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Köteles I, Foroughbakhshfasaei M, Dobó M, Ádám M, Boldizsár I, Szabó ZI, Tóth G. Determination of the Enantiomeric Purity of Solriamfetol by High-Performance Liquid Chromatography in Polar Organic Mode Using Polysaccharide-Type Chiral Stationary Phases. Chromatographia 2020. [DOI: 10.1007/s10337-020-03911-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Juhász S, Tóth G, Lengyel B. Brokering the core and the periphery: Creative success and collaboration networks in the film industry. PLoS One 2020; 15:e0229436. [PMID: 32106266 PMCID: PMC7046270 DOI: 10.1371/journal.pone.0229436] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 02/06/2020] [Indexed: 11/18/2022] Open
Abstract
In collaboration-based creative industries, such as film production, creators in the network core enjoy prestige and legitimacy that are key for creative success. However, core creators are challenged to maintain diverse access to new ideas or alternative views that often emerge from the network periphery. In this paper, we demonstrate that creators in the network core can increase the probability of their creative success by brokering peripheral collaborators to the core. The argument is tested on a dynamic collaboration network of movie creators constructed from a unique dataset of Hungarian feature films for the 1990-2009 period. We propose a new way to capture brokers' role in core/periphery networks and provide evidence that being in the core and at the same time bridging between the core and the periphery of the network significantly increases the likelihood of award winning.
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Bartha GS, Tóth G, Horváth P, Kiss E, Papp N, Kerényi M. Analysis of aristolochlic acids and evaluation of antibacterial activity of
Aristolochia clematitis L. Biol Futur 2020; 70:323-329. [DOI: 10.1556/019.70.2019.36] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 11/17/2019] [Indexed: 11/19/2022]
Abstract
Introduction
Several Aristolochia species were used as medicinal
herb across Europe and in recent years, their antimicrobial activity has also been
investigated.
Materials and methods
In this study, A. clematitis was selected to evaluate
the aristolochic acids I and II (AA I and AA II) concentrations and the antimicrobial
activity of methanol, hexane, butanol, and ethyl acetate extracts of the root, stem,
leaf, root, and fruit. AA I and AA II contents were measured by a validated
high-performance liquid chromatography–ultraviolet method.
Results
Each fraction of the plant contained AA I and AA II and the root was found to
have the highest contents of AA I (1.09%) and AA II (0.7454%). The minimum inhibitory
concentrations of all extracts were determined by standard microdilution method. The
fruit’s extracts showed the most efficient antimicrobial effect against both
methicillin sensitive and resistant Staphylococcus aureus
strains.
Conclusion
Correlation between the AA I and AA II concentrations and the antimicrobial
effect was not found.
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Tóth G, Háhn J, Kriszt B, Szoboszlay S. Acute and chronic toxicity of herbicides and their mixtures measured by Aliivibrio fischeri ecotoxicological assay. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 185:109702. [PMID: 31585394 DOI: 10.1016/j.ecoenv.2019.109702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
The purpose of our work was to determine the acute and chronic toxicity of three of the EU's most common herbicides - mesotrione, S-metolachlor, terbuthylazine - and their mixtures by Aliivibrio fischeri ecotoxicological assays. While comparing the sensitivity of the acute (30 min) Microtox® standard assay with the chronic (25 h) test adapted to microtiter plate, joint effects (antagonism, additive effect and synergism) to the bioluminescence inhibition (consequently the metabolic damage) in A. fischeri were also determined by Combination Index (CI) method. 30 min of exposure to mesotrione and S-metolachlor resulted in a relatively low acute toxicity (EC50 values were 118 and 265 mg/L), while terbuthylazine did not cause bioluminescence inhibition at all. Results showed that the chronic toxicity of S-metolachlor and terbuthylazine to A. fischeri (EC5010h = 59.2 and 4.9 mg/L and EC5015h = 54.0 and 9.6 mg/L, respectively) is larger by at least one order of magnitude than that after 30 min of contact time. Considering mesotrione no significant difference was experienced in toxicity. Regarding the EC50 values, all of the mixtures had synergistic joint effects in the acute assay. However, in the chronic test all the mixtures showed antagonistic responses with the exception of mesotrione and S-metolachlor (ratio 1:1) combination, which also had additive and synergistic effects after 10 and 15 h of exposure, similarly to the short-term test. This is also the first report of the joint effects of these herbicides. The chronic test is a more sensitive indicator to the active ingredients; both acute and chronic assays supply valuable data of the toxic properties of the pesticides. Moreover, the short- and long-term joint effects of their mixtures supporting a more accurate and reliable risk assessment.
