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1.
J Chromatogr A ; 1628: 461439, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822979

RESUMO

Numerous structurally different amides and imides including succinimide derivatives exhibit diverse bioactive potential. The development of new compounds requires rationalization in the design in order to provide structural changes that guarantee favorable physico-chemical properties, pharmacological activity and safety. In the present research, a comprehensive study with comparison of the chromatographic lipophilicity and other physico-chemical properties of five groups of 1-arylsuccinimide derivatives was conducted. The chemometric analysis of their physico-chemical properties was carried out by using unsupervised (hierarchical cluster analysis and principal component analysis) and supervised pattern recognition methods (linear discriminant analysis), while the correlations between the in silico molecular features and chromatographic lipophilicity were examined applying linear and non-linear Quantitative Structure-Retention Relationship (QSRR) approaches. The main aim of the conducted research was to determine similarities and dissimilarities among the studied 1-arylsuccinimides, to point out the molecular features which have significant influence on their lipophilicity, as well as to establish high-quality QSRR models which can be used in prediction of chromatographic lipophilicity of structurally similar 1-arylsuccinimides. This study is a continuation of analysis and determination of the physico-chemical properties of 1-arylsuccinimides which could be important guidelines in further in vitro and eventually in vivo studies of their biological potential.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia em Camada Delgada , Relação Quantitativa Estrutura-Atividade , Solventes/química , Succinimidas/química , Análise por Conglomerados , Simulação por Computador , Análise de Componente Principal
2.
J Chromatogr A ; 1626: 461335, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797820

RESUMO

On-spot fixed-charge derivatization has been suggested for the modification of α-amino acids for their analysis by thin layer chromatography/matrix-assisted laser desorption ionization (TLC/MALDI) mass spectrometry. The approach was based on post-chromatographic treatment of separated analytes by tris(2,6-dimethoxyphenyl)methenium salt and triethylamine. The reaction proceeded smoothly in mild conditions and gave rise to pink-red colored derivatives, containing permanent positive charge. Their MALDI mass spectra, recorded directly from TLC plates, revealed intense peaks corresponding to decarboxylated cationic parts. All derivatives are characterized by high ionization efficiency, which indicates the high sensitivity of the developed method for analyzing amino acids. Applicability of the method to analysis of amino acids was demonstrated on artificial mixtures and dietary supplement.


Assuntos
Aminoácidos/análise , Cromatografia em Camada Delgada/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Aminoácidos/química , Etilaminas/química
3.
J Chromatogr A ; 1625: 461230, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709311

RESUMO

Two isomeric biphenyl neolignans, magnolol and honokiol, are considered as constituents responsible for the healing effect of magnolia bark, a traditional Oriental medicine. To survey the increasing number of dietary supplements that contain magnolia bark or its extract, an affordable quantitative thin-layer chromatography (TLC) - densitometry method was developed. The methanol extracts were analyzed on the silica gel plates after manual sample application using n-hexane - ethyl acetate - ethanol (16:3:1, v/v/v) as a mobile phase. For quantitation, the chromatograms were scanned in the absorbance mode at the wavelength λ = 290 nm. The limits of detection and quantitation were 90 and 280 ng/zone for magnolol and 70 and 200 ng/zone for honokiol, respectively. None of the two targeted neolignans were detected in two of the six analyzed supplements. In the other four samples, the measured amounts were between 0.95-114.69 mg g-1 for magnolol and 4.88-84.86 mg g-1 for honokiol. Moreover, separations of these two neolignans on the TLC and high-performance TLC (HPTLC) layers were compared and HPTLC was combined with antioxidant (DPPH) and antibacterial (Bacillus subtilis and Aliivibrio fischeri) assays and mass spectrometry (MS), using the elution-based interface. Both magnolol and honokiol exhibited effects in all bioactivity assays. The HPTLC-MS tests confirmed purity of neolignan zones in the extracts of dietary supplements and supported tentative identification of the alkaloid piperine and the isoflavone daidzein as additional bioactive components of the investigated dietary supplements. Using the same mobile phase in the orthogonal directions 2D-HPTLC-MS experiments proved degradation, i.e., instability of magnolol and honokiol on the silica gel adsorbent.


