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1.
Molecules ; 26(9)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33923006

RESUMO

Phosphine-borane complexes are novel chemical entities with preclinical efficacy in neuronal and ophthalmic disease models. In vitro and in vivo studies showed that the metabolites of these compounds are capable of cleaving disulfide bonds implicated in the downstream effects of axonal injury. A difficulty in using standard in silico methods for studying these drugs is that most computational tools are not designed for borane-containing compounds. Using in silico and machine learning methodologies, the absorption-distribution properties of these unique compounds were assessed. Features examined with in silico methods included cellular permeability, octanol-water partition coefficient, blood-brain barrier permeability, oral absorption and serum protein binding. The resultant neural networks demonstrated an appropriate level of accuracy and were comparable to existing in silico methodologies. Specifically, they were able to reliably predict pharmacokinetic features of known boron-containing compounds. These methods predicted that phosphine-borane compounds and their metabolites meet the necessary pharmacokinetic features for orally active drug candidates. This study showed that the combination of standard in silico predictive and machine learning models with neural networks is effective in predicting pharmacokinetic features of novel boron-containing compounds as neuroprotective drugs.


Assuntos
Boranos/química , Aprendizado de Máquina , Fármacos Neuroprotetores/química , Fosfinas/química , Barreira Hematoencefálica/efeitos dos fármacos , Boranos/farmacologia , Simulação por Computador , Humanos , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fosfinas/farmacologia , Ligação Proteica/efeitos dos fármacos
2.
Biochem Biophys Res Commun ; 539: 15-19, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33412416

RESUMO

BACKGROUND: Treatment of neurodegenerative diseases, such as Parkinson's disease, Huntington's chorea, Alzheimer's disease, is one of the priority directions in modern medicine. Thus, search and production of new physiologically active substances for the treatment of neurodegenerative disorders is one of the most important tasks for organic chemistry. The approach based on the replacement of a peptide bond in a peptide molecule with a structural isostere, non-hydrolyzable methylene phosphoryl fragment makes it possible to increase the metabolic stability of peptide molecules to the destructive action of peptidases. METHODS: This work is devoted to the approbation of a new synthetic approach to the production of physiologically active substances in a series of peptide-type compounds with activity by replacing the peptide bond with isosteric methylene-phosphoryl fragment with the preservation of the original amino acid sequence. RESULTS: A phosphine analog of the known physiologically active tripeptide proline-glycine-proline was obtained, cytotoxicity and neuroprotective properties of the initial tripeptide and its phosphine analog were studied. CONCLUSION: Preliminary biological tests have shown that the obtained phosphine analog of the proline-glycine-proline tripeptide is involved in modulating the formation of sediments in the cellular system of proteinopathy, which may indicate their potential antiaggregatory properties.


Assuntos
Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Oligopeptídeos/farmacologia , Fosfinas/química , Prolina/análogos & derivados , Agregação Patológica de Proteínas/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/química , Oligopeptídeos/química , Fosfinas/farmacologia , Prolina/química , Prolina/farmacologia , Agregação Patológica de Proteínas/metabolismo
3.
Nat Protoc ; 15(10): 3527-3555, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32968252

RESUMO

Solid acid catalysts are used extensively in various advanced chemical and petrochemical processes. Their catalytic performance (namely, activity, selectivity, and reaction pathway) mostly depends on their acid properties, such as type (Brønsted versus Lewis), location, concentration, and strength, as well as the spatial correlations of their acid sites. Among the diverse methods available for acidity characterization, solid-state nuclear magnetic resonance (SSNMR) techniques have been recognized as the most valuable and reliable tool, especially in conjunction with suitable probe molecules that possess observable nuclei with desirable properties. Taking 31P probe molecules as an example, both trimethylphosphine (TMP) and trimethylphosphine oxide (TMPO) adsorb preferentially to the acid sites on solid catalysts and thus are capable of providing qualitative and quantitative information for both Brønsted and Lewis acid sites. This protocol describes procedures for (i) the pretreatment of typical solid acid catalysts, (ii) adoption and adsorption of various 31P probe molecules, (iii) considerations for one- and two-dimensional (1D and 2D, respectively) NMR acquisition, (iv) relevant data analysis and spectral assignment, and (v) methodology for NMR mapping with the assistance of theoretical calculations. Users familiar with SSNMR experiments can complete 31P-1H heteronuclear correlation (HETCOR), 31P-31P proton-driven spin diffusion (PDSD), and double-quantum (DQ) homonuclear correlation with this protocol within 2-3 d, depending on the complexity and the accessible acid sites of the solid acid samples.


