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1.
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
2.
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
3.
Macromol Rapid Commun ; 41(4): e1900468, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31880037

RESUMO

Catalytic dehydropolymerization of halogen-functionalized phosphine-boranes (4-X-C6 H4 )PH2 ⋅BH3 (1a: X = Br, 1b: X = I) with [CpFe(CO)2 (OTf)] at 100 °C provides convenient access to halogen-functionalized polyphosphinoboranes [(4-X-C6 H4 )PH-BH2 ]n (2a: X = Br, 2b: X = I). These polymers are useful precursors for post-polymerization functionalization, which is demonstrated by Sonogashira coupling under mild conditions to yield the alkynyl-functionalized polyphosphinoborane [(4-PhCC-C6 H4 )PH-BH2 ]n (3).


Assuntos
Boranos/química , Halogênios/química , Fosfinas/química , Polímeros/química , Polímeros/síntese química , Alquinos/química , Catálise , Polimerização
4.
Chem Commun (Camb) ; 56(2): 313-316, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31808779

RESUMO

A host-guest recognition-regulated aggregation-induced emission (AIE) strategy is developed based on the interaction between cyclodextrin-functionalized copper nanoclusters and di(adamantan-1-yl)phosphine as a connector, which significantly improves the AIE efficiency and stability and can be applied to long-term in situ imaging of MUC1 protein.


Assuntos
Adamantano/análogos & derivados , Nanopartículas Metálicas/química , Mucina-1/análise , Fosfinas/química , beta-Ciclodextrinas/química , Linhagem Celular Tumoral , Cobre/química , Corantes Fluorescentes/química , Humanos , Medições Luminescentes/métodos , Microscopia Confocal/métodos
5.
Mikrochim Acta ; 186(12): 856, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784833

RESUMO

A porous carbon nitride (PCN) modified with cobalt phosphides (CoP) was synthesized. In this nanocomposite, the CoP (in different weight fractions) serves (a) as the electron acceptor to accelerate the photoinduced charge separation, and (b) as the photosensitizer to increase the photoelectrochemical (PEC) response to visible light. Dissolved oxygen acts as the electron acceptor to generate PEC current. If glucose oxidase (GOx) catalyzes the oxidation of glucose, dissolved oxygen is consumed. This leads to the suppression of photocurrent. The photocathode biosensor has a linear response in the 0.05 to 0.7 mM glucose concentration range and a 1.1 µM limit of detection. Graphical abstractSchematic of a photoelectrochemical glucose biosensor based on the use of cobalt phosphide-modified porous carbon nitrides. PCN: porous carbon nitride; CoP: cobalt phosphide.


Assuntos
Glucose Oxidase/metabolismo , Glucose/análise , Luz , Nanocompostos/química , Nitrilos/química , Fosfinas/química , Biocatálise , Técnicas Biossensoriais , Técnicas Eletroquímicas , Glucose/metabolismo , Tamanho da Partícula , Processos Fotoquímicos , Porosidade , Propriedades de Superfície
6.
Molecules ; 24(23)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31817055

RESUMO

Despite the recurrence of aurophilic interactions in the solid-state structures of gold(I) compounds, its rational control, modulation, and application in the generation of functional supramolecular structures is an area that requires further development. The ligand effects over the aurophilic-based supramolecular structures need to be better understood. This paper presents the supramolecular structural diversity of a series of new 1,3-bis(diphenylphosphane)propane (dppp) gold(I) fluorinated thiolates with the general formula [Au2(SRF)2(µ-dppp)] (SRF = SC6F5 (1); SC6HF4-4 (2); SC6H3(CF3)2-3,5 (3); SC6H4CF3-2 (4); SC6H4CF3-4 (5); SC6H3F2-3,4 (6); SC6H3F2-3,5 (7); SC6H4F-2 (8); SC6H4F-3 (9); SC6H4F-4 (10)). These compounds were synthesized and characterized, and six of their solid-state crystalline structures were determined using single-crystal X-ray diffraction. In the crystalline arrangement, they form aurophilic-bridged polymers. In these systems, the changes in the fluorination patterns of the thiolate ligands tune the aurophilic-induced self-assembly of the compounds causing tacticity and chiral differentiation of the monomers. This is an example of the use of ligand effects on the tune of the supramolecular association of gold complexes.