Assuntos
Compostos de Bifenilo/análise , Cromatografia em Camada Delgada/métodos , Suplementos Nutricionais/análise , Lignanas/análise , Densitometria , Limite de Detecção , Magnolia/química , Magnolia/metabolismo , Medicina Tradicional do Leste Asiático , Casca de Planta/química , Casca de Planta/metabolismo
4.
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
5.
Food Chem ; 331: 127221, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32540697

RESUMO

Herein, a two-photon (TP) ratiometric fluorescent probe (NpFA) was developed for detecting formaldehyde (FA) in real food samples, living onion tissues and zebrafish by fluorescence resonance energy transfer (FRET) strategy. Specifically, a TP fluorophore as the donor and a FA turn-on naphthalimide fluorophore as the acceptor were connected by a non-conjugated linker to construct the TP-FRET-based NpFA, which exhibited a target-modulated ratiometric fluorescence response to FA rapidly with high selectivity and sensitivity during 65 s, and a large ratio ~5-fold enhancement at I550/I410 after addition of FA, displaying ~60-fold enhancement at 550 nm and a quite low DOC of 5.8 ± 0.2 nM. Moreover, NpFA has a good imaging resolution and depth of deep tissue penetration. Therefore, based on the above results, NpFA has the capability to be a useful tool for investigating FA in real samples application, and we also hope NpFA will further study of the physiological and pathological function of FA.


Assuntos
Corantes Fluorescentes/química , Análise de Alimentos/métodos , Formaldeído/análise , Microscopia Confocal/métodos , Imagem Óptica/métodos , Peixe-Zebra/metabolismo , Animais , Cromatografia em Camada Delgada , Transferência Ressonante de Energia de Fluorescência , Formaldeído/metabolismo , Células HeLa , Humanos
6.
J Chromatogr A ; 1624: 461239, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540077

RESUMO

Effect-directed analysis (EDA) is increasingly used in environmental monitoring to detect and identify key toxicants. High-performance thin-layer chromatography (HPTLC) has proven to be a very suitable fractionation technique for this purpose. However, HPTLC is limited in its separation efficiency. Thus, separated fractions could still contain many different components and identification of the effective substances remains difficult. Therefore, in this study a workflow for selective EDA with two-dimensional HPTLC in combination with high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) was developed. The aim of the workflow was the stepwise reduction of the sample complexity in order to reduce the number of signals that could be responsible for the measured effects. As a consequence, the identification of effective substances should be facilitated. The acetylcholinesterase inhibition assay (AChE assay) for the detection of potential neurotoxic compounds was applied for biotesting. The transfer of effective zones from the first to the second dimension and also to the mass spectrometric measurement was enabled by extraction. A proof of concept was performed by spiking six acetylcholinesterase inhibiting substances into three different water matrices that were investigated with the developed workflow. The successful prioritization of all spiked compounds confirmed the efficiency of the workflow, regardless of the sample matrix. Biotesting of different water samples resulted in numerous potentially neurotoxic effects, which overlapped strongly in the first separation dimension. The higher peak capacity reached by two-dimensional HPTLC, on the other hand, resulted in discrete effective zones and enabled the identification of several compounds. For the substances lumichrome, a derivate of riboflavin and paraxanthine as well as for linear alkylbenzene sulfonates that were applied as anionic surfactants in detergents, the inhibiting effect to the AChE could be confirmed.


