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1.
Antimicrob Resist Infect Control ; 9(1): 129, 2020 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-32771064

RESUMO

OBJECTIVES: Hand sanitisers are urgently needed in the time of COVID-19, and as a result of shortages, some people have resorted to making their own formulations, including the repurposing of distilleries. We wish to highlight the importance of those producing hand sanitisers to avoid methylated spirits containing methanol and to follow WHO recommended formulations. METHODS: We explore and discuss reports of methanol toxicity through ingestion and transdermal absorption. We discuss the WHO formulations and explain the rationale behind the chosen ingredients. SHORT CONCLUSION: We advise those producing hand sanitisers to follow WHO recommended formulations, and advise those producing hand sanitisers using methylated spirits, to avoid formulations which contain methanol.


Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/prevenção & controle , Desinfetantes/farmacologia , Etanol/farmacologia , Metanol/farmacologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus/fisiologia , Infecções por Coronavirus/virologia , Desinfetantes/química , Desinfetantes/normas , Desinfetantes/toxicidade , Composição de Medicamentos , Etanol/química , Desinfecção das Mãos/instrumentação , Humanos , Metanol/química , Metanol/toxicidade , Pneumonia Viral/virologia , Organização Mundial da Saúde
2.
PLoS One ; 15(8): e0236297, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780750

RESUMO

Naproxen is a widely used non-steroidal anti-inflammatory drug for the control of postoperative inflammatory signs and symptoms in dentistry. Its association with esomeprazole has been widely studied and has yielded good results for the control of acute pain, even with the delayed absorption of naproxen owing to the presence of esomeprazole. To further understand the absorption, distribution, and metabolism of this drug alone and in combination with esomeprazole, we will analyze the pharmacokinetic parameters of naproxen and its major metabolite, 6-O-desmethylnaproxen, in saliva samples. A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometric method for the simultaneous determination of naproxen and 6-O-desmethylnaproxen in saliva will be developed and validated. Sequential saliva samples from six patients will be analyzed before and 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6 8, 11, 24, 48, 72, and 96 h after the ingestion of one naproxen tablet (500 mg) and esomeprazole-associated naproxen tablets (500 + 20 mg), at two different times. After liquid-liquid extraction with ethyl acetate and HCl, the samples will be analyzed using an 8040 Triple Quadrupole Mass Spectrometer (Shimadzu, Kyoto, Japan). Separation of naproxen and its major metabolic products will be performed using a Shim-Pack XR-ODS 75Lx2.0 column and C18 pre-column (Shimadzu, Kyoto, Japan) at 40°C using a mixture of methanol and 10 mM ammonium acetate (70:30, v/v) with an injection flow of 0.3 mL/min. The total analytical run time will be 5 min. The detection and quantification of naproxen and its metabolite will be validated, which elucidate the pharmacokinetics of this drug, thereby contributing to its proper prescription for the medical and dental interventions that cause acute pain.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Monitoramento de Medicamentos/métodos , Esomeprazol/farmacocinética , Naproxeno/análogos & derivados , Saliva/química , Administração Oral , Adolescente , Adulto , Anti-Inflamatórios não Esteroides/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Esomeprazol/administração & dosagem , Esomeprazol/isolamento & purificação , Feminino , Absorção Gastrointestinal , Humanos , Masculino , Metanol/química , Pessoa de Meia-Idade , Naproxeno/administração & dosagem , Naproxeno/isolamento & purificação , Naproxeno/farmacocinética , Dor Processual/tratamento farmacológico , Reprodutibilidade dos Testes , Comprimidos , Espectrometria de Massas em Tandem/métodos , Adulto Jovem
3.
J Chromatogr A ; 1626: 461352, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797832