Assuntos
Ouro/química , Fosfinas/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Polímeros/química
7.
Int J Pharm ; 572: 118790, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31678382

RESUMO

Three-dimensional (3D) printing enables the production of different objects adjusted for the specific application, which has particular importance of providing personalized therapy, whereby the challenge is to apply pharmaceutical materials into 3D printing technology. In this study, effect of poly(ethylene glycol) 400 (PEG 400), sodium chloride (NaCl), and mannitol, as hydrophilic excipients, was investigated in order to overcome very slow and incomplete drug release from tablets (printlets) fabricated by photopolymerization using digital light processing (DLP) technology. Paracetamol (acetaminophen) was used as a model drug, while polyethylene glycol diacrylate (PEGDA) was used as a photopolymer and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide as a photoinitiator in photoreactive mixtures. Most of printlet formulations exhibit sustained release over 8 h, wherein drug release kinetics is the best described with Korsmeyer-Peppas kinetics. Variation in the content of photopolymer and excipients had an influence on the dissolution rate, mechanical characteristics, and internal structure of the investigated samples. The addition of hydrophilic polymers increased drug release rate, while PEGDA had the greatest influence on the tensile strength of printlets. The results indicate the possibility of implementation of traditional excipients into different formulations for photopolymerization based 3D printing for the production of small batches of tablets with tailored drug release.


Assuntos
Acetaminofen/química , Excipientes/química , Luz , Manitol/química , Polietilenoglicóis/química , Impressão Tridimensional , Cloreto de Sódio/química , Tecnologia Farmacêutica/métodos , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Dureza , Interações Hidrofóbicas e Hidrofílicas , Cinética , Fosfinas/química , Polimerização , Solubilidade , Comprimidos , Resistência à Tração
8.
Inorg Chem ; 58(22): 15536-15551, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31697068

RESUMO

New alkynylgold(I) with P(NMe2)3 (HMPT) phosphane complexes, [Au(C≡C-R)(HMPT)] (R= 4-Ph, 4-MePh, 4-OMe, 4-Br, 4-Cl, 2-py, and 3-py) have been synthesized and characterized, including X-ray studies of complexes with R= 4-OMe and 4-Br; additionally, their physicochemical properties and anticancer activity have been tested. Due to the great water solubility of the HMPT phosphane, all the complexes exhibit an optimal balance of hydrophilicity/lipophilicity. Also, all of these complexes are quite stable in physiological conditions and interact well enough with the transport protein BSA. All complexes exhibit a higher anticancer activity against Caco-2 cells than cisplatin, and some of them do not present cytotoxic activity against enterocyte-like differentiated cells. The selective complexes are proapoptotic drugs by the exposure of phosphatidylserine, results that are also confirmed in primary cultures from mouse colon tumors. Complexes with a halogen unit also arrest the cell cycle in G2/M phase. It is thought that maybe these apoptosis processes are promoted by the observed oxidative damage in the membrane lipids, as a consequence of the inhibition of the thioredoxin reductase enzyme. Based on our results, we conclude that five of our complexes are good candidates to be used in chemotherapy.


Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Compostos Organoáuricos/química , Compostos Organoáuricos/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Células CACO-2 , Cristalografia por Raios X , Feminino , Humanos , Camundongos Endogâmicos ICR , Modelos Moleculares , Fosfinas/química , Fosfinas/uso terapêutico
9.
Int J Nanomedicine ; 14: 8345-8360, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695371

