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1.
PLoS One ; 15(7): e0235444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614863

RESUMO

Commercial storage of potatoes often relies on the use of sprout inhibitors to prolong storage and reduce spoilage. The compound 1,4-dimethylnaphthalene (DMN) has seen increase application as a sprout inhibitor in the potato industry as older chemistries are being phased out. The mode of action of DMN is poorly understood as is the sensitivity of potato tissues to this new class of inhibitor. During storage potato tubers transition from a state of endo-dormant to eco-dormant and it is not known if the DMN response is consistent across this developmental transition. RNA-seq gene expression profiling was used to establish if stored potato tubers (Solanum tuberosum cv La Chipper) have differential sensitivity to DMN as tubers age. DMN was applied at three different times during storage; just after harvest when tubers are in endo-dormancy, midwinter at early eco-dormancy, and in spring during late eco-dormancy when sprouting was prevented via exposure to cold storage temperatures. Changes in gene expression were lowest during endo-dormancy while midwinter and spring treatments exhibited a greater and more diverse expression response. Functional analysis of differential gene expression demonstrated gene sets associated with DNA replication, cell division, and DNA methylation are suppressed after DMN treatment. However, gene sets associated with salicylic acid, jasmonic acid, abiotic and biotic stress responses are elevated by DMN only after endodormancy terminates. Gene clusters associated with pathogenesis related proteins PR-4 and PR-5 are also upregulated in response to DMN. These results indicate that DMN sensitivity changes as potato tubers age and transition from endo-dormant to eco-dormant in storage and the overall response is a shift in gene classes that regulate growth and response to stress.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Meristema , Dormência de Plantas , Tubérculos , Solanum tuberosum , Armazenamento de Alimentos , Perfilação da Expressão Gênica/métodos , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Naftalenos/química , Tubérculos/genética , Tubérculos/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo
2.
Nucleic Acids Res ; 48(9): 4627-4642, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32282912

RESUMO

Targeting of G-quadruplexes, non-canonical conformations that form in G-rich regions of nucleic acids, has been proposed as a novel therapeutic strategy toward several diseases, including cancer and infections. The unavailability of highly selective molecules targeting a G-quadruplex of choice has hampered relevant applications. Herein, we describe a novel approach, based on naphthalene diimide (NDI)-peptide nucleic acid (PNA) conjugates, taking advantage of the cooperative interaction of the NDI with the G-quadruplex structure and hybridization of the PNA with the flanking region upstream or downstream the targeted G-quadruplex. By biophysical and biomolecular assays, we show that the NDI-PNA conjugates are able to specifically recognize the G-quadruplex of choice within the HIV-1 LTR region, consisting of overlapping and therefore mutually exclusive G-quadruplexes. Additionally, the conjugates can induce and stabilize the least populated G-quadruplex at the expenses of the more stable ones. The general and straightforward design and synthesis, which readily apply to any G4 target of choice, together with both the red-fluorescent emission and the possibility to introduce cellular localization signals, make the novel conjugates available to selectively control G-quadruplex folding over a wide range of applications.


Assuntos
Quadruplex G , Repetição Terminal Longa de HIV , Ácidos Nucleicos Peptídicos/química , DNA/química , HIV-1/genética , Células HeLa , Humanos , Imidas/química , Ligantes , Modelos Genéticos , Naftalenos/química , Ácidos Nucleicos Peptídicos/metabolismo
3.
Nat Commun ; 11(1): 1830, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286350

RESUMO

A synthetic biology method based on heterologous biosynthesis coupled with genome mining is a promising approach for increasing the opportunities to rationally access natural product with novel structures and biological activities through total biosynthesis and combinatorial biosynthesis. Here, we demonstrate the advantage of the synthetic biology method to explore biological activity-related chemical space through the comprehensive heterologous biosynthesis of fungal decalin-containing diterpenoid pyrones (DDPs). Genome mining reveals putative DDP biosynthetic gene clusters distributed in five fungal genera. In addition, we design extended DDP pathways by combinatorial biosynthesis. In total, ten DDP pathways, including five native pathways, four extended pathways and one shunt pathway, are heterologously reconstituted in a genetically tractable heterologous host, Aspergillus oryzae, resulting in the production of 22 DDPs, including 15 new analogues. We also demonstrate the advantage of expanding the diversity of DDPs to probe various bioactive molecules through a wide range of biological evaluations.


