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1.
Nat Prod Bioprospect ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415420

RESUMO

Betulin (BE) has exceedingly become a potential natural product, providing multiple pharmacological and biological activities, including anti-cancer, anti-viral, and anti-inflammatory benefits. Previous research indicated that the solvatomorphism of BE can easily occur through crystallization with different organic solvents. This property of BE can directly affect its extraction, isolation, and preparation process. In this study, a system of thermogravimetry (TG)-differential thermal analysis (DTA) coupled with mass spectrometry (MS) with electron ionization (EI) and photoionization (PI) capability, equipped with the skimmer-type interface (i.e., skimmer-type interfaced TG-DTA-EI/PI-MS system), as a real-time and onsite analysis technique, was employed. Then, four solvatomorphs of BE, namely, with pyridine and water (A), sec-butanol (B), n,n-dimethylformamide (DMF) (C), and isopropanol (V), were analyzed for the first time. Finally, five kinds of the main volatile gaseous species, including H2O, pyridine, sec-butanol, DMF, and isopropanol, were identified clearly. Furthermore, the multi-step desolvation processes of the four solvatomorphs of BE were revealed by this system for the first time. This system showed great potential for the rapid and accurate analysis of various solvatomorphs of natural products.

2.
Nat Prod Bioprospect ; 2020 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-32306209

RESUMO

Salvianolic acid A (Sal A), a water-soluble ingredient in Danshen, has various biological activities. Sal A and its impurities have similar physical and chemical properties, as well as strong reducibility; therefore, they are difficult to prepare and purify. In this study, high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography. Furthermore, HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis, ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product. The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry, and their contents were quantified as well. Following the principles of ISO Guides 34:2009 and 35:2005, a Sal A reference material was certified, covering homogeneity studies, stability studies, characterization, and uncertainty estimations.

3.
Biochem Biophys Res Commun ; 525(3): 759-766, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32145915

RESUMO

Formononetin (FN), a methoxy isoflavone abundant in many plants and herbs, has been evidently proven to possess multiple medicinal properties. Our study aimed to clarify the impact of FN on myocardial ischemia/reperfusion (I/R) injury (MIRI) and the involved mechanism. A rat model of MIRI was produced by ligation and loosening of the left anterior descending (LAD) branch of the coronary artery. Rats received 10 and 30 mg/kg of FN when the reperfusion started. At 24 h after surgery, cardiac function, infarct size, and sera levels of the cardiac markers and inflammatory mediators were measured. To mimic the inflammasome activation in cardiomyocytes, neonatal rat cardiomyocytes (NRCMs) were cultured and treated with lipopolysaccharide (LPS) plus nigericin. Cell death and reactive oxygen species (ROS) were determined. Myocardial expression and activation of the nucleotide-binding domain and leucine-rich repeat-containing protein 3 (NLRP3) inflammasome in rats were examined by western blotting. The level of thioredoxin interacting protein (TXNIP)-NLRP3 interaction was assessed. FN notably attenuated cardiac dysfunction, infarct size, release of cardiac markers, and elevation of TNF-α, IL-1ß, and IL-6. FN alleviated LPS plus nigericin-induced injury and ROS increase in NRCMs. Western blotting revealed that FN suppressed the activation of NLRP3 inflammasome and TXNIP-NLRP3 interaction in rats. These findings indicate that FN ameliorated MIRI in rats and inhibited the activation of the NLRP3 inflammasome, at least partially, attributable to suppression of the ROS-TXNIP-NLRP3 pathway.

4.
Mikrochim Acta ; 187(2): 124, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31932975

RESUMO

A sensitive method based on the use of green deep eutectic solvents (DESs) was designed for the determination of bisphenol-A, bisphenol-AF, tetrabromobisphenol-A and 4-tert.-octylphenol followed by HPLC. This method takes advantage of magnetic solid-phase extraction purification and acid-base induced DES liquid-liquid microextraction. The Mg(II)-Al(III) layered double hydroxide-coated magnetic nanoparticles were selected to purify samples. The DESs were systematically prepared by a range of medium-chain saturated fatty acids (C8-C12) and D,L-menthol. The melting point and the extraction efficiency of phenolic compounds were adjusted by changing the carbon chain length of fatty acid in suitable proportions. Acid-base induction significantly improves the extraction efficiency. The method has lower limits of detection ranging from 6 to 11 ng L-1, good linearity (0.05-500 µg L-1) and high enrichment factors (86-91). The method was successfully applied for the determination of four phenolic compounds in beverage samples. The recoveries ranged from 84.4 to 101.3%. Graphical abstract Schematic representation of the extraction of four phenolic compounds by medium chain (C8-C12) fatty acid-based eutectic solvent (DES) through acid-base-induction.