RESUMO

Background: The protective role of puerarin (PUE) against myocardial infarction is closely related to its regulation on mitochondria. However, free PUE can hardly reach the mitochondria of ischemic cardiomyocytes due to the lack of mitochondrial targeting of PUE. Here PUE was loaded into mitochondria-targeted micelles (PUE@TPP/PEG-PE) for precisely delivering PUE into mitochondria with the aim of enhancing the anti-apoptosis effect. Methods: The mitochondriotropic polymer TPP-PEG-PE was synthesized for the preparation of PUE@TPP/PEG-PE micelles modified with triphenylphosphonium (TPP) cation. The physicochemical properties and anti-apoptosis effect of PUE@TPP/PEG-PE micelles were investigated. The coumarin 6 (C6)-labeled TPP/PEG-PE (C6@TPP/PEG-PE) micelles were used to observe the enhanced cellular uptake, mitochondrial targeting and lysosomes escape. Moreover, in vivo and ex vivo biodistribution of lipophilic near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR)-labeled PUE@TPP/PEG-PE (DiR@TPP/PEG-PE) micelles were detected through fluorescence imaging. Results: The successful synthesis of TPP-PEG-PE conjugate was confirmed. PUE@TPP/PEG-PE micelles had a particle size of 17.1 nm, a zeta potential of -6.2 mV, and a sustained-release behavior. The in vitro results showed that the intracellular uptake of C6@TPP/PEG-PE micelles was significantly enhanced in H9c2 cells. C6@TPP/PEG-PE micelles could deliver C6 to mitochondria and reduce the capture of lysosomes. In addition, compared with the PUE@PEG-PE micelles and free PUE, the PUE@TPP/PEG-PE micelles exerted an enhanced protective effect against isoprenaline-induced H9c2 cell apoptosis, as evident by the decreased percentage of apoptotic cells, Caspase-3 activity, ROS level, Bax expression, and increased Bcl-2 expression. The in vivo detecting results of the targeting effect using DiR probe also indicated that TPP/PEG-PE micelles could accumulate and retain in the ischemic myocardium. Conclusion: The results of this study demonstrate the promising potential of applying PUE@TPP/PEG-PE micelles in mitochondria-targeted drug delivery to achieve maximum therapeutic effects of PUE.


Assuntos
Apoptose/efeitos dos fármacos , Cardiotônicos/farmacologia , Isoflavonas/farmacologia , Micelas , Mitocôndrias/metabolismo , Miócitos Cardíacos/patologia , Fosfinas/química , Animais , Cátions , Linhagem Celular , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Isoproterenol , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Fosfatidiletanolaminas/química , Polietilenoglicóis/química , Ratos , Eletricidade Estática , Distribuição Tecidual/efeitos dos fármacos
10.
Molecules ; 24(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31717713

RESUMO

H-phosphonates, H-phosphinates and secondary phosphine oxides may be preligands, and are important building blocks in the synthesis of pharmaceuticals, pesticides, and P-ligands. The prototropic tautomerism influenced by substituent effects plays an important role in the reactivity of these species. The main goal of our research was to study the tautomerism of the >P(O)H reagents by means of computational investigations applying several DFT methods at different levels. We focused on the effect of implicit solvents, and on explaining the observed trends with physical chemical molecular descriptors. In addition, multiple reaction pathways incorporating three P-molecules were elucidated for the mechanism of the interconversion.


Assuntos
Organofosfonatos/química , Compostos Organofosforados/química , Fosfinas/química , Estrutura Molecular , Óxidos/química
11.
Chem Commun (Camb) ; 55(80): 12040-12043, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31531449

RESUMO

A visible light-induced self-powered sensor for the detection of tyrosinase activity was proposed. A tyrosinase-responsive photoelectrochemical-chemical redox cycling strategy was integrated with a photofuel cell for signal amplification.


Assuntos
Técnicas Biossensoriais/métodos , Monofenol Mono-Oxigenase/análise , Nanoestruturas/química , Técnicas Biossensoriais/instrumentação , Bismuto/química , Catálise , Catecóis/química , Fontes de Energia Elétrica , Técnicas Eletroquímicas/métodos , Eletrodos , Grafite/química , Hemina/química , Luz , Nitrilos/química , Oxirredução , Fosfinas/química , Sulfetos/química
12.
Eur J Med Chem ; 183: 111661, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31546196

