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1.
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
2.
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
3.
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
4.
J Chromatogr A ; 1610: 460516, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31526639

RESUMO

The new approach to the development of planar chromatogram with controlled developing solvent velocity was implemented for gradient reversed-phase chromatography of a test mixture of dyes. The developing solvent components were directly delivered onto the surface of the C18 type of silica adsorbent layer with controlled velocity by moving pipette combined with two syringe pumps. The eluent components were mixed onto the adsorbent layer, so in this way, there was no dwell volume of the developing solvent during gradient chromatogram development. The delivery of the developing solvent solution to the adsorbent layer was adjusted to its absorption rate by the adsorbent layer. Under such conditions, there was no excess of the eluent solution on the surface of the adsorbent layer, so the high performance of the chromatographic system could be obtained. In the paper, the results of the repeatability and reproducibility test of migration distances of selected separated solute zones are presented.


Assuntos
Cromatografia de Fase Reversa/métodos , Cromatografia em Camada Delgada/métodos , Corantes , Solventes/química , Corantes/análise , Corantes/isolamento & purificação
5.
J Chromatogr A ; 1610: 460542, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31558273

RESUMO

We herein report the use of a sulfo-based column and hydrophilic interaction chromatography (HILIC) to separate 14 ginsenosides, namely Rb1, Rb2, Rb3, Rc, Rd, Rf, Re, Rg1, Rg2, Rg3, Rh1, Rh2, F2, and C-K. In addition to its rapid and efficient ability to separate these ginsenosides, the sulfo-based column exhibited a good relationship between the ginsenoside capacity factor (k') and molecular weight (Mw) and a strict elution order corresponding to the polarity (P) of the ginsenosides, as confirmed by thin layer chromatography.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ginsenosídeos , Cromatografia em Camada Delgada/métodos , Ginsenosídeos/análise , Ginsenosídeos/química , Peso Molecular
6.
J Chromatogr A ; 1609: 460438, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31447207

RESUMO

Plants are an important source of natural iridoids. This study demonstrates for the first time the acetylcholinesterase (AChE) inhibitory activity of iridoids belonging to the class of antirrhinosides. As iridoids distinguish the chemical composition of most species of the Plantaginaceae family, the active AChE inhibitors were investigated in the hydro-alcoholic extract of Anarrhinum pubescens Fresen. High-performance thin-layer chromatography (HPTLC) in combination with the AChE inhibition assay is a time and material saving methodology, and thus was employed to directly point to the individual enzyme inhibitors occurring in the plant. The effect-directed screening successfully discovered three active metabolites. These were characterized as antirrhinoside-derived iridoids. Two of these are here reported as newly isolated natural compounds. Identification of the two new metabolites was based on analysis of their collected spectroscopic data (HRMS, 1D and 2D NMR). Their structures were elucidated to be 6-O-, 6'-O-di-trans-cinnamoyl-antirrhinoside (1) and 5-O-, 6-O-difoliamenthoyl-antirrhinoside (3), while the previously known compound 6-O-foliamenthoyl-(6'-O-cinnamoyl)-antirrhinoside (2) was assigned by extensive analysis of its HRMS and HRMS/MS data. The activity of the isolated compounds was referred to the known AChE inhibitor rivastigmine, i.e. their activity were calculated and expressed as values equivalently to rivastigmine. This neuroprotective potential of iridoids mediated through AChE inhibition promote them to compete as natural curatives for neurodegenerative disorders like Alzheimer's disease.