Assuntos
Diterpenos/farmacologia , Fungos/química , Naftalenos/farmacologia , Pironas/farmacologia , Biologia Sintética , Peptídeos beta-Amiloides/metabolismo , Animais , Fármacos Anti-HIV/farmacologia , Aspergillus/química , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Proliferação de Células/efeitos dos fármacos , Diterpenos/química , Drosophila/efeitos dos fármacos , Fungos/genética , Genoma Fúngico , HIV-1/efeitos dos fármacos , Humanos , Células MCF-7 , Naftalenos/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Agregados Proteicos , Pironas/química , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Estereoisomerismo
4.
Chemosphere ; 252: 126541, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32217411

RESUMO

Emission factor and removal efficacy of PCNs are evaluated via the flue gas sampling of two MWIs equipped with different air pollution control devices (APCDs) in Taiwan. MWI-A is equipped with ESP, wet scrubber (WS) and selective catalytic reduction (SCR), while cyclone (CY), semi-dry absorber (SDA), activated carbon injection (ACI) and baghouse (BH) are employed in MWI-B. The average concentrations of PCNs measured at stacks of MWI-A and MWI-B are 2.1 ng Nm-3 (0.218 pg TEQ Nm-3) and 23.2 ng Nm-3 (0.425 pg TEQ Nm-3), respectively. The emission factors of PCNs calculated from feeding rates of waste and stack sampling results range from 6.7 to 6.95 µg t-1 (0.790-1.45 ng TEQ t-1). PCNs are formed in ESP via chlorination, while SCR and SDA + ACI + BH are effective in removing PCNs with the overall efficacies of 97.6% and 94.3%, respectively. PCN removal efficiencies achieved with SCR and SDA + ACI + BH increase as chlorination level increases. Specifically, around 72% and 82% of Mono-CN are removed by SCR and SDA + ACI + BH, respectively. The removal efficacies of other homologues achieved with SCR are consistently high (96-100%). Dominances of Mono-to Tri-CNs in scrubbing liquid collected from WS and higher removal efficacies of these homologues achieved with WS + ESP compared with ESP alone indicate that WS can capture low chlorinated PCNs to some extent. The results suggest that CY + SDA + ACI + BH should be equipped in MWI for effective removal of PCNs, while ESP, WS and SCR should be utilized with precaution to eliminate PCNs formation and enhance the PCNs removal efficiency.


Assuntos
Monitoramento Ambiental , Incineração/métodos , Naftalenos/química , Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Catálise , Taiwan
5.
Environ Pollut ; 259: 113838, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023785

RESUMO

To date limited information's are available concerning unintentional productions, screening, profiling, and health risks of polychlorinated naphthalenes (PCNs) in ambient environment and occupational environment. Literature reveals that dust is a neglected environmental matrix never measured for PCNs. To our knowledge, this is the first study to investigate the concentrations and health risks of PCNs in indoor dust, air, and blood of major e-waste recycling hubs in Pakistan. Indoor air (n = 125), dust (n = 250), and serum (n = 250) samples were collected from five major e-waste hubs and their vicinity to measure 39 PCN congeners using GC-ECNI-MS. ∑39PCN concentrations in indoor air, dust, and serum (worker > resident > children) samples ranged from 7.0 to 9583 pg/m3, from 0.25 to 697 ng/g, and from 0.15 to 401 pg/g lipid weight, respectively. Predominant PCN congeners in indoor air and dust were tri- and tetra-CNs, while tetra- and penta-CNs were dominant in human serum samples. The higher PCNs contribution was recorded at the recycling units, while the lower was observed at the shops of the major e-waste hubs. Higher contribution of combustion origin CNs in air, dust and human samples showed combustion sources at the major e-waste hubs, while Halowax and Aroclor based technical mixture showed minor contribution in these samples. Mean toxic equivalent (TEQ) concentrations of PCNs were 2.79E+00 pg-TEQ/m3, 1.60E-02 ng-TEQ/g, 8.11E-01 pg-TEQ/g, 7.14E-01 pg-TEQ/g, and 6.37E-01 pg-TEQ/g for indoor air, dust, and serum samples from workers, residents, and children, respectively. In our study, CNs- 66/67 and -73 in indoor air, dust, and human serum were the great contributors to total TEQ concentrations of PCNs. This first base line data directs government and agencies to implement rules, regulation to avoid negative health outcomes and suggests further awareness in regard of provision of proper knowledge to the target population.