5.
Nanoscale ; 12(4): 2648-2656, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31939957

RESUMO

Aggregation-induced emission (AIE) materials have shown attractive prospects in the fields of biological probes, chemical sensing, optoelectronic systems and stimuli responses. Here, we have successfully fabricated photomultiplication-type organic photodetectors based on an AIE material by designing a device structure. The high photoconductive gain was attributed to the interfacial trap-assisted hole-tunneling injection caused by MoO3 as the trap for electrons. The fabricated AIE-based photomultiplication-type organic photodetectors exhibited the figures of merits of high external quantum efficiency in excess of 60 000%, responsivity of 172 A W-1, detectivity of 3.08 × 1012 Jones, and photoresponse with a rise time of 1.69 ms. Moreover, the devices also showed good stability with a half-life of 700 hours at continuous testing under ambient conditions, which makes them one of the most stable OPDs reported so far. The results demonstrate that AIE molecules are an excellent kind of photodetective material.

6.
Anal Bioanal Chem ; 412(4): 871-880, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31901958

RESUMO

Novel carbon dots (CDs) were synthesized by a one-pot hydrothermal approach using ampicillin as a precursor, and the as-prepared CDs exhibited a high quantum yield (23%). The CDs were found to possess abundant surface functional groups, thus providing good permeability to the cell, and the antibacterial activity of CDs was evaluated. S. aureus and L. monocytogenes were selected as model bacteria, and our results showed that the CDs exhibited antibacterial activity against S. aureus and L. monocytogenes under visible light illumination, even at low concentrations. The antibacterial mechanism is believed to be the production of reactive oxygen species (ROS) from CDs under visible light irradiation, which attacked the bacterial cell membranes, resulting in the death of the bacteria. In addition, because of the multicolor fluorescence properties of CDs, staining of S. aureus and L. monocytogenes obtained multicolor fluorescence images at different excitation wavelengths. Based on these results, CDs are a promising candidate material for biological applications. Graphical abstract.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Carbono/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Ampicilina/análogos & derivados , Ampicilina/síntese química , Antibacterianos/síntese química , Antibacterianos/química , Carbono/química , Humanos , Listeriose/tratamento farmacológico , Nanopartículas/química , Infecções Estafilocócicas/tratamento farmacológico
7.
ACS Appl Mater Interfaces ; 11(34): 31078-31086, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31381286

RESUMO

Based on exciplexes as hosts, the monochromatic organic light-emitting diodes (OLEDs) have achieved high power and external quantum efficiencies. However, the high-quality white OLEDs (WOLEDs) with high color rendering index (CRI) have the unsatisfactory efficiencies at high luminance, particularly in terms of power efficiency (PE), resulting in high energy consumption. Here, a new design concept using multiple exciplexes as hosts to match different phosphors has been demonstrated to develop high-performance WOLEDs. It can be seen that the resulting WOLEDs work at a low turn-on voltage of 2.3 V and exhibit the large forward-viewing PE and external quantum efficiency (EQE) of 79 lm W-1 and 22.5%, respectively, without light out-coupling techniques. Significantly, the PE and EQE still remain 48.0 lm W-1 and 21.4% at 1000 cd m-2, showing extremely low efficiency roll-off. The CRI is as high as 81. The keys to success are the selection of the different exciplex hosts matched to different phosphors and the reasonable arrangement of emissive layers, which are beneficial to regulate the exciton distribution and reduce the energy losses.

8.
iScience ; 19: 316-325, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31404832

RESUMO

Lithium-sulfur (Li-S) batteries with high theoretical energy density attract great research attention. Although tremendous efforts have been made, heat tolerance capability of Li-S batteries is a topic rarely touched, although it is essential for practical application. At high temperatures, the dissolution of the polysulfides is aggravated, and the safety issue becomes severe. Herein, by using sulfur/polyacrylonitrile (SPAN) composites as positive electrode materials and a gel polymer membrane with carbonate electrolyte, we successfully realized a Li-S battery with remarkable heat-resistant performance at 50°C and 60°C. The SPAN-positive materials allow the Li-S battery operated in safer carbonate-containing electrolyte. The gel polymer electrolyte enhances the charge transfer, maintains the morphology of Li metal during cycling, and suppresses the migration of the soluble polysulfides, which is also observed when SPAN is used as positive electrode material. This contribution would bring new opportunity to extend the application of lithium batteries at high temperatures.