RESUMO

In the present study, we characterize a famous Pirkle-type enantioselective stationary phase ((R,R)-Whelk-O1 from Regis Technologies) and an equivalent enantiomeric phase (ReproSil Chiral-NR from Dr. Maisch) in supercritical fluid chromatography (SFC) with carbon dioxide - methanol (90:10 v/v) mobile phase. First, the interactions contributing to retention are evaluated with a modified version of the solvation parameter model, comprising five Abraham descriptors (E, S, A, B, V), two additional descriptors to take account of molecular shape (flexibility F and globularity G), and two additional descriptors to take account of interactions with ionizable species (D- and D+). Linear solvation energy relationships (LSER) are established based on the retention of 212 achiral analytes. As expected, π-π interactions are the most significant to explain retention, while dipole-dipole, hydrogen bonding and ionic interactions with cationic species are of secondary importance. Secondly, the contributions of interactions to enantioseparations are discussed, based on the analysis of 79 racemates. Discriminant analyses (DA) were computed to gain some insight on retention mechanisms. The set of racemates is first divided between racemates eluted earlier than expected based on the LSER models, and those eluted later than expected. Small spherical molecules are more retained than expected, as they may better fit inside the cleft of the chiral selector. They are also most frequently resolved, probably for the same reason. Among the molecules that are less retained than expected, which are rather large and/or non-spherical, other features are favourable to enantiorecognition: π-electrons, dipoles and electron-donating properties. Contrary to the observations on other sorts of chiral selectors, flexibility was found to have no contribution on the enantiorecognition process.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Dióxido de Carbono/química , Análise Discriminante , Ligação de Hidrogênio , Íons , Metanol/química , Modelos Teóricos , Estereoisomerismo
4.
J Chromatogr A ; 1626: 461371, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797850

RESUMO

Effect of mobile phase (water-methanol) composition on the enantioseparation of dipeptides on the chiral stationary phase Chirobiotic R was investigated using Ala-Ala, Leu-Leu, Gly-Leu, and Leu-Gly as case studies. The lipophilicity of dipeptides was found to be an essential factor in the dependence of their retention on the methanol percentage, the retention factor of lipophobic dipeptides increasing monotonously and that of lipophilic dipeptides changing according to an asymmetric U-shaped trajectory as methanol concentration increases. The behavior of enantioselectivity as a function of the methanol content also depends on the lipophilicity of dipeptide. For lipophilic Leu-Leu, the dependence has a dome-like shape, and for more lipophobic dipeptides, Ala-Ala and Gly-Leu, it is an increasing function of the methanol concentration. The importance of solvation equilibria in the bulk liquid and on the surface of the stationary phase for the total retention is discussed from the thermodynamic point of view. Special consideration is given to the adsorption of the water-methanol mixture on the surface of the Chirobiotic R stationary phase.


Assuntos
Antibacterianos/química , Cromatografia Líquida de Alta Pressão/métodos , Dipeptídeos/química , Metanol/química , Adsorção , Interações Hidrofóbicas e Hidrofílicas , Estereoisomerismo , Termodinâmica
5.
J Chromatogr A ; 1625: 461277, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709329

RESUMO

The influence of impregnation the chromatographic plate adsorbent layer, silica, with hen's egg white albumin (OVA) or bovine serum albumin (BSA) on the retention of some popular medicines (paracetamol, aminophenazone, theophylline, caffeine, acetanilide, ciprofloxacin, tramadol, acetylsalicylic acid, acebutolol) is investigated. The effect of composition and buffer pH of the mobile phase on solute separation selectivity is also studied. The chromatographic systems with and without above mentioned albumins and their influence on investigated drug retention are compared. In general, it has been turned out that retention of tested medicines in systems with the sorbent impregnated with albumin significantly increase relative to those with non-impregnated.


Assuntos
Cromatografia em Camada Delgada/métodos , Clara de Ovo/química , Preparações Farmacêuticas/análise , Soroalbumina Bovina/química , Sílica Gel/química , Adsorção , Animais , Bovinos , Galinhas , Feminino , Concentração de Íons de Hidrogênio , Metanol/química , Compostos Orgânicos/química , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tolueno/química
6.
J Chromatogr A ; 1625: 461280, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709331