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Nagy-Győr L, Farkas E, Lăcătuș M, Tóth G, Incze D, Hornyánszky G, Bódai V, Paizs C, Poppe L, Balogh-Weiser D. Conservation of the Biocatalytic Activity of Whole Yeast Cells by Supported Sol – Gel Entrapment for Efficient Acyloin Condensation. PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING 2019. [DOI: 10.3311/ppch.14645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In this study, an efficient and generally applicable 2nd generation sol – gel entrapment method was developed for immobilization of yeastcells. Cells of Lodderomyces elongisporus, Candida norvegica, Debaryomyces fabryi, Pichia carsonii strains in admixture with hollow silica microspheres support were immobilized in sol – gel matrix obtained from polycondensation of tetraethoxysilane. As biocatalysts in theselective acyloin condensation of benzaldehyde catalyzed by pyruvate decarboxylase of the yeast, the novel immobilized whole-cell preparations were compared to other states of the cells such as freshly harvested wet cell paste, lyophilized cells and sol – gel entrapped preparations without hollow silica microspheres support. Reusability and storability studies designated this novel 2nd generation sol – gel method as a promising alternative for solid formulation of whole-cells bypassing expensive and difficult downstream steps while providing easy-to-handle and stable biocatalysts with long-term preservation of the biocatalytic activity.
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Papp LA, Foroughbakhshfasaei M, Fiser B, Horváth P, Kiss E, Sekkoum K, Gyéresi Á, Hancu G, Noszál B, Szabó ZI, Tóth G. Reversed-phase HPLC enantioseparation of pantoprazole using a teicoplanin aglycone stationary phase-Determination of the enantiomer elution order using HPLC-CD analyses. Chirality 2019; 32:158-167. [PMID: 31795019 DOI: 10.1002/chir.23146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/11/2019] [Accepted: 10/16/2019] [Indexed: 01/27/2023]
Abstract
A direct HPLC method was developed for the enantioseparation of pantoprazole using macrocyclic glycopeptide-based chiral stationary phases, along with various methods to determine the elution order without isolation of the individual enantiomers. In the preliminary screening, four macrocyclic glycopeptide-based chiral stationary phases containing vancomycin (Chirobiotic V), ristocetin A (Chirobiotic R), teicoplanin (Chirobiotic T), and teicoplanin-aglycone (Chirobiotic TAG) were screened in polar organic and reversed-phase mode. Best results were achieved by using Chirobiotic TAG column and a methanol-water mixture as mobile phase. Further method optimization was performed using a face-centered central composite design to achieve the highest chiral resolution. Optimized parameters, offering baseline separation (resolution = 1.91 ± 0.03) were as follows: Chirobiotic TAG stationary phase, thermostated at 10°C, mobile phase consisting of methanol/20mM ammonium acetate 60:40 v/v, and 0.6 mL/min flow rate. Enantiomer elution order was determined using HPLC hyphenated with circular dichroism (CD) spectroscopy detection. The online CD signals of the separated pantoprazole enantiomers at selected wavelengths were compared with the structurally analogous esomeprazole enantiomer. For further verification, the inline rapid, multiscan CD signals were compared with the quantum chemically calculated CD spectra. Furthermore, docking calculations were used to investigate the enantiorecognition at molecular level. The molecular docking shows that the R-enantiomer binds stronger to the chiral selector than its antipode, which is in accordance with the determined elution order on the column-S- followed by the R-isomer. Thus, combined methods, HPLC-CD and theoretical calculations, are highly efficient in predicting the elution order of enantiomers.
