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1.
Chem Commun (Camb) ; 56(20): 3065-3068, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32049076

RESUMO

Herein, a novel stacked hexagonal prism, Ag@Ni-MOF-1, was designed and developed as an integrated SERS platform not only for successfully catalyzing the in situ synthesis of DA-quinone under physiological pH, but also for establishing an approach for specific determination of Cys, an important species in the brain related to Alzheimer's disease (AD).


Assuntos
Benzoquinonas/síntese química , Materiais Biomiméticos/química , Dopamina/síntese química , Níquel/química , Compostos Organometálicos/química , Prata/química , Benzoquinonas/química , Catálise , Cisteína/análise , Dopamina/química , Humanos , Concentração de Íons de Hidrogênio , Compostos Organometálicos/síntese química , Análise Espectral Raman
2.
J Photochem Photobiol B ; 203: 111770, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31918236

RESUMO

Dopamine (DA) is a monoamine neurotransmitter of phenethylamine and catecholamine families, which is present in the central nervous system (CNS) and its periphery. Since DA is associated with several functions in the brain and body (motivational salience, reward, motor control, paracrine messenger, etc.), any imbalance in the DA level can trigger several neurodegenerative and other diseases. On the other hand, the spherical gold nanoparticles (AuNPs) can be used for drug delivery in several parts of the body. In addition, AuNPs also have the potentiality to penetrate through the blood-brain barrier and interact with the central nervous system without causing any toxicity. In view of many applications, it is important to look into the interaction between DA and AuNPs for a potential drug delivery model in DA related diseases. Here, we have used the steady-state and time-resolved fluorescence spectroscopic tools to investigate the binding interaction of DA with AuNPs. The nature of the quenching mechanism was confirmed through both steady-state and time-resolved fluorescence measurements. The binding constants along with the number of binding sites were estimated from the steady-state fluorescence measurements. The distance between DA and AuNPs was calculated using Förster's theory to verify the possibility of fluorescence resonance energy transfer (FRET) from DA to AuNPs.


Assuntos
Dopamina/química , Ouro/química , Nanopartículas Metálicas/química , Sítios de Ligação , Transferência Ressonante de Energia de Fluorescência , Espectrometria de Fluorescência , Termodinâmica
3.
Phys Chem Chem Phys ; 22(2): 607-614, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31776536

RESUMO

The two-electron electrochemical oxidation of dopamine is studied voltammetrically at gold macroelectrodes around neutral pH with simulations used to give kinetic and mechanistic data. In particular, the system shows "potential inversion" in which the thermodynamic oxidation potential of dopamine to form the corresponding semi-quinone formation occurs at a more positive potential than that of the oxidation of the semi-quinone to the quinone form. The use of Tafel slopes measured from the voltammograms as a function of the voltage scan rate is show to be a particularly sensitive indicator of mechanism showing the effect of the follow-up chemistry in which the two-electron oxidation product undergoes an irreversible cyclization reaction.


Assuntos
Dopamina/química , Ouro/química , Técnicas Eletroquímicas , Eletrodos , Concentração de Íons de Hidrogênio , Cinética , Estrutura Molecular , Oxirredução
4.
Talanta ; 206: 120181, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514843

RESUMO

On-line SPE HPLC method using nanofibrous sorbents for the extraction and determination of resveratrol in wine was developed and validated. Different types of nanofibrous and microfibrous polymers were tested and compared with commercial monolithic C18 sorbent. Polyamide and polyacrylonitrile nanofibers and composite materials composed of respective polycaprolactone and poly(vinylidene difluoride) nanofibers at microfibrous scaffold were included among tested materials. Two different polycaprolactone-based materials were prepared and their effect on the extraction properties studied. Alternatively, dopamine-coated polycaprolactone fibers were also used. Poly(vinylidene difluoride) nanofibers/polycaprolactone microfibers composite was found as the most effective sorbent and utilized for the method validation. Resveratrol in red wine was determined using our validated on-line SPE HPLC method.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Nanofibras/química , Resveratrol/análise , Extração em Fase Sólida/métodos , Vinho/análise , Dopamina/química , Polímeros/química
5.
Inorg Chem ; 59(1): 900-912, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31869218

