RESUMO
While thiocarbonyl-stabilised phosphonium ylides generally react upon flash vacuum pyrolysis by the extrusion of Ph3PS to give alkynes in an analogous way to their carbonyl-stabilised analogues, two examples with a hydrogen atom on the ylidic carbon are found to undergo a quite different process. The net transfer of a phenyl group from P to S gives (Z)-configured 1-diphenylphosphino-2-(phenylsulfenyl)alkenes in a novel isomerisation process via intermediate λ5-1,2-thiaphosphetes. These prove to be versatile hemilabile ligands with a total of seven complexes prepared involving five different transition metals. Four of these are characterised by X-ray diffraction with two involving the bidentate ligand forming a five-membered ring metallacycle and two with the ligand coordinating to the metal only through phosphorus.
RESUMO
The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of -23 mV, compared to -12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.
Assuntos
Azul de Metileno/química , Modelos Químicos , Nanotubos/química , Titânio/química , Adsorção , CinéticaRESUMO
Two models for self-assembled dopamine on the surface of trititanate nanotubes are proposed: individual monomer units linked by π-π stacking of the aromatic regions and mono-attached units interacting through hydrogen bonds. This was investigated with solid state NMR spectroscopy studies and powder X-ray diffraction.
Assuntos
Dopamina/química , Nanotubos/química , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Difração de Raios XRESUMO
Photothermal conversion represents one crucial approach for solar energy harvesting and its exploitation as a sustainable alternative to fossil fuels; however, an efficient, cost-effective, and generalized approach to enhance the photothermal conversion processes is still missing. Herein, we develop a feasible and efficient photothermal conversion strategy that achieves simultaneous light and heat management using supported metal clusters and WSe2 interlayer toward enhanced CO2 hydrogenation photothermal catalysis. The interlayer can simultaneously reduce heat loss in the catalytic layer and improve light absorption, leading to an 8-fold higher CO2 conversion rate than the controls. The optical and thermal performance of WSe2 interlayered catalysts on different substrates was quantified using Raman spectroscopy. This work demonstrates a feasible and generalized approach for effective light and heat management in solar harvesting. It also provides important design guidelines for efficient photothermal converters that facilitate the remediation of the energy and environmental crises faced by humans.
RESUMO
A series of potent carboxylic acid DGAT1 inhibitors with high permeability were developed from a virtual screening hit. Strategies were employed to reduce Pgp substrate recognition and increase passive permeability, resulting in the discovery of a series showing good inhibition of cellular triglyceride synthesis. The mutagenic potential of prospective metabolites was evaluated in the Ames assay, and one aniline was shown to be devoid of mutagenicity.
Assuntos
Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Células CACO-2 , Diacilglicerol O-Aciltransferase/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Estrutura Molecular , Permeabilidade/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Substituted azaquinazolinones were identified as antagonists of the GHSr-1A receptor for the treatment of type II diabetes and obesity. Optimisation for potency and LogD lead to the identification of orally bioavailable, potent antagonists with improved selectivity over hERG.
Assuntos
Compostos Aza/síntese química , Hipoglicemiantes/síntese química , Quinazolinonas/síntese química , Receptores de Grelina/antagonistas & inibidores , Administração Oral , Animais , Compostos Aza/farmacocinética , Compostos Aza/farmacologia , Disponibilidade Biológica , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Desenho de Fármacos , Canais de Potássio Éter-A-Go-Go/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/farmacologia , Cinética , Masculino , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Quinazolinonas/farmacocinética , Quinazolinonas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Grelina/metabolismo , Relação Estrutura-AtividadeRESUMO
Tungsten oxide nanorods were prepared from commercial crystalline WO(3) particles treated with triethylamine under electron beam irradiation in an electron microscope operating at 200 kV. The amine acts as a molecular knife, cleaving the particles under beam irradiation.
RESUMO
A novel Cu2O-Au-BFO heterostructure photocathode was constructed which significantly improved the efficiency of photo-generated carrier transfer for solar hydrogen production. A BiFeO3 (BFO) ferroelectric film was synthesized on top of a Cu2O layer by a sputtering process. The BFO layer acted to protect the Cu2O layer from photochemical corrosion, increasing photoelectrochemical (PEC) stability. The p-n heterojunction between Cu2O and BFO layers enhanced the PEC properties by suppressing charge recombination and improved interfacial charge transfer efficiency. When Cu2O and BFO are interfaced by Au Nanoparticles (NPs) the PEC performance was further enhanced, due to hot-electron transfer at the plasmonic resonance. After positive poling, the depolarization field across the whole volume of BFO film drove electrons into the electrolyte solution, inducing a significant anodic shift, Vop of 1.01 V vs. RHE, together with a significantly enhanced photocurrent density of -91 µA/cm2 at 0 V vs. RHE under 100 mW/cm2 illumination. The mechanism was investigated through experimental and theoretivcal calculations.
RESUMO
An X-ray crystal structure of Kelch-like ECH-associated protein (Keap1) co-crystallised with (1S,2R)-2-[(1S)-1-[(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)methyl]-1,2,3,4-tetrahydroisoquinolin-2-carbonyl]cyclohexane-1-carboxylic acid (compound (S,R,S)-1 a) was obtained. This X-ray crystal structure provides breakthrough experimental evidence for the true binding mode of the hit compound (S,R,S)-1 a, as the ligand orientation was found to differ from that of the initial docking model, which was available at the start of the project. Crystallographic elucidation of this binding mode helped to focus and drive the drug design process more effectively and efficiently.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas do Citoesqueleto/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Isoquinolinas/farmacologia , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Ftalimidas/farmacologia , Animais , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/síntese química , Isoquinolinas/química , Proteína 1 Associada a ECH Semelhante a Kelch , Camundongos , Modelos Moleculares , Estrutura Molecular , Ftalimidas/síntese química , Ftalimidas/química , Relação Estrutura-AtividadeRESUMO
Three forms of nano-trititanate (H(2)Ti(3)O(7) nanomaterial) were prepared by a hydrothermal method to replace nano-TiO(2) for sterilizing the environment. The bactericidal capabilities of these nano-trititanates were observed to be more significant compared to nano-TiO(2) both with and without exposure to UV light. For the future commercial applications of those nano-trititanates, we investigated their cytotoxicity and genotoxicity to HEp-2 cells. As data in our study shows, nanoplate, one of the nano-trititanates, possesses the lowest toxicity to HEp-2 cells. The results indicated that the shape and length of the material only affect the toxicity of nano-trititanate but not its bactericidal effect. Thus, through manipulating the shape or length of nano-trititanate, we may obtain a more powerful bactericidal reagent with lower toxicity to the human body.
Assuntos
Antibacterianos/toxicidade , Dano ao DNA , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Óxidos/toxicidade , Titânio/toxicidade , Antibacterianos/química , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Humanos , Microscopia Eletrônica de Transmissão , Mutagênicos/química , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Óxidos/química , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície , Titânio/química , Testes de Toxicidade/métodos , Difração de Raios XRESUMO
While thermolysis of thiocarbonyl-stabilised phosphonium ylides generally results in extrusion of Ph(3)PS to give alkynes, those with a P=CH function instead undergo a novel P to S transfer of a phenyl group to give (Z)-configured 1-phosphino-2-sulfenylalkenes of interest as bidentate ligands.