RESUMO

Polysaccharide-based chiral stationary phases (CSPs) are outstandingly suitable to play a key role in chiral HPLC method selection strategies, since they provide high success rates. One reason for this ability is that they adopt a diversity of higher order structures in various eluents, resulting in versatile chiral environments. A potential to extend this versatility further was expected and examined in the present study, based on the recently discovered hysteretic behavior of a widely used chiral selector (CS), amylose tris(3,5-dimethylphenylcarbamate). The hindered transitions of its structure, which are behind the history dependence of its separation ability, were used as a tool to identify distinct states of the chiral selector in order to exploit an extended selectivity space. The identification was carried out using a single diagnostic compound, as opposed to the common approach where testing a library of compounds is required. Eluent mixtures consisting of 2-propanol and either methanol or ethanol were scrutinized in terms of stability and robustness of the observed retentions. The solvent mixtures that were eligible for practical application in these respects were used to construct a screening sequence, including identical compositions combined with different column pretreatment. The gain achievable by using the proposed sequence was then evaluated using 15 enantiomer pairs with focus on resolution, enantiomer elution order and chemoselectivity.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Compostos Orgânicos/química , 2-Propanol/química , Amilose/análogos & derivados , Amilose/química , Etanol/química , Indanos/química , Metanol/química , Oxidiazóis/química , Fenilcarbamatos/química , Solventes/química , Estereoisomerismo , Estilbenos/química
7.
J Chromatogr A ; 1625: 461303, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709346

RESUMO

The chromatographic performances of four coated and immobilized amylose phenylcarbamate-based chiral columns were evaluated and compared under normal phase (NP) elution conditions by using chiral 4,4'-bipyridine derivatives as analytes. n-Hexane/2-propanol 90:10 and n-hexane/2-propanol/methanol 90:5:5 mixtures were employed as mobile phases (MPs), and the effect of adding methanol in the MP on retention and selectivity was considered. The effect of temperature on retention and selectivity was also evaluated, and overall thermodynamic parameters associated with the analyte adsorption onto the CSP surface were derived from van't Hoff plots. Interesting cases of enantiomer elution order (EEO) reversal, which are dependent on the nature of polar modifier, analyte structure, column-type, and temperature, were observed. The impact of substitution pattern and electronic properties of analytes and selectors on the separation behaviour was investigated by correlating chromatographic parameters and molecular properties determined by using density functional theory (DFT) calculations. Both coated and immobilized amylose tris(3,5-dimethylphenylcarbamate) columns allowed for the baseline enantioseparation (2.0 ≤ RS ≤ 4.9) of all 4,4'-bipyridines considered in this study. These results appear particularly useful because both enantiomers of these 4,4'-bipyridine derivatives are currently under investigation as new inhibitors of transthyretin fibrillogenesis, a biochemical phenomenon which is implicated to cause amyloid diseases.


Assuntos
Amilose/química , Piridinas/química , 2-Propanol/química , Adsorção , Hexanos/química , Metanol/química , Modelos Moleculares , Fenilcarbamatos/química , Eletricidade Estática , Estereoisomerismo , Temperatura
8.
Nucleic Acids Res ; 48(13): 7041-7051, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32678885

RESUMO

Z-DNA is known to be a left-handed alternative form of DNA and has important biological roles as well as being related to cancer and other genetic diseases. It is therefore important to investigate Z-DNA structure and related biological events in living cells. However, the development of molecular probes for the observation of Z-DNA structures inside living cells has not yet been realized. Here, we have succeeded in developing site-specific trifluoromethyl oligonucleotide DNA by incorporation of 8-trifluoromethyl-2'-deoxyguanosine (FG). 2D NMR strongly suggested that FG adopted a syn conformation. Trifluoromethyl oligonucleotides dramatically stabilized Z-DNA, even under physiological salt concentrations. Furthermore, the trifluoromethyl DNA can be used to directly observe Z-form DNA structure and interaction of DNA with proteins in vitro, as well as in living human cells by19F NMR spectroscopy for the first time. These results provide valuable information to allow understanding of the structure and function of Z-DNA.


