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1.
J Chromatogr Sci ; 57(10): 910-919, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31644804

RESUMO

A new ultra-high-performance liquid chromatography method for the simultaneous quantification of sofosbuvir, daclatasvir and ledipasvir was developed. Two combinations of these direct-acting antivirals are used in hepatitis C virus infection therapy and show high efficacy and safety. Fractional factorial design was used for screening the most influential factors on separation and time analysis. These significant factors were optimized using a central composite design. The optimum resolution was carried out by using a Waters XBridge C18 column (150 mm, 4.6 mm ID, 5 µm) at a temperature of 35°C ± 2°C and acetonitrile/sodium perchlorate buffer (10 mM, pH = 3.2) (40: 60 v/v) as mobile phase at a flow rate of 1.5 mL min-1. UV detection was set at λ = 210 nm. A short chromatographic separation time was achieved. The developed method was validated according to the accuracy profile approach and was found specific, precise, faithful and accurate. The detection limits were between 0.07 and 0.13 µg mL-1. Hence, this novel method can be employed for the routine quality control analysis and in dissolution profile studies of generics containing these products.


Assuntos
Benzimidazóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Fluorenos/análise , Imidazóis/análise , Sofosbuvir/análise , Benzimidazóis/química , Fluorenos/química , Imidazóis/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Sofosbuvir/química , Comprimidos
2.
Chem Commun (Camb) ; 55(95): 14238-14254, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31724667

RESUMO

The spirobifluorene (SBF) fragment constitutes one of the most important scaffolds used in the design of Organic Semi-Conductors (OSCs) for organic electronics. In the last ten years, new generations of SBF positional isomers have appeared in the literature. The different positions of substitution (C1, C3 or C4) have allowed the tuning of the electronic properties of great interest for the further design of functional materials. The high potential of these new generations of organic semi-conductors in electronics has been demonstrated notably when they are used as host materials for Phosphorescent Organic Light-Emitting Diodes (OLEDs) or for Thermally Activated Delayed Fluorescence OLEDs. In the present feature article, we present these new generations of SBF compounds and the impact of positional isomerism on the electronic properties and device performance. Particularly, we show how the different structural and electronic parameters (nature of the linkages, bridge substitution and steric hindrance) drive the electrochemical and photophysical properties of SBF regioisomers and can be modulated. Such studies lay the foundation for material design for organic electronics.


Assuntos
Fluorenos/química , Compostos de Espiro/química , Eletrônica , Fluorenos/síntese química , Estrutura Molecular , Compostos de Espiro/síntese química , Estereoisomerismo
3.
Molecules ; 24(19)2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31597324

RESUMO

A three-dimensional bay-annulated-indigo (BAI) tetramer has been prepared by appending BAI units onto a low-cost spiro[fluorene-9,9'-xanthene] (SFX) core. The target compound 4BAI-SFX exhibits strong and broad absorption in the visible region covering the range of 450~700 nm. The electrochemical measurement illuminates the characteristics of a deep lowest unoccupied molecular orbital (LUMO) level and multiple redox states of 4BAI-SFX. These results suggest that 4BAI-SFX should be a selectable electron-transporting material for eco-friendly organic semiconductors.


Assuntos
Fluorenos/química , Índigo Carmim/química , Xantenos/química , Fenômenos Químicos , Técnicas de Química Sintética , Índigo Carmim/síntese química , Estrutura Molecular , Processos Fotoquímicos
4.
Chemistry ; 25(69): 15759-15764, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31628819

RESUMO

A general and robust method for the incorporation of aspartates with a thioacid side chain into peptides has been developed. Pseudoproline tripeptides served as building blocks for the efficient fluorenylmethyloxycarbonyl (Fmoc) solid-phase synthesis of thioacid-containing peptides. These peptides were readily converted to complex N-glycopeptides by using a fast and chemoselective one-pot deprotection/ligation procedure. Furthermore, a novel side reaction that can lead to site-selective peptide cleavage using thioacids (CUT) was discovered and studied in detail.