Assuntos
Resíduo Eletrônico , Exposição Ambiental , Naftalenos , Criança , Poeira , Resíduo Eletrônico/efeitos adversos , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Naftalenos/análise , Naftalenos/química , Naftalenos/toxicidade , Paquistão , Medição de Risco
6.
J Environ Sci (China) ; 90: 67-77, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081342

RESUMO

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO4], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO4] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.


Assuntos
Poluentes Ambientais/química , Ferro/química , Naftalenos/química , Solo , Brasil , Compostos Ferrosos , Oxirredução , Sulfatos , Água
7.
Chem Commun (Camb) ; 56(10): 1505-1508, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31917382

RESUMO

A bio-inspired, ATP-driven nucleation growth assembly is demonstrated using an amphiphilic naphthalene diimide (NDI) derivative appended with guanidinium receptors to promote specific salt-bridge type interaction with nucleotide phosphates. Detailed spectroscopic and microscopic probing revealed a pathway-dependent co-operative self-assembly to yield two-dimensional and scrolled nano-tubular bilayer assemblies under kinetic and thermodynamic conditions, respectively.


Assuntos
Trifosfato de Adenosina/química , Imidas/química , Naftalenos/química , Guanidina/química , Ligação de Hidrogênio , Cinética , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Espectrofotometria , Temperatura , Termodinâmica
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117898, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901802

RESUMO

The native and synchronous fluorescence spectroscopy procedures have been established and validated for the simultaneous determination of a binary mixture of dapoxetine hydrochloride (DAP) and avanafil (AVA). The first procedure is based on measurement of native fluorescence intensity of both drugs at λEm 337 nm and 370 nm using λEx 290 nm and 314 nm for DAP and AVA in methanol respectively. The second procedure describes a measurement of synchronous fluorescence intensity of these drugs at 232 nm for DAP, and 267 nm for AVA, using Δλ of 90nm. In the first procedure the fluorescence concentration were 0.1-4.0 µg/mL for DAP and 0.5-16 µg/mL for AVA. For the second procedure fluorescence concentrations were 0.025-1.0 µg/mL and 0.5-16 µg/mL for DAP and AVA respectively, with lower detection limit and quantification limits. The processes were successfully used for the limitation of DAP and AVA in their drug product without pre-separation. Then, the techniques were utilized for the determination of DAP and AVA in biological fluids. There is a good agreement between these results and the results obtained using a reference method.


Assuntos
Benzilaminas , Naftalenos , Pirimidinas , Benzilaminas/química , Benzilaminas/farmacocinética , Composição de Medicamentos , Humanos , Limite de Detecção , Naftalenos/química , Naftalenos/farmacocinética , Pirimidinas/análise , Pirimidinas/farmacocinética , Espectrometria de Fluorescência
9.
Mar Drugs ; 18(1)2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31963874

RESUMO

Five new perylenequinone derivatives, altertoxins VIII-XII (1-5), as well as one known compound cladosporol I (6), were isolated from the fermentation broth of the marine-derived fungus Cladosporium sp. KFD33 from a blood cockle from Haikou Bay, China. Their structures were determined based on spectroscopic methods and ECD spectra analysis along with quantum ECD calculations. Compounds 1-6 exhibited quorum sensing inhibitory activities against Chromobacterium violaceum CV026 with MIC values of 30, 30, 20, 30, 20 and 30 µg/well, respectively.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Cladosporium/química , Perileno/análogos & derivados , Quinonas/química , Percepção de Quorum/efeitos dos fármacos , China , Testes de Sensibilidade Microbiana/métodos , Naftalenos/química , Naftalenos/farmacologia , Perileno/química , Perileno/farmacologia , Quinonas/farmacologia
10.
Talanta ; 209: 120557, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892065