Assuntos
Ácidos/química , Catálise , Ressonância Magnética Nuclear Biomolecular/métodos , Imagem por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares , Fosfinas/química , Prótons
4.
J Med Chem ; 63(13): 7081-7107, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32479078

RESUMO

Phosphine oxides and related phosphorus-containing functional groups such as phosphonates and phosphinates are established structural motifs that are still underrepresented in today's drug discovery projects, and only few examples can be found among approved drugs. In this account, the physicochemical and in vitro properties of phosphine oxides and related phosphorus-containing functional groups are reported and compared to more commonly used structural motifs in drug discovery. Furthermore, the impact on the physicochemical properties of a real drug scaffold is exemplified by a series of phosphorus-containing analogs of imatinib. We demonstrate that phosphine oxides are highly polar functional groups leading to high solubility and metabolic stability but occasionally at the cost of reduced permeability. We conclude that phosphine oxides and related phosphorus-containing functional groups are valuable polar structural elements and that they deserve to be considered as a routine part of every medicinal chemist's toolbox.


Assuntos
Fenômenos Químicos , Desenho de Fármacos , Óxidos/química , Fosfinas/química , Células CACO-2 , Química Farmacêutica , Estabilidade de Medicamentos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Óxidos/metabolismo , Permeabilidade
5.
Int J Nanomedicine ; 15: 1951-1965, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256071

RESUMO

Introduction: Indium phosphide (InP) quantum dots (QDs) have shown a broad application prospect in the fields of biophotonics and nanomedicine. However, the potential toxicity of InP QDs has not been systematically evaluated. In particular, the effects of different surface modifications on the biodistribution and toxicity of InP QDs are still unknown, which hinders their further developments. The present study aims to investigate the biodistribution and in vivo toxicity of InP/ZnS QDs. Methods: Three kinds of InP/ZnS QDs with different surface modifications, hQDs (QDs-OH), aQDs (QDs-NH2), and cQDs (QDs-COOH) were intravenously injected into BALB/c mice at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively. Biodistribution of three QDs was determined through cryosection fluorescence microscopy and ICP-MS analysis. The subsequent effects of InP/ZnS QDs on histopathology, hematology and blood biochemistry were evaluated at 1, 3, 7, 14 and 28 days post-injection. Results: These types of InP/ZnS QDs were rapidly distributed in the major organs of mice, mainly in the liver and spleen, and lasted for 28 days. No abnormal behavior, weight change or organ index were observed during the whole observation period, except that 2 mice died on Day 1 after 25 mg/kg BW hQDs treatment. The results of H&E staining showed that no obvious histopathological abnormalities were observed in the main organs (including heart, liver, spleen, lung, kidney, and brain) of all mice injected with different surface-functionalized QDs. Low concentration exposure of three QDs hardly caused obvious toxicity, while high concentration exposure of the three QDs could cause some changes in hematological parameters or biochemical parameters related to liver function or cardiac function. More attention needs to be paid on cQDs as high-dose exposure of cQDs induced death, acute inflammatory reaction and slight changes in liver function in mice. Conclusion: The surface modification and exposure dose can influence the biological behavior and in vivo toxicity of QDs. The surface chemistry should be fully considered in the design of InP-based QDs for their biomedical applications.