RESUMO

The design of multi-targeted drugs has gained considerable interest in the last decade thanks to their advantages in the treatment of different diseases, including cancer. The simultaneous inhibition of selected targets from cancerous cells to induce their death represents an attractive objective for the medicinal chemist in order to enhance the efficiency of chemotherapy. In the present work, several alkynyl gold(I) phosphane complexes derived from 3-hydroxyflavones active against three human cancer cell lines, colorectal adenocarcinoma Caco-2/TC7, breast adenocarcinoma MCF-7 and hepatocellular carcinoma HepG2, have been synthesized and characterized. Moreover, these compounds display high selective index values towards differentiated Caco-2 cells, which are considered as a model of non-cancerous cells. The antiproliferative effect of the most active complexes [Au(L2b)PPh3] (3b) and [Au(L2c)PTA] (4c) on Caco-2 cells, seems to be mediated by the inhibition of the enzyme cyclooxygenase-1/2 and alteration of the activities of the redox enzymes thioredoxin reductase and glutathione reductase. Both complexes triggered cell death by apoptosis, alterations in cell cycle progression and increased of ROS production. These results provide support for the suggestion that multi-targeting approach involving the interaction with cyclooxygenase-1/2 and the redox enzymes that increases ROS production, enhances cell death in vitro. All these results indicate that complexes [Au(L2b)PPh3] and [Au(L2c)PTA] are promising antiproliferative agents for further anticancer drug development.


Assuntos
Alquinos/química , Antineoplásicos , Neoplasias do Colo/tratamento farmacológico , Complexos de Coordenação , Flavonoides/química , Ouro , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/uso terapêutico , Descoberta de Drogas , Ouro/química , Humanos , Fosfinas/química
13.
ACS Appl Mater Interfaces ; 11(39): 35630-35640, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31496235

RESUMO

Many attempts have been made to synthesize cadmium-free quantum dots (QDs), using nontoxic materials, while preserving their unique optical properties. Despite impressive advances, gaps in knowledge of their intracellular fate, persistence, and excretion from the targeted cell or organism still exist, precluding clinical applications. In this study, we used a simple model organism (Hydra vulgaris) presenting a tissue grade of organization to determine the biodistribution of indium phosphide (InP)-based QDs by X-ray fluorescence imaging. By complementing elemental imaging with In L-edge X-ray absorption near edge structure, unique information on in situ chemical speciation was obtained. Unexpectedly, spectral profiles indicated the appearance of In-O species within the first hour post-treatment, suggesting a fast degradation of the InP QD core in vivo, induced mainly by carboxylate groups. Moreover, no significant difference in the behavior of bare core QDs and QDs capped with an inorganic Zn(Se,S) gradient shell was observed. The results paralleled those achieved by treating animals with an equivalent dose of indium salts, confirming the preferred bonding type of In3+ ions in Hydra tissues. In conclusion, by focusing on the chemical identity of indium along a 48 h long journey of QDs in Hydra, we describe a fast degradation process, in the absence of evident toxicity. These data pave the way to new paradigms to be considered in the biocompatibility assessment of QD-based biomedical applications, with greater emphasis on the dynamics of in vivo biotransformations, and suggest strategies to drive the design of future applied materials for nanotechnology-based diagnosis and therapeutics.


Assuntos
Hydra/metabolismo , Índio , Fosfinas , Pontos Quânticos/química , Espectrometria por Raios X , Animais , Índio/química , Índio/farmacocinética , Índio/farmacologia , Fosfinas/química , Fosfinas/farmacocinética , Fosfinas/farmacologia
14.
Molecules ; 24(18)2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487944

RESUMO

Monovalent NHC-nickel complexes bearing triarylphosphine, in which fluorine is incorporated onto the aryl groups, have been synthesized. Tris(3,5-di(trifluoromethyl)-phenyl)phosphine efficiently gave a monovalent nickel bromide complex, whose structure was determined by X-ray diffraction analysis for the first time. In the solid state, the Ni(I) complex was less susceptible to oxidation in air than the triphenylphosphine complex, indicating greatly improved solid-state stability. In contrast, the Ni(I) complex in solution can easily liberate the phosphine, high catalytic activity toward the Kumada-Tamao-Corriu coupling of aryl bromides.