RESUMO

The combination between dyshomeostatic levels of catecholamine neurotransmitters and redox-active metals such as copper and iron exacerbates the oxidative stress condition that typically affects neurodegenerative diseases. We report a comparative study of the oxidative reactivity of copper complexes with amyloid-ß (Aß40) and the prion peptide fragment 76-114 (PrP76-114), containing the high-affinity binding site, toward dopamine and 4-methylcatechol, in aqueous buffer and in sodium dodecyl sulfate micelles, as a model membrane environment. The competitive oxidative and covalent modifications undergone by the peptides were also evaluated. The high binding affinity of Cu/peptide to micelles and lipid membranes leads to a strong reduction (Aß40) and quenching (PrP76-114) of the oxidative efficiency of the binary complexes and to a stabilization and redox silencing of the ternary complex CuII/Aß40/PrP76-114, which is highly reactive in solution. The results improve our understanding of the pathological and protective effects associated with these complexes, depending on the physiological environment.


Assuntos
Peptídeos beta-Amiloides/química , Cobre/química , Dopamina/química , Príons/química , Dodecilsulfato de Sódio/química , Sítios de Ligação , Humanos , Micelas , Conformação Molecular , Solubilidade
6.
Macromol Rapid Commun ; 41(2): e1900533, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31856366

RESUMO

Mussel-inspired polymers attract much research interest due to their potential as effective adhesives. In this work, a new kind of mussel-inspired polymer, poly(dopamine phosphonate-co-PEGMA), is prepared via a one-pot multicomponent polymerization system. The multicomponent polymerization system refers to a combination of multicomponent Kabachnik-Fields (KF) reaction and reversible addition-fragmentation chain transfer (RAFT) polymerization system. Reactants are converted to dopamine phosphonate monomers in situ through the KF reaction and polymerized simultaneously along with poly(ethylene glycol methyl ether) methacrylate (PEGMA) co-monomers by the RAFT process in a one-pot operation. Target polymers with dopamine phosphonate as side groups and well-defined polymer structures are thus facilely and successfully prepared. Afterwards, a series of polymers with various ratios of dopamine phosphonates as well as the crosslinked polymer analogues are prepared. Benefiting from the dopamine phosphonate side groups, aqueous solutions of those polymers show potential as effective adhesives in both dry and wet conditions, and their adhesive strengths are highly related to ratios of dopamine phosphonates in the polymers. Those polymers are non-cytotoxic and show strong bonding affinities on various substrates including metals, polymers, and bovine bones, suggesting their potential as environmentally friendly general adhesives in broad areas.


Assuntos
Bivalves/química , Dopamina/química , Metacrilatos/química , Polietilenoglicóis/química , Polímeros/química , Adesivos , Animais , Organofosfonatos/química , Polimerização , Resistência ao Cisalhamento
7.
Biosens Bioelectron ; 147: 111781, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31629214

RESUMO

This work presents a chitosan based resorbable biostrip for label-free electrochemical detection of dopamine (DA).The biostrip consists of mesoporous-chitosan-graphene oxide (m-Chit-GO) composite-based sensing electrode and graphene-based interconnects. Obtained with particulate leaching, the m-chit-GO showed average pore size of 1µmwith slow (2 h) curing process. The response of DA on m-Chit-GO was investigated and compared with their bulk counterpart to study the effect of mesoporosity on voltammogram output signals. The voltammetric investigations were performed with three-electrode set-up using m-Chit-GO electrode as working electrode whereas Ag/AgCl and Graphene were used as a reference and counter electrodes, respectively. The quantitative analysis of concentration-dependent voltammetric peak-current enhancement revealed significantly higher response for m-Chit-GO (10pM) as compared to their bulk state (100 nM) on DA. The presented resorbable biostrip offers a limit of detection of 10pM and thereby shows great promise for detection of DA levels for early diagnosis of neurodegenerative diseases.


