Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 556
Filtrar
1.
Biomed Chromatogr ; 34(1): e4720, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31634409

RESUMO

Apple peel is frequently exposed to pesticides, especially in the last stages of the pesticide treatment practice. For a certain period, peel retains most of the applied pesticides, which precisely indicates the presence of pesticide residues. This study was conducted to establish and evaluate the method for the residue analysis of pyrimethanil, cyprodinil, trifloxystrobin, bifenthrin and boscalid by GC-MS in peel of Granny Smith, Golden Delicious and Idared varieties. The method consisted of few steps, without the routine usage of sorbents, and resulted in efficient removal of waxes, targeted as main interferences in GC-MS analysis. The matrix effect, boscalid selectivity issue, trend of lower trueness for bifenthrin in all matrices and for all analytes in Granny Smith matrix were in some way associated with the waxes. Finally, the method was applied to the analysis of three varieties of apple orchard samples, after 9 and 5 months of treatment with commercial formulations that contain pyrimethanil, cyprodinil and boscalid as active ingredients. Since the developed method consisted of few steps and used nontoxic and economic reagents, it could be implemented as a fast, economic and reliable screening method.


Assuntos
Frutas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Malus/química , Resíduos de Praguicidas/análise , Compostos de Bifenilo/análise , Compostos de Bifenilo/química , Limite de Detecção , Modelos Lineares , Niacinamida/análogos & derivados , Niacinamida/análise , Niacinamida/química , Resíduos de Praguicidas/química , Pirimidinas/análise , Pirimidinas/química , Reprodutibilidade dos Testes , Ceras/química , Ceras/isolamento & purificação
2.
Artigo em Inglês | MEDLINE | ID: mdl-31622183

RESUMO

Packaging may represent a source of food contamination, as different organic compounds and degradation compounds may migrate from packaging to foodstuff. For fatty foods, rectified olive oil is the common simulant, which implies time-consuming and laborious liquid-liquid extraction (LLE) procedures to isolate the contaminant(s) from the oil. Here we propose a Multisyringe Flow Injection Analysis manifold to automate this sample treatment, using the monomer 4,4´-dihydroxybiphenyl as the contaminant. The LLE procedure, using water as extractant, was fully automated. After the on-line LLE, the resulting extract was pumped through a fluorescence detector, inside which a flow-cell filled with C18 silica gel solid support was placed. The analyte was pre-concentrated on the solid support (in which the analytical signal was directly recorded), so improving the sensitivity of the system. Under optimum conditions, the method detection limit is 0.05 mg kg-1, well within the specific migration limit of 6 mg kg-1. The method developed was compared with the standard CEN test method (off-line LLE and HPLC determination) observing savings in sample and reagents of 90% and a 7-fold increase in sample throughput.


Assuntos
Automação , Compostos de Bifenilo/análise , Análise de Injeção de Fluxo , Análise de Alimentos , Contaminação de Alimentos/análise , Extração Líquido-Líquido , Embalagem de Alimentos
3.
J Environ Sci Health B ; 55(4): 388-395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31868560

RESUMO

To stipulate the rationale of spraying doses and to determine the safe interval period of boscalid suspension concentrate (SC), the degradation dynamics and residual levels were investigated in cucumber and soil using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Field trials were conducted according to Chinese Guideline on pesticide residue trials. Following application, the degradation kinetics was best ascribed to first-order kinetic models with half-life of 2.67-9.90 d in cucumber. Spraying boscalid SC at 1.5-fold the recommended dosage yield terminal residues, which are clearly lower than the maximum residue limit (MRL) established by China (MRL =5 mg.kg-1) in cucumber. At variance, the dissipation dynamics in soil did not fit to first-order kinetics and the half-life was more than 17 days, the finding which denotes that the degradation behavior of boscalid in soil proceeds slowly. It has therefore been shown that boscalid is safe for use on cucumbers under the recommended dosage.