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Ferencz E, Kovács B, Boda F, Foroughbakhshfasaei M, Kelemen ÉK, Tóth G, Szabó ZI. Simultaneous determination of chiral and achiral impurities of ivabradine on a cellulose tris(3-chloro-4-methylphenylcarbamate) chiral column using polar organic mode. J Pharm Biomed Anal 2019; 177:112851. [PMID: 31499427 DOI: 10.1016/j.jpba.2019.112851] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 11/15/2022]
Abstract
A high performance liquid chromatographic method was developed for the simultaneous determination of the related substances (R-ivabradine, dehydro-S-ivabradine, N-demethyl-S-ivabradine, ((S)-3,4-dimethoxy-bicyclo[4.2.0]octa-1,3,5-triene-7-yl-methyl)-methyl-amine) and 1-(7,8-dimethoxy-1,3,4,5-tetrahydro-2H-3-benzazepine-2-on-3-yl)-3-chloro-propane) of the heart-rate lowering drug, ivabradine. The separation capability of seven different polysaccharide-type chiral columns (Lux Amylose-1, Lux i-Amylose-1, Lux Amylose-2, Lux Cellulose-1, Lux Cellulose-2, Lux Cellulose-3 and Lux Cellulose-4) was investigated with a mobile phase consisting of 0.1% diethylamine in methanol, 2-propanol and acetonitrile. During the screnning experiments the best results were obtained on Lux Cellulose-2 (based on cellulose tris(3-chloro-4-methylphenylcarbamate) column with methanol with an ideal case, where all the impurities eluted before the S-ivabradine peak. Chromatographic parameters (flow rate, temperature and mobile phase constituents) were optimized by a full factorial screening design. Using optimized parameters (Lux Cellulose-2 column with 0.06% (v/v) diethylamine in methanol/acetonitrile 98/2 (v/v) with 0.45 mL/min flow rate at 12 °C) baseline separations were achieved between all compounds. The optimized method was validated according to the International Council on Harmonization Q2(R1) guideline and proved to be reliable, linear, precise and accurate for determination of at least 0.05% for all impurities in S-ivabradine samples. Method application was tested on a commercial tablet formulation and proved to be suitable for routine quality control of both chiral and achiral related substances of S-ivabradine.
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Pálla T, Fogarasi E, Noszál B, Tóth G. Characterization of the Site-Specific Acid-Base Equilibria of 3-Nitrotyrosine. Chem Biodivers 2019; 16:e1900358. [PMID: 31364276 DOI: 10.1002/cbdv.201900358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 07/30/2019] [Indexed: 11/07/2022]
Abstract
The complete macro- and microequilibrium analyses of 3-nitrotyrosine, a biomarker of oxidative stress damage, are presented for the first time. The protonation macroconstants were determined by 1 H-NMR-pH titration, while microconstants were elucidated by a combination of deductive and NMR methods, in which properties of the methyl ester derivative as an auxiliary compound were also studied. Combination of the NMR-pH characterization of the title and auxiliary compounds and the pair-interactivity parameters of 3-iodotyrosine provided the sufficient system to evaluate all the microconstants. NMR-pH profiles, macroscopic and microscopic protonation schemes, and species-specific distribution diagrams are included. The phenolate basicity of 3-nitrotyrosine is 500 times below that of tyrosine, and it is even lower than that of 3-iodotyrosine. This phenomenon can be explained by the stronger electron withdrawing and the negative mesomeric effect of the nitro group. Based on our results, 89 % of the phenolic OH groups are deprotonated in 3-NT molecules at the pH of the blood plasma.