Assuntos
Pontos Quânticos/toxicidade , Animais , Análise Química do Sangue , Feminino , Índio/química , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Fosfinas/química , Pontos Quânticos/química , Sulfetos/química , Propriedades de Superfície , Distribuição Tecidual , Compostos de Zinco/química
6.
Dalton Trans ; 49(14): 4225-4229, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32196051

RESUMO

Readily available phosphinoferrocene guanidines coordinate Pd(ii) as P,N-chelating or κ3P,N,Fe-bound ligands. As the latter, they give rise to the first donor-asymmetric complexes featuring Fe-Pd dative bonds, which were studied using direct (spectroscopic and electrochemical) methods and theoretical (DFT) approaches.


Assuntos
Complexos de Coordenação/síntese química , Compostos Ferrosos/química , Metalocenos/química , Paládio/química , Fosfinas/química , Complexos de Coordenação/química , Teoria da Densidade Funcional , Técnicas Eletroquímicas , Ligantes , Estrutura Molecular , Espectrofotometria Ultravioleta
7.
Molecules ; 25(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204399

RESUMO

Modern solid-state NMR techniques offer a wide range of opportunities for the structural characterization of frustrated Lewis pairs (FLPs), their aggregates, and the products of cooperative addition reactions at their two Lewis centers. This information is extremely valuable for materials that elude structural characterization by X-ray diffraction because of their nanocrystalline or amorphous character, (pseudo-)polymorphism, or other types of disordering phenomena inherent in the solid state. Aside from simple chemical shift measurements using single-pulse or cross-polarization/magic-angle spinning NMR detection techniques, the availability of advanced multidimensional and double-resonance NMR methods greatly deepened the informational content of these experiments. In particular, methods quantifying the magnetic dipole-dipole interaction strengths and indirect spin-spin interactions prove useful for the measurement of intermolecular association, connectivity, assessment of FLP-ligand distributions, and the stereochemistry of adducts. The present review illustrates several important solid-state NMR methods with some insightful applications to open questions in FLP chemistry, with a particular focus on supramolecular associates.


Assuntos
Boranos/química , Fosfinas/química , Reação de Cicloadição , Bases de Lewis/química , Ressonância Magnética Nuclear Biomolecular
8.
Molecules ; 25(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204523

RESUMO

An extensive series of 128 halogen-bonded complexes formed by trimethylphosphine oxide and various F-, Cl-, Br-, I- and At-containing molecules, ranging in energy from 0 to 124 kJ/mol, is studied by DFT calculations in vacuum. The results reveal correlations between R-X⋅⋅⋅O=PMe3 halogen bond energy ΔE, X⋅⋅⋅O distance r, halogen's σ-hole size, QTAIM parameters at halogen bond critical point and changes of spectroscopic parameters of phosphine oxide upon complexation, such as 31P NMR chemical shift, ΔδP, and P=O stretching frequency, Δν. Some of the correlations are halogen-specific, i.e., different for F, Cl, Br, I and At, such as ΔE(r), while others are general, i.e., fulfilled for the whole set of complexes at once, such as ΔE(ΔδP). The proposed correlations could be used to estimate the halogen bond properties in disordered media (liquids, solutions, polymers, glasses) from the corresponding NMR and IR spectra.


Assuntos
Halogênios/química , Fosfinas/química , Teoria da Densidade Funcional , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Eletricidade Estática
9.
Molecules ; 25(3)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041130

RESUMO

The reactions of the PMe3 adduct of the silylated germylene [(Me3Si)3Si]2Ge: with GeCl2·dioxane were found to yield 1,1-migratory insertion products of GeCl2 into one or two Ge-Si bonds. In a related reaction, a germylene was inserted with tris(trimethylsilyl)silyl and vinyl substituents into a Ge-Cl bond of GeCl2. This was followed by intramolecular trimethylsilyl chloride elimination to another cyclic germylene PMe3 adduct. The reaction of the GeCl2 mono-insertion product (Me3Si)3SiGe:GeCl2Si(SiMe3)3 with Me3SiC≡CH gave a mixture of alkyne mono- and diinsertion products. While the reaction of a divinylgermylene with GeCl2·dioxane only results in the exchange of the dioxane of GeCl2 against the divinylgermylene as base, the reaction of [(Me3Si)3Si]2Ge: with one GeCl2·dioxane and three phenylacetylenes gives a trivinylated germane with a chlorogermylene attached to one of the vinyl units.