Assuntos
Compostos de Bifenilo/análise , Cucumis sativus/química , Niacinamida/análogos & derivados , Resíduos de Praguicidas/análise , Poluentes do Solo/análise , Compostos de Bifenilo/farmacocinética , China , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Fungicidas Industriais/farmacocinética , Niacinamida/análise , Niacinamida/farmacocinética , Poluentes do Solo/farmacocinética , Espectrometria de Massas em Tandem/métodos
4.
J Sci Food Agric ; 100(5): 1980-1989, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31849062

RESUMO

BACKGROUND: In this study, an infrared-based prediction method was developed for easy, fast and non-destructive detection of pesticide residue levels measured by reference analysis in strawberry (Fragaria × ananassa Duch, cv. Albion) samples using near-infrared spectroscopy and demonstrating its potential alternative or complementary use instead of traditional pesticide determination methods. Strawberries of Albion variety, which were supplied directly from greenhouses, were used as the study material. A total of 60 batch sample groups, each consisting of eight strawberries, was formed, and each group was treated with a commercial pesticide at different concentrations (26.7% boscalid + 6.7% pyraclostrobin) and varying residual levels were obtained in strawberry batches. The strawberry samples with pesticide residuals were used both to collect near-infrared spectra and to determine reference pesticide levels, applying QuEChERS (quick, easy, cheap, rugged, safe) extraction, followed by liquid chromatographic-mass spectrometric analysis. RESULTS AND CONCLUSION: Partial least squares regression (PLSR) models were developed for boscalid and pyraclostrobin active substances. During model development, the samples were randomly divided into two groups as calibration (n = 48) and validation (n = 12) sets. A calibration model was developed for each active substance, and then the models were validated using cross-validation and external sets. Performance evaluation of the PLSR models was evaluated based on the residual predictive deviation (RPD) of each model. An RPD of 2.28 was obtained for boscalid, while it was 2.31 for pyraclostrobin. These results indicate that the developed models have reasonable predictive power. © 2019 Society of Chemical Industry.


Assuntos
Contaminação de Alimentos/análise , Fragaria/química , Resíduos de Praguicidas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Compostos de Bifenilo/análise , Frutas/química , Fungicidas Industriais/análise , Análise dos Mínimos Quadrados , Niacinamida/análogos & derivados , Niacinamida/análise , Estrobilurinas/análise
5.
Molecules ; 24(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842368

RESUMO

The accumulation of chemical constituents of some medicinal plants, such as Paeonia ostii T. Hong et J. X. Zhang, Houpoëa officinalis (Rehder and E. H. Wilson) N. H. Xia and C. Y. Wu. and Atractylodes lancea (Thunb.) DC, can precipitate on the surface and form frosts after natural or artificial intervention. The characteristics of these three medicinal plants and their frosts were analyzed by light microscope, polarizing microscope, stereomicroscope, and metalloscope. The results of ordinary Raman of P. ostii and H. officinalis showed that the frosts of P. ostii matched paeonol, while that of H. officinalis matched magnolol and honokiol. In P. ostii and its frost, 19 peaks were identified by UPLC-Q/TOF-MS, and the main component was paeonol. Eleven components were identified in H. officinalis and its frosts, and the main components were magnolol and honokiol. A. lancea and its frosts were analyzed by gas chromatography-mass spectrometry (GC-MS), 21 were identified, and its main components were hinesol and ß-eudesmol. These three medicinal plants accumulate compounds and precipitate frosts on the surface. The results show that the components of the frosts provide a basis for quality evaluation and research on similar medicinal plants, and reveals the scientific connotation of "taking the medicinal materials' precipitated frosts as the best" of P. ostii, H. officinalis, and A. lancea, to some extent.


