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1.
J Chromatogr A ; 1638: 461887, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33477026

RESUMO

In the presented work, MIL-101(Cr) and chitosan were directly embedded on the skeleton of melamine sponge material using a simple and environmentally friendly method. Chitosan acts not only as an adhesive during the preparation of functionalized sponges, but also as an adsorption adjuvant in herbicide detection. Unlike other polymers, chitosan has excellent hydrophilicity and contains numerous adsorption sites; thus, it enables the sponge material to be used for determination of contaminants in an aqueous phase. Scanning electron microscopic (SEM) analysis showed that the coating material was uniformly distributed on the skeleton of melamine sponge. The prepared material was used as a sorbent in a vortex-assisted solid-phase extraction and combined with high performance liquid phase tandem mass spectrometry for the extraction and trace determination of six triazines in water samples (Atraton, Desmetryn, Prometon, Ametryn, Prometryn and Dimethametryn). Several parameters that affect the extraction efficiencies were investigated. Under the optimal conditions (MIL-101(Cr) loading, 150 mg; sample pH, 7; salt concentration, 0%; adsorption time, 3 min; desorption solvent, 1.5 mL acetonitrile; desorption time, 4 min), the proposed method was successfully used in the determination of trace triazines in five real water samples (drinking water, tap water, lake waters and river water), satisfactory recoveries were obtained in the range of 78.9%-118.6%. The limits of detection of the proposed method in detecting triazine herbicides in spiked water samples ranged from 0.014 to 0.045 ng mL-1.


Assuntos
Herbicidas/análise , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas/química , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Triazinas/análise , Poluentes Químicos da Água/análise , Adsorção , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Reprodutibilidade dos Testes , Sais/química , Solventes/química , Fatores de Tempo , Triazinas/química
2.
J Chromatogr A ; 1636: 461735, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33316560

RESUMO

A novel magnetic solid-phase extraction (MSPE) material (Fe3O4@SiO2-NH2-G2) had been prepared and employed for adsorption and analysis of seven quaternary ammonium compounds (QACs) in infant fruit and vegetable products coupled with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In this paper, Fe3O4@SiO2-NH2-G2 was synthesized based on Fe3O4@SiO2-NH2 and dendrimer (G2) consisting of cyanuric chloride and imidazole. The morphology, configuration and magnetic behavior of the magnetic material were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Critical parameters affecting extraction efficiency, such as the adsorbent amount, sample pH, extraction time, the type of eluent, and desorption time, were optimized. The proposed method provided good linearity with the correlation coefficients (R2) of 0.9992-0.9999, low limits of detection (LODs) (0.05-0.50 µg kg-1) and limits of quantitation (LOQs) (0.20-2.00 µg kg-1). The satisfactory method recoveries in three spiked infant fruit and vegetable products samples were between 80.12% and 101.35% with the relative standard deviations (RSDs) less than 12.04%. In summary, the established method was an effective sample preparation method and showed good prospect for the analysis of QACs in complex matrices.


Assuntos
Dendrímeros/química , Alimentos Infantis/análise , Magnetismo , Nanopartículas/química , Compostos de Amônio Quaternário/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Frutas/química , Frutas/metabolismo , Humanos , Imidazóis/química , Lactente , Limite de Detecção , Compostos de Amônio Quaternário/isolamento & purificação , Dióxido de Silício/química , Extração em Fase Sólida , Triazinas/química , Verduras/química , Verduras/metabolismo , Difração de Raios X
3.
J Chromatogr A ; 1636: 461711, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33316563

RESUMO

Endogenous glycopeptides are significantly important in diverse pathological and physiological systems, but their direct analysis is severely hampered by their low abundance and presence of interfering species in biological fluids. In this study, we synthesized the amine-functionalized titanium metal-organic framework (NH2-MIL-125(Ti)) by a simple hydrothermal method, characterized and used for glycopeptides enrichment. The designed separation media is highly hydrophilic and stable which is suitable for hydrophilic interaction chromatography (HILIC). To make the process smooth, simple, reliable, and robust, NH2-MIL-125(Ti) crystals were packed in pipette-tip using hydrophilic melamine foam, as supporting frit. Free amine groups, present in the structure imparted hydrophilicity and a unique pattern of porosity, contributing to the size exclusion effect that excluded the large-sized proteins up to 1:700 peptide to protein ratio. The prepared MOF particles possessed regular porosity, high surface area, good hydrophilicity, and offered an in-tip flow-based set-up enhanced the enrichment performance for N-linked glycopeptides. The affinity material showed a detection limit of 1 fmol.µL-1 and selectivity up to 1:1000 (HRP digest to BSA digest). Moreover, repeatability and reusability were evaluated up to five rounds of enrichment using the same affinity tip, and scanning electron microscopic images revealed no structural changes in the MOF crystals. Finally, the MOF packed in pipette tip was applied to selectively capture the N-linked endogenous glycopeptides from a healthy saliva sample and 64 unique endogenous glycopeptides were identified. These results demonstrated the excellent potential of NH2-MIL-125(Ti) based affinity tip for glycopeptides which can be used to enrich trace glycopeptide biomarkers from the biological fluids.