Assuntos
Complexos de Coordenação/síntese química , Dioxanos/química , Fosfinas/química , Complexos de Coordenação/química , Estrutura Molecular , Silanos
10.
Molecules ; 25(3)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32013217

RESUMO

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.


Assuntos
Compostos Organometálicos/química , Indicadores e Reagentes/química , Ligantes , Modelos Moleculares , Fosfinas/química , Difração de Raios X
11.
Molecules ; 25(4)2020 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-32102166

RESUMO

A family of complexes of the formula trans-[RuCl2(L)(R-pybox)] (R-pybox = (S,S)-iPr-pybox, (R,R)-Ph-pybox, L = monodentate phosphonite, PPh(OR)2, and phosphinite, L = PPh2(OR), ligands) were screened in the catalytic asymmetric transfer hydrogenation of acetophenone, observing a strong influence of the nature of both the R-pybox substituents and the L ligand in the process. The best results were obtained with complex trans-[RuCl2{PPh2(OEt)}{(R,R)-Ph-pybox}] (2c), which provided high conversion and enantioselectivity (up to 96% enantiomeric excess, e.e.) for the reduction of a variety of aromatic ketones, affording the (S)-benzylalcohols.


Assuntos
Cetonas/química , Oxazóis/química , Compostos de Fósforo/química , Piridinas/química , Rutênio/química , Acetofenonas/química , Catálise , Complexos de Coordenação/química , Cristalografia por Raios X , Hidrogenação , Isomerismo , Ligantes , Fosfinas/química , Fosfitos/química
12.
Mikrochim Acta ; 187(2): 101, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912240

RESUMO

A freestanding and flexible buckypaper modfied with CoP/Co (CoP/Co-BP) is described. It has a sponge-like nanostructure and is shown to enable improved nonenzymatic sensing of glucose. The CoP/Co-BP was prepared by first depositing a uniform layer of ZIF- 67 crystals on BP, followed by two steps of pyrolysis treatment and phosphidation under an argon atmosphere. The morphology and structure of the material were characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical properties were investigated by cyclic voltammetry and amperometric response. The amperometric sensor, best operated at 0.45 V (vs. SCE) at pH 13 has a linear range that extends from 0.5 µM to 1.8 mM of glucose, a 0.2 µM detection limit (at S/N = 3), and a sensitivity of 6427 µA mM-1 cm-2 in alkaline solution. This is mainly attributed to the synergistic effect between the highly active CoP nanostructure and BP which results in excellent conductivity. The uniformly distributed CoP nanoparticles in the network of BP prevent the formation of close-packed structure and facilitate electron transfer. The sensor has good selectivity and excellent long-term stability. It was applied to the determination of glucose in spiked human serum, and satisfactory results were obtained. Graphical abstractSchematic presentation of a freestanding and flexible buckypaper modfied with CoP/Co. It has a sponge-like nanostructure and exhibits improved catalytic activity toward glucose oxidation. This material was used for high-performance electrochemical glucose sensing.


Assuntos
Glicemia/análise , Cobalto/química , Nanoestruturas/química , Fosfinas/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Humanos , Limite de Detecção , Nanoestruturas/ultraestrutura
13.
Mikrochim Acta ; 187(2): 100, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912282

RESUMO

The authors describe Ni-Co bimetal phosphide (NiCoP) nanocages that exhibit enhanced electrocatalytic performance toward glucose oxidation. The nanocages offer an appealing architecture, large specific area, and good accessibility for the analyte glucose. When placed on a glassy carbon electrode, the sensor exhibits attractive figures of merit for sensing glucose in 0.1 M NaOH solution including (a) a wide linear range (0.005-7 mM), (b) a low determination limit (0.36 µM), (c) high sensitivity (6115 µA•µM-1•cm-2), (d) a relatively low working potential (0.50 V vs. Ag/AgCl), and (e) good selectivity, reproducibility, and stability. The sensor is successfully applied to the determination of glucose in human serum samples. Graphical abstractSchematic representation of a glassy carbon electrode modified with Ni-Co bimetal phosphide (NiCoP) nanocage. NiCoP nanocage exhibits excellent electrocatalytic activity toward glucose oxidation. NiCoP nanocage is applied in a sensitive non-enzymatic glucose sensor.