Assuntos
Atractylodes/química , Paeonia/química , Casca de Planta/química , Plantas Medicinais/química , Acetofenonas/análise , Compostos de Bifenilo/análise , Lignanas/análise , Sesquiterpenos/análise , Sesquiterpenos de Eudesmano/análise , Compostos de Espiro/análise
6.
Zhongguo Zhong Yao Za Zhi ; 44(17): 3601-3607, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31602929

RESUMO

Magnoliae Officinalis Cortex( MOC),the stem bark of Magnolia officinalis( MO) and M. officinalis var. biloba( MOB),is a main ingredient in more than 200 types of Chinese formulae commonly used in clinics. MO and MOB are widely distributed in China,from Sichuan of the west to Zhejiang province of the east and from Shannxi province in the north to Guangxi province in the south. This review summarizes new findings on geo-heralism of MOC concerning textual research,plants taxonomy,genetic study,chemical study,and pharmacological activity,resulting in the following views. ①The original plants of MOC are suggested to be divided into three geographic clans according to the form of leave and the result of genetic research; ②Concentrations of magnolol,honokiol,magnoloside A,magnoloside B,magnoflorine,and ß-eudesmol in samples collected from different geographic areas are varied;③Samples of MOC produced in Hubei and Sichuan were traditionally regarded as Dao-di herbs,which were called Chuanpo,and the pure haplotype of MOC produced in Hubei may become a genetic index.


Assuntos
Compostos de Bifenilo/análise , Medicamentos de Ervas Chinesas/análise , Lignanas/análise , Magnolia/química , China , Compostos Fitoquímicos/análise
7.
Mol Med Rep ; 20(2): 1103-1112, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31173186

RESUMO

DL0410, a dual­action cholinesterase inhibitor and histamine­3 receptor antagonist with a novel structural scaffold, may be a potential candidate for the treatment of Alzheimer's disease (AD). To the best of the authors' knowledge, this is the first study to demonstrate a reliable method for the measurement of DL0410 in rat plasma, brain, bile, urine and feces samples, and identification of its primary metabolites. The pharmacokinetic properties of DL0410 were analyzed by liquid chromatography­mass spectrometry at oral doses of 25, 50 and 100 mg/kg and intravenous dose of 5 mg/kg. The investigation of the excretion and metabolism of DL0410 was determined following liquid­liquid extraction for biliary, urinary and fecal samples. Finally, the cytochrome (CY)P450 isoforms involved in the production of DL0410 metabolites with recombinant human cytochrome P450 enzymes were characterized. The results suggested that DL0410 was not well absorbed; however, was distributed to the entorhinal cortex and hippocampus of the brain. A total of two common metabolites of the reduction of DL0140 in the bile, urine and feces were identified and CYP2D6 was involved in this reaction. The pharmacokinetic results of DL0410 provided information for the illustration of its pharmacodynamic properties, mechanism of action and promoted its continued evaluation as a therapeutic agent for AD treatment.


Assuntos
Compostos de Bifenilo/farmacocinética , Inibidores da Colinesterase/farmacocinética , Citocromo P-450 CYP2D6/metabolismo , Antagonistas dos Receptores Histamínicos H3/farmacocinética , Piperidinas/farmacocinética , Doença de Alzheimer/tratamento farmacológico , Animais , Bile/metabolismo , Compostos de Bifenilo/análise , Compostos de Bifenilo/uso terapêutico , Líquidos Corporais/metabolismo , Encéfalo/metabolismo , Inibidores da Colinesterase/análise , Inibidores da Colinesterase/uso terapêutico , Fezes/química , Feminino , Antagonistas dos Receptores Histamínicos H3/análise , Antagonistas dos Receptores Histamínicos H3/uso terapêutico , Humanos , Masculino , Piperidinas/análise , Piperidinas/uso terapêutico , Ratos , Ratos Sprague-Dawley
8.
IET Nanobiotechnol ; 13(2): 134-143, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051443