Assuntos
Complexos de Coordenação/química , Flúor/química , Níquel/química , Fosfinas/química , Catálise , Cristalografia por Raios X , Teoria da Densidade Funcional , Modelos Moleculares , Modelos Teóricos , Conformação Molecular , Estrutura Molecular , Oxirredução
15.
Chemistry ; 25(62): 14089-14100, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31414501

RESUMO

Four cycloaurated phosphine sulfide complexes, [Au{κ2 -2-C6 H4 P(S)Ph2 }2 ][AuX2 ] [X=Cl (2), Br (3), I (4)] and [Au{κ2 -2-C6 H4 P(S)Ph2 }2 ]PF6 (5), have been prepared and thoroughly characterized. The compounds were found to be stable under physiological-like conditions and showed excellent cytotoxicity against a broad range of cancer cell lines and remarkable cytotoxicity in 3D tumor spheroids. Mechanistic studies with cervical cancer (HeLa) cells indicated that the cytotoxic effects of the compounds involve the inhibition of thioredoxin reductase and induction of apoptosis through mitochondrial disruption. In vivo experiments in nude mice bearing HeLa xenografts showed that treatment with compounds 4 and 5 resulted in significant inhibition of tumor growth (35.8 and 46.9 %, respectively), better than that of cisplatin (29 %). The newly synthesized gold complexes were also evaluated for their in vitro and in vivo anti-inflammatory activity through the study of lipopolysaccharide (LPS)-activated macrophages and carrageenan-induced hind paw edema in rats, respectively.


Assuntos
Anti-Inflamatórios/química , Antineoplásicos/química , Ouro/química , Compostos Organoáuricos/química , Fosfinas/química , Sulfetos/química , Animais , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Compostos Organoáuricos/farmacologia
16.
Chem Commun (Camb) ; 55(68): 10142-10145, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389424

RESUMO

Hydrogen sulfide, an endogenous signalling molecule, is central to several pathophysiological processes in mammalian systems. It scavenges reactive oxygen species and is known to ameliorate dopaminergic neuronal degeneration in neurotoxin-induced Parkinson's disease models. The rapid volatilization of H2S from spontaneously releasing sulfide salts being a challenge, we describe peptide conjugates which exhibit tris(2-carboxyethyl)phosphine mediated "slow and sustained" H2S release. These conjugates reduced hydrogen peroxide-induced oxidative stress and significantly increased dopamine levels in transgenic C. elegans.


Assuntos
Dopamina/metabolismo , Sulfeto de Hidrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Tionas/farmacologia , Tiofenos/farmacologia , Animais , Animais Geneticamente Modificados , Anti-Inflamatórios/metabolismo , Antioxidantes/metabolismo , Caenorhabditis elegans/genética , Liberação Controlada de Fármacos , Oxirredução , Peptídeos/síntese química , Peptídeos/química , Fosfinas/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tionas/síntese química , Tionas/química , Tiofenos/síntese química , Tiofenos/química , alfa-Sinucleína/genética
17.
Talanta ; 204: 833-839, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357372

RESUMO

The peroxidase-like activity of ficin is relatively low, which limits its application. It was found that thiol groups of ficin could inhibit its peroxidase-like activity. So, two procedures, i.e., direct blocking with N-ethylmaleimide (NEM), or using tris (2-carboxyethyl) phosphine hydrochloride (TCEP) to interrupt disulfide bonds then blocking thiol groups with NEM, were applied to block thiol groups of ficin, ficin-NEM (ficin-N) and ficin-TCEP-NEM (ficin-TN) were produced, respectively. The blocking of thiol groups accelerated the peroxidase activity dramatically. The peroxidase catalytic activity of ficin-N and ficin-TN toward the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2 was about 2.5-fold and 5-fold increase compared with ficin, respectively, which accompanied a color change from colorless to blue and followed classic Michaelis-Menten model. The kinetic parameters indicated that higher affinity of ficin-N (Km = 0.31) and ficin-TN (Km = 0.39) to H2O2 compared with ficin (Km = 0.58), and ficin-TN had the highest Kcat which increased by 6.5 times and 4.5 times for TMB and H2O2, respectively. According to these findings, a colorimetric method with high sensitivity for the detection of biothiols was developed due to sulfhydryl compounds inhibited the peroxidase activity of ficin. Comparing with ficin and ficin-N, ficin-TN had the widest detection range (0.01-16 µM) and the lowest detection limit (3 nM). The practical applications of ficin-TN for biothiol determination in human serum samples have been demonstrated with satisfactory results. Ficin-N and ficin-TN are promising to apply to the bioanalysis.