Assuntos
Glicemia/análise , Cobalto/química , Nanoestruturas/química , Níquel/química , Fosfinas/química , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Limite de Detecção , Nanoestruturas/ultraestrutura , Reprodutibilidade dos Testes
14.
Soft Matter ; 16(6): 1473-1484, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31971207

RESUMO

Soft biomaterials have a wide range of applications in many areas. However, one material can only cover a specific range of mechanical performance such as the elastic modulus and stretchability. In order to improve the mechanical performance of soft biomaterials, lattice structures are embedded to reinforce the biomaterials. In this paper, rectangular and triangular lattice structures formed by modified horseshoe microstructures are used because their mechanical properties are tunable and can be tailored precisely to match the desired properties by adjusting four geometrical parameters, the length L, radius R, width w and arc angle θ0. A theoretical design framework for the modified horseshoe lattice structures is developed to predict the dependence of the mechanical behaviors on geometrical parameters. Both experiments and finite element simulations on lattice structures are conducted to validate the theoretical models. Results show that a wide range of design space for the elastic modulus (a few kPa to hundreds of MPa), stretchability (strain up to 180%) and Poisson ratio (ranging from -0.5 to 1.2) can be achieved. Experiments on lattice-hydrogel composites are also conducted to verify the reinforcement effect of lattice structures on the hydrogel. This work provides a theoretical method to predict the mechanical behaviors of the lattice structures and aid the rational design of reinforced biomaterials, which has applications in tissue engineering, drug delivery and intraocular lenses.


Assuntos
Módulo de Elasticidade , Hidrogéis/química , Nanocompostos/química , Estresse Mecânico , Modelos Teóricos , Fosfinas/química , Polietilenoglicóis/química
15.
Inorg Chem ; 59(4): 2367-2378, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-31984731

RESUMO

Reaction of [ReOCl3(PPh3)2] or [ReO2I(PPh3)2] with 2,2'-diphenylglycine (dpgH2) in refluxing ethanol afforded the air-stable complex [ReO(dpgH)(dpg)(PPh3)] (1). Treatment of [ReO(OEt)I2(PPh3)2] with 1,2,3-triaza-7-phosphaadamantane (PTA) afforded the complex [ReO(OEt)I2(PTA)2] (2). Reaction of [ReOI2(PTA)3] with dpgH2 led to the isolation of the complex [Re(NCPh2)I2(PTA)3]·0.5EtOH (3·0.5EtOH). A similar reaction but using [ReOX2(PTA)3] (X = Cl, Br) resulted in the analogous halide complexes [Re(NCPh2)Cl2(PTA)3]·2EtOH (4·2EtOH) and [Re(NCPh2)(PTA)3Br2]·1.6EtOH (5·1.6EtOH). Using benzilic acid (2,2'-diphenylglycolic acid, benzH) with 2 afforded the complex [ReO(benz)2(PTA)][PTAH]·EtOH (6·EtOH). The potential for the formation of complexes using radioisotopes with relatively short half-lives suitable for nuclear medicine applications by developing conditions for [Re(NCPh2)(dpg)I(PTA)3] (7)[ReO4]- in a 4 h time scale was investigated. A procedure for the technetium analog of complex [Re(NCPh2)I2(PTA)3] (3) from 99mTc[TcO4]- was then investigated. The molecular structures of 1-7 are reported; complexes 3-7 have been studied using in vitro cell assays (HeLa, HCT116, HT-29, and HEK 293) and were found to have IC50 values in the range of 29-1858 µM.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Linhagem Celular Tumoral , Complexos de Coordenação/síntese química , Células HEK293 , Humanos , Estrutura Molecular , Compostos de Organotecnécio/síntese química , Compostos de Organotecnécio/química , Fosfinas/síntese química , Fosfinas/química , Fosfinas/toxicidade , Rênio/química , Solubilidade , Água/química
16.
Talanta ; 209: 120559, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892088