Assuntos
Aminas/química , Glicopeptídeos/química , Estruturas Metalorgânicas/química , Titânio/química , Triazinas/química , Cromatografia Líquida/métodos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Porosidade , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
4.
Food Chem ; 338: 127769, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32862067

RESUMO

Illegal addition of melamine (MEL) to milk has caused serious food safety accident. It is urgent to develop a highly sensitive method for detecting MEL in milk. ß-Cyclodextrin with inner hydrophobic and outer hydrophilic cavities have been widely used in smart sensors design. In this study, an "ON-OFF-ON" sensor for MEL detection was constructed based on ß-cyclodextrin modified carbon nanoparticles (ß-CD-CNPs). The sensor is switched "OFF" when Fe3+ interacts with ß-CD-CNPs and switched "ON" when MEL replaces Fe3+. Fluorescence recovery of ß-CD-CNPs exhibits good linear correlations with MEL concentration ranging from 10.00 ng/mL ~ 180.00 ng/mL and 180.00 ~ 1000.00 ng/mL, the detection limit is 6.82 ng/mL. The sensor was applied to analysis melamine in milk samples with recovery between 94.80% ~ 102.05%, and RSD bellow 12.61%. The results show that this method can meet the requirements of real sample analysis.


Assuntos
Carbono/química , Análise de Alimentos/métodos , Leite/química , Nanopartículas/química , Triazinas/análise , Triazinas/química , beta-Ciclodextrinas/química , Animais , Contaminação de Alimentos/análise , Limite de Detecção , Espectrometria de Fluorescência
5.
Antimicrob Agents Chemother ; 64(11)2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32868327

RESUMO

Remdesivir has reported efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro and in vivo Drug-drug interactions limit therapeutic options in transplant patients. Remdesivir and its metabolite GS-441524 are excreted principally in urine. In intensive care unit (ICU) settings, in which multiple-organ dysfunctions can occur rapidly, hemodialysis may be a viable option for maintaining remdesivir treatment, while improving tolerance, by removing both remdesivir's metabolite (GS-441524) and sulfobutylether ß-cyclodextrin sodium (SEBCD). Additional studies may prove informative, particularly in the evaluations of therapeutic options for coronavirus disease 2019 (COVID-19).


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/administração & dosagem , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/terapia , Furanos/urina , Pneumonia Viral/terapia , Pirróis/urina , Triazinas/urina , beta-Ciclodextrinas/urina , Monofosfato de Adenosina/administração & dosagem , Monofosfato de Adenosina/efeitos adversos , Monofosfato de Adenosina/química , Monofosfato de Adenosina/metabolismo , Alanina/administração & dosagem , Alanina/efeitos adversos , Alanina/química , Alanina/metabolismo , Antivirais/efeitos adversos , Antivirais/química , Antivirais/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/cirurgia , Infecções por Coronavirus/virologia , Interações Medicamentosas , Furanos/efeitos adversos , Furanos/química , Humanos , Unidades de Terapia Intensiva , Transplante de Pulmão , Insuficiência de Múltiplos Órgãos , Pandemias , Pneumonia Viral/cirurgia , Pneumonia Viral/virologia , Pirróis/efeitos adversos , Pirróis/química , Diálise Renal , Transplantados , Triazinas/efeitos adversos , Triazinas/química , beta-Ciclodextrinas/efeitos adversos , beta-Ciclodextrinas/química
6.
J Oleo Sci ; 69(9): 1021-1030, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788513