Assuntos
Inibidores da Colinesterase/análise , Cromatografia em Camada Delgada/métodos , Espectrometria de Massas/métodos , Água/química , Acetilcolinesterase/metabolismo , Ensaios Enzimáticos , Fluorescência , Processamento de Sinais Assistido por Computador , Poluentes Químicos da Água/análise
7.
Food Chem ; 327: 127060, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32454280

RESUMO

OBJECTIVES: This study set out to highlight the in vitro and in vivo antifungal activity of an Ethanolic Extract of Red Brazilian Propolis (EERBP) and identify bioactive fractions effective against Colletotrichum musae. METHODS: Active fractions were detected by the thin-layer chromatography-bioautography method and characterised by HPLC-MSn. RESULTS: The in vitro results showed that EERBP had strong antifungal properties againstC. musae (81 ± 1% inhibition at 1.6 g GAE L-1). Medicarpin, (3S)-vestitol and (3S)-neovestitol were the main compounds identified in the EERBP extract (45% of all detected peaks). Two isolated fractions displayed inhibition percentages of 35 ± 4 and 42 ± 1%, respectively, on C. musae mycelial growth compared to the EERBP extract. The biological activity of the two fractions displayed an additive effect. CONCLUSION: A further in vivo investigation revealed that EERBP is a potential natural alternative for controlling banana crown rot.


Assuntos
Antifúngicos/química , Extratos Vegetais/química , Própole/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Brasil , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Colletotrichum/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Própole/metabolismo , Espectrometria de Massas por Ionização por Electrospray
8.
Am J Trop Med Hyg ; 103(1): 73-76, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32400349

RESUMO

Reports that chloroquine and hydroxychloroquine may be effective against COVID-19 have received worldwide attention, increasing the risk of the introduction of falsified versions of these medicines. Five different types of falsified chloroquine tablets were discovered between March 31, 2020 and April 4, 2020, in Cameroon and the Democratic Republic of Congo by locally conducted thin layer chromatographic analysis. Subsequent investigation by liquid chromatography and mass spectrometry in Germany proved the absence of detectable amounts of chloroquine and the presence of undeclared active pharmaceutical ingredients, that is, paracetamol and metronidazole, in four of the samples. The fifth sample contained chloroquine, but only 22% of the declared amount. Such products represent a serious risk to patients. Their occurrence exemplifies that once medicines or vaccines against COVID-19 may be developed, falsified products will enter the market immediately, especially in low- and middle-income countries (LMICs). Timely preparations for the detection of such products are required, including the establishment of appropriate screening technologies in LMICs.


Assuntos
Cloroquina/análise , Infecções por Coronavirus/epidemiologia , Medicamentos Falsificados/análise , Pneumonia Viral/epidemiologia , Betacoronavirus , Camarões , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , República Democrática do Congo , Humanos , Espectrometria de Massas , Pandemias
9.
J Chromatogr A ; 1621: 461044, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32273090

RESUMO

The presented paper is the first to show thin layer chromatography (TLC) analysis based on eutectic mobile phases (Deep Eutectic Solvents - DES). During the experiment 25 eutectic mixtures were investigated for their chromatographic properties. Most of them belong to the natural deep eutectic solvents (NADES) group. Also, new eutectic liquids based on phenolics and terpenes, not previously employed in analytical practice, were tested. The eutectic liquids were investigated as pure or diluted with solvents used in chromatographic routine: methanol, water, acetone, chloroform or diethyl ether. The analyses were carried out using classic and high performance silica gel plates. The working solution was a mixture of five alkaloids found in genus Chelidonium, namely sanguinarine, coptisine, chelerythrine, chelidonine, and berberine, with UV light detection of 366 nm. This report proves that eutectic TLC is possible and that the eutectic interactions play a crucial role in the separation process. In most of the tested modifications at least partial separation was achieved. The most successful mobile phase, which enabled separation of all the tested alkaloids, was the equimolar mixture of menthol and phenol with a 35% addition of methanol. The system was also effective in separating alkaloids in the real Chelidonium maius extract sample.