Assuntos
Glicopeptídeos/síntese química , Oligopeptídeos/química , Prolina/análogos & derivados , Técnicas de Síntese em Fase Sólida/métodos , Tiazóis/química , Ácidos/química , Sequência de Aminoácidos , Fluorenos/síntese química , Fluorenos/química , Glicopeptídeos/química , Oligopeptídeos/síntese química , Prolina/síntese química , Prolina/química , Compostos de Sulfidrila/química , Tiazóis/síntese química
5.
Chem Commun (Camb) ; 55(81): 12231-12234, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31553001

RESUMO

The photophysical properties of a new series of fluorenyl porphyrins bearing water-solubilising oligoethyleneglycol chains are described. These biocompatible compounds present very good two-photon absorption and singlet oxygen generation properties, while retaining some fluorescence in water. After testing in vitro on breast cancer cells, some of them were shown to be efficient non-toxic two-photon photosensitisers allowing for fluorescence imaging, thus demonstrating their theranostic potential.


Assuntos
Fluorenos/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Porfirinas/química , Materiais Biocompatíveis/química , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Raios Infravermelhos , Células MCF-7 , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Estrutura Molecular , Imagem Óptica/métodos , Polietilenoglicóis/química , Oxigênio Singlete/química , Relação Estrutura-Atividade
6.
Molecules ; 24(17)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480760

RESUMO

A synthetic approach to a new group of stable chiral C2-symmetric diimines with the 4,5-diazafluorene core has been developed based on condensation of dipinodiazafluorene with aromatic diamines. The chemical structures of new compounds were proven by spectroscopic methods and X-ray crystallography. All the compounds form solvates with organic solvents (chloroform, benzene, 1,4-dioxane) and water. Specific spectral data of the new compounds are explained using calculated data (DFT). Diimines of the pinodiazafluorene series give colored reactions with transition metal ions and can be regarded as prospective polydentate ligands with interesting luminescent and chiroptical properties.


Assuntos
Fluorenos/química , Iminas/química , Cristalografia por Raios X , Iminas/síntese química , Luminescência , Conformação Molecular , Compostos de Espiro/síntese química , Compostos de Espiro/química , Estereoisomerismo , Temperatura
7.
Molecules ; 24(18)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540264

RESUMO

New 3D conformers were synthesized to show a nanomolecular configuration with geometrically branched 2-diphenylaminofluorene (DPAF-C2M) chromophores using a symmetrical 1,3,5-triaminobenzene ring as the center core for the connection of three fused DPAF-C2M moieties. The design led to a class of cis-cup-tris[(DPAF-C2M)-C60(>DPAF-C9)] 3D conformers with three bisadduct-analogous cages per nanomolecule facing at the same side of the geometrical molecular cis-cup-shape structure. A sequential synthetic route was described to afford this 3D configurated conformer in a high yield with various spectroscopic characterizations. In principle, a nanostructure with a non-coplanar 3D configuration in design should minimize the direct contact or π-stacking of fluorene rings with each other during molecular packing to the formation of fullerosome array. It may also prevent the self-quenching effect of its photoexcited states in solids. Photophysical properties of this cis-cup-conformer were also investigated.


Assuntos
Fluorenos/síntese química , Fulerenos/química , Transporte de Elétrons , Fluorenos/química , Conformação Molecular , Estrutura Molecular , Estereoisomerismo
8.
Molecules ; 24(16)2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31409040

RESUMO

Polymer dots (Pdots) represent newly developed semiconductor polymer nanoparticles and exhibit excellent characteristics as fluorescent probes. To improve the sensitivity and biocompatibility of Pdots ratiometric pH biosensors, we synthesized 3 types of water-soluble Pdots: Pdots-PF, Pdots-PP, and Pdots-PPF by different combinations of fluorescent dyes poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), poly[(9,9-dioctyl-fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadazole)] (PFBT), and fluorescein isothiocyanate (FITC). We found that Pdots-PPF exhibits optimal performance on pH sensing. PFO and FITC in Pdots-PPF produce pH-insensitive (λ = 439 nm) and pH-sensitive (λ = 517 nm) fluorescence respectively upon a single excitation at 380 nm wavelength, which enables Pdots-PPF ratiometric pH sensing ability. Förster resonance energy transfer (FRET) together with the use of PFBT amplify the FITC signal, which enables Pdots-PPF robust sensitivity to pH. The emission intensity ratio (I517/I439) of Pdots-PPF changes linearly as a function of pH within the range of pH 3.0 to 8.0. Pdots-PPF also possesses desirable reversibility and stability in pH measurement. More importantly, Pdots-PPF was successfully used for cell imaging in Hela cells, exhibiting effective cellular uptake and low cytotoxicity. Our study suggests the promising potential of Pdots-PPF as an in vivo biomarker.