9.
Front Microbiol ; 10: 1515, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333620

RESUMO

Histone-like nucleoid structuring protein (H-NS) in enterobacteria plays an important role in facilitating chromosome organization and functions as a crucial transcriptional regulator for global gene regulation. Here, we presented an observation that H-NS of Salmonella enterica serovar Typhimurium could undergo protein phosphorylation at threonine 13 residue (T13). Analysis of the H-NS wild-type protein and its T13E phosphomimetic substitute suggested that T13 phosphorylation lead to alterations of H-NS structure, thus reducing its dimerization to weaken its DNA binding affinity. Proteomic analysis revealed that H-NS phosphorylation exerts regulatory effects on a wide range of genetic loci including the PhoP/PhoQ-regulated genes. In this study, we investigated an effect of T13 phosphorylation of H-NS that rendered transcription upregulation of the PhoP/PhoQ-activated genes. A lower promoter binding of the T13 phosphorylated H-NS protein was correlated with a stronger interaction of the PhoP protein, i.e., a transcription activator and also a competitor of H-NS, to the PhoP/PhoQ-dependent promoters. Unlike depletion of H-NS which dramatically activated the PhoP/PhoQ-dependent transcription even in a PhoP/PhoQ-repressing condition, mimicking of H-NS phosphorylation caused a moderate upregulation. Wild-type H-NS protein produced heterogeneously could rescue the phenotype of T13E mutant and fully restored the PhoP/PhoQ-dependent transcription enhanced by T13 phosphorylation of H-NS to wild-type levels. Therefore, our findings uncover a strategy in S. typhimurium to fine-tune the regulatory activity of H-NS through specific protein phosphorylation and highlight a regulatory mechanism for the PhoP/PhoQ-dependent transcription via this post-translational modification.

10.
Nat Commun ; 10(1): 2380, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31147542

RESUMO

The emerging thermally activated delayed fluorescence materials have great potential for efficiencies in organic light-emitting diodes by optimizing molecular structures of the emitter system. However, it is still challenging in the device structural design to achieve high efficiency and stable device operation in white organic light-emitting diodes. Here we propose a universal design strategy for thermally activated delayed fluorescence emitter-based fluorescent white organic light-emitting diodes, establishing an advanced system of "orange thermally activated delayed fluorescence emitter sensitized by blue thermally activated delayed fluorescence host" combined with an effective exciton-confined emissive layer. Compared to reference single-layer and double-layer emissive devices, the external quantum efficiency improves by 31 and 45%, respectively, and device operational stability also shows nearly fivefold increase. Additionally, a detailed optical simulation for the present structure is made, indicating the validity of the design strategy in the fluorescent white organic light-emitting diodes.

11.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117141, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31247390

RESUMO

High photoluminescent quantum yield carbon nanomaterials doped with heteroatoms are of profound attention in various fields like bio-imaging, chemical sensors and electronics. Among all heteroatoms, zinc is one of the low toxic significant elements and also involves in various electron-transfer processes. These properties are added advantages to utilize zinc as a dopant in CDs synthesis. In this investigation, our group reports a one-step microwave digestion method to synthesize nitrogen and Zinc doped carbon dots (N, Zn-CDs). The optical properties of N, Zn-CDs were investigated using UV-Vis and fluorescence spectrophotometry and also the N, Zn-CDs structural features were studied with other characterization tools like XPS, TEM, EDX, FTIR and XRD. N, Zn-CDs inherent the appreciable photoluminescent quantum yields about 63.28%. And the synthesized N, Zn-CDs utilized for detection of Fe3+ and temperature. The observed results are promising and exhibited the detection limit of 0.027 µM. Also, the proposed sensing system was successfully adopted for the detection of Fe3+ in the river and circulating water samples for the practical applications and satisfactory results are observed. The current synthesis methodology and sensing potential might open up a new prospect to develop potential applications in environmental monitoring.