Assuntos
Cromatografia em Camada Delgada/métodos , Alcaloides/análise , Chelidonium/química , Fenóis/química , Extratos Vegetais/química , Solventes/química , Terpenos/química
10.
Bol. latinoam. Caribe plantas med. aromát ; 19(2): 167-178, mar. 2020. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1104197

RESUMO

The objective of this work was to evaluate the antioxidant and inhibitory activities of the ethanolic extracts of the mangosteen (Garcinia mangostana L.) grown in Montenegro, Quindío, Colombia, in three stages of maturation, including the edible (pulp) and inedible parts (pericarp and peduncle). The alcoholic samples were phytochemically characterized by Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and by Fourier Transformation Infrared Spectroscopy (FT-IR); the antioxidant capacities were also evaluated by the diphenyl-picrylhydrazyl (DPPH•) radical method and Oxygen Radical Absorbance Capacity (ORAC), in addition to the inhibitory activity of acetylcholinesterase (AchE) and the total content of phenols and flavonoids. The tests detected phytochemical compounds such as phenols, flavonoids, alkaloids, quinones and xanthones, to which the antioxidant activity and the inhibition of AChE presented, can be attributed. In conclusion, the inedible parts of mangosteen contain higher proportions of secondary metabolites, these being the most promising sources for industrial use.


El objetivo de este trabajo fue el de evaluar las actividades antioxidantes e inhibitoria de acetilcolinesterasa de los extractos etanólicos del mangostino (Garcinia mangostana L.) de Montenegro, Quíndio, Colombia, en tres estados de maduración, incluyendo las partes comestibles (pulpa) y no comestibles (pericarpio y pedúnculo). Las muestras alcohólicas fueron caracterizadas fitoquímicamente por Cromatografía de Capa Delgada (CCD), Cromatografía Líquida de Alta Eficiencia (HPLC) y Espectroscopía Infrarroja por Transformada de Fourier (FT-IR); la capacidad antioxidante fue evaluada también por el método de captación del radical libre 2,2-difenil-1-picrilhidracilo (DPPH• dejar el radical en superíndice) y la Capacidad de Absorción de Radicales de Oxígeno (ORAC), adicionalmente la actividad inhibitoria de la acetilcolinesterasa (AchE) y el contenido total de fenoles y flavonoides. Se detectaron compuestos fitoquímicos como fenoles, flavonoides, alcaloides, quinonas y xantonas, a quienes se les puede atribuir las actividades antioxidantes y de inhibición de la acetilcolinesterasa. En conclusión, las partes no comestibles del mangostino contienen una mayor proporción de metabolitos secundarios, siendo las fuentes más promisorias para uso industrial.


Assuntos
Extratos Vegetais/farmacologia , Extratos Vegetais/química , Garcinia mangostana/química , Antioxidantes/farmacologia , Antioxidantes/química , Fenóis/análise , Flavonoides/análise , Inibidores da Colinesterase , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Espectroscopia de Infravermelho com Transformada de Fourier , Colômbia , Clusiaceae , Etanol , Capacidade de Absorbância de Radicais de Oxigênio
11.
Int J Nanomedicine ; 15: 1253-1266, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32161456

RESUMO

Purpose: This study aimed to develop a chelate-free radiolabeled nanoparticle platform for simultaneous positron emission tomography (PET) and magnetic resonance (MR) imaging that provides contrast-enhanced diagnostic imaging and significant image quality gain by integrating the high spatial resolution of MR with the high sensitivity of PET. Methods: A commercially available super-paramagnetic iron oxide nanoparticle (SPION) (Feraheme®, FH) was labeled with the [89Zr]Zr using a novel chelate-free radiolabeling technique, heat-induced radiolabeling (HIR). Radiochemical yield (RCY) and purity (RCP) were measured using size exclusion chromatography (SEC) and radio-thin layer chromatography (radio-TLC). Characterization of the non-radioactive isotope 90Zr-labeled FH was performed by transmission electron microscopy (TEM). Simultaneous PET-MR phantom imaging was performed with different 89Zr-FH concentrations. The MR quantitative image analysis determined the contrast-enhancing properties of FH. The signal-to-noise ratio (SNR) and full-width half-maximum (FWHM) of the line spread function (LSF) were calculated before and after co-registering the PET and MR image data. Results: High RCY (92%) and RCP (98%) of the [89Zr]Zr-FH product was achieved. TEM analysis confirmed the 90Zr atoms adsorption onto the SPION surface (≈ 10% average radial increase). Simultaneous PET-MR scans confirmed the capability of the [89Zr]Zr-FH nano-platform for this multi-modal imaging technique. Relative contrast image analysis showed that [89Zr]Zr-FH can act as a dual-mode T1/T2 contrast agent. For co-registered PET-MR images, higher spatial resolution (FWHM enhancement ≈ 3) and SNR (enhancement ≈ 8) was achieved at a clinical dose of radio-isotope and Fe. Conclusion: Our results demonstrate FH is a highly suitable SPION-based platform for chelate-free labeling of PET tracers for hybrid PET-MR. The high RCY and RCP confirmed the robustness of the chelate-free HIR technique. An overall image quality gain was achieved compared to PET- or MR-alone imaging with a relatively low dosage of [89Zr]Zr-FH. Additionally, FH is suitable as a dual-mode T1/T2 MR image contrast agent.