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Papp LA, Hancu G, Gyéresi Á, Kelemen H, Szabó ZI, Noszál B, Dubský P, Tóth G. Chiral separation of lansoprazole and rabeprazole by capillary electrophoresis using dual cyclodextrin systems. Electrophoresis 2019; 40:2799-2805. [PMID: 31281995 DOI: 10.1002/elps.201900107] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/24/2019] [Accepted: 07/05/2019] [Indexed: 12/12/2022]
Abstract
Novel capillary electrophoresis methods using CDs as chiral selectors were developed and validated for the chiral separation of lansoprazole and rabeprazole, two proton pump inhibitors. Fourteen different neutral and anionic CDs were screened at pH 4 and 7 in the preliminary analysis. Sulfobutyl-ether-β-CD with a degree of substitution of 6.5 and 10 at neutral pH proved to be the most suitable chiral selector for both compounds. Various dual CD systems were also compared, and the possible mechanisms of enantiomer separation were investigated. A dual selector system containing sulfobutyl-ether-β-CD degree of substitution 6.5 and native γ-CD proved to be the most adequate system for the separations. Method optimization was carried out using an experimental design approach, performing an initial fractional factorial screening design, followed by a central composite design to establish the optimal analytical conditions. The optimized methods (25 mM phosphate buffer, pH 7, 10 mM sulfobutyl-ether-β-CD/20 mM γ-CD, +20 kV voltage; 17°C temperature; 50 mbar/3 s injection, detection at 210 nm for lansoprazole; 25 mM phosphate buffer, pH 7, 15 mM sulfobutyl-ether-β-CD/30 mM γ-CD, +20 kV voltage; 18°C temperature; 50 mbar/3 s injection, detection at 210 nm for rabeprazole) provided baseline separation for lansoprazole (Rs = 2.91) and rabeprazole (Rs = 2.53) enantiomers with favorable migration order (in both cases the S-enantiomers migrates first). The optimized methods were validated according to current guidelines and proved to be reliable, linear, precise, and accurate for the determination of 0.15% distomer as chiral impurity in dexlansoprazole and dexrabeprazole samples.
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Szabó ZI, Ludmerczki R, Fiser B, Noszál B, Tóth G. Chiral separation of rasagiline using sulfobutylether-β-cyclodextrin: capillary electrophoresis, NMR and molecular modeling study. Electrophoresis 2019; 40:1897-1903. [PMID: 30758065 DOI: 10.1002/elps.201800482] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/11/2019] [Accepted: 02/11/2019] [Indexed: 11/08/2022]
Abstract
Pressure-assisted stereospecific capillary electrophoresis method was developed for the determination of enantiomeric purity of the antiparkinsonian agent (R)-rasagiline. The optimized method, 50 mM glycine-HCl buffer pH 2, supplied with 30 mM sulfobutylether-β-cyclodextrin, at 35°C, applying 12 kV in reversed polarity, and -8 mbar pressure (vacuum), short-end injection with -25 mbar × 2 s, was successful for baseline separation of rasagiline enantiomers (Rs = 3.5 ± 0.1) in a short analysis time. The method was validated according to current guidelines and proved to be reliable, linear, precise and accurate for determination of 0.15% S-enantiomer as chiral impurity in R-rasagiline sample, as well as quantification of the eutomer. Method application was tested on a commercial tablet formulation. Determination of spatial structure of diastereomeric associates was based on 1 H and 2D ROESY NMR, indicating that the aromatic moiety of the molecule can enter the cyclodextrin cavity. NMR titration and molecular modeling revealed that S-rasagiline formed a more stable inclusion complex with sulfobutylether-β-cyclodextrin, than its antipode, which is in agreement with electrophoretic results.
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Pálla T, Tóth G, Kraszni M, Mirzahosseini A, Noszál B. Population, basicity and partition of short-lived conformers. Characterization of baclofen and pregabalin, the biaxial, doubly rotating drug molecules. Eur J Pharm Sci 2018; 123:327-334. [DOI: 10.1016/j.ejps.2018.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/26/2018] [Accepted: 07/02/2018] [Indexed: 10/28/2022]
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Mirzahosseini A, Pálla T, Orgován G, Tóth G, Noszál B. Dopamine: Acid-base properties and membrane penetration capacity. J Pharm Biomed Anal 2018; 158:346-350. [DOI: 10.1016/j.jpba.2018.06.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 11/17/2022]