Assuntos
Acetilcolinesterase/análise , Cromatografia em Camada Delgada/métodos , Ensaios Enzimáticos/métodos , Glucosídeos Iridoides/isolamento & purificação , Plantaginaceae/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Inibidores da Colinesterase/análise , Inibidores da Colinesterase/farmacologia , Fluorescência , Glucosídeos Iridoides/farmacologia , Metaboloma , Espectroscopia de Prótons por Ressonância Magnética
7.
Food Chem ; 303: 125399, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31470274

RESUMO

It is still a challenge to solve the matrix interferences in veterinary drug residue analysis. In this study, we reported a thin layer chromatography (TLC)-high-performance liquid chromatography (HPLC) method for determining total florfenicol (FF) residues, expressed as florfenicol amine (FFA), in porcine edible tissues. The tissue homogenate were acid-hydrolyzed to liberate the bound residues and convert them into FFA. The hydrolysates were washed with ethyl acetate and subsequently extracted with ethyl acetate under alkaline conditions. The supernatants were concentrated through evaporation, defatted with hexane, purified by TLC and analyzed by HPLC at 225 nm. The optimal developing solvent for TLC purification was ethyl acetate-acetone-ammonium hydroxide mixtures (2:8:0.5, v/v/v). The method was fully validated according to decision 2002/657/EC, and could be used for the routine monitoring of FF residues in pig. TLC showed excellent purification efficiency, and was expected to solve the matrix interferences in veterinary drug residue analysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Resíduos de Drogas/análise , Tianfenicol/análogos & derivados , Drogas Veterinárias/análise , Estruturas Animais/química , Animais , Cromatografia Líquida/métodos , Carne/análise , Suínos , Tianfenicol/análise
8.
J Pharm Biomed Anal ; 178: 112909, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31618702

RESUMO

A high-performance thin-layer chromatography (HPTLC) method combined with effect-directed-analysis (EDA) was developed to screen the antioxidant, neuroprotective and antidiabetic effects in essential oils derived from lavender flower, lemon myrtle, oregano, peppermint, sage, and rosemary leaves (Lamiaceae family). HPTLC hyphenated with microchemical (DPPH•, p-anisaldehyde, and ferric chloride) derivatizations, was used to evaluate antioxidant activity, presence of phytosterols and terpenoids, and polyphenolic content, while the combination with biochemical (α-amylase and acetylcholine esterase (AChE) enzymatic) derivatizations was used to asses α-amylase and AChE inhibitory activities. The superior antioxidant activity of oregano leaf extract is attributed to the presence of high levels of aromatic compounds, like polyphenolic acids. The strongest α-amylase inhibition was observed in lemon myrtle and rosemary plus extracts due to the presence of monoterpenes. Rosemary and sage extracts exhibit the highest AChE inhibition activity, with 1 µL essential oils being more potent than the recommended daily dose of donepezil. This superior neuroprotection was attributed to the presences of di- and triterpenes that displayed strong AChE inhibition and antioxidant potential in DPPH• free radical assay. Antioxidant activity was related to phenolic content (R = 0.49), while α-amylase inhibitory activity was positively related to antioxidant activity (R = 0.20) and terpenoid/sterol content (R = 0.31). AChE inhibitory activity was correlated (R = 0.80) to the combined effect of phenolics and terpenoids. Thus, the superior AChE inhibitory and neuroprotection potential of rosemary and sage essential oils could be attributed to joint effects of main phenolic and terpene constituents. The hyphenated HPTLC method provided rapid bioanalytical profiling of highly complex essential oil samples.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Hipoglicemiantes/química , Lamiaceae/química , Fármacos Neuroprotetores/química , Óleos Voláteis/química , Acetilcolinesterase/metabolismo , Antioxidantes/química , Antioxidantes/farmacologia , Bioensaio/métodos , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Hipoglicemiantes/farmacologia , Fármacos Neuroprotetores/farmacologia , Óleos Voláteis/farmacologia , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Terpenos/química , Terpenos/farmacologia , alfa-Amilases/metabolismo
9.
J Pharm Biomed Anal ; 178: 112953, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31718985