Assuntos
Técnicas Biossensoriais , Fluorenos/química , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Imagem Óptica/métodos , Polímeros/química , Pontos Quânticos/química , Transferência Ressonante de Energia de Fluorescência , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Semicondutores , Solubilidade , Água
9.
Dalton Trans ; 48(35): 13396-13405, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31432885

RESUMO

In this study, five ruthenium arene complexes with fluorene-bearing N,N-(1) and N,O-(2) donor Schiff base ligands were synthesized and fully characterized. Cationic ruthenium complexes 3[X], ([Ru(η6-C6H6)(Cl)(fluorene-N[double bond, length as m-dash]CH-pyridine)][X] (where X = BF4, PF6, BPh4), were obtained by reacting ligand 1 with [Ru(η6-C6H6)Cl2]2 in the presence of NH4X salts, whereas neutral complex 4, Ru(η6-C6H6)(Cl)(fluorene-N[double bond, length as m-dash]CH-naphtholate), was isolated by reacting ligand 2 with the same precursor. It was possible to obtain a cationic version of the latter, 5[BF4], by reacting 4 with AgBF4 in the presence of pyridine. All compounds were fully characterized by NMR and HR-ESI-MS whereas some of them were also analyzed by single crystal X-ray analysis. Their in vitro antiproliferative activity was also assessed in human breast cancer cell lines, notably MCF-7 and T47D. Complex 4 and its cationic counterpart 5[BF4] were found to be the most cytotoxic compounds of the series (IC50 = 6.2-16.2 µM) and displayed higher antiproliferative activities than cisplatin in both cell lines. It was found that 5[BF4] undergoes a ligand exchange reaction and readily converts to 4 in the presence of 0.1 M NaCl, explaining the similarity in their observed cytotoxicities. Whereas 3[BF4] and 3[PF6] were found inactive at the tested concentrations, 3[BPh4] displayed a considerable cytotoxicity (IC50 = 16.7-27.8 µM). Notably, 3[BPh4], 4 (and 5[BF4]) were active against T47D, a cisplatin resistant cell line. Interestingly, 4 (16.4 µM) was found to be less cytotoxic than 3[BPh4] and cisplatin (6.6 and 7.9 µM, respectively) in breast healthy cells (MCF-12A). However, in comparison to 4 and cisplatin (at 10 µM), a lower in vivo toxicity was observed for complex 3[BPh4] on the development of zebrafish (Danio rerio) embryos.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Fluorenos/química , Rutênio/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Complexos de Coordenação/síntese química , Complexos de Coordenação/toxicidade , Humanos , Células MCF-7 , Modelos Moleculares , Conformação Molecular , Peixe-Zebra/embriologia
10.
J Pept Sci ; 25(7): e3193, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31309675

RESUMO

Aspartimide (Asi) formation is a notorious side reaction in peptide synthesis that is well characterized and described in literature. In this context, we observed significant amounts of chain termination in Fmoc-SPPS while synthesizing the N-terminal Xaa-Asp-Yaa motif. This termination was caused by the formation of piperazine-2,5-diones. We investigated this side reaction using a linear model peptide and independently synthesizing its piperazine-2,5-dione derivative. Nuclear magnetic resonance (NMR) data of the side product present in the crude linear peptide proves that exclusively the six-membered ring is formed whereas the theoretically conceivable seven-membered 1,4-diazepine-2,5-dione is not found. We propose a mechanism where nucleophilic attack of the N-terminal amino function takes place at the α-carbon of the carbonyl group of the corresponding Asi intermediate. In addition, we systematically investigated the impact of (a) different adjacent amino acid residues, (b) backbone protection, and (c) side chain protection of flanking amino acids. The side reaction is directly related to the Asi intermediate. Hence, hindering or avoiding Asi formation reduces or completely suppresses this side reaction.