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Foroughbakhshfasaei M, Szabó ZI, Mirzahosseini A, Horváth P, Tóth G. Enantiomeric quality control of R-Tofisopam by HPLC using polysaccharide-type chiral stationary phases in polar organic mode. Electrophoresis 2018; 39:2566-2574. [PMID: 29999177 DOI: 10.1002/elps.201800220] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 07/01/2018] [Indexed: 11/09/2022]
Abstract
A novel, fast and economic chiral HPLC method was developed and validated for the resolution of the four isomers of tofisopam. The separation capacity of eleven different chiral columns: six polysaccharide-type including three amylose-based (Chiralpak AD, Chiralpak AD-RH and Chiralpak AS) and three cellulose-based (Chiralcel OD, Chiralcel OJ and Lux Cellulose-4); three cyclodextrin- (Quest-BC, Quest-C2 and Quest-CM) and two macrocyclic glycopeptide antibiotic-type (Chirobiotic T and Chirobiotic TAG) were screened using polar organic or reversed-phase mode. Chiralpak AD, based on amylose tris(3,5-dimethylphenylcarbamate) as chiral selector with neat methanol was identified as the most promising system. In order to improve resolution, an orthogonal experimental design was employed, altering the concentration of 2-propanol, column temperature, and flow rate in a multivariate manner. Using the optimized method (85/15 v/v methanol/2-propanol, 40°C, flow rate: 0.7 mL/min) we were not only able to separate the four isomers but also detect 0.1% S-enantiomer as chiral impurity in R-tofisopam. This is important since the latter is under development as a single enantiomeric agent. Thermodynamic investigation revealed an unusual entropy and enthalpy-entropy co-driven controlled enantioseparation on Chiralcel OJ and on Chiralpak AD column, respectively. Our newly developed HPLC method was validated according to the ICH guidelines and its application was tested on a pharmaceutical formulation containing the racemic mixture of the drug. As a further novelty, a separate circular dichroism method was applied for the investigation of the interconversion kinetics of tofisopam conformers, which proved to be crucial for sample preparation and method validation.
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Könye R, Tóth G, Sólyomváry A, Mervai Z, Zürn M, Baghy K, Kovalszky I, Horváth P, Molnár-Perl I, Noszál B, Béni S, Boldizsár I. Chemodiversity of Cirsium fruits: Antiproliferative lignans, neolignans and sesquineolignans as chemotaxonomic markers. Fitoterapia 2018; 127:413-419. [PMID: 29653155 DOI: 10.1016/j.fitote.2018.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 11/29/2022]
Abstract
While analyzing the fruit composition of nine European Cirsium species representing three sections (i.e., Cephalonoplos, Chamaeleon and Eriolepis), four lignans, three neolignans and three sesquineolignans were determined and used as chemotaxonomic markers. Among them, desmethyl balanophonin and desmethyl picrasmalignan were determined for the first time in the plant kingdom, as the main metabolites of the Chamaeleon section. Prebalanophonin and prepicrasmalignan, identified so far exclusively in C. eriophorum, were also confirmed in C. boujartii and C. vulgare, highlighting the chemotaxonomic significance of these compounds in the Eriolepis section. The antiproliferative assay of the compounds isolated from their optimum sources, confirmed a dose-dependent inhibitory effect of the structures bearing the 4',7-epoxy moiety (balanophonin, picrasmalignan, desmethyl balanophonin, desmethyl picrasmalignan) against SW480 colon cancer cells, while those bearing the 4',7-dihydroxy motif (prebalanophonin, prepicrasmalignan) were inactive.
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Varga E, Barabás C, Tóth A, Boldizsár I, Noszál B, Tóth G. Phenolic composition, antioxidant and antinociceptive activities of Syringa vulgaris L. bark and leaf extracts. Nat Prod Res 2018; 33:1664-1669. [PMID: 29336171 DOI: 10.1080/14786419.2018.1425855] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Metabolite profile, antioxidant and antinociceptive activities of Syringa vulgaris bark and leaf methanolic extracts were investigated. By means of HPLC-DAD-ESI-TOF and HPLC-DAD-ESI-MS/MS, a total of 33 phenolics were identified, including 15 secoiridoids, 6 phenylpropanoids, 3 flavonoids, 3 lignans and 6 low molecular weight phenols. Validated quantitative analysis show that syringin (2.52%) and rutin (1.13%) are the main phenolic compounds in bark and leaf, respectively. Notable radical scavenging and antinociceptive activities of the bark and leaf extracts were confirmed by in vitro DPPH● and ABTS●+ assays and by in vivo hot-plate method in mice, respectively. Our results could lay the scientific basic of future clinical perspectives of lilac bark and leaf.