RESUMO

Recently, we developed a bradykinin reporter assay and demonstrated the differing protease activity in Complex Regional Pain Syndrome patients vs. controls. In order to further characterize CRPS pathophysiology, the neuropeptide substance P was evaluated as possible reporter substance, here. It was labeled with a chromophore at the lysine residue and generated two major fragments following incubation with serum (amino acid residues 3-8 and 3-11) which were reproducibly separated by thin-layer chromatography. Dabsylated substance P was shown to be a substrate of angiotensin-converting enzyme. The combination of both bradykinin and substance P reporter substances with specific enzyme inhibitors will shed more light on biochemical pathways in inflammatory processes and pain. Comparative clinical studies are now needed to define the application range of both assays in more detail.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Substância P/química , Substância P/metabolismo , Bradicinina/metabolismo , Cromatografia em Camada Delgada/métodos , Humanos , Peptidil Dipeptidase A/metabolismo
10.
J Chromatogr Sci ; 58(1): 16-21, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31879753

RESUMO

Two selective and sensitive chromatographic methods were developed for simultaneous determination of new combination of quinfamide and mebendazole in bulk powder and in pharmaceutical formulation. The first method is HPTLC by which separation was obtained using silica gel HPTLC F254 plates and a simple mobile phase consisting of methanol:toluene (2:6, v/v) and the separated bands were scanned at 254 nm. The second method RP-HPLC that comprised isocratic separation of both drugs on a Phenomenex C18 column using a green mobile phase consisting of double distilled water:methanol (30:70, v/v) at a flow rate of 0.8 mL/min and UV detection at 254 nm. The developed methods were validated and proved to meet ICH guidelines. Successful application of the developed methods was carried out for determination of quinfamide and mebendazole in Vermox Plus® tablets. Statistical comparison between the developed chromatographic methods and the reported simultaneous equation spectrophotometric method showed that there was no significant difference between them, proving the ability of applying the proposed methods in quality control testing of the studied drugs. The developed methods are considered the first chromatographic methods for simultaneous determination of quinfamide and mebendazole; moreover, they offered sensitive and selective eco-friendly methods for analysis of the studied drugs.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Cromatografia em Camada Delgada/métodos , Mebendazol/análise , Quinolinas/análise , Reprodutibilidade dos Testes
11.
Molecules ; 24(23)2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31779124

RESUMO

The lipophilicity of a molecule is a well-recognized as a crucial physicochemical factor that conditions the biological activity of a drug candidate. This study was aimed to evaluate the lipophilicity of isoxazolo[3,4-b]pyridine-3(1H)-ones and their N1-substituted derivatives, which demonstrated pronounced antifungal activities. Several methods, including reversed-phase thin layer chromatography (RP-TLC), reversed phase high-performance liquid chromatography (RP-HPLC), and micellar electrokinetic chromatography (MEKC), were employed. Furthermore, the calculated logP values were estimated using various freely and commercially available software packages and online platforms, as well as density functional theory computations (DFT). Similarities and dissimilarities between the determined lipophilicity indices were assessed using several chemometric approaches. Principal component analysis (PCA) indicated that other features beside lipophilicity affect antifungal activities of the investigated derivatives. Quantitative-structure-retention-relationship (QSRR) analysis by means of genetic algorithm-partial least squares (GA-PLS)-was implemented to rationalize the link between the physicochemical descriptors and lipophilicity. Among the studied compounds, structure 16 should be considered as the best starting structure for further studies, since it demonstrated the lowest lipophilic character within the series while retaining biological activity. Sum of ranking differences (SRD) analysis indicated that the chromatographic approach, regardless of the technique employed, should be considered as the best approach for lipophilicity assessment of isoxazolones.