Assuntos
Técnicas Biossensoriais , Quitosana/química , Dopamina/isolamento & purificação , Doenças Neurodegenerativas/diagnóstico , Dopamina/química , Grafite/química , Humanos , Limite de Detecção , Nanocompostos/química
8.
Mater Sci Eng C Mater Biol Appl ; 107: 110217, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761166

RESUMO

Herein, we report a novel, one-step solvothermal assisted thermal decomposition synthesis of nanoflake-nanorod tungsten disulphide (WS2) nanomaterial and its application for non-enzymatic electrochemical sensing of uric acid (UA) and quercetin. The as-synthesised WS2 was characterized using X-ray diffraction (XRD), Raman spectrometer, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). SEM analysis revealed the growth of 2D-1D nanoflake-nanorod hybrid nanostructure of 2H phase WS2 with greater defects and metal edges. Under optimized conditions, the WS2 modified glassy carbon electrode (WS2/GCE) facilitated the effective sensing of UA and quercetin which was measured using differential pulse voltammetry (DPV) technique. The sensor exhibited a low limit of detection (LoD) of 1.2 µM, the sensitivity of 312 nA/µM.cm2 for the dynamic range from 5 µM to 1 mM towards UA while an even lower of 2.4 nM and sensitivity of 258 nA/nM cm2 in the dynamic range of 10 nM-50 µM for quercetin. The enhanced sensing ability of the sensor attributed towards the synergetic effect of 2D-1D hybrid structure of WS2, wherein the 2D nanoflakes enhance the electrocatalytic property of WS2 with shorter diffusion length and 1D nanorods offer large surface area which provides greater number of active sites for sensing. Further, the sensor showed a remarkable selectivity towards UA and quercetin in the presence of ascorbic acid (AA), dopamine (DA), sodium (Na+), chloride (Cl-), calcium (Ca2+) and glucose. The sensor was further employed in successful detection of UA and quercetin in the simulated blood serum sample with excellent recovery percentages. The proposed synthesis route can be used to develop WS2 based electrochemical sensing platforms useful for various bioanalytical applications.


Assuntos
Técnicas Eletroquímicas/métodos , Nanoestruturas/química , Nanotubos/química , Quercetina/sangue , Ácido Úrico/sangue , Ácido Ascórbico/química , Catálise , Dopamina/química , Eletrodos , Glucose/química , Humanos , Limite de Detecção , Tungstênio/química
9.
Talanta ; 207: 120296, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594571

RESUMO

Carbon materials and the metal nanocrystals enclosed by high-index facets have aroused considerable attention due to their large specific surface area, excellent electrical properties and catalysis activity, and easy accessibility for target molecules. In this study, the Pt concave nanocube (CNC) with high-index {410} and {510} facets was successfully prepared via a simple hydrothermal method. The multiwalled carbon nanotubes (MWCNT) and graphene oxide (GO) were chosen as the supporting materials to further improve the dispersion of Pt CNC and the electrical conductivity of nanocomposite. The nanocomposite was used to modify electrode for sensitive simultaneous detection dopamine and uric acid. The cyclic voltammetry and differential pulse voltammetry were applied to confirm the catalytic activity of proposed sensor. By using the as-synthesized nanomaterial as nonenzymatic sensing material, dopamine and uric acid can be detected with high sensitivity and selectivity. The linear range towards dopamine sensing is from 0.8 to 300 µM, and the limit of detection is 0.27 µM. For uric acid sensing, the sensor exhibited over two wide linear ranges (from 1 µM to 0.3 mM and from 0.3 mM to 1 mM) with a detection limit of 0.35 µM. The sensor also possessed a long-term stability, good reproducibility and a promising application for electrochemical detection of both dopamine and uric acid in real samples.