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Szabó ZI, Foroughbakhshfasaei M, Gál R, Horváth P, Komjáti B, Noszál B, Tóth G. Chiral separation of lenalidomide by liquid chromatography on polysaccharide-type stationary phases and by capillary electrophoresis using cyclodextrin selectors. J Sep Sci 2018; 41:1414-1423. [DOI: 10.1002/jssc.201701211] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 02/01/2023]
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Szöcs L, Völgyi G, Urai Á, Hosztafi S, Tóth G, Gergó L, Noszál B. Site- and species-specific hydrolysis rates of cocaine. J Pharm Biomed Anal 2017; 145:372-378. [PMID: 28715790 DOI: 10.1016/j.jpba.2017.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 11/30/2022]
Abstract
The hydroxide-catalyzed non-enzymatic hydrolysis of cocaine is quantified in terms of ten site- and species-specific rate constants in connection with also ten site- and species-specific acid-base equilibrium constants, comprising all the twelve coexisting species in solution. This characterization involves the major and minor decomposition pathways via benzoylecgonine and ecgonine methyl ester, respectively, leading to ecgonine, the final product. Hydrolysis has been found to be 10-330 times faster at site 2 than at site 3, depending on the ionization status of the amino moiety and the rest of the molecule. Nitrogen protonation accelerates the hydrolyses approximately ten times both at site 2 and site 3.
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Szabó ZI, Foroughbakhshfasaei M, Noszál B, Tóth G. Enantioseparation of racecadotril using polysaccharide-type chiral stationary phases in polar organic mode. Chirality 2017; 30:95-105. [DOI: 10.1002/chir.22772] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/13/2017] [Accepted: 09/13/2017] [Indexed: 01/11/2023]
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Vágvölgyi M, Martins A, Kulmány Á, Zupkó I, Tóth G, Hunyadi A. Preparation and chemo-sensitizing activity of nitrogen-containing ecdysteroid derivatives: 6-oximes, oxime ethers, and a lactam. Am J Transl Res 2017. [DOI: 10.1055/s-0037-1608147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Háhn J, Szoboszlay S, Tóth G, Kriszt B. Assessment of bacterial biodetoxification of herbicide atrazine using Aliivibrio fischeri cytotoxicity assay with prolonged contact time. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:648-657. [PMID: 28466204 DOI: 10.1007/s10646-017-1797-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 06/07/2023]
Abstract
In our study, we determined and compared the atrazine-biodetoxification ability of 41 bacterial strains and 21 consortia created of those with over 50% degradation rate in pure cultures. Biodegradation capacity was measured with GC-MS. Detoxification was assessed based on the cytotoxic effect of end-products to Aliivibrio fischeri in chronic bioluminescence inhibition assay with 25 h contact time. Chronic A. fischeri assay adapted to a microplate, which is suitable for examine numerous residues simultaneously, also appeared to be significantly more sensitive to atrazine compared to the standard acute (30 min) test. Due to its sensitivity, the chronic assay could be a valuable tool to provide a more comprehensive view of the ecological risks of atrazine and other chemicals. Thirteen strains were able to degrade more than 50% of 50 ppm atrazine. Four of these belong to Rhodococcus aetherivorans, R. qingshengii, Serratia fonticola and Olivibacter oleidegradans which species' atrazine degrading ability has never been reported before. Four consortia degrading ability was more effective than that of the creating individual strains; moreover, their residues did not show cytotoxic effects to A. fischeri. However, in several cases, the degradation products of sole strains and consortia resulted in significant bioluminescence inhibition. Thus high biodegradation (>90%) does not certainly mean the reduction or cessation of toxicity highlighting the importance of the evaluation of biological effects of degradation residues to improve the efficiency and abate the ecological risks of bioremediation techniques.