RESUMO

Monoamine oxidase (MAOs) is involved in several psychiatric and neurological disorders. The specific detection of MAOs is of great significance to elucidate their functions in various biological processes. Currently, however, fast detection of MAOs remains a great challenge. It is, therefore, important to develop novel fluorescent probes for the monitoring of intracellular MAO activity. In this study, we synthesized OTPP-3-Piperazine and OTNP-3-Piperazine by functionalizing triarylphosphine with piperazine groups for MAO detection, using the rational design ofmolecular structures. OTNP-3-Piperazine demonstrated higher sensitivity to MAOs than OTPP-3-Piperazine because MAOs induced an AIE process via oxidation to produce water-insoluble oxidation products in OTNP-3-Piperazine. Such a recognition mechanism instantly responded to MAOs. OTNP-3-Piperazine was also introduced into different cells to explore its application as a biological probe. These results showed that it differentiated MAO-overexpressing cells from other cells, which demonstrated its promise as a biological fluorescent probe.


Assuntos
Corantes Fluorescentes/química , Monoaminoxidase/análise , Fosfinas/química , Piperazina/química , Animais , Células Hep G2 , Humanos , Camundongos , Células NIH 3T3 , Imagem Óptica/métodos , Óxidos/química , Espectrometria de Fluorescência/métodos
17.
Macromol Rapid Commun ; 41(1): e1900521, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31788895

RESUMO

A Pd/Pt-Bu3 catalyst having bulky, electron-rich ligands significantly outperforms conventional "step-growth catalysts" Pd(PPh3 )4 and Pd(Po-Tol3 )3 in the Suzuki polycondensation of the AB-type arylene-based monomers, such as some of the substituted fluorenes, carbazoles, and phenylenes. In the AA+BB polycondensation, Pd/Pt-Bu3 also performs better under homogeneous reaction conditions, in combination with the organic base Et4 NOH. The superior performance of Pd/Pt-Bu3 is discussed in terms of its higher reactivity in the oxidative addition step and inherent advantages of the intramolecular catalyst transfer, which is a key step joining catalytic cycles of the AB-polycondensation. These findings are applied to the synthesis of a carbazole-based copolymer designed for the use as a hole conductor in solution-processed organic light-emitting diodes.


Assuntos
Paládio/química , Fosfinas/química , Carbazóis/química , Catálise , Cinética , Polimerização , Polímeros/síntese química , Polímeros/química
18.
J Med Chem ; 63(5): 2455-2469, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841324

RESUMO

Fungi cause serious nosocomial infections including candidiasis and aspergillosis, some of which display reduced susceptibility to current antifungals. Inorganic compounds have been found to be beneficial against various medical ailments but have yet to be applied to fungal infections. Here, we explore the activity of linear and square-planar gold(I)-phosphine complexes against a panel of 28 fungal strains including Candida spp., Cryptococcus spp., Aspergillus spp., and Fusarium spp. Notably, two square-planar gold(I) complexes with excellent broad-spectrum activity display potent antifungal effects against strains of Candida auris, an emerging multidrug-resistant fungus that presents a serious global health threat. To characterize the biological activity of these gold(I) complexes, we used a series of time-kill studies, cytotoxicity and hemolysis assays, as well as whole-cell uptake and development of resistance studies.