Assuntos
DNA Forma Z/análise , Desoxiguanosina/química , Espectroscopia de Ressonância Magnética/métodos , Oligonucleotídeos/química , Clonagem Molecular , Escherichia coli/genética , Células HeLa , Humanos , Metanol/análogos & derivados , Metanol/química
9.
PLoS One ; 15(7): e0236529, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32697797

RESUMO

In this study, functionalized multi-walled carbon nanotubes (MWCNT-NH2) were synthesized as an additive for the preparation of mixed matrix membranes (MMMs) and then were investigated by FTIR and FE-SEM techniques. Polyether sulfone (PES) polymeric membrane modified with functionalized MWCNT-NH2 carbon nanotubes was prepared by phase inversion method. The effect of MWCNT-NH2 on the morphology and property of the PES membrane was evaluated using scanning electron microscopy. The flux, enrichment factor and swelling properties of modified membranes were also used to investigate the membranes performance. The results showed that the flux and enrichment factor in modified PES membrane containing 5 wt.% of functionalized MWCNT-NH2 carbon nanotubes were obtained 1.2 L.m-2h-1 and 3.3, respectively. The influence of methanol concentration on the flux and enrichment factor was investigated. The results corroborated that the flux didn't change significantly, while the enrichment factor was decreased.


Assuntos
Membranas Artificiais , Nanotubos de Carbono/química , Polímeros/química , Sulfonas/química , Metanol/química , Porosidade , Água/química , Purificação da Água/métodos
10.
J Chromatogr A ; 1625: 461334, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709359

RESUMO

A comprehensive study on the chiral separation of bupivacaine, mepivacaine, prilocaine and propanocaine with eight commercial polysaccharide-based chiral stationary phases (CSPs) in reversed phase conditions compatible with MS detection is performed. Methanol and acetonitrile are used as organic modifiers. Retention and resolution values obtained for each compound in the different CSPs and mobile phases are compared. The polysaccharide-based CSPs tested present different enantioselectivity towards the analytes. From the results, the experimental conditions for determining the enantiomers of bupivacaine, mepivacaine, prilocaine and propanocaine in saline aqueous samples using MS detection are used, for the first time, to perform an enantioselective biodegradability study.


Assuntos
Anestésicos Locais/isolamento & purificação , Cromatografia de Fase Reversa/métodos , Polissacarídeos/química , Acetonitrilos/química , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Metanol/química , Peso Molecular , Estereoisomerismo , Água/química
11.
Arch Microbiol ; 202(8): 2311-2321, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32564100

RESUMO

Methanolic extract of Artemisia pallens (MEAP) (Asteraceae) was explored as greenbiocorrosion inhibitor for mild steel 1010 in 1.5% sodium chloride environment. Bacillus megaterium SKR7 induces the development of biofilm on the metal surface and forms the pitting corrosion. MEAP was showed (25 ppm) optimum inhibition effect of biocorrosion and further corrosion rate was highly reduced (0.3335 mm/year) than the control system (0.009 mm/year). The electrochemical study has supported the results with a higher value of total resistance (34 Ω cm2) when compared to control systems. It reveals the formation of a protective layer on the metal surface and reduces the adsorption of biofilm. This was due to the antimicrobial effect of MEAP. Overall, the results recognized that MEAP used as a green corrosion inhibitor for MS 1010 with 83% inhibition efficiency.


Assuntos
Artemisia/química , Bacillus megaterium/efeitos dos fármacos , Bacillus megaterium/metabolismo , Biofilmes/efeitos dos fármacos , Corrosão , Extratos Vegetais/farmacologia , Aço , Metanol/química
12.
J Vis Exp ; (160)2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32568242

RESUMO

Proteomic technologies are powerful methodologies that can aid our understanding of mechanisms of action in biological systems by providing a global view of the impact of a disease, treatment, or other condition on the proteome as a whole. This report provides a detailed protocol for the extraction, quantification, precipitation, digestion, labeling, and subsequent data analysis of protein samples. Our optimized TMT labeling protocol requires a lower tag-label concentration and achieves consistently reliable data. We have used this protocol to evaluate protein expression profiles in a variety of mouse tissues (i.e., heart, skeletal muscle, and brain) as well as cells cultured in vitro. In addition, we demonstrate how to evaluate thousands of proteins from the resulting dataset.