Assuntos
Antifúngicos/química , Piridinas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Cromatografia em Camada Delgada/métodos , Interações Hidrofóbicas e Hidrofílicas , Lipídeos/química , Análise de Componente Principal/métodos , Relação Quantitativa Estrutura-Atividade
12.
J Chromatogr Sci ; 57(9): 828-837, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31504290

RESUMO

Two simple validated and highly selective methods for analysis of paracetamol, codeine, guaifenesin and pseudoephedrine or phenylephrine quaternary mixtures were developed. The first method is a high performance liquid chromatography with diode array detection method where separation was successful using Agilent C18 (150 × 4.6 mm) column, gradient elution of phosphate buffer pH 3, methanol and acetonitrile and diode-array detection at 210 nm. The second method is a HPTLC method followed by densitometric measurement of the spots at 257 nm. Separation was carried out on Merck HPTLC aluminum sheets of silica gel using methylene chloride: methanol: glacial acetic acid: ammonia (17.8: 1.68: 0.4: 0.12, v/v) mobile phase. The methods were applied successfully for analysis of both quaternary mixtures in laboratory-prepared tablets and also validated in regards to linearity, precision, accuracy, sensitivity and stability.


Assuntos
Acetaminofen/análise , Cromatografia Líquida de Alta Pressão/métodos , Codeína/análise , Guaifenesina/análise , Fenilefrina/análise , Pseudoefedrina/análise , Cromatografia em Camada Delgada/métodos , Limite de Detecção , Modelos Lineares , Medicamentos Compostos contra Resfriado, Influenza e Alergia/análise , Medicamentos Compostos contra Resfriado, Influenza e Alergia/química , Reprodutibilidade dos Testes , Comprimidos
13.
J Chromatogr Sci ; 57(9): 799-805, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31504300

RESUMO

An innovative high-performance thin layer chromatographic (HPTLC) method was designed, optimized and validated for the quantification of R, R-glycopyrronium bromide (GLY) and its related impurities in drug substance and drug product. Separation was performed on HPTLC plates pre-coated with silica gel 60 F254 by dichloromethane:methanol:formic acid (10:0.5:0.5, v/v/v) as a developing system. GLY and its related impurities namely, glycopyrronium impurity G and glycopyrronium impurity J, were separated giving compact well-resolved spots with significant retardation factor (Rf) values of 0.17 ± 0.02, 0.34 ± 0.02 and 0.69 ± 0.02, respectively. Quantification was done at 220 nm in the ranges of 0.3-10 and 0.2-4.0 µg/spot with limits of detection and quantification of 0.1, 0.3 and 0.05, 0.2 µg/spot for GLY and its related impurities, respectively. Good accuracy was obtained with mean percentage recovery of 99.48 ± 1.36, 100.04 ± 1.32 and 99.61 ± 0.80 and R2 ≥ 0.9968 for GLY and its impurities, consecutively. Validation parameters were presented according to the International Conference on Harmonization. The method was used to investigate impurity profile of GLY in drug substance and drug product and could be applied in routine analysis of the drug. Comparison between the developed method and the reported method revealed no statistical difference.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Medicamentos , Glicopirrolato/análise , Cromatografia em Camada Delgada/métodos , Glicopirrolato/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
14.
Molecules ; 24(18)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514307

RESUMO

Essential oils (EOs) are becoming increasingly popular in medical applications because of their antimicrobial effect. Direct bioautography (DB) combined with thin layer chromatography (TLC) is a screening method for the detection of antimicrobial compounds in plant extracts, for example, in EOs. Due to their lipophilic character, the common microbiological assays (etc. disk diffusion) could not provide reliable results. The aim of this study was the evaluation of antibacterial and anti-biofilm properties of the EO of cinnamon bark, clove, peppermint, thyme, and their main components against Haemophilus influenzae and H. parainfluenzae. Oil in water (O/W) type Pickering nano-emulsions stabilized with silica nanoparticles from each oil were prepared to increase their water-solubility. Samples with Tween80 surfactant and absolute ethanol were also used. Results showed that H. influenzae was more sensitive to the EOs than H. parainfluenzae (except for cinnamon bark oil). In thin layer chromatography-direct bioautography (TLC-DB) the ethanolic solutions of thyme oil presented the best activity against H. influenzae, while cinnamon oil was the most active against H. parainfluenzae. Pickering nano-emulsion of cinnamon oil inhibited the biofilm formation of H. parainfluenzae (76.35%) more efficiently than samples with Tween80 surfactant or absolute ethanol. In conclusion, Pickering nano-emulsion of EOs could inhibit the biofilm production effectively.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cromatografia em Camada Delgada/métodos , Haemophilus/efeitos dos fármacos , Haemophilus/fisiologia , Óleos Voláteis/farmacologia , Emulsões/química , Testes de Sensibilidade Microbiana , Nanopartículas/química , Compostos Orgânicos Voláteis/análise
15.
Molecules ; 24(19)2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31546987