RESUMO

Profile the spatial distributions of endogenous metabolites in heterogeneous tissues is critical to elucidate the complex metabolic mechanisms during pathological progression. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a label-free technique for tissue imaging that allows simultaneous localisation and quantification of metabolites in different histological regions of interest. In the present study, 1,1'-binaphthyl-2,2'-diamine (BNDM) was developed as a novel MALDI matrix for the detection and imaging of metabolites because of its low background interference, high sensitivity, and applicability in both positive and negative ion modes. 301 negative metabolite ions and 175 positive metabolite ions, including amino acids, organic acids, nucleosides, nucleotides, nitrogenous bases, cholesterols, peptides, fatty acids, cholines, carnitines, polyamines, creatine, phospholipids, etc., were imaged in rat brain when BDMN was used as matrix. Furthermore, BNDM-assisted MALDI-MSI of mouse lung cancer tissue successfully characterized the spatial features of numerous metabolites in viable, necrotic, and connective tissue areas. Importantly, our results demonstrate that the viable area of lung cancer tissue contained a higher abundance of K+ adducts, while the necrotic area showed a stronger Na+ adducts intensity. Data-driven segmentation analysis based on the in situ tissue metabolic fingerprints clearly visualized the underlying metabolic heterogeneity of lung cancer, which may provide new insights into the profiling of tumor microenvironment. All these results suggest that the newly developed matrix has great potential application in the field of biomedical research.


Assuntos
Neoplasias Pulmonares/metabolismo , Metaboloma , Metabolômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Encéfalo/metabolismo , Química Encefálica , Diaminas/química , Neoplasias Pulmonares/química , Camundongos Endogâmicos BALB C , Naftalenos/química , Ratos
11.
J Nat Med ; 74(1): 119-126, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31392565

RESUMO

Five eudesmane-type sesquiterpene glycosides, named sonneratiosides A-E (1-5), were isolated from the leaves of Sonneratia alba (Lythraceae). The aglycone of sonneratioside A was identified as cryptomeridiol also known as proximadiol. X-ray crystallographic analysis of sonneratioside A confirmed its structure and its absolute stereochemistry. Eudesmol ß-D-glucopyranoside (6) was also isolated from nature for the first time. The tyrosinase inhibitory activity was assayed for the new compounds together with seven known compounds. Among them, arbutin (12) showed the expected activity and luteolin 7-O-rutinoside (10) showed comparable activity to arbutin.


Assuntos
Lythraceae/química , Sesquiterpenos de Eudesmano/química , Arbutina/química , Glicosídeos/química , Estrutura Molecular , Monofenol Mono-Oxigenase/antagonistas & inibidores , Naftalenos/química , Folhas de Planta/química , Sesquiterpenos/química
12.
J Chromatogr A ; 1614: 460714, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31761436

RESUMO

Developing highly selective stationary phases is essential to address the issues for separation of analytes with similar properties and various components in complex samples. Herein, we report a new triptycene-based material functionalized with polycaprolactone moieties (TP-PCL) as the stationary phase with high-resolution performance for gas chromatography (GC). The TP-PCL capillary column exhibited column efficiency of 5555 plates/m and moderate polarity. On the column, dozens of mixtures of positional and structural isomers can be well resolved, involving benzene derivatives with varying substituents (alkyl, halo, nitro, hydroxyl, amino), naphthalene derivatives, alkanes and alcohols. It exhibits advantageous performance for high resolution of the critical pairs of alkylbenzenes, phenols, anilines and alkanes over the PCL column and commercial DB-35 MS column with similar polarity. Moreover, the TP-PCL column showed excellent separation repeatability and reproducibility with RSD values of 0.02%-0.07% for run-to-run (n = 4), 0.11%-0.18% for day-to-day (n = 4) and 2.1%-4.7% for column-to-column (n = 4). In addition, it exhibited distinctly enhanced thermal stability in contrast to the PCL column. Its application to analysis of the essential oil from Artemisiae argyi proves its good potential for practical use.