Assuntos
Imagem por Ressonância Magnética/métodos , Nanopartículas de Magnetita/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Cromatografia em Gel , Cromatografia em Camada Delgada , Meios de Contraste/química , Óxido Ferroso-Férrico/química , Humanos , Nanopartículas de Magnetita/uso terapêutico , Imagens de Fantasmas , Radioisótopos/química , Razão Sinal-Ruído , Zircônio/química
12.
Sud Med Ekspert ; 63(1): 42-46, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32040087

RESUMO

The purpose of the study is to develop a method for detecting, isolating and quantifying lamivudine in biological substances. Lamivudine was isolated by liquid-liquid and solid phase extraction. The conditions for isolating lamivudine (extractant, pH of the medium, electrolyte, time and frequency of extraction) from aqueous solutions were selected and methods were developed for isolating it from biological substances, including urine, saliva and liver, using liquid-liquid and solid phase extraction methods. Qualitative and quantitative analysis of lamivudine in extracts from urine, saliva and liver was performed by thin layer chromatography, UV spectrophotometry and high-performance liquid chromatography. A validation assessment of the developed techniques indicates their suitability for chemical and toxicological analysis of lamivudine.


Assuntos
Lamivudina/análise , Fígado/química , Saliva/química , Urinálise , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Humanos , Extração em Fase Sólida , Espectrofotometria
13.
Clin Chim Acta ; 505: 73-77, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32092319

RESUMO

BACKGROUND: The objective of the study was to investigate the effectiveness of screening for hereditary galactosaemia with Benedict's test and thin layer chromatography (TLC) in a tertiary laboratory from a developing country. METHODS: We retrospectively analysed the results of tests done in suspected galactosaemia patients including Benedict's test, thin layer chromatography, GALT activity and DNA analysis. RESULTS: 878 paediatric patients were screened with Benedict's test; the age range was 5 days to 19 years. 48% tested positive/trace on the Benedict's test of which 52% of these had galactosuria evident on TLC. 22% of this sample had pathologically low GALT results on follow-up. 8 patients from the screened population were confirmed to have galactosaemia, in addition to 6 more patients diagnosed with galactosaemia without screening tests performed. Median ages at which the diagnoses were made in the screened and non-screened samples were 2 months and 6 months respectively. Confirmatory DNA testing was performed in 2 patients, whom were found to be heterozygous for S135L mutation. CONCLUSION: Inadequate performance of Benedict's test and TLC was demonstrated by false positive and false negative results leading us to conclude that screening test results require interpretation with caution.