Assuntos
Aminoácidos/química , Ácido Aspártico/análogos & derivados , Fluorenos/química , Peptídeos/síntese química , Piperazinas/síntese química , Técnicas de Síntese em Fase Sólida , Sequência de Aminoácidos , Ácido Aspártico/química , Estrutura Molecular , Peptídeos/química , Piperazinas/química
11.
Talanta ; 204: 592-601, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357339

RESUMO

Development of conjugated polymers with fluorescence sensing characteristics has received close attention from researchers in fields of environmental protection, biosensing and toxins detection on food. In this paper, novel polyaniline derivatives of poly(9-methyl-9H-carbazol-3-amine) and poly(9,9-dihexyl-9H-fluoren-2-amine) are prepared by facile chemical polymerization. Then they are characterized with NMR (Nuclear Magnetic Resonance), GPC (Gel Permeation Chromatography), XRD (X-Ray Diffraction), FT-IR (Fourier Transform Infrared spectroscopy), FL (Fluorescence spectrometry) and UV-vis (Ultraviolet-visible spectroscopy) characterizations and further applied to the fluorescence detection of different acids and amines. Moreover, the obtained poly(9-methyl-9H-carbazol-3-amine) displays excellent fluorescence properties in the detection for both acids and amines. Besides, this poly(9-methyl-9H-carbazol-3-amine) can not only be used for fluorescence detection in solution, but also can be prepared into solid state and applied in the gas phase fluorescence detection. This work has greatly expanded the scope of application to these polyaniline derivatives materials, opening a new path for the researches on multi-functional chemosensor.


Assuntos
Compostos de Anilina/química , Carbazóis/química , Fluorenos/química , Corantes Fluorescentes/química , Compostos de Anilina/síntese química , Carbazóis/síntese química , Etilenodiaminas/análise , Etilenodiaminas/química , Fluorenos/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Ácido Clorídrico/análise , Ácido Clorídrico/química , Ligação de Hidrogênio , Limite de Detecção , Metilaminas/análise , Metilaminas/química , Ácido Nítrico/análise , Ácido Nítrico/química , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/métodos
12.
Environ Sci Pollut Res Int ; 26(25): 25476-25490, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31264155

RESUMO

The rice husk ash (RHA) was used as an alternative source of silica for the synthesis of the functionalized mesoporous material, which was used in the removal of the PAHs naphthalene (Nap), benzo[b]fluoranthene (B[b]F), benzo[k]fluoranthene (B[k]F), and benzo[a]pyrene (B[a]P) from aqueous media. The PABA-MCM-41 (RHA) was characterized using FTIR, TGA, SAXS, and N2 adsorption-desorption analyses. Removal experiments were performed to determine the initial concentrations, individual adsorption in comparison with the mixture of the PAHs, PABA-MCM-41 (RHA) amount, pH, time, and temperature, and the results obtained were statistically analyzed. The PABA-MCM-41 (RHA) presented the SBET, VT, and DBJH values of 438 m2 g-1, 0.41 cm3 g-1, and 3.59 nm, respectively, and good thermal stability. The qe values found in the kinetic equilibrium for the PAHs mixture followed increasing order: Nap < B[a] P < B[k]F < B[b]F, with removal percentages of 89.08 ± 0.00, 93.85 ± 0.28, 94.54 ± 0.10, and 97.80 ± 0.05%, respectively. Graphical abstract.


Assuntos
Fluorenos/química , Oryza/química , Hidrocarbonetos Policíclicos Aromáticos/química , Dióxido de Silício/química , Adsorção , Cinética , Espalhamento a Baixo Ângulo , Temperatura , Água , Difração de Raios X
13.
Eur J Med Chem ; 178: 484-499, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202994

RESUMO

In our work, 19 novel 4,5-diazafluorene derivatives (11a-d, 12a-d, 13a-d, 14a-c, 15c, 16a-c) bearing a 1,3-disubstituted pyrazol/thioxothiazolidinone or thioxothiazolidinone-oxadiazole moieties were designed, synthesized, preliminarily explored for their antitumor activities and in vitro mechanism. All compounds showed different values of antiproliferative activity against A549, AGS, HepG2 and MCF-7 cell lines through CCK-8. Especially, the compound 14c exhibited the strongest activity and best selectivity against A549 cells with an IC50 1.13 µM and an SI value of 7.01 relative to MRC-5 cells, which was better than cisplatin (SI = 1.80) as a positive control. Experimental results at extracellular level demonstrated that compounds 14a-c could strongly interact with the G-quadruplex(es) formed in a 26 nt telomeric G-rich DNA, in particular, the 14c exhibits quite strong binding affinity with an association equilibrium constant (KA) of 7.04(±0.16) × 107 M-1 and more than 1000-fold specificity to G4-DNA over ds-DNA and Mut-DNA at the compound/G4-DNA ratio of 1:1. Further trap assay ascertained that compounds 14a-c owned strong inhibitory ability of telomerase activity in A549 cells, suggesting that these compounds have great possibility to target telomeric G-quadruplexes and consequently indirectly inhibit the telomerase activity. In addition, it is worthy of note that the remarkable inhibitory effects of 14a-c on the mobility of tested cancer cells were observed by wound healing assays. Furthermore, molecular docking and UV-Vis spectral results unclose the rationale for the interaction of compounds with such G-quadruplex(es). These results indicate that the growth and metastasis inhibition of cancer cells mediated by these 4,5-diazafluorene derivatives possibly result from their interaction with telomeric G-quadruplexes, suggesting that 4,5-diazafluorene derivatives, especially 14c, possess potential as anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Fluorenos/farmacologia , Quadruplex G/efeitos dos fármacos , Telômero/efeitos dos fármacos , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Fluorenos/síntese química , Fluorenos/química , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Cicatrização/efeitos dos fármacos
14.
Biosens Bioelectron ; 141: 111337, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31220724

RESUMO

We report on facile synthesis and characterization of phosphate-functionalized polymer dots (PDs) by doping tributyl phosphate (TBP) in a semiconducting polymer poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,10-3}-thiadiazole)] (PFBT). Then, the prepared TBP@PFBT PDs were used to develop a very high sensitive probe for detection Fe3+, Cu2+ ions and Cytochrome c based on aggregation induced fluorescence off mechanism. The PDs exhibited a linear dynamic range for Fe3+ from 0.1 to 2 nM with a detection limit of 30 pM and for Cu2+ from 2.0 to 50.0 nM with a detection limit of 0.35 nM. Meanwhile, this probe showed a linear dynamic range for Cyt c from 175 to 1750 pM with a detection limit of 32.7 pM. The TBP@PFBT PDs is a simple, one-step, fast, non-invasive, label-free, and inexpensive probe that is capable of online apoptosis monitoring response to drugs with an ever-present opportunity to contribute in a variety of in-vitro and in-vivo biological applications. We also obtained sharp, specific 2D and 3D imaging results for early stage apoptosis in breast cancer cells. Moreover, this technique possesses the advantage of rapid determination of Fe3+ ion in biological or environmental samples. Importantly, this label-free assay provides short determination time of only a few min, easy operation and very low LOD allowing 100-4000 times increased in sensitivity over previously reported probes, together with high selectivity without need to using biorecognition elements like enzymes, antibodys and/or aptamers. Such excellent features make the TBP@PFBT PDs an excellent probe for successful apoptosis imaging in live cells.


Assuntos
Apoptose , Técnicas Biossensoriais/métodos , Citocromos c/análise , Fluorenos/química , Corantes Fluorescentes/química , Ferro/análise , Polímeros/química , Cátions/análise , Linhagem Celular , Cobre/análise , Humanos , Limite de Detecção , Células MCF-7 , Imagem Óptica/métodos , Organofosfatos/química , Semicondutores
15.
Talanta ; 203: 314-321, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31202345

RESUMO

We reported a new strategy for sensitive monitoring in vitro RNA synthesis in real time based on fluorescence resonance energy transfer (FRET) from water-soluble conjugated polymer poly (9, 9-bis (6'-N, N, N,-trimethylammonium) hexyl) fluorene-co-alt-1,4-phenylene) bromide (PFP) to fluorogenic RNA aptamer/fluorophore (Spanich2/DFHBI and Broccoli/DFHBI) system. In this strategy, RNA of interest was transcribed accompanied by the Spanich2 or Broccoli. Then the 3, 5-difluoro-4-hydroxybenzylidene imidazolinone (DFHBI) bound to the RNA aptamer sequence and thereby induced a fluorescence signal. PFP was used as the fluorescence energy donor, and Spanich2/DFHBI was the fluorescence energy acceptor. The fluorescence signal of Spanich2/DFHBI was amplified by light-harvesting and fluorescence amplification ability of PFP via FRET. And the limit of detection (LOD) (0.29 nM) was near 10-fold lower than that of RNA aptamer/DFHBI (LOD is 2.8 nM) alone by measuring the FRET ratio, which greatly reduced the variation of background signals. Most importantly, the addition of PFP did not interfere with RNA transcription in vitro, so this method was successfully applied to sensitively monitor RNA transcription and effect of T7 RNA polymerase inhibitor in real time, supplying a sensitive and simple method to study the modulation and inhibitor of RNA polymerase in vitro.


Assuntos
RNA/análise , Transcrição Genética , Aptâmeros de Nucleotídeos/química , Compostos de Benzil/química , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , Dactinomicina/análogos & derivados , Dactinomicina/química , Fluorenos/química , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Heparina/química , Imidazolinas/química , Limite de Detecção , Compostos de Amônio Quaternário/química , RNA/genética , Transcrição Genética/efeitos dos fármacos , Proteínas Virais/antagonistas & inibidores
16.
Chemistry ; 25(46): 10954-10964, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31215691

RESUMO

Epicocconone 1 is a natural chromophore isolated from the fungus Epicoccum nigrum that has shown applications in proteomics and fluorescent microscopy thanks to its unique pro-fluorescence properties. The modification of the skeleton of the natural product by replacing the triene side chain by a fluorenyl scaffold can noticeably increase the fluorophore's absorption coefficient. The synthesis of the analogues of the natural product has been made possible by the use of a palladium-catalyzed carbonylation reaction, allowing the construction of the ß-keto-dioxinone key intermediate. Two-photon absorption cross-section measurements of the fluorenyl epicocconone analogues show a structure dependency with values ranging from 60 to 280 GM and live cell imaging show intense staining of intracellular vesicle-like structures around the nucleus.


Assuntos
Benzopiranos/química , Fluorenos/química , Corantes Fluorescentes/química , Furanos/química , Cetonas/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Benzopiranos/síntese química , Catálise , Fluorenos/síntese química , Corantes Fluorescentes/síntese química , Furanos/síntese química , Cetonas/síntese química , Imagem Óptica/métodos , Células PC12 , Paládio/química , Ratos
17.
Environ Sci Pollut Res Int ; 26(24): 25071-25083, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31250394

RESUMO

As the largest oil field in China, Daqing oil field has been developed in the past six decades. The objectives of this study were to measure the levels of polycyclic aromatic hydrocarbons (PAHs) and assess their ecological risk of PAHs in vegetation soil and bare soil near oil well in Daqing and surrounding soil. Ten sites were selected from two types of soil in grassland: vegetation soil (VS, n = 5) and bare soil (BS, n = 5). The mean concentration of 16 PAHs (∑16 PAHs) was 2240.2 µg/kg. The mean concentrations of eight carcinogenic PAHs (∑8c PAHs) was 1312.3 µg/kg which accounts for 59% of ∑16 PAHs. The sampling sites had higher proportions of high weight molecular ringed PAHs with higher proportions of benzo (a) pyren (BaP) and benzo (k) fluoranthene (BkF). The main source of PAHs was petroleum, coal/biomass combustion, and vehicular emission in these sampling sites. According to Canadian soil quality guidelines, 60% sites had a significant risk to human health. Moreover, 50% sites had high ecological risk and 30% sites were close to this critical value. Notably, PAH levels were significantly higher in VS than BS; moreover, VS had higher organic matter (OM) content, soil dehydrogenase (sDHA) activity, and lower pH and salt content. A structural equation model was established to explore the effects of soil properties on PAH concentration in VS. The result revealed that OM and sDHA were meaningful to enhance the adsorption and biological fixation of PAHs. This study will provide basic information on PAH level and potential application for phytoremediation.