Assuntos
Antracenos/química , Cromatografia Gasosa/métodos , Poliésteres/química , Álcoois/análise , Álcoois/química , Alcanos/análise , Alcanos/química , Compostos de Anilina/análise , Compostos de Anilina/química , Derivados de Benzeno/análise , Derivados de Benzeno/química , Isomerismo , Naftalenos/análise , Naftalenos/química , Fenóis/análise , Fenóis/química , Reprodutibilidade dos Testes
13.
Nucleic Acids Res ; 48(2): 709-718, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31713613

RESUMO

DNA interstrand crosslinks (ICLs) induced by the highly genotoxic agent azinomycin B (AZB) can cause severe perturbation of DNA structure and even cell death. However, Streptomyces sahachiroi, the strain that produces AZB, seems almost impervious to this danger because of its diverse and distinctive self-protection machineries. Here, we report the identification of a novel endonuclease-like gene aziN that contributes to drug self-protection in S. sahachiroi. AziN expression conferred AZB resistance on native and heterologous host strains. The specific binding reaction between AziN and AZB was also verified in accordance with its homology to drug binding proteins, but no drug sequestering and deactivating effects could be detected. Intriguingly, due to the high affinity with the drug, AziN was discovered to exhibit specific recognition and binding capacity with AZB-mediated ICL structures, further inducing DNA strand breakage. Subsequent in vitro assays demonstrated the structure-specific endonuclease activity of AziN, which cuts both damaged strands at specific sites around AZB-ICLs. Unravelling the nuclease activity of AziN provides a good entrance point to illuminate the complex mechanisms of AZB-ICL repair.


Assuntos
Proteínas de Transporte/química , DNA/química , Peptídeos e Proteínas de Sinalização Intercelular/química , Proteínas de Transporte/genética , Reagentes para Ligações Cruzadas/química , DNA/genética , Dano ao DNA/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Endonucleases/química , Endonucleases/genética , Humanos , Naftalenos/química , Streptomyces/genética
14.
Chemistry ; 26(1): 139-142, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31680317

RESUMO

Cyclic naphthalene diimides (cNDIs), with a ferrocene moiety (cFNDs) and different linker lengths between the ferrocene and cNDI moieties, were designed and synthesized as redox-active, tetraplex-DNA ligands. Intramolecular stacking was observed between ferrocene and the NDI planes, which could affect the binding properties for G-quadruplexes. Interestingly, the circular dichroism spectrum of one of these compounds clearly shows new Cotton effects around 320-380 and 240 nm, which can be considered a direct evidence of intramolecular stacking of ferrocene and the NDI. Regarding recognition of hybrid G-quadruplexes, the less rigid structures (longer linkers) show higher binding affinity (106 m-1 order of magnitude). All new compounds show higher selectivity for G4 during electrochemical detection than noncyclic FND derivatives, which further identifies the redox-active potentiality of the cFNDs. Two of the three compounds tested even show preferential inhibition of cell growth in cancer cells over normal cells in a low concentration range, highlighting the potential for bioapplications of these cFNDs.


Assuntos
Compostos Ferrosos/química , Quadruplex G , Imidas/química , Metalocenos/química , Naftalenos/química , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Células HeLa , Humanos , Imidas/farmacologia , Ligantes , Naftalenos/farmacologia , Oxirredução , Telômero/química
15.
J Enzyme Inhib Med Chem ; 35(1): 139-144, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31724435