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Sólyomváry A, Alberti Á, Darcsi A, Könye R, Tóth G, Noszál B, Molnár-Perl I, Lorántfy L, Dobos J, Őrfi L, Béni S, Boldizsár I. Optimized conversion of antiproliferative lignans pinoresinol and epipinoresinol: Their simultaneous isolation and identification by centrifugal partition chromatography and high performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1052:142-149. [PMID: 28384606 DOI: 10.1016/j.jchromb.2017.03.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/22/2017] [Accepted: 03/29/2017] [Indexed: 01/04/2023]
Abstract
High amount of the valuable lignan pinoresinol (PR) was determined in Carduus nutans fruit (7.8mg/g) for the first time. A preparative separation method using two consecutive, identical steps of centrifugal partition chromatography (CPC) was developed in order (i) to isolate PR and (ii) to subsequently isolate PR and its 7' epimer epipinoresinol (EPR) simultaneously after an optimized acid treatment which resulted in PR epimerization forming equal amounts of PR and EPR, from C. nutans fruit. As optimal conditions, a two-phase solvent system consisting of methyl tert-butyl ether:acetone:water (4:3:3, v/v/v) for CPC separation, and an acid treatment performed at 50°C for 30min for the epimerization were applied. Thus, 33.7mg and 32.8mg PR and EPR, in as high as 93.7% and 92.3% purity, were isolated from 10.0gC. nutans fruit, representing 86.4% and 84.1% efficiency, respectively. Conversion characteristic of PR and EPR in acidic medium, determined as a function of time and temperature of acid treatment provides their unambiguous identification by on-line high performance liquid chromatography (HPLC). Antiproliferative assay of isolated PR and EPR in two different types of colon cancer cell lines (HCT116 and SW480) confirmed that both epimers caused a more significant decrease of viability in HCT116 cells than in SW480 cells, suggesting their similar mechanism of antiproliferative action.
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Szabó ZI, Gál R, Gáll Z, Vancea S, Rédai E, Fülöp I, Sipos E, Donáth-Nagy G, Noszál B, Tóth G. Cyclodextrin complexation improves aqueous solubility of the antiepileptic drug, rufinamide: solution and solid state characterization of compound-cyclodextrin binary systems. J INCL PHENOM MACRO 2017. [DOI: 10.1007/s10847-017-0710-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Szabó ZI, Gál R, Szőcs L, Ludmerczki R, Muntean DL, Noszál B, Tóth G. Validated capillary electrophoretic method for the enantiomeric quality control of R-praziquantel. Electrophoresis 2017; 38:1886-1894. [PMID: 28221678 DOI: 10.1002/elps.201600492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 01/17/2023]
Abstract
The enantiomers of praziquantel, the drug of choice in schistosomiasis, were separated by electrokinetic chromatography with cyclodextrins. Nine anionic cyclodextrins were screened for their ability to discriminate between the uncharged enantiomers. Seven investigated selectors presented chiral interactions with the enantiomers, these cases being interpreted in terms of stability constants and complex mobilities. The best results were delivered by sulfated-β-cyclodextrin, where quasi-equal stability constants were accompanied by extreme selectivity values and was explained on the basis of highly different mobilities of the transient diastereomeric complexes. Since the enantiomer migration order was unfavorable, a simple polarity switch was employed (detection end at anode), which apart from migration order reversal, also resulted in extreme resolution values (Rs > 35) and increased migration times. After optimization (50 mM phosphate buffer pH 2.0, supplied with 15 mM sulfated-β-cyclodextrin, 15 kV, capillary temperature 25°C, short-end injection with 50 mbar × 2 s), analysis time under 10 min were obtained, while still maintaining high resolution (Rs > 10). The method was validated according to the ICH guidelines and application of the method was tested on in-house synthetized R-praziquantel batches and on commercial, combination tablets containing racemic mixture of the drug.
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Tóth G, Sándor GL, Reichel C, Domján G, Nagy ZZ, Ecsedy M. [Bilateral simultaneous central retinal vein occlusion in protein S deficiency]. Ophthalmologe 2016; 112:929-31. [PMID: 25666570 DOI: 10.1007/s00347-015-3234-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CASE REPORT This article reports a case of bilateral simultaneous central retinal vein occlusion (CRVO) and protein S deficiency. The 27-year-old male patient presented with a sudden decrease in vision in both eyes. The patient's medical history documented the death of his father at the age of 33 years due to pulmonary embolism. Thrombophilia screening revealed protein S deficiency. OBJECTIVES We report this case to emphasize that in any case of young onset retinal vein occlusion, protein S deficiency should be suspected. CONCLUSIONS Thrombophilia assays and taking a thorough medical history should be performed.
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