RESUMO

Both environmental and economic issues are increasingly pushing for the revalorization of agri-food by-products, including those arising from wine industry. Wastes produced from wine-making processes are important sources of biologically active compounds, mainly phenolic acids and flavonoids, which could be re-used for several applications, for example as additive surrogates or new ingredients in foodstuffs and/or pharmaceuticals. Therefore, the development of methods aimed at isolating, characterizing and quantifying molecules present in winery by-products acquires considerable importance in view of their re-utilization on a large scale. In this connection, this study demonstrated that high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography with diode array detection (HPLC-DAD) can operate in synergy for the investigation of pomace and seed materials arising from both white and red cultivars of Vitis Vinifera. By virtue of fingerprint profiling, mass spectrometry (MS) interfacing and band comparison method, HPTLC enabled detection and identification of phenolic acids, non-anthocyanic flavonoids and anthocyanins. On the contrary, only anthocyanins could be identified by HPLC-DAD, and their subsequent quantification showed that malvidin-3-O-glucoside (oenin) was the most abundant one. In parallel, HPTLC has allowed to detect and quantify proanthocyanidins (PAC), showing that only catechin was present in the test samples. Both quantitative analytical methods were validated in terms of linearity, detection and quantification limits and precision.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Vitis/química , Vinho , Antocianinas/análise , Flavonoides/análise , Glucosídeos/análise
16.
J Mass Spectrom ; 54(10): 834-842, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31498519

RESUMO

Recently in Canada and some states of the United States, marijuana (cannabis) has become fully legalized and regulated, for both medical and recreational purposes. This fact is going to make cannabis products such as edibles even more popular than ever before. Therefore, it is assumed that there will be a high demand for analytical methods, which are accurate and sensitive enough to be used in different forensic and pharmaceutical cannabis-related applications. Cannabis derivatives have an extreme range and number of constituents with possible interactions with one another. Thus, this characteristic leads to their vast and highly complex chemistry, which requires robust analytical tools to be able to precisely and accurately quantify and qualify them. We developed and validated an analytical method using desorption electrospray ionization (DESI)-mass spectrometry (MS) to accurately detect, characterize, and quantify cannabinoids and also offer an easy, cost-effective, and reliable technique, which can be performed in a short time for infused edibles in complex matrices such as chocolate. We evaluated a quantitative analysis of tetrahydrocannabinol (THC) in cannabis-infused chocolate with thin-layer chromatography (TLC)-DESI-MS and QuEChERS extraction method. Both techniques of TLC and QuEChERS are cost-effective and can be run in short time.


Assuntos
Cannabis/química , Chocolate/análise , Dronabinol/análise , Cromatografia em Camada Delgada/métodos , Dronabinol/análogos & derivados , Humanos , Limite de Detecção , Espectrometria de Massas por Ionização por Electrospray , Detecção do Abuso de Substâncias
17.
Molecules ; 24(17)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480762