Assuntos
Análise de Dados , Proteômica , Manejo de Espécimes , Espectrometria de Massas em Tandem , Animais , Clorofórmio/química , Indicadores e Reagentes , Metanol/química , Camundongos , Peptídeos/metabolismo , Proteínas/isolamento & purificação , Proteoma/análise
13.
Chemosphere ; 258: 127273, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32554005

RESUMO

This work describes the design, optimization and validation of an analytical method for the simultaneous determination of 14 pharmaceuticals and personal care products (PPCPs) in sewage sludge. A thorough optimization of the sample pre-treatment was carried out. As a result, microwave-assisted extraction (MAE) was combined with an in-situ clean-up stage and a filtration step. A combination of MilliQ® water/MeOH 95:5 (v/v) adjusted to pH 9 turned out to be the optimal solvent mixture for extraction. The instrumental part of the method presents a significant novelty based on a fully automated sample preparation for the analysis of PPCPs. It consisted of a direct immersion solid phase microextraction followed by on-fiber derivatization, online coupled to gas chromatography - mass spectrometry (DI-SPME-On-fiber derivatization - GC-MS). An isotope dilution approach was used for quantifying, which conferred high reliability to the method. This methodology was validated for 10 compounds with good analytical performance, limit of detection below 20 ng g-1 and absolute recovery in the range of 30-70% for most of the compounds. It supposes an ecological analytical alternative for many routine analysis laboratories around the world. The developed method was applied to different real samples generated in both a pilot-scale thermal hydrolysis treatment plant and an anaerobic digester operated in mesophilic conditions. Salicylic acid and naproxen were found at concentrations above 1000 ng g-1.


Assuntos
Cosméticos/análise , Micro-Ondas , Preparações Farmacêuticas/análise , Esgotos/química , Solventes/química , Poluentes Químicos da Água/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metanol/química , Reprodutibilidade dos Testes , Microextração em Fase Sólida/métodos , Água/química
14.
Food Chem ; 328: 127091, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32474237

RESUMO

Methanol is highly toxic for human, so methanol detection is valuable especially in water and ethanol medium without complicated and time consuming procedure. In this work, we present a new fluorescence probe for direct detection of methanol in aqueous and ethanol medium based on the ZnS:Mn2+ quantum dot (QDs) and soluble N-methylpolypyrrole (NMPPy) hybrid. Moreover, the number of spectroscopic techniques were used to study the chemical composition and optical properties of the resultant QDs as well as investigation on the sensing mechanism toward methanol. Also, methanol can be determined by using ZnS:Mn2+ QDs/NMPPy hybrid based switchable fluorescence sensing system, with high sensitivity, high selectivity and a very good detection limit of 1 mM with linearity in the concentration range of 25-230 mM (~0.1-0.9% v/v) in aqueous solution. Finally, the ZnS:Mn2+ QDs/NMPPy hybrid as optical sensor was successfully utilized to determine the amount of methanol in real alcoholic beverage samples.


Assuntos
Etanol/química , Metanol/análise , Polímeros/química , Pirróis/química , Pontos Quânticos/química , Espectrometria de Fluorescência/instrumentação , Sulfetos/química , Água/química , Compostos de Zinco/química , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Magnésio/química , Metanol/química
15.
J Chromatogr A ; 1624: 461172, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32376027

RESUMO

The enantiomers of a chiral building block to be used in pre-clinical manufacturing were separated using supercritical fluid chromatography (SFC). Despite an extensive evaluation of different columns and solvent combinations followed by a careful optimization of the chromatographic method, the preparative separation suffered from low throughput and high solvent consumption. Consequently, additional improvements were necessary. By utilizing stacked injections, the chromatographic run time was almost halved, and the high solvent consumption was reduced by recycling of the two mobile phase components, carbon dioxide and methanol. The carbon dioxide was reprocessed by the SFC instrument, whereas methanol was evaporated and recycled from the fractions collected. Hence, the originally inefficient separation method was turned into a more sustainable one, and the desired enantiopure intermediate was delivered to be used in the following synthesis of the selected candidate drug. Unfortunately, when the intermediate was used in the subsequent amide coupling, a surprisingly poor yield was obtained. This was caused by an unexpected formation of a stable carbonate salt of the intermediate under the chromatographic conditions used. By removal of the carbonate prior to the amide coupling reaction, the manufacturing campaign could be saved, and the candidate drug was successfully delivered in time.