RESUMO

A novel jellyfish-shaped triazine hexamer quaternary ammonium chloride surfactant (TH12QC) was synthesized, which consisted of one triazine spacer group and six long flexible hydrophobic chains. The molecular structure and aggregation behavior of TH12QC was investigated by nuclear magnetic resonance (NMR), surface tension, electrical conductivity, dynamic light scattering (DLS), transmission electron microscope (TEM), etc. The results show that the jellyfish-shaped TH12QC has better surface activity and lower surface tension than traditional ionic and Gemini surfactants in aqueous solution. There are two inflection points in the curve of conductivity versus concentration of the TH12QC aqueous solution, which correspond to the critical aggregation concentration (CAC) and the critical micelle concentration (CMC) respectively. The existence of CAC indicates that there is a pre-aggregation process before TH12QC forms micelles. The results of DLS and TEM show that network pre-aggregation, spherical aggregation and dense spherical aggregation were observed in different concentration of TH12QC aqueous solution, and the electrostatic equilibrium of the system subtly depends on the concentration of the solution. In addition, intramolecular and intermolecular hydrogen bonding is also an important factor. This study provides a method for studying the aggregation behavior and morphology of oligomeric surfactants with rigid spacer groups.


Assuntos
Cloreto de Amônio/química , Cloreto de Amônio/síntese química , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/síntese química , Tensoativos/química , Tensoativos/síntese química , Triazinas/química , Triazinas/síntese química , Fenômenos Químicos , Difusão Dinâmica da Luz , Condutividade Elétrica , Ligação de Hidrogênio , Micelas , Estrutura Molecular , Soluções , Tensão Superficial , Água/química
7.
Food Chem ; 333: 127532, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32668396

RESUMO

Poly(melamine) (PMel) was synthesized via the electropolymerization of melamine monomer, which was then characterized by field-emission scanning electron microscopy (FESEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The possible polymerization mechanisms of melamine were also revealed by FT-IR spectroscopy and UV-Vis spectroscopy. Next, the PMel modified GCE (PMel/GCE) was used for the simultaneous determination of nitrite (NO2-) and tartrazine, and the parameters were optimized. The kinetic study showed that the electrochemical oxidation of nitrite and tartrazine at the surface of PMel/GCE is a typical surface-controlled electrode process. Under the optimun conditions, the developed sensor outperformed those previously reported, and it also exhibited high selectivity and reproducibility. Finally, the PMel/GCE was used for the simultaneous determination of nitrite and tartrazine in foodstuffs, and the results indicated that the proposed sensor could be a promising candidate for accurate determination of nitrite and tartrazine in real food samples.


Assuntos
Nitritos/análise , Polimerização , Tartrazina/análise , Triazinas/química , Espectroscopia Dielétrica , Eletroquímica , Eletrodos , Microscopia Eletrônica de Varredura , Nitritos/química , Oxirredução , Reprodutibilidade dos Testes , Tartrazina/química , Fatores de Tempo
8.
Ecotoxicol Environ Saf ; 203: 110995, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678763

RESUMO

In the present study, silver (Ag) atoms were chemically deposited on γ-alumina (Al2O3) nanospheres to be further functionalized with trithiocyanuric acid (TTC). The result was Al2O3@Ag@TTC composites, which were used for the selective extraction and preconcentration of Fe (III) and Pb (II) ions in seawater and river water samples. TTC is a potent scavenger of heavy metal ions with multiple nitrogen- and sulfur-containing functional groups. The concentrations of analytes were determined by flame atomic absorption spectrometry, and the structure of the synthetic adsorbent was characterized by spectral and microscopic techniques. Furthermore, the fundamental parameters influencing the extraction and desorption of the target ions were evaluated. Under optimized conditions, the calibration curve was linear in the range of 10-100 ng mL-1 for both analytes. The detection limits of the proposed method for Fe (III) and Pb (II) ions were 1.5 ng mL-1 and 0.8 ng mL-1, respectively, with a relative standard deviation of less than 6.1% (n = 7). Moreover, the proposed method tolerated salinities of up to 50.0 g L-1 without exhibiting any decrease in selectivity or recovery. The developed method was successfully applied to extract Fe (III) and Pb (II) ions from seawater and river water samples. The extraction recovery rates of the spiked ions were at least 93% for Fe (III) and 97 % for Pb (II).