RESUMO

The aim of this study was to assess the lipophilicity of selected antiparasitic, antihypertensive and non-steroidal anti-inflammatory drugs (NSAIDs) by means of reversed phase-thin layer chromatography (RP-TLC) as well by using Soczewinski-Wachtmeister's and J. Oscik's equations. The lipophilicity parameters of all examined compounds obtained under various chromatographic systems (i.e., methanol-water and acetone-water, respectively) and those determined on the basis of Soczewinski-Wachtmeister's and Oscik's equations (i.e., RMWS and RMWO) were compared with the theoretical ones (e.g., AlogPs, AClogP, milogP, AlogP, MlogP, XlogP2, XlogP3) and the experimental value of the partition coefficient (logPexp). It was found that the RMWS parameter may be a good alternative tool in describing the lipophilic nature of biologically active compounds with a high and low lipophilicity (i.e., antihypertensive and antiparasitic drugs). Meanwhile, the RMWO was more suitable for compounds with a medium lipophilicity (i.e., non-steroidal anti-inflammatory drugs). The chromatographic parameter 0(a) can be helpful for the prediction of partition coefficients, i.e., AClogP, XlogP3, as well as logPexp of examined compounds.


Assuntos
Anti-Inflamatórios/análise , Anti-Hipertensivos/análise , Antiparasitários/análise , Cromatografia de Fase Reversa/métodos , Cromatografia em Camada Delgada/métodos , Lipídeos/química
18.
Nucl Med Biol ; 74-75: 34-40, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31473490

RESUMO

INTRODUCTION: After its intravenous injection, [18F]fluorocholine is oxidized by choline-oxidase into its main plasma metabolite, [18F]fluorobetaine. If PET kinetic modeling quantification of [18F]fluorocholine uptake is intended, the plasma input time-activity-curve of the parent tracer must be obtained, i.e., the fraction of the total plasma radioactivity corresponding to the nonmetabolized [18F]fluorocholine at each time has to be known. Hence our aim was to develop an easy-routine Thin-Layer-Chromatography (TLC) method to separate and quantify the relative fractions of [18F]fluorocholine and [18F]fluorobetaine as a function of time during PET imaging in humans. METHODS: First, we tested several combinations of solvents systems and layers to select the one showing the best resolution on non-radioactive standards. Thereafter, [18F]fluorobetaine was obtained through chemical oxidation of an [18F]fluorocholine sample at diferent incubation times and we applied the selected TLC-system to aliquots of this oxidation solution, both in a saline and in human deproteinized plasma matrices. The plates were detected by a radio-TLC-scanner. This TLC-system was finally applied to arterial plasma samples from 9 patients with high-grade-glioma undergoing brain PET imaging and a parent fraction curve was obtained in each of them. RESULTS: A TLC-system based on Silica-Gel-60//MeOH-NH3 was selected from the choline/betaine non-radioactive standards assay. Radiochromatograms of [18F]fluorocholine oxidation solution yielded two separated and well-defined peaks, Rf = 0,03 ([18F]fluorocholine) and Rf = 0.78 (18F]fluorobetaine) consistent with those observed on non-radioactive standards. During the oxidation, the [18F]fluorocholine radioactivity peak decreased progressively at several incubation times, while the other peak ([18F]fluorobetaine) increased accordingly. The mean values of the parent fraction of [18F]fluorocholine of the 9 patients studied (mean+/-SD) were 94% ±â€¯6%, 58% ±â€¯15%, 43% ±â€¯10%, 39% ±â€¯6% and 37% ±â€¯6% at 2.8 min, 5.8 min, 8.8 min, 11.7 min and 14.7 min post-injection, respectively. CONCLUSIONS: We have developed a TLC-system, easy to perform in a standard radiopharmacy unit, that enables the metabolite correction of arterial input function of [18F]fluorocholine in patients undergoing PET oncologic quantitative imaging.