Assuntos
Carbonatos/química , Cromatografia com Fluido Supercrítico/métodos , Dióxido de Carbono/química , Metanol/química , Sais , Solventes/química , Estereoisomerismo
16.
J Chromatogr A ; 1623: 461169, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32376016

RESUMO

Artifacts due to metabolite extraction, derivatization, and detection techniques can result in aberrant observations that are not accurate representations of actual cell metabolism. Here, we show that α-ketoglutarate (α-KG) is reductively aminated to glutamate in methanol:water metabolite extracts, which introduces an artifact into metabolomics studies. We also identify pyridoxamine and urea as amine donors for α-KG to produce glutamate in methanol:water buffer in vitro, and we demonstrate that the addition of ninhydrin to the methanol:water buffer suppresses the reductive amination of α-KG to glutamate in vitro and in metabolite extracts. Finally, we calculate that glutamate levels have been overestimated by 10-50%, depending on cell line, due to α-KG reductive amination. These findings suggest that precautions to account for α-KG reductive amination should be taken for the accurate quantification of glutamate in metabolomics studies.


Assuntos
Artefatos , Ácido Glutâmico/análise , Ácidos Cetoglutáricos/química , Metabolômica , Aminação , Animais , Linhagem Celular , Ácido Glutâmico/química , Metanol/química , Ninidrina/química , Piridoxamina , Ureia/química
17.
Mutat Res ; 852: 503168, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32265044

RESUMO

A large number of species belonging to the genus Teucrium are used in pharmacy and traditional medicine for the treatment of different diseases. This study aimed to evaluate the polyphenolic composition as well as genotoxic and cytotoxic effects of methanolic extracts from T. arduini and T. flavum, two native species found in Montenegro. We determined the total phenolic and flavonoid contents of these plants using spectrophotometric methods; the qualitative content of polyphenolic compounds was investigated by high-performance liquid chromatography (HPLC). Genotoxicity in cultured human lymphocytes was measured in the cytokinesis-block micronucleus assay (CBMN) and comet assay in the range between 125 and 1000 µg/mL. Cytotoxicity was assessed by the MTT viability assay in normal human MRC-5 fibroblasts and MDA-MB-231 breast carcinoma cells. The content of total phenolics and flavonoids in T. arduini extract was higher than in T. flavum (200.35 mg GA/g vs. 171.08 mg GA/g; 96.32 mg RU/g vs. 78.14 mg RU/g). The polyphenolic composition of both extracts was qualitatively similar and eight phenol compounds were identified. The most commonly present phenol was caffeic acid and among four flavonoids, the most common was quercetin. Both plant extracts were genotoxic in both the CBMN and comet assays at concentrations of 250, 500 and 1000 µg/mL. After 72 h of exposure, the extracts of T. arduini and T. flavum were found to induce cytotoxicity in MRC-5 fibroblasts but not in MDA-MB-231 breast cancer cells. The results suggest that the constituents of both plant species are genotoxic and cytotoxic, therefore these extracts warrant additional evaluation to be safely applied in humans.


Assuntos
Flavonoides/toxicidade , Mutagênicos/toxicidade , Polifenóis/toxicidade , Teucrium/química , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Flavonoides/isolamento & purificação , Humanos , Metanol/química , Testes para Micronúcleos , Montenegro , Mutagênicos/isolamento & purificação , Especificidade de Órgãos , Extratos Vegetais/química , Plantas Medicinais , Polifenóis/isolamento & purificação , Solventes/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-32334391

