Bases de Schiff/síntese química
19.
Ecotoxicol Environ Saf ; 184: 109580, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31493585

RESUMO

Ionic Liquids (ILs) are generically regarded as environmentally "harmless" and thus, assumed as "non-toxic". However, due to the endless design possibilities, their ecotoxicological profile is still poorly known. An accurate knowledge on the toxicity of a substance is required, under the scope of environmental regulation worldwide, before their application and commercialization. Knowledge on the relationship between the chemical structure and toxic effects is essential for the future design of more biocompatible solvents. Focusing on the use of ILs as base lubricants, lubricant additives, or even as potential working fluids for absorption heat pumps, the knowledge on its environmental impact is of great importance, due to the possibility of spills. In this specific context, four analogues of glycine-betaine-based ILs (AGB-ILs) and four glycine-betaine based ILs (GB-ILs) were synthesized and characterized. Their ecotoxicity was assessed using representatives of two trophic levels in aquatic ecosystems, the bacteria Allivibrio fischeri (commonly used as a screening test organism) and the microalgae Raphidocelis subcapitata (as an alternative test organism that has been proven very sensitive to several IL families). The microalgae were more sensitive than the bacteria, hence, following a precautionary principle, we recommend considering the toxicity towards microalgae as an indicator in future studies regarding the focused ILs. Although four of the studied ILs were derived from a natural amino acid, all were considered hazardous for the aquatic environment, disproving the primary theory that all ILs derived from natural compounds are benign. Furthermore, the modification in the structure of anion and the cation can lead to the increase of toxicity.


Assuntos
Betaína/química , Glicina/química , Líquidos Iônicos/toxicidade , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Ânions/química , Cátions/química , Clorofíceas/efeitos dos fármacos , Ecotoxicologia , Biomarcadores Ambientais/efeitos dos fármacos , Líquidos Iônicos/síntese química , Líquidos Iônicos/química , Poluentes Químicos da Água/síntese química , Poluentes Químicos da Água/química
20.
Anal Chim Acta ; 1083: 110-118, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31493801

RESUMO

A paper-based analytical device (PAD) with an integrated composite electrode for non-enzymatic creatinine sensing was developed. The electrode was produced and optimization was efficiently accomplished using a rapid digital dispensing approach. The electrochemical sensor was fabricated using an HP D300 digital dispenser to deliver a copper oxide and ionic liquid composite onto an electrochemically reduced graphene modified screen-printed carbon electrode (CuO/IL/ERGO/SPCE) on a PAD. The modified electrode was characterized using electrochemical and microscopic techniques. Electrochemical detection of creatinine was performed on the SPCE using amperometry at a constant potential. Under optimized conditions, the paper-based sensor exhibited a linear range of 0.01-2.0 mM (R2 = 0.99) and the limit of detection was 0.22 µM (S/N = 3, IUPAC definition) for creatinine. The simple fabrication process, low cost, and clinically appropriate creatinine sensitivity make this device applicable for point-of-care use.


Assuntos
Cobre/química , Creatinina/sangue , Grafite/química , Líquidos Iônicos/química , Papel , Carbono/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Reprodutibilidade dos Testes
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