RESUMO

This work explores the rapid synthesis of silver nanoparticles (AgNPs) from Musa paradisiaca (M. paradisiaca) bract extract. The bio-reduction of Ag+ ion was recorded using ultraviolet-visible spectroscopy by a surface plasmon resonance extinction peak with an absorbance at 420 nm. The phytoconstituents responsible for the reduction of AgNPs was probed using Fourier transform infrared spectroscopy. The X-ray diffraction pattern confirmed the formation of crystalline AgNPs that were analogous to selected area electron diffraction patterns. Morphological studies showed that the obtained AgNPs were monodispersed with an average size of 15 nm. The biologically synthesised AgNPs showed higher obstruction against tested phytopathogens. The synthesised AgNPs exhibited higher inhibitory zone against fungal pathogen Alternaria alternata and bacterial pathogen Pseudomonas syringae. Free radical scavenging potential of AgNPs was investigated using 1,1-diphenyl-2-picryl hydroxyl and 2,2-azinobis (3-ethylbenzothiazoline)-6-sulphonic acid assays which revealed that the synthesised AgNPs act as a potent radical scavenger. The catalytic efficiency of the synthesised AgNPs was investigated for azo dyes, methyl orange (MO), methylene blue (MB) and reduction of o-nitrophenol to o-aminophenol. The results portrayed that AgNPs act as an effective nanocatalyst to degrade MO to hydrazine derivatives, MB to leucomethylene blue, and o-nitro phenol to o-amino phenol.


Assuntos
Anti-Infecciosos/química , Depuradores de Radicais Livres/química , Nanopartículas Metálicas/química , Musa/química , Extratos Vegetais/metabolismo , Prata/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Compostos Azo/análise , Compostos Azo/metabolismo , Bactérias/efeitos dos fármacos , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Fungos/efeitos dos fármacos , Química Verde , Picratos/análise , Picratos/metabolismo , Extratos Vegetais/química , Prata/metabolismo
9.
IET Nanobiotechnol ; 13(2): 214-218, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051453

RESUMO

Selenium (Se) is a rare and essential element for the human body and other living organisms because of its role in the structure of several proteins and having anti-oxidant properties to reduce oxidative stress at cells. Some microorganisms can absorb Se oxyanions and convert them into zero-valent Se (Se0) in the nanoscale dimensions, which can be used for producing Se nanoparticles (SeNPs). In the present study, SeNPs were intracellularly biosynthesised by yeast Nematospora coryli, which is an inexpensive method and does not involve using materials hazardous for human and environment. The produced NPs were refined by a two-phase system and then characterised and identified by ultraviolet-visible, X-ray diffraction, X-ray fluorescence, transmission electron microscope, and Fourier transform infrared spectroscopy analyses. The structural analysis of biosynthesised SeNPs showed spherical-shaped NPs with size ranging from 50 to 250 nm. Also, extracted NPs were applied to explore their anti-candida and anti-oxidant activities. The results of this investigation confirm the biological properties of Se.


Assuntos
Antifúngicos/metabolismo , Antioxidantes/metabolismo , Nanopartículas/química , Saccharomycetales/metabolismo , Selênio/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Candida/efeitos dos fármacos , Tamanho da Partícula , Picratos/análise , Picratos/metabolismo , Saccharomycetales/química , Selênio/química
10.
Food Chem ; 287: 338-345, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30857708

RESUMO

Recently, new approaches for measuring antioxidant activity have been developed to eliminate or reduce the use of a spectrophotometer. All analytical methods must provide consistent and reliable results, which should be compared with statistical models. Therefore, we compared the conventional and dropping DPPH methods with three widely used standards. We employed and compared with three statistical methods. Good R-squared (R2 = ≥0.96) confirmed the similarity in comparison of using dropping DPPH method compared with the conventional DPPH method and reported lower deviations (ARD = -0.32 to 0.13; RMSD = 0.10 to 1.15). Bland-Altman method (95% CI) demonstrated a good agreement between the two methods using standards and grape extracts (skin and seed). These findings suggested that the dropping DPPH method proved cheaper (without spectrophotometer) and correlated well with the conventional DPPH method. Therefore, this method could be affordably conducted in research laboratories in developing and less developed countries.