RESUMO

A rapid procedure for the determination of amphenicol antibiotics in human urine by liquid chromatography with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) is proposed. The presence of thiamphenicol (TAP), florfenicol (FF) and chloramphenicol (CAP) in the human body can be attributed to their administration to treat certain diseases or by eating food of animal origin. The TAP, FF and CAP excreted in urine is mainly in the form of glucuronide conjugates, although their free forms may also be excreted to a lesser extent. In the procedure described, the enzymatic hydrolysis of amphenicol glucuronide forms in urine was carried out using ß-glucuronidase and sulfatase at pH 5 (37 °C, overnight) in order to discriminate the free and conjugated forms. Then, amphenicol antibiotics were submitted to dispersive liquid-liquid microextraction (DLLME) for preconcentration. All the parameters affecting DLLME efficiency were optimized, and the following conditions were selected: 0.9 g NaCl in 10 mL of urine, to which 1.2 mL methanol (as dispersant solvent) and 1 mL of 4-methyl-2-pentanone (as extractant solvent) were added. The absence of a matrix effect allowed quantification of the samples against aqueous standards. Detection limits were 29, 6 and 3 pg mL-1 for TAP, FF and CAP, respectively. Relative standard deviations were calculated to evaluate the intra- and inter-day precision and values lower than 10% were obtained in all cases. The trueness of the method was tested through recovery studies, obtaining satisfactory values (83-104%). Ten urine samples obtained from volunteers were analysed and all of them were free of the studied antibiotics.


Assuntos
Antibacterianos/urina , Cloranfenicol/urina , Glucuronídeos/urina , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão , Glucuronidase/metabolismo , Humanos , Hidrólise , Limite de Detecção , Microextração em Fase Líquida , Metabolômica , Metanol/química , Metil n-Butil Cetona/química , Padrões de Referência , Solventes/química , Sulfatases/metabolismo , Tianfenicol/análogos & derivados , Tianfenicol/urina
19.
Food Chem ; 321: 126672, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244136

RESUMO

The phenols in Diaphragma juglandis fructus (DJF), walnut pellicle (WP), and flowers of Juglans regia (FJR) from walnut were extracted using three methods (methanolic condensation reflux extraction, ultrasonic wave extraction, and enzyme assisted-extraction), and phenolics and antioxidant capacities of different extractions were compared. Overall, 50 phenolics were identified by HPLC-MS/MS with 41 compounds in DJF, 32 in WP, and 29 in FJR. It was observed that tannins in WP was higher than those in DJF and FJR. As for PCA, more than 70% of the variance was explained with the obvious comparison between the phenolic constituents. The phenolics in walnut contributed to remarkable antioxidant effect, with the highest effect observed in WP. This study presents the analysis and comparison of the phenols can be further extended for the development of functional walnut instant foods.


Assuntos
Juglans/química , Fenóis/química , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Flores/química , Frutas/química , Metanol/química , Extratos Vegetais/química , Espectrometria de Massas em Tandem , Ondas Ultrassônicas
20.
J Chromatogr A ; 1624: 461099, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32327223

RESUMO

In this short communication, we report the use of a second-generation macrolide antibiotic, gamithromycin (Gam), as a novel chiral selector for enantioseparation in capillary electrophoresis (CE). A preliminary analysis of the experiment results shows that Gam is especially suitable for the separation of chiral primary amines. Factors influencing enantioseparations were systematically investigated including the composition of the background electrolyte (BGE), concentration of Gam, the type and proportion of organic solvents, applied voltage, etc. In particular, N-Methylformamide (NMF) was successfully used as a non-aqueous solvent for Gam, and shown to be extremely effective for the separation of primaquine (PMQ) and 1-aminoindan (AMI) when used alone or mixed with other commonly used non-aqueous solvents (e.g. methanol). To our knowledge this was also the first application of NMF as a non-aqueous solvent for antibiotic chiral selectors in CE. The best separations were obtained with 100 mM Tris, 125 mM H3BO3 and 80 mM Gam in methanol/NMF (25:75) solvent for PMQ and AMI, or 80-100 mM Gam in methanol for the other model analytes. Among the analytes, the resolution (Rs) of amlodipine (AML) reached up to 15.65, which is to our knowledge the highest value ever reported in CE studies for this compound (except for using molecularly imprinted polymers technique).


Assuntos
Antibacterianos/química , Eletroforese Capilar , Macrolídeos/química , Anlodipino/análise , Eletrólitos , Formamidas/química , Indanos/análise , Metanol/química , Primaquina/análise , Solventes/química , Estereoisomerismo
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