12.
mBio ; 10(2)2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992361

RESUMO

We have shown that the ligand-responsive MarR family member SlyA plays an important role in transcription activation of multiple virulence genes in Salmonella enterica serovar Typhimurium by responding to guanosine tetraphosphate (ppGpp). Here, we demonstrate that another MarR family member, EmrR, is required for virulence of S. Typhimurium and another enteric bacterium, Yersinia pestis EmrR is found to activate transcription of an array of virulence determinants, including Salmonella pathogenicity island 2 (SPI-2) genes and several divergent operons, which have been shown to be activated by SlyA and the PhoP/PhoQ two-component system. We studied the regulatory effect of EmrR on one of these genetic loci, i.e., the pagC-pagD divergent operon, and characterized a catecholamine neurotransmitter, dopamine, as an EmrR-sensed signal. Dopamine acts on EmrR to reduce its ability to bind to the target promoters, thus functioning as a negative signal to downregulate this EmrR-activated transcription. EmrR can bind to AT-rich sequences, which particularly overlap the SlyA and PhoP binding sites in the pagC-pagD divergent promoter. EmrR is a priming transcription regulator that binds its target promoters prior to successive transcription activators, by which it displaces universal silencer H-NS from these promoters and facilitates successive regulators to bind these regions. Regulation of the Salmonella-specific gene in Escherichia coli and Y. pestis reveals that EmrR-dependent regulation is conserved in enteric bacteria. These observations suggest that EmrR is a transcription activator to control the expression of virulence genes, including the SPI-2 genes. Dopamine can act on the EmrR-mediated signal transduction, thus downregulating expression of these virulence factors.IMPORTANCE In this study, MarR family regulator EmrR is identified as a novel virulence factor of enteric bacteria, here exemplified by Salmonella enterica serovar Typhimurium and Yersinia pestis EmrR exerts an essential effect as a transcription activator for expression of virulence determinants, including Salmonella pathogenicity island 2 genes and a set of horizontally acquired genetic loci that formed divergent operons. EmrR senses the neurotransmitter dopamine and is subsequently released from target promoters, resulting in downregulation of the virulence gene expression. Through this action on EmrR, dopamine can weaken Salmonella resistance against host defense mechanisms. This provides an explanation for the previous observation that dopamine inhibits bacterial infection in animal gastrointestinal tracts. Our findings provide evidence that this neurotransmitter can modulate bacterial gene expression through interaction with virulence regulator EmrR.


Assuntos
Dopamina/metabolismo , Regulação Bacteriana da Expressão Gênica , Salmonella typhimurium/genética , Transdução de Sinais , Fatores de Virulência/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dopamina/genética , Regulação para Baixo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Regiões Promotoras Genéticas , Proteínas Repressoras/genética , Salmonella typhimurium/patogenicidade , Fatores de Transcrição , Virulência/genética
13.
Ecotoxicol Environ Saf ; 178: 130-136, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31002967

RESUMO

A simple, effective and convenient method for determination of phenolic compounds by acid-base induced deep eutectic solvents (DESs) microextraction was developed. The binary and ternary DESs were prepared by a range of fatty acids (C8-C12), which can act as hydrogen bond donors and hydrogen bond acceptors simultaneously. The gas-assisted mixing customization provides excellent mixing performance and concentration efficiency through the bubble adsorption mechanism for the handling of large-volume aqueous sample. In extraction process, NH3·H2O can act as the emulsifier agent and reacted with DESs to form salts with a cloudy solution, which can obviously improve the extraction efficiency. HCl can act as the phase separation agent, and there is no need to centrifuge, which increases the efficiency of analysis procedure. The factors affected on extraction efficiency were carefully optimized. At optimum conditions and molar ratio of C8:C9:C12 (3:2:1), the limit of detections (LODs), the preconcentration factor, the repeatability (RSDs%) were in the range of 0.22-0.53 µg L-1, 235-244, and 2.6-6.7%, respectively. Finally, the proposed method was applied to analyze four phenolic compounds in real water samples and the recoveries were between 87.4% and 106.6%.