Assuntos
Óxido de Alumínio/química , Ferro/análise , Chumbo/análise , Nanoconjugados/química , Prata/química , Triazinas/química , Poluentes Químicos da Água/análise , Água Doce/química , Concentração de Íons de Hidrogênio , Íons , Água do Mar/química , Extração em Fase Sólida/métodos
9.
Chemosphere ; 260: 127590, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32679376

RESUMO

A new treatment method using a deep eutectic solvent embedded melamine sponge (DES-MS) was studied for the removal of organic pollutants from water and soil samples. Five organophosphorus pesticides (OPPs) consisting of azinphos-methyl (AZP), parathion-methyl (PRT), fenitrothion (FNT), diazinon (DIZ) and chlorpyrifos (CPF), and two dyes including acid blue 29 (AB29) and malachite green (MG) were used as the model pollutants. DESs were easily prepared from tetrabutylammonium bromide (TBABr) and various fatty acids. The synthesised DESs were loaded into the sponge before being utilized for the removal of the studied pollutants. After the removal, the residual OPPs or dyes in the supernatant was quantified by high performance liquid chromatography or derivative spectrophotometry, respectively. The proposed method was simple, rapid, environmentally friendly and effective with the removal efficiency higher than 70% for various samples. Moreover, the removal of various dyes was successfully achieved with the efficiency greater than 65% under the optimum condition.


Assuntos
Corantes/análise , Praguicidas/análise , Resinas Sintéticas/química , Poluentes do Solo/análise , Solventes/química , Triazinas/química , Poluentes Químicos da Água/análise , Recuperação e Remediação Ambiental/métodos , Limite de Detecção , Solo/química , Águas Residuárias/química , Purificação da Água/métodos
10.
Chemosphere ; 255: 126848, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32388255

RESUMO

Insensitive high explosives are increasingly being used to replace more sensitive formulations, however large quantities of environmentally hazardous wastewater are generated from loading, assembling and packing processes. Currently, there is limited literature regarding the treatment of wastewater contaminated with these hazardous insensitive high explosive materials such as 1,3,5-trinitroperhydro- 1,3,5-triazine (RDX), 2,4-dinitoranisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The preferred method of explosive wastewater treatment is adsorption by activated carbon, usually through treatment columns or fluidised beds that are simple to operate and cost effective. The aim of this research was to assess whether commercially available activated carbons would be suitable and economically viable to treat explosive wastewater containing RDX, DNAN and NTO. Bottle point tests were used to determine adsorption capacity and adsorption kinetics for the individual insensitive high explosives with three different activated carbons. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherms to determine the mechanisms of adsorption. Six hour bottle point tests for a mixture of the three insensitive high explosive constituents were used to consider possible preferential adsorption. As expected, RDX and DNAN were adsorbed at concentrations up to 40 mg.L-1 and 150 mg.L-1 respectively by the activated carbons tested, demonstrating the viability of treatment by adsorption. However, at the high concentrations of NTO expected in wastewater (1400 mg.L-1) activated carbons were rapidly saturated, suggesting that treatment of NTO contaminated wastewater would require prohibitively large quantities of activated carbon compared to RDX and DNAN.


Assuntos
Anisóis/química , Carvão Vegetal/química , Nitrocompostos/química , Triazinas/química , Triazóis/química , Adsorção , Substâncias Explosivas , Cinética , Modelos Químicos , Águas Residuárias
11.
Food Chem ; 326: 126988, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32447162

RESUMO

In this study, a simple and quick ionic liquid- based ultrasonic-assisted microextraction (IL-UA-ME) procedure has been improved for extraction of melamine in dairy productsfollowed by UV-VIS spectrometry. For the analysis of stability and reactivity of melamine and its some metal complexes, quantum chemical parameters like frontier orbital energy-HOMO-LUMO energy gap, hardness and softness were calculated using computational chemistry tools. The results regarding to stability analysis made considering density functional theory showed that theoretical data obtained are compatible with experimentally obtained results, and Fe-melamine complex is more stable compared to others. Under optimum conditions, the linearity was in the range of 0.05-400 ng mL-1 with detection limit of 0.015 ng mL-1. Following the validation studies, recovery and relative standard deviation were obtained in range of 92.5-104.3% and 1.4-2.1%, respectively. The first research article in which experimental and theoretical studies are used together for the determination of melamine in dairy products.