Assuntos
Cisteína/sangue , Ficina/química , Glutationa/sangue , Homocisteína/sangue , Peroxidases/química , Benzidinas/química , Compostos Cromogênicos/química , Colorimetria/métodos , Etilmaleimida/química , Humanos , Peróxido de Hidrogênio/química , Indicadores e Reagentes/química , Cinética , Limite de Detecção , Fosfinas/química
18.
Molecules ; 24(11)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31159257

RESUMO

GC20, a novel soluble bis-chelated gold(I)-diphosphine compound, has been reported as a promising anticancer candidate. Assessing the pharmacokinetic properties of GC20 is critical for its medicinal evaluation. First, a sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and well validated to determine GC20 in rat plasma and rat tissue homogenate after one step protein precipitation. Chromatographic separation was achieved on an Angilent ZORBAX-C18 column (3.5 µm, 2.1 × 50 mm) with gradient elution and mass spectrometry was performed on a triple quadrupole in positive ion mode using an electrospray ionization source. This method was then applied to investigate the pharmacokinetics and tissue distribution of GC20 in rats after intravenous administration. The results showed that the plasma exposure of GC20 in vivo increased with increasing doses after a single dose. However, after multiple doses, a significant accumulation and a saturation at elimination were observed for GC20 in rats. Moreover, after intravenous administration, GC20 was widely distributed in various tissues, with the highest levels in the lung, spleen, liver, and pancreas, followed by the kidney and heart, while the lowest level was found in the brain. This is the first report on the pharmacokinetic properties of GC20.


Assuntos
Quelantes/farmacocinética , Ouro , Fosfinas/farmacocinética , Animais , Quelantes/química , Cromatografia Líquida , Ouro/química , Estrutura Molecular , Fosfinas/química , Ratos , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Distribuição Tecidual
19.
Molecules ; 24(11)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31159332

RESUMO

Herein, we report the homo- and co-polymerization of ethylene (E) with norbornene (NB) catalyzed by vanadium(III) phosphine complexes of the type VCl3(PMenPh3-n)2 [n = 2 (1a), 1 (1b)] and VCl3(PR3)2 [R = phenyl (Ph, 1c), cyclohexyl (Cy, 1d), tert-butyl (tBu, 1e)]. In the presence of Et2AlCl and Cl3CCOOEt (ETA), 1a-1e exhibit good activities for the polymerization of ethylene, affording linear, semicrystalline PEs with a melting temperature of approximately 130 °C. Mainly alternating copolymers with high comonomer incorporation were obtained in the E/NB copolymerization. A relationship was found between the electronic and steric properties of the phosphine ligands and the catalytic performance. Overall, the presence of electron-withdrawing ligand substituents increases the productivity, complexes with aryl phosphine (weaker σ-donor character) exhibiting a higher (co)polymerization initiation rate than those with alkyl phosphines (stronger σ-donor character). Steric effects also seem to play a key role since 1d and 1e, having large size phosphines (PCy3 θ = 170° and PtBu3 θ = 182°, respectively) are more active than 1a (PMe2Ph θ = 122°). In this case, the larger size of PtBu3 and PCy3 likely compensates for their higher donor strength compared to PMe2Ph.


Assuntos
Etilenos/química , Norbornanos/química , Fosfinas/química , Vanádio/química , Catálise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Polimerização
20.
Molecules ; 24(12)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234454

RESUMO

Two novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with tert-butyl(diphenyl)phosphine (PtBuPh2) and (S)-(+)neomenthyldiphenylphosphine [(S)-NMDPP]. The crystal structure of the former was determined by single-crystal X-ray diffraction studies. The two complexes were then used in combination with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene: crystalline highly syndiotactic 1,2 poly(1,3-butadiene)s were obtained, with a 1,2 content and a syndiotactic index (percentage of syndiotactic triads [rr]) up to 95% and 85%, respectively. The results obtained further support and confirm what was already observed in the polymerization of 1,3-butadiene with CoCl2(PRPh2)2-MAO (R = methyl, ethyl, normal-propyl, iso-propyl, and cyclohexyl): the nature of the phosphine ligand strongly affects the polymerization stereoselectivity, the polymer syndiotacticity increasing with increasing phosphine ligand steric hindrance.


Assuntos
Butadienos/química , Cobalto/química , Complexos de Coordenação/síntese química , Fosfinas/química , Catálise , Complexos de Coordenação/química , Ligantes , Modelos Moleculares , Estrutura Molecular , Polimerização
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