Assuntos
Dopamina/análise , Eletroquímica/instrumentação , Grafite/química , Limite de Detecção , Nanotubos de Carbono/química , Platina/química , Ácido Úrico/análise , Dopamina/química , Eletrodos , Modelos Moleculares , Conformação Molecular , Nanocompostos/química , Fatores de Tempo , Ácido Úrico/química
10.
Talanta ; 207: 120318, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594597

RESUMO

This study designed a simplistic, efficient, and greener procedure to synthesize CeO2-CNTs. The analysis of structural and morphological characteristics of nano-composites has been done with regard to different procedures (e.g., EDX, XRD, & FESEM). In addition, simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and acetaminophen (AC) has been examined at the modified glassy carbon electrode with CeO2-CNTs nano-composites. The surface area and electron transfer speed of the interplay between neuro-transmitters and electrode may be efficiently enhanced due to the existence of CeO2 nano-particles on CNTs surfaces. Moreover, electro-chemical behavior of electrodes has been dealt with by differential pulse voltammetry (DPV), impedance analysis (EIS), and cyclic voltammetry (CV). Acceptable linear response of AA, DA, UA and AC respectively have been ranged 0.01-900.0 µM, 0.01-700.0 µM, 0.01-900.0 µM, and 0.01-900.0 µM with determination limits (S/N = 3) of 3.1 nM, 2.6 nM, 2.4 nM and 4.4 nM. Ultimately, this procedure was used with successful results for determining AA, DA, UA and AC in real specimens, which suggested probable uses in other sensing studies.


Assuntos
Acetaminofen/análise , Ácido Ascórbico/análise , Cério/química , Dopamina/análise , Micro-Ondas , Nanotubos de Carbono/química , Ácido Úrico/análise , Acetaminofen/química , Ácido Ascórbico/química , Dopamina/química , Eletroquímica , Eletrodos , Química Verde , Concentração de Íons de Hidrogênio , Limite de Detecção , Nanopartículas/química , Nanotecnologia , Propriedades de Superfície , Fatores de Tempo , Ácido Úrico/química
11.
Phys Chem Chem Phys ; 22(1): 203-211, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31799519

RESUMO

The formation of amyloid fibrils by α-synuclein (αS) protein inside the Lewy bodies and Lewy neurites is the prominent pathological hallmark of Parkinson's disease (PD). The fibrillation of αS in vitro is described by a nucleation-elongation process involving the formation of a critical nucleus. Finding the critical/smallest nuclei and effective inhibitors of αS aggregation is a crucial step for the development of drugs against PD. Recent experiments reported that dopamine (DA) and norepinephrine (NE), two prominent naturally occurring neurotransmitters, can effectively disrupt the preformed αS fibrils. The level of DA/NE in blood can be markedly increased by exercise. However, the size and structure of the critical nucleus and the disruptive mechanism by DA/NE are largely unknown. In this work, we performed multiple molecular dynamics (MD) simulations to find the critical nucleus size and examine the influences of DA/NE molecules on preformed αS44-96 (Greek-key-like core of full length αS) protofibrils. Our results show that the trimer is the critical nucleus for the αS44-96 fibril formation, and the tetramer is the minimal stable nucleus. When DA/NE molecules bind to the fibril-like trimer and tetramer, they strongly destabilize the αS protofibrils by disrupting the ß-sheet structure and inter-chain E46-K80 salt bridges. Two common binding sites are identified for both DA and NE molecules on αS oligomers: residues 57-70 and 81-83. A different binding site is also observed, which is located at the N-terminal region (residues 45-52). The binding of DA/NE molecules to αS oligomers is mostly driven by hydrophobic and electrostatic interactions. We found two disruptive modes, and binding to the turn region of αS oligomers but disrupting the adjacent ß-sheet structure is the dominant one. Our work identified the critical nucleus of Greek-key-like core of αS protofibrils and revealed the disruptive mechanism of αS protofibrils by DA/NE molecules, which may be helpful to the design of effective drugs against αS aggregation.


Assuntos
Dopamina/química , Norepinefrina/química , alfa-Sinucleína/química , Amiloide/metabolismo , Sítios de Ligação , Humanos , Simulação de Dinâmica Molecular , Norepinefrina/metabolismo , Ligação Proteica , Conformação Proteica , Eletricidade Estática
12.
Biomed Khim ; 65(6): 485-497, 2019 Oct.
Artigo em Russo | MEDLINE | ID: mdl-31876519