Assuntos
Antioxidantes/análise , Compostos de Bifenilo/análise , Modelos Estatísticos , Picratos/análise , Espectrofotometria/métodos , Antioxidantes/química , Compostos de Bifenilo/química , Cromatografia em Camada Delgada , Picratos/química
11.
Food Chem ; 274: 291-297, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30372941

RESUMO

A QuEChERS technique employing multi-walled carbon nanotubes was developed and validated for the simultaneous quantitation of boscalid and pyraclostrobin in grape field samples using rapid resolution liquid chromatography triple- quadrupole tandem mass spectrometry. The validated method was successfully applied to determine the levels of residual boscalid and pyraclostrobin in soil and grapes. The dissipation behavior of each fungicide followed first-order kinetics, with a linear correlation coefficient of 0.995-0.998 at 95% confidence. The highest levels of boscalid and pyraclostrobin in grape, with a pre-harvest interval of 14 days and doses of 380-570 mg a.i. kg-1 in three or four applications, were 3.99 mg kg-1 and 0.792 mg kg-1, respectively. These are below the maximum residue limits for boscalid and pyraclostrobin in grape, as recommended by the Chinese Ministry of Agriculture. Risk quotients (RQs) of these pesticides were evaluated by comparing national estimated daily intake with acceptable daily intake. The results yielded RQs for boscalid and pyraclostrobin in grape of 54% and 31.7%, respectively, which suggest a low health risk to consumers.


Assuntos
Compostos de Bifenilo/análise , Contaminação de Alimentos/análise , Niacinamida/análogos & derivados , Poluentes do Solo/análise , Estrobilurinas/análise , Vitis/química , Agricultura/métodos , China , Cromatografia Líquida/métodos , Exposição Dietética/análise , Fungicidas Industriais/análise , Humanos , Nanotubos de Carbono , Niacinamida/análise , Nível de Efeito Adverso não Observado , Resíduos de Praguicidas/análise , Reprodutibilidade dos Testes , Medição de Risco , Espectrometria de Massas em Tandem/métodos
12.
J Cosmet Sci ; 69(4): 233-243, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30311899

RESUMO

3-O-ethyl ascorbic acid may be a good whitening ingredient in cosmetics. However, before it can be successfully used in cosmetics, its biofunctionality and stability need to be comprehensively investigated. The reduction and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability of this compound were analyzed to assess its antioxidant potential. In addition, the tyrosinase inhibitory ability was analyzed to show the whitening capacity of 3-O-ethyl ascorbic acid. Response surface methodology (RSM) was used to determine the optimal conditions for the ascorbic acid derivative in cosmetics. Based on the DPPH radical scavenging ability results, the half-inhibitory concentration (IC50) value of 3-O-ethyl ascorbic acid was 0.032 g/L. It also showed a good reducing ability at 1.5 g/L concentration. Based on the tyrosinase inhibition analysis, the IC50 value was 7.5 g/L. The optimal conditions to achieve the best stability were determined from the RSM as 36.3°C and pH 5.46.


Assuntos
Antioxidantes/química , Ácido Ascórbico/análogos & derivados , Cosméticos/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Antioxidantes/farmacologia , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Ácido Ascórbico/farmacologia , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Estabilidade de Medicamentos , Picratos/análise , Picratos/metabolismo
13.
Biocontrol Sci ; 23(3): 85-96, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30249967

RESUMO

Studies have reported that cell density, ultraviolet (UV) irradiation, and redox reactions, can induce bioluminescence in bacteria. Conversely, the relationship between seawater components and luminescence is not well understood. The efficacy of marine luminous bacteria as biosensors, and their reactivity to fungicides (for example postharvest pesticides) are also unknown. Therefore, we studied the relationship between the luminescence of Aliivibrio fischeri and the composition of artificial seawater media and analyzed the toxicity of fungicides using A. fischeri grown only with the elements essential to induce luminescence. Luminescence was activated in the presence of KCl, NaHCO3, and MgSO4. In addition, we cultivated A. fischeri with other compounds, including K+, HCO3-, and SO42- ions. These results suggested that A. fischeri requires K+, HCO3-, and SO42- ions to activate cell density-independent luminescence. Additionally, A. fischeri cultured in 2.81% NaCl solutions containing KCl, NaHCO3, and MgSO4 exhibited a decrease in luminescence in the presence of sodium orthophenylphenol at >10 ppm. This result suggests that A. fischeri can be used as a biosensor to detect the presence of sodium ortho-phenylphenol.