Assuntos
Galactosemias/diagnóstico , Programas de Rastreamento/métodos , Adolescente , Criança , Pré-Escolar , Cromatografia em Camada Delgada , Sulfato de Cobre , DNA/genética , Análise Mutacional de DNA , Países em Desenvolvimento , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Galactosemias/genética , Galactosemias/urina , Humanos , Indicadores e Reagentes , Lactente , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos , África do Sul , UTP-Hexose-1-Fosfato Uridililtransferase/análise , UTP-Hexose-1-Fosfato Uridililtransferase/genética , Adulto Jovem
14.
Sud Med Ekspert ; 63(1): 47-52, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32040088

RESUMO

The objective of the work was to study felodipine distribution in warm-blooded animals (rats). The methods of TLC, GC-MS, and UV spectrophotometry were used in the experiments. A lethal dose of felodipine (1.05 g/kg) preliminary suspended in water was introduced intragastric into test animals (male rats of the Wistar line). The analyzed compound was isolated from solid tissues and blood of the animals with acetone, purified by the solvent replacement, and by macrocolumn chromatography with the Silasorb S-18 sorbent of 30 µm and polar eluent, acetonitrile-water (7:3). The analyte was identified by chromatographic behavior in a thin sorbent layer, retention time, and a set of positive ions in its mass spectrum, as well as by the UV spectrum. The analyte was quantitatively detected in biological matrices using UV spectrophotometry. The method was validated by the criteria of linearity, selectivity, accuracy, precision, limits of detection, and quantitative determination. The predominant content of felodipine was detected in tissues of the stomach (312.303±25.980 µg/g), small intestine with its contents (93.235±12.310 µg/g), stomach contents (80.072±8.510 µg/g), and in the spleen (26.083±1.758 µg/g).


Assuntos
Anti-Hipertensivos , Felodipino , Animais , Anti-Hipertensivos/farmacocinética , Cromatografia em Camada Delgada , Felodipino/farmacocinética , Toxicologia Forense , Masculino , Ratos , Ratos Wistar , Distribuição Tecidual
15.
Biomed Chromatogr ; 34(4): e4804, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32012304

RESUMO

Green TLC-densitometric and RP-HPLC methods were developed and validated for the determination of the active prodrug sulfasalazine (SZ), its active metabolite mesalazine (MZ) and the major active metabolite of mesalazine, N-acetyl-5-aminosalicylic acid (AS). In the developed TLC-densitometric method, chromatographic separation was carried out on TLC silica gel plates 60 F254 using a developing system consisting of ethyl acetate-methanol-ammonia solution 33% (8:2.5:0.3, by volume) and then scanning the separated bands at 215 nm using hydrochlorothiazide as an internal standard with linearity ranges of 0.4-3, 0.4-2.4 and 0.3-2 for SZ, MZ and AS, respectively. The developed RP-HPLC method depended on chromatographic separation using a C18 column with a solvent mixture of methanol-aqueous acetic acid solution (pH 5) as a mobile phase with gradient elution mode and UV scanning at 243 nm using pyrazinamide as internal standard with linearity ranges of 5-50, 5-40, and 3-20 for SZ, MZ and AS, respectively. US Food and Drug Administration guidelines were followed during validation of the methods. The greenness of the developed methods was estimated using the greenness profile and the Eco-Scale approach. Both methods passed the four quadrants of the greenness profile and had Eco-Scale score ˃75, thus they were considered to be green according to these approaches.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Química Verde/métodos , Sulfassalazina/sangue , Densitometria , Estabilidade de Medicamentos , Humanos , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
BMC Complement Med Ther ; 20(1): 30, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32020886