Assuntos
Laticínios/análise , Líquidos Iônicos/química , Triazinas/análise , Complexos de Coordenação/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Teoria Quântica , Microextração em Fase Sólida , Sonicação , Temperatura , Triazinas/química , Triazinas/isolamento & purificação
12.
J Oleo Sci ; 69(6): 627-634, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32404552

RESUMO

Present study has successfully synthesized melamine-based covalent organic polymers (MCOPs) and applied it as lipase carrier for recyclable esters hydrolysis and transesterification. The synthesized MCOPs are composed of dense nanosheet structures having a thickness of 3.5 nm. Three immobilization methods namely physical adsorption, cross-linking and carrier activation were employed to prepare the MCOPs-immobilized CRL. Cross-linked MCOPs-immobilized CRL (41.30 mg protein/g MCOPs) and carrier activated MCOPs-immobilized CRL (33.20 mg protein/g MCOPs) had higher enzyme loading as compared to physical absorb MCOPs-immobilized CRL (29.30 mg protein/g MCOPs). Nevertheless, physical absorb MCOPs-immobilized CRL demonstrated the highest esters hydrolysis (49.85 U) and transesterification (1.04 U) activities. Despite having the highest enzymatic activity, physical absorb MCOPs-immobilized CRL were not able to maintain its catalytic stability with more than 30% decreased in enzymatic activity during consecutive hydrolysis and transesterification activities. Meanwhile, cross-linked MCOPs-immobilized CRL demonstrated highest catalytic stability with highest enzymatic activities at the end of consecutive reactions. All the MCOPs-immobilized CRL can be easily recovered and reused through centrifugation with more than 85% of recovery rate.


Assuntos
Polímeros/química , Polímeros/síntese química , Triazinas/química , Triazinas/síntese química , Catálise , Enzimas Imobilizadas , Esterificação , Ésteres , Hidrólise , Lipase
13.
Food Chem ; 322: 126770, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32305874

RESUMO

Honey, a highly nutritious functional food, might be contaminated by polycyclic aromatic hydrocarbons (PAHs) during its production and/or harvest. The preconcentration and analysis of trace levels of PAHs from the complex sample matrices like honey still poses challenges for analytical researchers. In this study, three different covalent triazine-based frameworks (CTFs) were synthesized and explored as the solid-phase microextraction (SPME) coating for the extraction of some PAHs from various honey samples. Among the CTFs, cyanuric chloride-p-quaterphenyl (CC-QP) exhibited the highest extraction capability toward PAHs due to its largest specific surface area and π-electrons system. Under the optimum experimental conditions, the CC-QP based SPME method exhibited wide linearity (0.10-100 ng g-1), low limits of detection (0.03-0.19 ng g-1) and good reproducibility (relative standard deviations < 9.9%). The new SPME method coupled with chromatography-mass spectrometry detection was successfully applied for the determination of PAHs in honey samples with satisfactory recoveries (82.0-116.8%).


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Mel/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Microextração em Fase Sólida/métodos , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Reprodutibilidade dos Testes , Triazinas/química
14.
Sci Rep ; 10(1): 6137, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273529

RESUMO

Different novel 1,2,4-triazolo[4,3-b][1,2,4,5]tetrazines and 1,2,4-triazolo[4,3-b][1,2,4]triazines have been obtained from heterocyclization of 3-substituted-4-amino-5-substituted-amino-1,2,4-triazoles (3a-d) and 3-substituted-4-amino-5-hydrazino-1,2,4-triazoles (9a,b) with (α and ß) bifunctional compounds like chloromethyl biphenyl-phosphanoxide, pyruvic acid, phenacyl bromide, diethyl oxalate, triethyl orthoformate, triethyl phosphite, fluorinated benzaldehydes, carbon disulfide and ethyl chloroformate under different experimental settings. Fourier transformer infrared analysis (FTIR), Proton nuclear magnetic resonance (1H NMR) and 13C nuclear magnetic resonance (13C NMR), as well as that of the mass spectral data, were used as the appropriate characterization techniques for the chemical structures of all newly synthesized compounds. The newly prepared compounds were examined as an anti-inflammatory, antibacterial agents (against E. coli (Escherichia coli) and P. aeruginosa (Pseudomonas aeruginosa) as examples for Gram-negative bacteria and S. aureus (Staphylococcus aureus) as examples for Gram-positive bacteria), as well as antifungal (against C. albicans (Candida albicans)) agents. The newly prepared compound showed high antibacterial, antifungal, and anti-inflammatory activities in comparing with the commercial antibiotics Indomethacin, Nalidixic acid, Imipenem, and Nystatin. Docking of the most active compounds was performed depending on the results of antibacterial screening and the anti-inflammatory assay.