RESUMO

A series of naphthalene-chalcone derivatives (3a-3t) were prepared and evaluated as tubulin polymerisation inhibitor for the treatment of breast cancer. All compounds were evaluated for their antiproliferative activity against MCF-7 cell line. The most of compounds displayed potent antiproliferative activity. Among them, compound 3a displayed the most potent antiproliferative activity with an IC50 value of 1.42 ± 0.15 µM, as compared to cisplatin (IC50 = 15.24 ± 1.27 µM). Additionally, the promising compound 3a demonstrated relatively lower cytotoxicity on normal cell line (HEK293) compared to tumour cell line. Furthermore, compound 3a was found to induce significant cell cycle arrest at the G2/M phase and cell apoptosis. Compound 3a displayed potent tubulin polymerisation inhibitory activity with an IC50 value of 8.4 µM, which was slightly more active than the reference compound colchicine (IC50 = 10.6 µM). Molecular docking analysis suggested that 3a interact and bind at the colchicine binding site of the tubulin.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Chalconas/farmacologia , Naftalenos/farmacologia , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Chalconas/química , Colchicina/antagonistas & inibidores , Colchicina/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Naftalenos/química , Relação Estrutura-Atividade , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química
16.
Biosens Bioelectron ; 151: 111961, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31868607

RESUMO

The direct electrical connection of laccase on the electrode surface is a key feature in the design of efficient and stable biocathodes. However, laccase can perform a direct electron transfer only when it is in the preferred orientation toward the electrode. Here we report the investigation of the orientation of laccase from white rot fungus on multi-walled carbon nanotube surface modified with a naphthalene group. Naphthylated multi wall carbon nanotubes were synthesized and the kinetics of laccase from white rot fungus adsorption and its direct electro-catalytic activity toward oxygen reduction was investigated by QCM and electrochemical techniques. Compared to pristine multi-walled carbon nanotubes laccase shows a high affinity to be adsorbed onto the surface of naphthylated carbon nanotubes at a very fast rate. The subsequent wiring to the naphthylated multi-walled carbon nanotubes is accompanied by a reorientation and arrangement of adsorbed laccase to create a composite biocathode that exhibits a high-performance for oxygen reduction by direct electron transfer with maximum current densities of 3 mA cm-2.


Assuntos
Lacase/química , Nanotubos de Carbono/química , Naftalenos/química , Técnicas Biossensoriais , Catálise , Técnicas Eletroquímicas , Eletrodos , Transporte de Elétrons , Cinética , Oxirredução , Oxigênio/química , Propriedades de Superfície
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117389, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31377683

RESUMO

Rational design chelating fluorescent sensors probing metal ions in biological system are continuously hot essays nowadays, especially for zinc detection. Herein, a naphthylideneimine based zinc fluorescence probe (3) was prepared and characterized in this work. Structural features and optical properties of 3 and its metallic complexes were characterized. Fluorescent experiment indicates 3 is extremely sensitive and selective for Zn2+ with a strong fluorescence enhancement (∼34 folds) in aqueous buffer solution with a limit of detection (LOD) of 3.78 × 10-7 mol L-1. Formation constant (logKa) of the chelating complex of 3 and Zn2+ ion was determined to be 4.45. Theoretical studies were carried out to get deep insight into the response mechanism in the sensing process. Density functional theory (DFT) methods calculated formation Gibbs free energy (ΔrGmÓ©) of the deprotonated complexes model (32- ⊃ Zn) is -2.9 kcal/mol, which is in good agreement with the experimental result. The calculation results show that the low excitation states can be ascribe to S0 → T2 and S0 → S1 at 390-430 nm and 310-330 nm, respectively, due to the π → π∗ transition. Finally, yeast cell imaging experiments indicate that 3 can monitor intracellular Zn2+ as well. These findings would enable this fluorescent probe to be used as a Zinc sensor.