RESUMO

BACKGROUND: Several Host defence peptides (HDPs) are low molecular weight (< 50 amino acids residues) peptides detected in several ethnomedicinal plants and have particularly gained research interest in recent times. Due to their wide range of bioactivity, occurrence, abundance and ability to induce very little resistance, they hold promising potentials in drug development. This study investigated the presence of bioactive peptides in the roots of Calliandra portoricensis (CPr) (Mimosaceae) and evaluated its antimicrobial activity against gram-negative and gram-positive bacteria. METHODS: The crude peptide extract was obtained and pre-purified on pre-loaded tube of RP-C18 solid phase cartridges (strata giga tube C18-E; 5 g, 20 mL, Phenomenex, Germany). Peptide enriched fraction was chemically analysed for arginine-rich/aromatic amino acid-rich peptides using a modified G-250 analytical stain and ninhydrin on thin layer chromatography (TLC) for a preliminary screening. Furthermore, MALDI TOF/TOF peptidomics was used to detect the presence and masses of the peptides. Extracts from CPr were used to test the ability to inhibit microbial growth using p-INT (Para-iodonitrotetrazolium violet) dye, with 0.1% gentamycin as positive control. The concentration that inhibits the growth of microorganisms by 50% (IC50) were determined. Toxicity of the two extracts was accessed using freshly hatched nauplii of Artemia salina. Data analysis were evaluated using Microsoft excel and GraphPad Prism5. RESULTS: Low molecular weight (LMW) peptides were detected in CPr using TLC and MALDI-TOF MS. Generally, the extracts exhibited good inhibition (70-95%) against the gram-negative and gram-positive bacteria, except MRSA6 typed strain. Enhanced activity was observed in the pre-purified peptide fraction than in the methanol crude, except on MRSA6. The greatest antimicrobial inhibition by pre-purified peptide fraction was against MRSA22 (IC50 = 0.69 ± 0.33 µg/mL). The crude methanol extract (LC50 = 5.13 µg/mL) was slightly more toxic than the peptide extract (LC50 = 6.12 µg/mL). CONCLUSIONS: This is the first report on detection of bioactive LMW peptides in Mimosaceae family. These peptides appear to be rich in arginine and aromatic amino acids. The peptide extract, in its pre-purified form showed a lower Brine shrimp cytotoxicity and an enhanced antimicrobial activity against the tested gram-negative and gram-positive bacteria.


Assuntos
Anti-Infecciosos/farmacologia , Fabaceae/química , Peptídeos/farmacologia , Peptídeos/toxicidade , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Animais , Artemia , Cromatografia em Camada Delgada , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Peso Molecular , Nigéria , Raízes de Plantas/química
17.
J Chromatogr A ; 1619: 460945, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32057445

RESUMO

A new platform was developed for determination of drugs in plasma without extraction or instrumental analysis just using TLC, smart phone digital camera and free image processing software. Lamotrigine, antiepileptic drug was used as model analyte. The proposed platform depends on using oil-in-water (O/W) microemulsion to isolate the drug from plasma proteins and using water-in-oil (W/O) microemulsion as mobile phase for TLC which results in complete separation between lamotrigine and plasma as viewed under UV lamp. The composition of both microemulsions was optimized using Taguchi orthogonal array and Plackett- Burman design. The optimal (O/W) microemulsion predicted composition was 0.01 mL Butyl acetate, 4 mL butanol, 0.925 gm SDS and 8.6 mL water while the (W/O) mobile phase microemulsion was 9 mL Butyl acetate, 1 mL butanol, 0.25 gm SDS, 0.25 mL water. Separation was carried out on a silica gel 60F-254 plate eluted with the (W/O) microemulsion in about 30 min development time. The images of TLC plates were processed using 4 different programs, by comparing their results it was found that "integrated density" measured by Fiji software was the most accurate response that could measure the concentration of lamotrigine in spiked plasma in the range of (20-200) ng/spot. This method was applied also for determination of lamotrigine in lamictal® tablet dosage form using the same mobile phase. The precision of the method was satisfactory; the maximum value of relative standard deviations did not exceed 1.5%. While the accuracy was proved by the low values of % error and high values of recovery.


Assuntos
Análise Química do Sangue/métodos , Cromatografia em Camada Delgada , Processamento de Imagem Assistida por Computador , Smartphone , Anticonvulsivantes , Análise Química do Sangue/instrumentação , Emulsões/química , Humanos , Lamotrigina/análise , Plasma/química , Software
18.
J Chromatogr A ; 1620: 460970, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32089291

RESUMO

This study focuses on the health benefits of several fresh herbs that are commonly used in the Mediterranean diet. Antioxidant activity, phytosterol content and α-amylase inhibitory activity of fresh basil, lavender, oregano, rosemary, sage, and thyme are analyzed and compared. High-performance thin-layer chromatography (HPTLC) combined with effect directed analysis was used to detect and quantify biological active compounds on chromatograms. The highest antioxidant activity was measured in the extract from oregano leaf, while the highest terpenoid content was in basil leaf extract. All extracts except lavender leaf and lavender flower extracts showed α-amylase inhibition. The same compound at hRF = 68 in basil, oregano, rosemary, sage, and thyme extracts was responsible for α-amylase inhibition. Combined with effect-directed assays and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, hyphenated HPTLC allowed a fast characterization of the active compound. ATR spectral analysis of this band tentatively identified oleanolic acid (or its derivative) to be responsible for the α-amylase inhibition.