Assuntos
Triazinas/síntese química , Triazóis/síntese química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Simulação de Acoplamento Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Triazinas/química , Triazinas/farmacologia , Triazóis/química , Triazóis/farmacologia
15.
J Am Soc Mass Spectrom ; 31(2): 249-256, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32031404

RESUMO

Identification and confirmation of known as well as unknown (bio)chemical entities in ambient mass spectrometry (MS) and MS imaging (MSI) mostly involve accurate mass determination, often in combination with MS/MS or MSn work flows. To further improve structural assignment, additional molecular information is required. Here we present an ambient hydrogen/deuterium exchange (HDX) laser ablation electrospray ionization (LAESI) MS method in which, apart from the accurate mass and MS/MS data, the number of exchangeable protons in (un)known molecules is obtained. While eventually presenting ambient HDX-LAESI-MSI, samples were not preincubated with deuterated solvents, but instead HDX occurred following fusion of ablated sample material with microdroplets generated by ESI of deuterated solvents. Therefore, the degree of HDX was first studied following ablation of nondeuterated sample solutions of melamine and monosaccharides. From these experiments, it was concluded that the set-up used could provide meaningful HDX data in support of molecular structure elucidation by significantly reducing the number of structure options from a measured elemental composition. This reduction was demonstrated with an unknown accurate m/z value obtained in the analysis of an orange slice, reducing the possible number of molecular structures having the same elemental composition by 87% due to the number of H/D exchanges observed. Next, deuterated and nondeuterated MS/MS experiments showed the number of exchangeable protons in the substructures from deuterated neutral losses in the product ion spectra, confirming the compound to be arginine. Finally, the potential of ambient HDX-LAESI-MSI was demonstrated by the imaging of (secondary) plant metabolites in a Phalaenopsis petal.


Assuntos
Medição da Troca de Deutério/métodos , Monossacarídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Triazinas/química , Hidrogênio/química , Terapia a Laser , Prótons , Espectrometria de Massas em Tandem/métodos
16.
Anal Bioanal Chem ; 412(7): 1497-1508, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32025769

RESUMO

Analysis of glycoprotein sialylation is challenging due to the relatively low abundance of sialylated glycopeptides (SGPs) in complex biosamples and low signals of SGPs in mass spectrometry. In this study, a mesoporous poly-melamine-formaldehyde (mPMF) polymer was prepared and utilized as the high-efficiency sorbent for SGPs. The mPMF polymer featured high surface area (755.4 m2 g-1) and high density of amine and triazine functional groups. This polymer demonstrated high enrichment selectivity (resistant to 100 molar fold interference of BSA) and superior adsorption capacity (560 mg g-1) for SGPs. The high performance of mPMF toward SGPs ascribes to the unique physicochemical properties of mPMF and high density of accessible binding sites for glycopeptides. Further application of mPMF to HeLa S3 cell lysate resulted in 576 characterized glycopeptides with 218 unique glycosylation sites. This finding provides a new choice of promising extraction approach for characterization of protein glycosylation. Graphical abstract A mesoporous poly-melamine-formaldehyde (mPMF) polymer was prepared and utilized as the high-efficiency enrichment sorbent for sialylated glycopeptides (SGPs).


Assuntos
Glicopeptídeos/química , Ácido N-Acetilneuramínico/química , Polímeros/química , Triazinas/química , Cromatografia Líquida/métodos , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Massas/métodos , Porosidade
18.
J Nanobiotechnology ; 18(1): 34, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070342

RESUMO

BACKGROUND: The polymer-based drug/gene delivery is promising for the treatment of inherent or acquire disease, because of the polymer's structural flexibility, larger capacity for therapeutic agent, low host immunogenicity and less cost. Antisense therapy is an approach to fighting genetic disorders or infections using antisense oligonucleotides (AOs). Unfortunately, the naked AOs showed low therapeutic efficacy in vivo and in clinical trial due to their poor cellular uptake and fast clearance in bloodstream. In this study, a series of triazine-cored amphiphilic polymers (TAPs) were investigated for their potential to enhance delivery of AOs, 2'-O-methyl phosphorothioate RNA (2'-OMePS) and phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. RESULTS: TAPs significantly enhanced AO-induced exon-skipping in a GFP reporter-based myoblast and myotube culture system, and observed cytotoxicity of the TAPs were lower than Endoporter, Lipofectamine-2000 or PEI 25K. Application of optimized formulations of TAPs with AO targeted to dystrophin exon 23 demonstrated a significant increase in exon-skipping efficiency in dystrophic mdx mice. The best ones for PMO and 2'-OMePS delivery have reached to 11-, 15-fold compared with the AO only in mdx mice, respectively. CONCLUSION: The study of triazine-cored amphiphilic polymers for AO delivery in vitro and in mdx mice indicated that the carrier's performances are related to the molecular size, compositions and hydrophilic-lipophilic balance (HLB) of the polymers, as well as the AO's structure. Improved exon-skipping efficiency of AOs observed in vitro and in mdx mice accompanied with low cytotoxicity demonstrated TAP polymers are potentials as safe and effective delivery carrier for gene/drug delivery.