RESUMO

In socially isolated male outbred albino mice, the changes of monoaminergic systems under acute hypoxia with hypercapnia were studied. In cerebral cortex, hippocampus and striatum of the right and left sides of the brain, the concentrations of norepinephrine, dopamine, serotonin and their metabolites - dihydroxyphenylacetic, homovanillic and 5-hydroxyindoleacetic acids were investigated using the HPLC method. In isolated mice, which were not subjected to hypoxia with hypercapnia, higher levels of dopamine and serotonin in the left cortex were found. There was no asymmetry in monoamines and their metabolites in other studied brain structures. 10 min after the onset of exposure, acute hypoxia with hypercapnia resulted in a right-sided increase in norepinephrine levels and a decrease in dopamine levels in the striatum and serotonin levels in the hippocampus. In the cerebral cortex, 10 min after of hypoxic exposure beginning, there was a left-sided decrease in the dopamine content, while the original asymmetry found in the cortex of intact animals disappeared. In isolated mice perished of hypoxia with hypercapnia, almost all parameters returned to the control level. The exception was the ratio of serotonin metabolite level to the neurotransmitter, which in the right cortex became lower than in control animals. In white outbred mice, the brain monoaminergic systems are suggested to be relatively resistant to the negative consequences of hypoxia and hypercapnia, and corresponding shifts resulting in the reflex brain response to changes in the gas composition of the respiratory air.


Assuntos
Química Encefálica , Dopamina/química , Hipercapnia/metabolismo , Hipóxia/metabolismo , Norepinefrina/química , Serotonina/química , Animais , Encéfalo , Ácido Homovanílico , Masculino , Camundongos
13.
Biomed Khim ; 65(6): 498-506, 2019 Oct.
Artigo em Russo | MEDLINE | ID: mdl-31876520

RESUMO

Boc-Gly-Pro-DP, Z-Gly-Pro-DP, LA-Gly-Pro-DP, Boc-Gly-Pro-Srt, Z-Gly-Pro-Srt were synthesized for the first time. The stability of these compounds in the presence of leucine aminopeptidase, carboxypeptidase Y, carboxypeptidase B and proline endopeptidase (PEP) was determined. It turned out that the compounds are stable in the presence of aminopeptidases and carboxypeptidases. In the presence of PEP, dopamine (DP) and serotonin (Srt) are cleaved from the synthesized preparations. Thus, new proline-containing Srt and DP derivatives were obtained, Srt and DP could be gradually released from them. This suggest the possibility of a prolonged action of these biologically active compounds on the vital activity of cells and, consequently, of the whole organism.


Assuntos
Dopamina/química , Prolina/química , Serotonina/química , Carboxipeptidases , Cinética , Leucil Aminopeptidase , Serina Endopeptidases
14.
PLoS One ; 14(12): e0226680, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31881046

RESUMO

This paper focuses on determining the structural similarity of two molecules, i.e., the similarity of the interconnection of all the elementary cycles in the corresponding molecular graphs. In this paper, we propose and analyze an algorithmic approach based on the resolution of the Maximum Common Edge Subgraph (MCES) problem with graphs representing the interaction of cycles molecules. Using the ChEBI database, we compare the effectiveness of this approach in terms of structural similarity and computation time with two calculations of similarity of molecular graphs, one based on the MCES, the other on the use of different fingerprints (Daylight, ECFP4, ECFP6, FCFP4, FCFP6) to measure Tanimoto coefficient. We also analyze the obtained structural similarity results for a selected subset of molecules.


Assuntos
Desenho de Fármacos , Preparações Farmacêuticas/química , Algoritmos , Antineoplásicos/química , Gráficos por Computador , Convulsivantes/química , Docetaxel/química , Dopamina/química , Estrutura Molecular , Estricnina/química
15.
Chem Commun (Camb) ; 55(100): 15057-15060, 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31777882

RESUMO

We report a novel nanophotosensitizer via one-step covalent assembly of dopamine and genipin. This is the first report unveiling the photodynamic effect of dopamine-based materials. These nanophotosensitizers can also act as pH-responsive drug nanocarriers via a catechol-boronate linkage, thus achieving combined PDT and chemotherapy for highly efficient cancer treatment.