Assuntos
Lamiaceae/química , Extratos Vegetais/química , alfa-Amilases/antagonistas & inibidores , Antioxidantes/farmacologia , Bioensaio , Cromatografia em Camada Delgada , Inibidores Enzimáticos/farmacologia , Fitosteróis/análise , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Terpenos/análise
19.
J Chromatogr A ; 1618: 460912, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32014289

RESUMO

Solvent Front Position Extraction (SFPE) procedure has been recently introduced as a novel concept for multi-component sample preparation. According to the procedure, thin-layer chromatography (TLC) is used to separate the compounds of interest from matrix components, and to focus them into a common zone from which the compounds are extracted and transferred to apparatus for instrumental analysis. In the paper, we investigate different adsorbent types of the chromatographic plates and various mobile phases, including pH of their buffers, in respect of optimization conditions of the SFPE procedure. The research was carried out using a test sample containing 9 compounds characterised by different chemical properties, hence the conclusions from the obtained results can be applied to other multi-component samples. Under the optimal conditions, all target compounds are separated from other compounds (matrix), and evenly distributed along a narrow strip, which is advantageous for their quantitation. The determination results are good, the percentage values of relative error and relative standard deviation do not exceed 6%.


Assuntos
Cromatografia em Camada Delgada/métodos , Cromatografia em Camada Delgada/instrumentação , Solventes/química
20.
J Chromatogr A ; 1618: 460942, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32057448

RESUMO

The fruit of Schisandra chinensis (Chinese magnolia vine), the medicinal plant well-known in Traditional Chinese Medicine, gains great popularity in the modern phytopharmacology. This phenomena is related to the wide and powerful healing properties, including supporting immune, nervous and digestive systems activity. S. chinensis is also known for its adaptogenic properties which can support the treatment of neurodegenerative disorders, particularly Alzheimer's disease. The components of S. chinensis have been analyzed mostly using chromatography, including HPLC, GC and TLC. The last technique can be easily hyphenated with biological assays performed directly on a TLC plate that is using effect directed detection. TLC-direct bioautography (TLC-DB) for acetylcholinesterase (AChE) inhibition and TLC-DB against Bacillus subtilis were performed, followed by micro-preparative separation of fractions which were subsequently subjected to LC-MS tentative identification. Additionally, screening analysis was done using both biological detection and derivatization reagents (e.g. PMA, thymol, NP-PEG). Both TLC screening and effect-directed analysis (TLC-DB followed by MS analysis) of S. chinensis fruit revealed components with biological activity, especially antibacterials (e.g. citric acid) and inhibitors of AChE (mainly dibenzocyclooctadiene lignans). AChE inhibition activities were confirmed by TLC-DB for nine standards that is: 6-O-benzoylgomisin, deoxyschisandrin, gomisin A, gomisin G, schisandrin, schisandrin C, schisanhenol, schisantherin A and schisantherin B. These lignans were further identified by LC-ESI-MS in the isolated fraction revealing AChE inhibition. Moreover three other lignans: γ-schisandrin, schisandrin B and gomisin J were tentatively identified by LC-ESI-MS.


Assuntos
Cromatografia em Camada Delgada/métodos , Lignanas/análise , Schisandra/química , Acetilcolinesterase , Inibidores da Colinesterase/análise , Inibidores da Colinesterase/química , Cromatografia Líquida , Ciclo-Octanos/análise , Frutas/química , Lignanas/química , Espectrometria de Massas
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