Assuntos
Aliivibrio fischeri/química , Técnicas Biossensoriais , Compostos de Bifenilo/análise , Fungicidas Industriais/análise , Medições Luminescentes/normas , Água do Mar/química , Aliivibrio fischeri/efeitos dos fármacos , Aliivibrio fischeri/fisiologia , Organismos Aquáticos , Carga Bacteriana , Imidazóis/análise , Luminescência , Medições Luminescentes/métodos , Sulfato de Magnésio/química , Sulfato de Magnésio/farmacologia , Cloreto de Potássio/química , Cloreto de Potássio/farmacologia , Água do Mar/microbiologia , Sensibilidade e Especificidade , Bicarbonato de Sódio/química , Bicarbonato de Sódio/farmacologia , Cloreto de Sódio/química , Cloreto de Sódio/farmacologia
14.
ACS Nano ; 12(8): 8197-8207, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30080036

RESUMO

The enzyme sphingomyelinase (SMase) is an important biomarker for several diseases such as Niemann Pick's, atherosclerosis, multiple sclerosis, and HIV. We present a two-component colorimetric SMase activity assay that is more sensitive and much faster than currently available commercial assays. Herein, SMase-triggered release of cysteine from a sphingomyelin (SM)-based liposome formulation with 60 mol % cholesterol causes gold nanoparticle (AuNP) aggregation, enabling colorimetric detection of SMase activities as low as 0.02 mU/mL, corresponding to 1.4 pM concentration. While the lipid composition offers a stable, nonleaky liposome platform with minimal background signal, high specificity toward SMase avoids cross-reactivity of other similar phospholipases. Notably, use of an SM-based liposome formulation accurately mimics the natural in vivo substrate: the cell membrane. We studied the physical rearrangement process of the lipid membrane during SMase-mediated hydrolysis of SM to ceramide using small- and wide-angle X-ray scattering. A change in lipid phase from a liquid to gel state bilayer with increasing concentration of ceramide accounts for the observed increase in membrane permeability and consequent release of encapsulated cysteine. We further demonstrated the effectiveness of the sensor in colorimetric screening of small-molecule drug candidates, paving the way for the identification of novel SMase inhibitors in minutes. Taken together, the simplicity, speed, sensitivity, and naked-eye readout of this assay offer huge potential in point-of-care diagnostics and high-throughput drug screening.


Assuntos
Compostos de Bifenilo/análise , Colorimetria , Desipramina/análise , Inibidores Enzimáticos/análise , Naftalenos/análise , Pirimidinonas/análise , Esfingomielina Fosfodiesterase/análise , Animais , Compostos de Bifenilo/farmacologia , Bovinos , Desipramina/farmacologia , Inibidores Enzimáticos/farmacologia , Lipossomos/química , Estrutura Molecular , Naftalenos/farmacologia , Tamanho da Partícula , Pirimidinonas/farmacologia , Esfingomielina Fosfodiesterase/antagonistas & inibidores , Esfingomielina Fosfodiesterase/metabolismo , Propriedades de Superfície
15.
Molecules ; 23(8)2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30082651

RESUMO

Different kinds of freshwater fish soups show a diverse range of health functions, due to their different nutritional substances and corresponding bioactivities. In the current study, in order to learn the theoretical basis of the potential role fish soup plays in diet therapy functions, the changes of nutrient profiles and antioxidant activities in crucian carp soup and snakehead soup (before and after simulated gastrointestinal digestion) were investigated, such as chemical composition, free amino acids, mineral and fatty acid contents, DPPH radical scavenging activity, ferrous ion chelating activity, hydroxyl radical-scavenging activity and the reducing power effect. Results show that the content of mineral elements in snakehead fish soup was significantly higher than that of crucian carp soup, especially for the contents of Ca, Zn, Fe. The content of total amino acid (TAA) of crucian carp soup (82.51 mg/100 mL) was much higher than that of snakehead fish soup (47.54 mg/100 mL) (p < 0.05). Furthermore, the antioxidant capacity of crucian carp soup was stronger than that of snakehead soup. The intensive profiles of nutritional composition and antioxidant activities of these two kinds of fish soups were expected to partly provide the theoretical basis of therapeutic effects.