Assuntos
Ácidos Graxos/química , Química Verde/métodos , Microextração em Fase Líquida/métodos , Fenóis/análise , Solventes/química , Poluentes Químicos da Água/análise , Adsorção , Limite de Detecção , Modelos Teóricos , Água/química
14.
J Photochem Photobiol B ; 194: 61-70, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30927703

RESUMO

In recent times, fluorescent carbon quantum dots (CQDs) as an optical sensor have attained massive attention owing to their excellent optical properties. In current investigation, our group presented an easy and economical methodology to synthesize the nitrogen and phosphorous doped carbon quantum dots (N, P doped CQDs) for sensing dopamine (DA) and temperature in aqueous medium. The synthesized CQDs were characterized by using XRD, XPS, TEM, UV-Vis, FT-IR and fluorescence techniques. The N, P doped CQDs were synthesized via one-step microwave digestion method by using citric acid, ethylenediamine and urea phosphate as precursors. This method established the noble water solubility, good optical performances and fluorescence thermosensitivity of N, P doped CQDs. Also, N, P doped CQDs demonstrated a wide linear range of 10-500 µM (R2 = 0.994) and offered an electrifying detection limit of 0.021 µM for quantifying the dopamine. Moreover, this sensor possessed a good sensitivity, reversibility and linearity in the range of 10-70 °C. In addition, the CQDs sensing system repel the interference from probable foreign substances in real sample analysis, and attained good recoveries, which revealed the tremendous selectivity and adequate accuracy of the carbon quantum dots for sensing dopamine. The proposed N, P doped CQDs are simple as well as effective optical nanosensor and clasps venerable potential to widen the applications in analysis of biomolecules and other areas.


Assuntos
Carbono/química , Técnicas de Química Analítica/instrumentação , Dopamina/análise , Nitrogênio/química , Fósforo/química , Pontos Quânticos/química , Temperatura , Dopamina/sangue , Dopamina/química , Dopamina/urina , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Substâncias Luminescentes/química , Espectrometria de Fluorescência
15.
Steroids ; 143: 18-24, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30513323

RESUMO

Solvatomorphism occurred in diosgenin solvates. A series of solvates including DMSO, DMF, DMAC, Methanol of diosgenin were obtained and crystallized in order to compare their structures and properties in the solid state. Single-crystal X-ray diffraction was used to analyze the crystal structures and the solvent types and the stoichiometric ratio of the diosgenin solvates. Hirshfeld surface analyses, especially dnorm surface and fingerprint plots, were used to determine intermolecular interactions in the crystal structure. Powder X-ray diffraction, differential scanning calorimetry, thermogravimetric, Fourier transform Infrared spectroscopy were all used to characterize the diosgenin solvates. And the solvates transformation have been reported for the first time.

16.
Ecotoxicol Environ Saf ; 170: 383-390, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30550968

RESUMO

Magnetic nanoparticles (MNPs) have already proven their efficacy in the disposal of a wide array of environmental contaminants in recent years. However, the difficulties in dispersibility and agglomeration of MNPs arising from its own physical and chemical properties limit its large-scale application. Herein, we fabricated the carbon dots/fatty acid-coated MNPs (CDs/C11-Fe3O4) through a facile and simple method. To utilize the advantage of carbon dots, these limitations can be mitigated by diminishing the size of MNPs and modifying the surface of MNPs. Detailed characterization including VSM, FT-IR, XPS and TEM conformed that the higher adsorption capacity of CDs/C11-Fe3O4 is mainly attributed to low average size (<8 nm), which is obviously lower than that of C11-Fe3O4 (about 13 nm). The CDs/C11-Fe3O4 showed higher adsorption performance than that of C11-Fe3O4 nanocomposites (76.23 ng mg-1 for CDs/C11-Fe3O4 and 59.89 ng mg-1 for C11-Fe3O4). The adsorption processes of BaP on both C11-Fe3O4 and CDs/C11-Fe3O4 nanocomposites are exothermic, and well simulated by pseudo-second-order model. Moreover, the CDs/C11-Fe3O4 were also applied for the detection of BaP in large-volume water samples, which satisfies the China environmental protection standard, are promising candidates for water remediation.