Assuntos
Corantes Fluorescentes/química , Naftalenos/química , Bases de Schiff/química , Espectrometria de Fluorescência/métodos , Zinco/análise , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/química
18.
Chemosphere ; 245: 125602, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864042

RESUMO

As emerging contaminants of global concern, nanoplastics are significantly potential carriers of hydrophobic organic compounds in aquatic and soil environment. However, little is known about the interactions between the transports of nanoplastics and organic contaminants in porous media. In this study, the cotransport of naphthalene with polystyrene nanoplastics (PSNP) in saturated sand columns as influenced by the PSNP/naphthalene ratio and ionic strength (IS) was investigated. The presence of PSNP dramatically enhanced the mobility of naphthalene at low IS (0.5 mM), but such effect was prohibited at high IS (5 mM and 50 mM). The mobility of PSNP in the sand column was higher when it was solely exist in the pore-water than that when in the presence of naphthalene, because of the charge-shielding effect. This work showed that the coexistence of PSNP and naphthalene would influence the mobility of each other in the saturated porous media, which highly related to their concentration ratio and IS levels.


Assuntos
Microplásticos/química , Movimento , Naftalenos/química , Poliestirenos/química , Concentração Osmolar , Porosidade , Areia , Solo
19.
Chem Biol Interact ; 316: 108924, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31843629

RESUMO

Parameritannin A-2 (PA-2) is a natural product extracted from the stems of the plant Urceola huaitingii. Our previous studies have shown that PA-2 exhibits significant synergistic anticancer effects with doxorubicin (DOX) in HGC27 gastric cancer cell lines. Here we report that our isobolographic analysis confirms the synergistic cytotoxic effects of PA-2 and DOX in HGC27 cells. Flow cytometry and immunoblotting indicate that PA-2 enhances DOX-mediated apoptosis. Importantly, PA-2 enhances the intracellular accumulation of DOX in HGC27 cells. The combination of DOX and PA-2 remarkably increases the release of cytochrome C and the activation of caspase-3 and caspase-9, compared with DOX treatment alone. Moreover, PA-2 attenuates the DOX-induced activation of Akt, ERK1/2 and p38 signaling pathways, providing a molecular mechanism for the synergistic effects of DOX and PA-2 in the induction of apoptosis. In conclusion, our studies demonstrate that PA-2 and DOX synergistically induce mitochondria-dependent apoptosis as PA-2 inhibits the PI3K/Akt, ERK1/2 and p38 pathways in HGC27 cells. These findings suggest that the combination treatment with PA-2 and DOX may represent a potent therapy for gastric cancer.


Assuntos
Apocynaceae/química , Apoptose/efeitos dos fármacos , Benzopiranos/farmacologia , Produtos Biológicos/farmacologia , Mitocôndrias/metabolismo , Naftalenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Apocynaceae/metabolismo , Benzopiranos/química , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Sinergismo Farmacológico , Humanos , Mitocôndrias/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Naftalenos/química , Fosfatidilinositol 3-Quinases/metabolismo , Caules de Planta/química , Caules de Planta/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Talanta ; 208: 120279, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816747

RESUMO

Intracellular pH, especially cytoplasmic pH (~7.2) plays a crucial role in cell functions and metabolism. A ratiometric fluorescent probe namely, 6-(2-(benzothiazol-2-yl)vinyl)naphthalen-2-ol (BTNO) was facilely synthesized by the condensation of 6-hydroxy-2-naphthaldehyde and 2-methylbenzothiazole. BTNO exhibited a remarkable ratiometric emission (F456/F526) enhancement in response to a pH change with a linear range of pH = 9.50-7.00 and a pKa value of 7.91 ±â€¯0.03, which is desirable for measuring and monitoring the cytoplasmic pH fluctuations. In addition, because of the high fluorescence quantum yield of BTNO (Φ = 0.88 in DMSO and 0.61 in water relative to quinine sulfate solution in 0.1 M H2SO4), the interferences of the probe on the physiological functions could be greatly reduced. This could also provide enhanced measurement sensitivity. The successful demonstration of BTNO in detecting and monitoring the intracellular pH changes in live HeLa cells via a ratiometric approach confirmed that BTNO held a practical potential in biomedical research.


Assuntos
Citoplasma/metabolismo , Fluorescência , Corantes Fluorescentes/química , Imagem Molecular/métodos , Naftalenos/química , Triazóis/química , Proliferação de Células , Corantes Fluorescentes/administração & dosagem , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Naftalenos/administração & dosagem , Espectrometria de Fluorescência
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