Assuntos
Aminoácidos/análise , Antioxidantes/análise , Ácidos Graxos/análise , Animais , Compostos de Bifenilo/análise , Carpas , Digestão , Peixes , Análise de Alimentos/métodos , Picratos/análise
16.
Artigo em Inglês | MEDLINE | ID: mdl-30121456

RESUMO

Traditional Tibetan medicine (TTM) has been valuable for the identification of new therapeutic leads. Nevertheless, reports about the chemical constituents of TTM are meager owing to the lack of suitable purification techniques. In this study, an off-line two-dimensional reversed-phase/hydrophilic interaction liquid chromatography (2D RP/HILIC) technique guided by on-line HPLC-DPPH has been established for the isolation of pure antioxidants from the extract of Dracocephalum heterophyllum. According to the chromatographic recognition outcome of the HPLC-DPPH system, the first-dimensional (1D) separation on the Megress C18 preparative column yielded 6 antioxidative fractions (61.4% recovery) from the ethyl acetate fraction (6.1 g). In the second-dimensional (2D) separation, a HILIC XAmide preparative column was employed. In total, 8 antioxidants were isolated from D. heterophyllum with a purity of >95%, which indicated the efficiency of the developed method to prepare antioxidative compounds with high purity from plant extracts. In addition, this method was highly efficient for the preparation of structural analogues of the antioxidative polyphenols and could be applied for the purification of structural analogues from other resources.


Assuntos
Antioxidantes/isolamento & purificação , Cromatografia de Fase Reversa/métodos , Lamiaceae/química , Extratos Vegetais/química , Antioxidantes/análise , Antioxidantes/química , Antioxidantes/metabolismo , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Interações Hidrofóbicas e Hidrofílicas , Picratos/análise , Picratos/metabolismo
17.
J Environ Sci Health B ; 53(10): 652-660, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30024824

RESUMO

The aim of this study is to assess the disappearance of boscalid (IUPAC name: 2-chloro-N-[2-(4-chlorophenyl)phenyl]pyridine-3-carboxamide) and pyraclostrobin (IUPAC name: methyl N-[2-[[1-(4-chlorophenyl)pyrazol-3-yl]oxymethyl]phenyl]-N-methoxycarbamate) residues in apple fruit, and to verify whether an organic fertilizer enriched with strains of antagonistic microorganisms can reduce pesticide residue levels. Field trials were conducted in a commercial orchard on apples of the Gloster variety, during 21 days after the treatment with Bellis 38 WG and the subsequent application of Zumba Plant formulation containing Bacillus spp., Trichoderma spp. and Glomus spp. In control samples, the decrease rate of boscalid and pyraclostrobin residue levels followed an exponential function, described by formulae Rt = 0.2824e-0.071t and Rt = 0.1176e-0.060t, with the coefficient of determination of r2 = 0.8692 and r2 = 0.9268, respectively. These levels dropped to half (t1/2) of their initial values after 9.8 and 11.5 days, respectively. The treatment with Zumba Plant resulted in a reduction in boscalid and pyraclostrobin residue levels by 52% and 41%, respectively. The results of this study are of importance for horticulture sciences and for producers of apples using plant protection products (PPPs).


Assuntos
Compostos de Bifenilo/farmacologia , Frutas/química , Fungicidas Industriais/farmacologia , Malus/química , Niacinamida/farmacologia , Resíduos de Praguicidas/farmacologia , Estrobilurinas/farmacologia , Bacillus/efeitos dos fármacos , Compostos de Bifenilo/análise , Fungicidas Industriais/análise , Niacinamida/análise , Resíduos de Praguicidas/análise , Polônia , Estrobilurinas/análise , Trichoderma/efeitos dos fármacos
18.
Planta Med ; 84(16): 1151-1164, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29925102