Assuntos
Carvão Mineral/análise , Fluorenos/química , Campos de Petróleo e Gás/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo/química , Emissões de Veículos/análise , Canadá , China , Humanos , Hidrocarbonetos Policíclicos Aromáticos/química
18.
Molecules ; 24(13)2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31252565

RESUMO

The emission properties of three 4-azafluorenone and five new α-carboline fluorophores in both solution and thin solid films were investigated. Fluorescence of the azafluorenone is clearly enhanced in thin solid films due to the presence of phenyl/biphenyl rotors, and these derivatives can be classified as green Aggregation-Induced Emission luminogens (AIEgens) with a non-emissive heteroaromatic core structure. Compared to azafluorenones, emission of α-carbolines is hypsochromically shifted to the blue region of the electromagnetic spectrum, and most of these derivatives exhibit strong violet-blue fluorescence in both solution and thin solid film layers. Further, the effective mobility and electroluminescence of new α-carbolines were investigated in prepared organic field-effect transistors and organic light-emitting diodes, respectively.


Assuntos
Carbolinas/síntese química , Fluorenos/síntese química , Corantes Fluorescentes/síntese química , Carbolinas/química , Fluorenos/química , Corantes Fluorescentes/química , Estrutura Molecular , Soluções
19.
Electrophoresis ; 40(15): 1951-1958, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31111508

RESUMO

A MEKC methodology with UV detection was developed for the enantioselective separation of selenomethionine (SeMet). The use of (+)-1-(9-fluorenyl)ethyl chloroformate (FLEC) as chiral derivatization reagent to form SeMet diastereomers enabled their subsequent separation using ammonium perfluorooctanoate (APFO) as a volatile pseudostationary phase. The effect of APFO concentration and pH, temperature, injection volume, and derivatization conditions (time and FLEC/SeMet ratio) were evaluated in order to select the best separation conditions. A chiral resolution of 4.4 for DL-SeMet was achieved in less than 6 min using 100 mM APFO at pH 8.5 as electrophoretic buffer. Satisfactory results were obtained in terms of linearity, precision (RSD from 3.4 to 5.1% for migration times and from 1.8 to 4.6% for corrected peak areas), accuracy, and LODs (3.1 × 10-6  M and 3.7 × 10-6  M for d and l enantiomers, respectively). The method was successfully applied to the determination of l-SeMet in food supplements.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Selenometionina/isolamento & purificação , Tensoativos/química , Caprilatos/química , Fluorenos/química , Fluorcarbonetos/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Selenometionina/análise , Selenometionina/química , Estereoisomerismo
20.
Chemosphere ; 228: 398-411, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31048237

RESUMO

Endocrine disruptor chemicals induce adverse effects to animals' development, reproduction and behavior in environment. We investigated the effects of fluorene-9-bisphenol (BHPF), one substitute of bisphenol A, on courtship behavior and exploratory behavior of adult zebrafish. Customized apparatus was used to evaluate courtship behavior. The result showed that the male spent less time with BHPF and anti-oestrogenic fulvestrant (FULV) treated female in region of approaching (ROA). Courtship index between BHPF-exposed female and male decreased. The body orientation of BHPF- and FULV-exposed female to male decreased. Furthermore, BHPF exposure downregulated the expression of genes related to estrogen receptor, steroidogenesis and upregulated oxidative stress related genes. It indicated that BHPF exposure interfered the preference of male and female in courtship, and induced detrimental effects on reproduction. BHPF treatment decreased locomotor activity and time spent in top, increased freezing bouts, and induced anxiety/depression-like behavior. The tyrosine hydroxylase in brain decreased under BHPF exposure. Here we showed the potential adverse effects of BHPF on reproduction and exploratory behaviors.


Assuntos
Compostos Benzidrílicos/efeitos adversos , Comportamento Exploratório/efeitos dos fármacos , Fluorenos/química , Fenóis/efeitos adversos , Reprodução/efeitos dos fármacos , Animais , Compostos Benzidrílicos/química , Feminino , Fenóis/química , Peixe-Zebra
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