Assuntos
Dopamina/química , Portadores de Fármacos/química , Nanopartículas/química , Fármacos Fotossensibilizantes/química , Ácidos Borônicos/química , Catecóis/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Oxigênio Singlete/metabolismo
16.
Biosens Bioelectron ; 143: 111634, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473379

RESUMO

In this work, Ni(OH)2 nanocages@MnO2 nanosheets core-shell architecture (Ni(OH)2 NCs@MnO2 NSs CSA) was successfully prepared through coordinated etching and precipitation (CEP) route followed by hydrothermal reaction, and then tested as sensitive electrode material for detection of dopamine (DA). The three dimensional (3D) hollow Ni(OH)2 core effectively prevented the aggregation of MnO2 NSs, leading to high utilization rate of MnO2 NSs. Meanwhile, the two dimensional (2D) MnO2 shell endowed Ni(OH)2 NCs with larger specific area and abundant diffusion channels, facilitating mass transport. Ni(OH)2 NCs@MnO2 NSs CSA modified glassy carbon electrode (GCE) exhibited two satisfying sensitivities of 467.1 and 1249.9 µA mM-1 cm-2 within the two linear ranges of 0.02-16.30 µM and 18.30-118.58 µM, respectively. Furthermore, Ni(OH)2 NCs@MnO2 NSs CSA/GCE presented low detection limit of 1.75 nM and short response time of 1.14 s. Overall, Ni(OH)2 NCs@MnO2 NSs/GCE looks promising for analytical sensing of DA thanks to its prominent electrocatalytic dynamic issued from the 3D hollow structure@2D nanosheets core-shell architecture.


Assuntos
Técnicas Biossensoriais , Dopamina/isolamento & purificação , Técnicas Eletroquímicas , Nanoestruturas/química , Dopamina/química , Hidróxidos/química , Compostos de Manganês/química , Níquel/química
17.
Mikrochim Acta ; 186(10): 683, 2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529296

RESUMO

A boronate-modified magnetic affinity sorbent was prepared by adopting hyperbranched polyethyleneimine as the scaffold to amplify initiator sites. 3-Acrylamidophenylboronic acid was employed as monomer to proceed in situ free-radical polymerization on magnetite (Fe3O4) nanoparticles. Due to the improved density of boronic acid polymers, the adsorbent exhibited high adsorption capacity, typically (134 ± 8) µg mg-1 for dopamine, (92 ± 7) µg mg-1 for catechol, (363 ± 14) µg mg-1 for ovalbumin and (464 ± 22) µg mg-1 for horseradish peroxidase. These capacities are much higher than those of other adsorbents. The sorbent was applied to the enrichment of catecholamines from spiked human urine. Owing to the high adsorption capacity, only 1.0 mg of adsorbent was sufficient to eliminate the interferences and enrich the targets (dopamine, norepinephrine and epinephrine) within 5 min. They were quantified by HPLC. The recoveries from spiked samples range between 83.5% ~106%, with relative standard deviations of 3.2 ~ 9.4% (n = 5). The separation of glycoproteins from egg white was also accomplished prior to their analysis by PAGE. In the authors' perception, this approach is promising in that the density of functional groups on the adsorbent is strongly increased. Graphical abstract The preparation routine of boronate affinity magnetic adsorbent (Fe3O4@HpAAPBA). The adsorbent is used for the magnetic solid phase extraction of cis-dol compounds from real sample.


Assuntos
Ácidos Borônicos/química , Catecolaminas/urina , Nanopartículas de Magnetita/química , Polietilenoimina/química , Catecóis/química , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Dopamina/química , Clara de Ovo/química , Epinefrina/química , Glicoproteínas/isolamento & purificação , Peroxidase do Rábano Silvestre/química , Humanos , Norepinefrina/química , Ovalbumina/química , Extração em Fase Sólida
18.
Int J Mol Sci ; 20(18)2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31540025