Assuntos
Antifúngicos/farmacologia , Complexos de Coordenação/farmacologia , Fungos/efeitos dos fármacos , Ouro/farmacologia , Fosfinas/farmacologia , Antifúngicos/química , Complexos de Coordenação/química , Ouro/química , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Micoses/tratamento farmacológico , Fosfinas/química
19.
ChemSusChem ; 13(2): 351-359, 2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31721453

RESUMO

Transition metal phosphides (TMPs) are regarded as highly active electrocatalysts for the hydrogen evolution reaction (HER). However, traditional synthetic routes usually use expensive and dangerous precursors as P donors. The development of a low-cost and ecofriendly method for the synthesis of TMPs is significant for sustainable energy development. Herein, cobalt phosphides anchored on or embedded in a spirulina-derived porous N-doped carbon matrix (Co2 P/NC) was fabricated by two-step hydrothermal treatment and carbonization method, which utilized the intrinsic C, N, and P of biomass cleverly as the sources of C, N, and P, respectively. As a result of the high surface area and porosity that enhance the mass-transfer dynamics, Co2 P/NC shows good electrocatalytic activity at all pH values in the HER. This work not only provides a facile and effective method for the fabrication of TMP nanoparticles loaded onto carbon materials but also opens a new strategy for the utilization of the intrinsic ingredients of biomass for the preparation of other functional electrocatalysts.


Assuntos
Hidrogênio/química , Nanopartículas Metálicas/química , Fosfinas/química , Spirulina/química , Concentração de Íons de Hidrogênio , Porosidade
20.
Dalton Trans ; 49(1): 35-46, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31740907

RESUMO

Rhenium(i) di- and tri-carbonyl complexes of the form fac-[Re(CO)3(L,L'-Bid)X] and [Re(CO)2(L,L'-Bid)X2], where X = aqua (H2O), methanol (CH3OH), triphenylphosphine (PPh3), 1,3,5-triaza-7-phosphaadamantane (PTA), tricyclohexylphosphine (PCy3) and L,L'-Bid = O,O' bidentate ligands (tropolone = TropH and 3-hydroxyflavone = FlavH) and N,O bidentate ligands (8-hydroxyquinoline = QuinH, 5,7-chloro-8-hydroxyquinoline = diCl-QuinH and quinoline-2,4-dicarboxylic acid = QuinH2), were synthesized and unambiguously characterized by 1H-, 13C-and 31P-NMR, IR, UV/Vis and micro-analysis. The crystal structures of four complexes, namely fac-[Re(CO)3(QuinH)(H2O)]·H2O (5), fac-[Re(CO)3(Quin)(PPh3)] (11), fac-[Re(CO)3(diCl-Quin)(PPh3)] (12) and [Re(CO)2(Trop)(PPh3)2]·2C6H5CH3 (20) were obtained. Re-P bonding distances for 11 and 12 are 2.4948(8) and 2.4908(8) Å, respectively, indicating the effect of the electron-withdrawing substituents of the diCl-Quin- ligand. The second-order rate constants for the substitutions of methanol at 25.1 °C in fac-[Re(CO)3(L,L'-Bid)(CH3OH)] (L,L'-Bid = Trop, Flav and QuinH) type complexes by different entering phosphine ligands (PPh3, PCy3, and PTA) varied between 7.23(7) × 10-5 and 1.32(3) × 10-3 M-1 s-1 and were found to depend on the coordinated bidentate ligand (in general k1 (QuinH) < k1 (Trop) < k1 (Flav)). The toxicity of fac-[Re(CO)3(QuinH)(PTA)], fac-[Re(CO)3(Trop)(PTA)], fac-[Re(CO)3(Trop)(PPh3)] and fac-[Re(CO)3(Flav)(PPh3)] on the cervical cancer HeLa and epithelial RPE-1 cell lines was then evaluated. Complex fac-[Re(CO)3(Flav)(PPh3)] (16) and fac-[Re(CO)3(Trop)(PPh3)] (13) displayed the highest cytotoxicity with IC50 values of 12.21 ± 0.17 µM and 13.35 ± 0.94 µM, respectively in HeLa cells. Interestingly, a small selectivity towards cancer over non-cancerous cells was observed for these compounds (IC50 = 18.41 ± 3.16 µM and >25 µM in RPE-1 cells).


Assuntos
Complexos de Coordenação/síntese química , Fosfinas/química , Rênio/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/metabolismo , Complexos de Coordenação/farmacologia , Cristalografia por Raios X , Humanos , Cinética , Ligantes , Conformação Molecular
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