Assuntos
Benzo(a)pireno/análise , Carbono/química , Nanocompostos/química , Poluentes Químicos da Água/análise , Adsorção , Magnetismo , Modelos Teóricos , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Medchemcomm ; 9(8): 1340-1350, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30151089

RESUMO

A series of AKT inhibitors possessing a piperidin-4-yl side chain was designed and synthesized. Some of them showed high AKT1 inhibitory activity and potent anti-proliferative effect on PC-3 prostate cancer cells in the preliminary screening. Further studies revealed the most potent compound, 10h, as a pan-AKT inhibitor. Compound 10h was able to inhibit the cellular phosphorylation of AKT effectively and induce apoptosis of PC-3 cells. It also showed high metabolic stability in human liver microsomes. Preclinical characterization of 10h, a promising lead AKT inhibitor, as a potential anti-prostate cancer therapeutic needs to be further investigated.

18.
Arch Pharm (Weinheim) ; 351(7): e1700369, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29741794

RESUMO

B cell receptor (BCR) signaling plays a key role in B cell development and function. Aberrant BCR signaling has been confirmed as a central driver for the pathogenesis of various B cell malignancies. Bruton's tyrosine kinase (BTK) is a vital component of BCR signaling and exhibits overexpression in various B cell leukemias and lymphomas. Inhibiting BTK has been proved as an efficient way for B cell malignancy intervention. Remarkable achievements have been made in the pursuit of selective BTK inhibitors, represented by the success of the irreversible BTK inhibitors, ibrutinib and acalabrutinib. Constantly emerging agents exhibiting superior efficacy and safety in preclinical and clinical studies provide promising therapeutics for the treatment of B cell malignancies.


Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/enzimologia , Benzamidas/efeitos adversos , Benzamidas/farmacologia , Humanos , Leucemia de Células B/tratamento farmacológico , Leucemia de Células B/enzimologia , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/enzimologia , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Tirosina Quinases/metabolismo , Pirazinas/efeitos adversos , Pirazinas/farmacologia , Pirazóis/efeitos adversos , Pirazóis/farmacologia , Pirimidinas/efeitos adversos , Pirimidinas/farmacologia
19.
Food Chem ; 261: 96-102, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-29739611

RESUMO

A novel liquid-phase microextraction based on the ferrofluid was successfully applied for the extraction and determination of four phenolic compounds (bisphenol-A, bisphenol-AF, tetrabromobisphenol-A and 4-tert-octylphenol) in milks and fruit juices. In this study, a range of alkyl (C4-C10) alcohols as the carrier liquid were used for the preparation of ferrofluids. The study showed that an appropriate chain length of alkyl alcohol may improve the extraction efficiency and maintain the integrity of ferrofluids during extraction, so 1-heptanol (C7) was selected as the optimal carrier liquid. Specifically, the effects of various parameters on the extraction of phenolic compounds were investigated and optimized. Under the optimized conditions, the limits of detection were between 0.35 and 0.66 µg L-1. The intra-day and inter-day precision (RSD %) for the analytes at 10 and 50 µg L-1 were in the range of 3.2-6.7 % and 2.9-7.1%, respectively.


Assuntos
Sucos de Frutas e Vegetais/análise , Microextração em Fase Líquida/métodos , Leite/química , Fenóis/análise , Fenóis/isolamento & purificação , Alquilação , Animais , Limite de Detecção
20.
Food Chem ; 237: 870-876, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28764080

RESUMO

A magnesium-aluminum layered double hydroxides coated on magnetic nanoparticles (Fe3O4@MgAl-LDHs NPs) combined with the supramolecular solvents (SUPRASs) as the magnetic supramolecular fluids were successfully applied to the extraction and determination of four phenolic compounds (Bisphenol-A (BPA), bisphenol-AF (BPAF), tetrabromobisphenol-A (TBBPA) and 4-tert-octylphenol (4-TOP)). Magnetic supramolecular fluids (ferrofluids) composites were prepared through adding the mixture of n-octanol and tetrahydrofuran in distilled water as the supramolecular solvents into the solution containing magnetic Fe3O4@MgAl-LDHs NPs. Under the optimized conditions, the calibration curve was obtained in range of 5-1000µgL-1. The limits of detection (S/N=3) for BPA, BPAF, TBBPA and 4-TOP, were obtained for 0.54, 0.48, 0.37 and 0.63µgL-1, respectively. The intra-day and inter-day precision (RSDs %) for bisphenols (BPs) and 4-TOP at 100 and 300µgL-1 were in the range of 4.0-7.8. The enrichment factors were between 16 and 24.


Assuntos
Sucos de Frutas e Vegetais , Hidróxidos , Nanopartículas de Magnetita , Fenóis , Solventes
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