Assuntos
Portadores de Fármacos/química , Oligonucleotídeos Antissenso/química , Polímeros/química , Triazinas/química , Animais , Permeabilidade da Membrana Celular , Distrofina/química , Feminino , Técnicas de Transferência de Genes , Terapia Genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lipídeos/química , Masculino , Camundongos Endogâmicos mdx , Estrutura Molecular , Morfolinos/química , Mioblastos/metabolismo , Polietilenoimina/química , Relação Estrutura-Atividade , Transfecção
19.
Talanta ; 211: 120705, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32070571

RESUMO

Barium sulfate-coated CsPbBr3 perovskite nanocrystals (CsPbBr3 NCs@BaSO4) was successfully synthesized that exhibited stable and intense fluorescence property in aqueous buffer. With the CsPbBr3 NCs@BaSO4 as signal readout, an ultrasensitive fluorescence nanosensor was developed for turn-on determination of melamine by the manipulation of inner filter effect of citrate-protected gold nanoparticles (AuNPs). The fluorescence of the CsPbBr3 NCs@BaSO4 was remarkably quenched by the AuNPs due to inner filter effect. This inner filter effect could be weakened by the addition of melamine as a result of melamine-triggering aggregation of the AuNPs and subsequently led to a recovery in the fluorescence of the CsPbBr3 NCs@BaSO4. The recovery ratio was proportional to the concentration of melamine in the range of 5.0-500.0 nmol/L. The limit of detection was 0.42 nmol/L and the relative standard deviation was 4.0% for the repetitive determination of 500.0 nmol/L melamine solution (n = 11). The nanosensor was successfully applied to analysis of melamine in dairy product samples.


Assuntos
Compostos de Cálcio/química , Laticínios/análise , Contaminação de Alimentos/análise , Ouro/química , Nanopartículas/química , Óxidos/química , Titânio/química , Triazinas/análise , Animais , Sulfato de Bário/química , Ácido Cítrico/química , Fluorescência , Limite de Detecção , Triazinas/química
20.
J Chromatogr A ; 1618: 460847, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31928768

RESUMO

The functionalization of covalent organic frameworks (COFs) enhances chemical properties and expands future applications. Herein, a facile strategy for sulfoacid-functionalized COF is presented through post-modification of covalent triazine frameworks (CTFs) platform. The magnetic solid phase extraction (MSPE) material is obtained by anchoring in situ Ni particles on CTF support (Ni/CTF-SO3H) possessing a dual retention mechanism combining hydrophilic-lipophilic-balance (HLB) and cation-exchange interaction. We established the (Ni/CTF-SO3H)-MSPE method for selectively enriching carbendazim (CBZ) and thiabendazole (TBZ) from food samples and reducing matrix effect simultaneously. The method detection limit is 1.23-7.05 µg kg-1 for CBZ and TBZ in vegetable, fruit and juice samples, determined by high-performance liquid chromatography-ultraviolet detector. The recoveries of spiked CBZ and TBZ in the samples are 80.2-115.1% and RSDs 6.0-11.4%, depending on both analytes and samples. Our work provides a unique perspective in the development of functionalized COFs as a versatile HLB/cation-exchange mixed-mode SPE sorbent for extraction of basic analytes in complex matrix.


Assuntos
Benzimidazóis/análise , Bebidas/análise , Frutas/química , Fungicidas Industriais/análise , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas/química , Ácidos Sulfônicos/química , Triazinas/química , Verduras/química , Adsorção , Cátions , Limite de Detecção , Reprodutibilidade dos Testes , Extração em Fase Sólida , Ácidos Sulfônicos/síntese química
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