Assuntos
Encéfalo/metabolismo , Colina/análogos & derivados , Cromatografia em Camada Delgada/métodos , Radioisótopos de Flúor/metabolismo , Glioma/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/metabolismo , Encéfalo/diagnóstico por imagem , Colina/metabolismo , Glioma/diagnóstico por imagem , Glioma/patologia , Humanos
19.
Anal Chim Acta ; 1081: 218-230, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31446961

RESUMO

The combination of classic in vitro bioassays with high-performance thin-layer chromatography (HPTLC) is a promising technique to directly link chemical analysis of contaminants to their potential adverse biological effects. With respect to endocrine disruption, much work is focused on estrogenicity. While a direct combination of HPTLC and the yeast estrogen screen is already developed, it is well accepted that further endocrine effects are relevant for monitoring environmental wellbeing. Here we show that non-estrogenic specific biological endpoints, (partly) related to the endocrine system, can also be addressed by combining respective yeast reporter gene assays with HPTLC to support effect-directed analysis (EDA). These are: androgenicity (YAS), thyroidogenicity (YTS), dioxin-like effects (YDS), effects on the vitamin D (YVS) and the retinoic acid receptor (YRaS). A proof of principle is demonstrated within this study by the characterization of dose-dependent responses to different model compounds for the respective receptors with and without chromatographic development of the HPTLC-plate. Limits of quantification (LOQ) for several model compounds were determined, e.g. 37 pg for testosterone (p-YAS), 0.476 ng for ß-naphthoflavone (p-YDS) and 1.02 ng for calcipotriol hydrate (p-YVS) with chromatographic development. The LOQ for p-YTS and p-YRaS were 10.16 pg for 3,3',5-triiodothyroacetic acid (p-YTS) and 0.41 pg for tamibarotene (p-YRaS), without chromatographic separation. Furthermore, we challenged the developed methodology using environmental samples, demonstrating an elimination efficiency of androgenic activity from municipal wastewater by a wastewater treatment plant between 99.4 and 100%. We anticipate our methodology to substantially broaden the spectrum of specific endpoints combined with HPTLC for an efficient and robust screening of environmental samples to guide a subsequent in-depth EDA.


Assuntos
Bioensaio/métodos , Calcitriol/análogos & derivados , Cromatografia em Camada Delgada/métodos , Testosterona/análise , Poluentes Químicos da Água/análise , beta-Naftoflavona/análise , Calcitriol/análise , Genes Fúngicos , Genes Reporter , Limite de Detecção , Estudo de Prova de Conceito , Receptores de Calcitriol/genética , Receptores do Ácido Retinoico/genética , Saccharomyces cerevisiae/genética , Águas Residuárias/análise
20.
Anal Bioanal Chem ; 411(25): 6767-6775, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31420710

RESUMO

Nonylphenols (NP) are ubiquitous in the environment and show toxic effects and estrogenic activity. According to the corresponding framework directive in the field of water quality, isomers of NP (including 4-n-NP and branched 4-NP) are classified as priority hazardous substances and are regulated as a group of chain and ring isomers with a maximum acceptable concentration of 2 µg/L in inland and other surface waters. This study presents a new sensitive and innovative screening approach for estrogen active NP based on high-performance thin-layer chromatography. NP were focused in a single target zone on thin-layer plates by planar solid phase extraction (pSPE) and detected by a planar yeast estrogen screen (pYES) on the basis of their estrogenic activity. The mean limits of detection and quantitation were 14 and 26 ng per zone, respectively. After liquid-liquid extraction of water samples with dichloromethane, the mean recovery was close to 100% (relative standard deviation of 21% or less), and estrogen active NP were detectable down to 1 µg/L. Thus, pSPE-pYES provides both the detection and the quantitation of estrogenic NP in surface waters at the maximum acceptable concentration. Application of the approach on extracts of surface waters showed the use of pSPE-pYES for environmental samples, and no complex and time-consuming clean-up of the extracts was required. Estrogenic NP were not detectable in any of the investigated surface waters by means of the screening approach presented.


Assuntos
Disruptores Endócrinos/análise , Fenóis/análise , Poluentes Químicos da Água/análise , Cromatografia em Camada Delgada/métodos , Disruptores Endócrinos/efeitos adversos , Monitoramento Ambiental/métodos , Fenóis/efeitos adversos , Extração em Fase Sólida/métodos , Água/análise , Poluentes Químicos da Água/efeitos adversos , Leveduras/efeitos dos fármacos
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