RESUMO

In order to search for novel antipsychotics acting through the D2 receptor, it is necessary to know the structure-activity relationships for dopamine D2 receptor antagonists. In this context, we constructed the universal three-dimensional quantitative structure-activity relationship (3D- QSAR) model for competitive dopamine D2 receptor antagonists. We took 176 compounds from chemically different groups characterized by the half maximal inhibitory concentration (IC50)from the CHEMBL database and docked them to the X-ray structure of the human D2 receptor in the inactive state. Selected docking poses were applied for Comparative Molecular Field Analysis (CoMFA) alignment. The obtained CoMFA model is characterized by a cross-validated coefficient Q2 of 0.76 with an optimal component of 5, R2 of 0.92, and an F value of 338.9. The steric and electrostatic field contributions are 67.4% and 32.6%, respectively. The statistics obtained prove that the CoMFA model is significant. Next, the IC50 of the 16 compounds from the test set was predicted with R2 of 0.95. Finally, a progressive scrambling test was carried out for additional validation. The CoMFA fields were mapped onto the dopamine D2 receptor binding site, which enabled a discussion of the structure-activity relationship based on ligand-receptor interactions. In particular, it was found that one of the desired steric interactions covers the area of a putative common allosteric pocket suggested for some other G protein-coupled receptors (GPCRs), which would suggest that some of the known dopamine receptor antagonists are bitopic in their essence. The CoMFA model can be applied to predict the potential activity of novel dopamine D2 receptor antagonists.


Assuntos
Antipsicóticos/química , Antagonistas dos Receptores de Dopamina D2/química , Receptores de Dopamina D2/química , Sítios de Ligação/efeitos dos fármacos , Dopamina/química , Dopamina/farmacologia , Composição de Medicamentos , Humanos , Ligantes , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Relação Quantitativa Estrutura-Atividade , Software , Eletricidade Estática
19.
Int J Mol Sci ; 20(18)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540228

RESUMO

The reaction-based deposition on various surfaces of an all-organic fluorescent coating is reported here, involving autoxidation of 2 mM dopamine in carbonate buffer at pH 9.0, in the presence of a 1 mM diamine-resorcinol coupler (Bis-Res) prepared from 2,4-dihydroxybenzaldehyde and hexamethylenediamine (HMDA). Spectral analysis of the films coupled with an LC-MS investigation of the yellow fluorescent mixture was compatible with the formation and deposition of HMDA-linked methanobenzofuroazocinone fluorophores. Both the emission properties and hydrophobicity of the film were abated in a reversible manner following exposure to acid vapors. These results provide an entry to efficient and practical fluorescent coating methodologies based on in situ generation and the deposition of wet adhesive, as well as fluorescent materials combining a strongly emitting fluorophore with the film-forming properties of long chain diamines.


Assuntos
Diaminas/química , Dopamina/química , Corantes Fluorescentes/química , Benzaldeídos/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Oxirredução , Propriedades de Superfície
20.
Biomater Sci ; 7(9): 3741-3750, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31389408

RESUMO

Developing a facile and versatile strategy to endow blood-contacting devices with surface in situ nitric oxide (NO) generation properties by catalytically decomposing endogenously existing S-nitrosothiols (RSNO) from blood is of immense scientific and engineering interest. However, most available strategies involve drawbacks of low efficiency, complex processes, and toxic chemicals. In this work, we report a facile method to deposit a NO-generating coating on a 316L stainless steel (SS) substrate through dopamine-mediated one-step assembly of CuII-dopamine (CuII-DA) coordination complexes. The chelation of CuII in the CuII-DA network endowed the coating with high in situ NO catalytic capacity by decomposing RSNO endogenously existing in blood. Of special importance is that this dopamine-mediated method possesses the merits of a simple preparation process, friendliness to the environment, high controllability of the CuII-DA surface chemistry, highly effective surface coating formation, and long-term and durable catalytic activity of NO. The continuous release of NO from the CuII-DA-coated 316L SS impressively improved its antithrombogenicity and selectively enhanced endothelial cell (EC) growth while inhibiting smooth muscle cell (SMC) proliferation.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Cobre/farmacologia , Dopamina/farmacologia , Óxido Nítrico/biossíntese , Catálise , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Cobre/química , Dopamina/química , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Estrutura Molecular , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico/sangue , Adesividade Plaquetária/efeitos dos fármacos
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