RESUMO

Magnolia officinalis and Magnolia obovata bark extracts have been used for thousands of years in Chinese and Japanese traditional medicines and are still widely employed as herbal preparations for their sedative, antioxidant, anti-inflammatory, antibiotic, and antispastic effects. Neolignans, particularly magnolol and honokiol, are the main substances responsible for the beneficial properties of the magnolia bark extract (MBE). The content of magnolol and honokiol in MBE depends on different factors, including the Magnolia plant species, the area of origin, the part of the plant employed, and the method used to prepare the extract. The biological and pharmacological activities of magnolol and honokiol have been extensively investigated. Here we review the safety and toxicological properties of magnolol and honokiol as pure substances or as components of concentrated MBE, including the potential side-effects in humans after oral intake. In vitro and in vivo genotoxicity studies indicated that concentrated MBE has no mutagenic and genotoxic potential, while a subchronic study performed according to OECD (Organisation for Economic Co-operation and Development) guidelines established a no adverse effect level for concentrated MBE > 240 mg/kg b.w/d. Similar to other dietary polyphenols, magnolol and honokiol are subject to glucuronidation, and despite a relatively quick clearance, an interaction with pharmaceutical active principles or other herbal constituents cannot be excluded. However, intervention trials employing concentrated MBE for up to 1 y did not report adverse effects. In conclusion, over the recent years different food safety authorities evaluated magnolol and honokiol and considered them safe.


Assuntos
Compostos de Bifenilo/efeitos adversos , Compostos de Bifenilo/farmacocinética , Compostos de Bifenilo/toxicidade , Lignanas/efeitos adversos , Lignanas/farmacocinética , Lignanas/toxicidade , Animais , Compostos de Bifenilo/análise , Interações Medicamentosas , Humanos , Lignanas/análise , Magnolia/química , Testes de Mutagenicidade , Extratos Vegetais/química , Distribuição Tecidual
19.
Food Chem ; 267: 2-9, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29934157

RESUMO

Boscalid is an agrochemical recently developed for crop protection and the most significant member of the succinate dehydrogenase inhibitor group of fungicides. In this study, a collection of high-affinity monoclonal antibodies was generated to boscalid. By using a series of haptens with a linker at alternative tethering sites of the boscalid framework, specific antibodies were isolated as well as antibodies that also recognized the main boscalid metabolite. Two immunoassays were developed using different ELISA formats. Optimized assays displayed very high sensitivities (limits of detection were near 0.01µg/L). Trueness and precision for the determination of the target analyte in strawberry samples was evaluated. Moreover, immunoassay performance was validated with a reference chromatographic method using QuEChERS extracts of fruits from fungicide-treated crops. A monitoring study with strawberry samples from local markets was carried out by immunoassay, showing an occurrence of boscalid of 15% with a maximum residue concentration of 43µg/kg.


Assuntos
Anticorpos Monoclonais/imunologia , Compostos de Bifenilo/análise , Ensaio de Imunoadsorção Enzimática/métodos , Fragaria/química , Fungicidas Industriais/análise , Niacinamida/análogos & derivados , Compostos de Bifenilo/química , Compostos de Bifenilo/metabolismo , Fragaria/metabolismo , Frutas/química , Frutas/metabolismo , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Haptenos/química , Haptenos/imunologia , Limite de Detecção , Niacinamida/análise , Niacinamida/química , Niacinamida/metabolismo
20.
J AOAC Int ; 101(5): 1285-1294, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29852892

RESUMO

This paper reviews a selection of the most important studies on antioxidants in foods (including beverages), food ingredients, and dietary supplements by effect-directed analysis using TLC with DPPH*, ABTS*+, and ß-carotene direct bioautography. Total antioxidant activity by visible mode spectrometry (colorimetry) with TLC used offline to obtain additional analytical results, mostly for identification and quantification of phenolic compounds in samples, is also discussed. Finally, dot-blot assay for total antioxidant activity, carried out on a TLC plate without mobile-phase development, is reviewed as an alternative with possible advantages compared with spectrometry.


Assuntos
Antioxidantes/análise , Cromatografia em Camada Delgada/métodos , Suplementos Nutricionais/análise , Análise de Alimentos/métodos , Ingredientes de Alimentos/análise , Animais , Bebidas/análise , Compostos de Bifenilo/análise , Colorimetria/métodos , Humanos , Espectrometria de Massas/métodos , Picratos/análise , beta Caroteno/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA