References of "Crommen, Jacques"
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See detailInsulin aggregation assessment by capillary gel electrophoresis without sodium dodecyl sulfate: Comparison with size-exclusion chromatography
Demelenne, Alice ULiege; NAPP, Aurore ULiege; Bouillenne, Fabrice ULiege et al

in Talanta (2019), 199

Size-exclusion chromatography (SEC) is a method of choice for the analysis of protein aggregates in pharmaceuticals. The United States and European Pharmacopoeias currently use a SEC method with an acidic ... [more ▼]

Size-exclusion chromatography (SEC) is a method of choice for the analysis of protein aggregates in pharmaceuticals. The United States and European Pharmacopoeias currently use a SEC method with an acidic pH mobile phase to assess the content of aggregates in insulin formulations. In this article, we analyzed aggregated human insulin samples and demonstrated that both methods under neutral conditions, namely neutral pH SEC (nSEC) and capillary gel electrophoresis (CGE), yield to similar aggregate content contrary to SEC under acidic conditions (aSEC). aSEC showed polymeric complexes that were not observed in nSEC and CGE. During method development, the effect on SEC profiles of arginine and acetonitrile were highlighted. In CGE, the effect of SDS on disruption of non-covalent insulin aggregates was confirmed and the benefit of sodium deoxycholate addition in sieving gel was discussed. The three methods were applied to the analysis of an insulin formulation and similar results to those obtained for human insulin as raw material were observed. Finally, the CGE method was used to study the stability of human insulin under different storage conditions. In view of the obtained results one may question the relevance of the current pharmacopoeia method to study insulin aggregates by emphasizing the importance of the mobile phase composition and pH in SEC. The new CGE method developed is an easy method for studying non-covalent aggregates of insulin, which could be applied to other proteins. © 2019 Elsevier B.V. [less ▲]

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See detailUltra-high-performance liquid chromatography-mass spectrometry method for neutrophil gelatinase-associated lipocalin as a predictive biomarker in acute kidney injury
Ion, Valentin ULiege; Nys, Gwenaël ULiege; COBRAIVILLE, Gaël ULiege et al

in Talanta (2019), 195

Neutrophil gelatinase associated lipocalin (NGAL) is a protein that was found to be overexpressed in acute kidney injury (AKI). The rise in NGAL concentration, both in urine or plasma, appears earlier ... [more ▼]

Neutrophil gelatinase associated lipocalin (NGAL) is a protein that was found to be overexpressed in acute kidney injury (AKI). The rise in NGAL concentration, both in urine or plasma, appears earlier than for other classical renal function markers such as serum creatinine, thus making it a suitable marker for early pathology detection. The aim of this study was to develop a method involving tryptic digestion, solid phase extraction and LC-MS/MS analysis to analyze NGAL in plasma medium using an isotope labeled surrogate protein, containing NGAL signature tags, as internal standard (QPrEST). The method was validated for the analysis of NGAL in an analytical range from 50 to 1250 ng/mL using two different proteotypic peptides. The method was further used to quantify the NGAL in human plasma samples for whom elevated NGAL values were expected. NGAL values were between 190.8 and 242.6 ng/mL for control group and between 228.1 and 3526.2 ng/mL for patient group. This study proved that the selection of the right internal standard is of utmost importance in targeted proteomics studies as the digestion steps might cause high variability. This study also confirmed that, although NGAL is highly resistant to proteases such as trypsin, the method could be fully validated according to FDA guidelines and subsequently used to assess NGAL levels in patient plasma with high analytical confidence. © 2018 [less ▲]

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See detailSelectivity evaluation of phenyl based stationary phases for the analysis of amino acid diastereomers by liquid chromatography coupled with mass spectrometry
Moldovan, R.-C.; Bodoki, E.; Servais, Anne-Catherine ULiege et al

in Journal of Chromatography A (2019)

D-amino acids (AA) analysis is becoming more and more relevant for metabolomics, therefore new analytical tools need to be developed. A common approach to achieve AA enantioseparation is chiral ... [more ▼]

D-amino acids (AA) analysis is becoming more and more relevant for metabolomics, therefore new analytical tools need to be developed. A common approach to achieve AA enantioseparation is chiral derivatization. Among the chiral derivatization reagents, (+) or (-)-1-(9-fluorenyl) ethyl chloroformate ((+) or (-)-FLEC) has proved to be one of the most versatile. Suitable chiral selectivity for FLEC derivatives of amino acids could be obtained in reversed-phase HPLC using nonpolar stationary phases (C4, C8 and C18) and tetrahydrofuran (THF) based mobile phases. This study is meant to provide alternatives to the use of THF as organic modifier by evaluating the selectivity obtained on two phenyl based stationary phases for 19 FLEC-DL-AA pairs of diastereomers using UHPLC-MS. Several mobile phases consisting of ammonium acetate and different common organic solvents (acetonitrile (ACN), methanol (MeOH), 2-propanol (IPA)) were tested using gradient elution. Experimental design was employed for the optimization of the separation conditions. In the optimized conditions, complete chiral separation can be achieved for 18 out of 19 FLEC-DL-AAs in less than 30 min. © 2019 Elsevier B.V. [less ▲]

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See detailSeparation and determination of alpha-synuclein monomeric and oligomeric species using two electrophoretic approaches
Napp, Aurore ULiege; Houbart, V.; Demelenne, Alice ULiege et al

in Electrophoresis (2018), 39(23), 3022-3031

Parkinson's disease (PD) is a frequent degenerative disorder that is diagnosed based on clinical symptoms. When the first symptoms appear, more than 70% of the dopaminergic cells are already lost ... [more ▼]

Parkinson's disease (PD) is a frequent degenerative disorder that is diagnosed based on clinical symptoms. When the first symptoms appear, more than 70% of the dopaminergic cells are already lost. Therefore, it is of utmost importance to have reliable biomarkers to diagnose much earlier PD. In this context, alpha-synuclein (aSyn) is a protein of high interest because of its tendency to form oligomers and amyloid fibrils. The oligomeric forms seem to play a critical pathological role in PD. To date, most of studies aiming at detecting and quantifying aSyn oligomers were performed by immunoassays, mainly by ELISA using specific antibodies. In this study a capillary gel electrophoresis (CGE) coupled with fluorescence detection method was developed to detect and quantify the oligomeric forms of aSyn formed in vitro. All the results obtained were supported by SDS–PAGE analysis, a widely used and well-known technique but exhibiting a main drawback since it is not an automated technique. The repeatability and the intermediate precision of the method were evaluated, as well as the stability of the labeled and non-labeled aSyn samples. After careful screening and optimization of various labeling reagents, 4-fluoro-7-nitrobenzofurazan (NBD-F) was selected and used to establish a calibration curve with monomeric fluorescently-labeled aSyn. Finally, the method was used to study the effect of doxycycline on the oligomerization process. Altogether, our results show that CGE is a very promising automated technique to analyze aSyn monomers, as well as small oligomers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [less ▲]

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See detailCapillary electrophoresis, high-performance liquid chromatography, and thin-layer chromatography analyses of phenolic compounds from rapeseed plants and evaluation of their antioxidant activity.
Huang, Yang; Jansen, Olivia ULiege; Frederich, Michel ULiege et al

in Journal of Separation Science (2018)

Rapeseed plants, known for oil production, are also known to contain phenolic compounds such as phenolic acids and flavonoids, with potential antioxidant and anticancer activities. The separation and ... [more ▼]

Rapeseed plants, known for oil production, are also known to contain phenolic compounds such as phenolic acids and flavonoids, with potential antioxidant and anticancer activities. The separation and identification of 11 phenolic acids in rapeseed extracts (including leaves, flowers, Chinese seeds, Belgian seeds, and cake) by capillary electrophoresis were investigated. The results were compared with those obtained with high-performance liquid chromatography and thin-layer chromatography and showed that the capillary electrophoresis technique offers several advantages for the identification of phenolic compounds in various rapeseed extracts. The antioxidant activity of rapeseed extracts and reference compounds was evaluated using four different approaches, namely, 2,2'-azinobis- (3-ethylbenzohiazoline-6-sulfonic acid assay, free radical 2,2-diphenyl-1-picrylhydrazyl assay, electron paramagnetic resonance spectroscopy and the measurement of the total polyphenol content. The contents of total polyphenols in the tested extracts were ranging between 5.4 and 21.1% m/m and ranked as follows: Chinese seeds > Belgian seeds > Flowers > Cake > Leaves. [less ▲]

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See detailCapillary electrophoresis-mass spectrometry of derivatized amino acids for targeted neurometabolomics – pH mediated reversal of diastereomer migration order
Moldovan, Radu-Cristian ULiege; Bodoki, Ede; Servais, Anne-Catherine ULiege et al

in Journal of Chromatography. A (2018), 1564

A targeted CE-MS approach was developed for the chiral analysis of biologically relevant amino acids in artificial cerebrospinal fluid (aCSF). In order to achieve chiral resolution, the five amino acids ... [more ▼]

A targeted CE-MS approach was developed for the chiral analysis of biologically relevant amino acids in artificial cerebrospinal fluid (aCSF). In order to achieve chiral resolution, the five amino acids (Ser, Asn, Asp, Gln and Glu) were derivatized with (+)-1-(9-fluorenyl)ethyl chloroformate ((+)-FLEC). The diastereoselectivity was found to be highly dependent on pH for all analytes and the optimized background electrolyte (BGE) consisted of 150 mM acetic acid, adjusted to pH 3.7 with NH4OH. Furthermore, a reversal of the migration order of Asp derivatives was observed. This phenomenon seems to be caused by intra-molecular interactions affecting the pKa of the second ionizable group (the side chain carboxyl). The applicability of this method was evaluated using aCSF. A solid phase extraction (SPE) protocol was developed for the selective extraction of the FLEC derivatives. A full evaluation of the matrix effect and extraction yield was performed concluding that the matrix effect is marginal and the recoveries are between 46 and 92%. The method offers adequate sensitivity (limits of detection below 1 μM). [less ▲]

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See detailSupercritical Fluid Chromatography in Traditional Chinese Medicine Analysis
Huang, Yang ULiege; Tang, Guangyun; Zhang, Tingting et al

in Journal of Pharmaceutical and Biomedical Analysis (2017)

Traditional Chinese medicines (TCMs) are gaining increasing popularity throughout the world due to their long historical clinical practices. Highly efficient analytical separation tools are essential for ... [more ▼]

Traditional Chinese medicines (TCMs) are gaining increasing popularity throughout the world due to their long historical clinical practices. Highly efficient analytical separation tools are essential for investigating the mysterious properties of TCMs and their quality control. Supercritical fluid chromatography (SFC) showed a great potential in TCM analysis for both nonpolar and polar components. In this paper, an overview of the experimental conditions (i.e. detection mode, stationary phase, mobile phase composition, pressure and temperature) used in SFC for achiral separations of TCM components is presented and recent applications to the analysis of different classes of compounds extracted from TCMs, such as lipids, terpene and terpenoids, phenolic compounds, flavonoids, alkaloids, saponins and carbohydrates, will be briefly described. [less ▲]

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See detailSimultaneous Determination of Free Amino Acid Content in Different Teas using Supercritical Fluid Chromatography Coupled with Single Quadrupole Mass Spectrometry
Huang, Yang ULiege; Fillet, Marianne ULiege; Crommen, Jacques ULiege et al

Poster (2017, July 02)

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this ... [more ▼]

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this study, a novel method for high-performance liquid chromatography with mass spectrometry (SFC-MS) has been developed to simultaneously determine the contents of 11 free amino acids in different types of teas (pu-erh tea, green tea, black tea and oolong tea). The separation conditions for the selected amino acids were carefully optimized such as the column type, temperature and backpressure, the type of additive. The best compromise for tested analytes in terms of chromatographic performance was obtained when water (5%) and trifluoroacetate acid (0.4%) were added to the supercritical carbon dioxide/methanol mobile phase. Finally, the developed SFC-MS method was successfully applied to the analysis of the 11 amino acids present in the teas and fully validated as well. The results indicated a good linearity (r ≥0.995), precision (RSD≤ 2.99%), stability (RSD≤ 2.88%) and accuracy (91.95%~107.99%). The limits of detection ranged from 1.42 to 14.69 ng/mL, respectively, while the limits of quantification were between 4.53 and 47.0 ng/mL. The content of the amino acids in six different tea samples were also determined and presented some difference basing on the fermentation processes. The proposed SFC-MS method showed a great potential in further investigations to differentiate tea varieties [less ▲]

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See detailFully automated MEKC-MS method with in-capillary derivatization for the chiral analysis of amino acids
Crommen, Jacques ULiege; Moldovan, Radu-Cristian; Bodoki, Ede et al

Conference (2017, July)

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See detailOptimization of an electrophoretic approach for the screening and the development of new antithrombotic drugs
Farcas, Elena ULiege; Bouckaert, Charlotte; Servais, Anne-Catherine ULiege et al

Conference (2017, June 20)

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations ... [more ▼]

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations. Fragment-based drug discovery (FBDD) approach is an attractive tool for the identification of new selective inhibitors of a target of interest, but its success largely depends on the ability to develop screening bioassays capable to detect and gauge weak affinity binders. To achieve this goal, we investigated capillary electrophoresis (CE) for identifying and ranking fragments from an initial library. Indeed, due to its ability to evaluate weak interactions, CE seems to be promising for fragment-based screening. This technique is a powerful analytical tool with a unique separation mechanism, speed, efficiency and versatility. Its main advantages are low protein consumption, higher throughput compared to NMR and X-ray crystallography and the fact that screening can be carried out using native protein in physiological solution without the need of immobilization. We developed a proof of concept study on thrombin, a serine protease implicated in the coagulation cascade using affinity capillary electrophoresis (ACE) for ranking fragments from an initial library. For this study, we followed a probe ligand, benzamidine, and we investigated interactions with the target by monitoring the changes of its electrophoretic mobility upon binding. The first step of this study consisted in the optimization of the experimental conditions suitable for the CE method (target and probe ligand concentrations, separation buffer composition, voltage, separation effective length, target partial filling…). Then, numerous thrombin inhibitors with a wide range of inhibitory potency (i.e. Ki 200 µM – 5 nM) were tested to validate our system demonstrating the possibility to fish binders in the optimized conditions. We also checked the absence of non-specific binding with the target using the inactivated enzyme at the binding site. It is noteworthy that in this operating system (ACE assay), binding occurs in free solution using physiological buffers, thus preventing artifacts that may result from target immobilization, which is a requirement for some techniques such as SPR. [less ▲]

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See detailOptimiaztion of an electrophoretic approach for the screening and the development of new antithrombotic drugs
Farcas, Elena ULiege; Bouckaert, Charlotte; Servais, Anne-Catherine ULiege et al

Poster (2017, June 19)

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations ... [more ▼]

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations. Fragment-based drug discovery (FBDD) approach is an attractive tool for the identification of new selective inhibitors of a target of interest, but its success largely depends on the ability to develop screening bioassays capable to detect and gauge weak affinity binders. To achieve this goal, we investigated capillary electrophoresis (CE) for identifying and ranking fragments from an initial library. Indeed, due to its ability to evaluate weak interactions, CE seems to be promising for fragment-based screening. This technique is a powerful analytical tool with a unique separation mechanism, speed, efficiency and versatility. Its main advantages are low protein consumption, higher throughput compared to NMR and X-ray crystallography and the fact that screening can be carried out using native protein in physiological solution without the need of immobilization. We developed a proof of concept study on thrombin, a serine protease implicated in the coagulation cascade using affinity capillary electrophoresis (ACE) for ranking fragments from an initial library. For this study, we followed a probe ligand, benzamidine, and we investigated interactions with the target by monitoring the changes of its electrophoretic mobility upon binding. The first step of this study consisted in the optimization of the experimental conditions suitable for the CE method (target and probe ligand concentrations, separation buffer composition, voltage, separation effective length, target partial filling…). Then, numerous thrombin inhibitors with a wide range of inhibitory potency (i.e. Ki 200 µM – 5 nM) were tested to validate our system demonstrating the possibility to fish binders in the optimized conditions. We also checked the absence of non-specific binding with the target using the inactivated enzyme at the binding site. It is noteworthy that in this operating system (ACE assay), binding occurs in free solution using physiological buffers, thus preventing artifacts that may result from target immobilization, which is a requirement for some techniques such as SPR. [less ▲]

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See detailDEVELOPMENT AND VALIDATION OF A FAST SFC METHOD FOR THE ANALYSIS OF FLAVONOIDS IN PLANT EXTRACTS
Huang, Yang ULiege; Jiang, Zhengjin; Fillet, Marianne ULiege et al

Poster (2017, June 18)

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the ... [more ▼]

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the separation of 12 flavonoids. After careful optimization, the 12 flavonoids were baseline separated on a ZORBAX RX-SIL column using gradient elution. A 0.1% phosphoric acid solution in methanol was found to be the most suitable polar mobile phase component for the separation of flavonoids. From the viewpoint of retention and resolution, a backpressure of 200 bar and a temperature of 40 °C were shown to give the best results. Compared with a previously developed reverse phase liquid chromatography method, the SFC method could provide flavonoid separations that were about three times faster, while maintaining good peak shape and comparable peak efficiency. This SFC method was validated and applied to the analysis of five flavonoids (kaempferol, luteolin, quercetin, luteoloside, buddleoside) present in Chrysanthemum morifolium Ramat. from different cultivars (Chuju, Gongju, Hangju, Boju). The results indicated a good repeatability and sensitivity for the quantification of the five analytes with RSDs for overall precision lower than 3%. The limits of detection ranged from 0.73 to 2.34 μg/mL, while the limits of quantification were between 2.19 and 5.86 μg/mL. The method showed that SFC could be employed as a useful tool for the quality assessment of Traditional Chinese medicines (TCMs) containing flavonoids as active components. [less ▲]

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See detailSeparation of FLEC diastereomers by CE vs. LC approaches in the context of neurometabolomics
Moldovan, Radu-Cristian ULiege; Bodoki, Ede; Servais, Anne-Catherine ULiege et al

Poster (2017, June)

Some of the D-amino acids (D-Ser, D-Asp, D-Glu) have gained an increasing attention during the last decades, due to the discovery of their role as neurotransmitters and their implication in different ... [more ▼]

Some of the D-amino acids (D-Ser, D-Asp, D-Glu) have gained an increasing attention during the last decades, due to the discovery of their role as neurotransmitters and their implication in different neurological pathologies (Alzheimer’s disease, schizophrenia etc.). Nevertheless, their use as biomarkers is particularly relevant when correlated with the levels of other neurotransmitters. In order to develop a fast and efficient separation method widely accessible for the quantitation of these molecules, we used only common separation tools such as RP-18 stationary phases for reversed phase liquid chromatography (RP-LC) or bare fused capillaries for capillary zone electrophoresis (CZE). For achieving chiral resolution, a derivatization procedure was implemented. (-)-FLEC was the chiral derivatization agent of choice due to its fast and quantitative reaction with primary and secondary amines and the ability of performing in-capillary derivatization. Moreover, the derivatization process implies only a simple mix of the sample and reagent, at room temperature. The separation of the FLEC derivatives of several biologically relevant D- and L- amino acids (Asp, Glu, Ser, Tyr, Trp, Phe, His) together with certain neurotransmitter molecules have been optimized using CZE or RP-LC, chiral resolution being achievable for all amino acids of interest. By the CZE approach the running buffer’s pH turned out to be critical in achieving baseline separation of the targeted analytes. The derivatives of most amino acids could be separated using 60mM acetate buffer at pH 5, while for Asp derivatives the separation could be achieved only at pH 4. Being stronger bases, a third run at a more alkaline pH was needed for the separation of the remainder neurotransmitters. Moreover, the implemented in-capillary derivatization allows a fast and fully automated separation procedure. As for the RP-LC approach 50 mM acetate buffer in combination with an organic modifier (methanol, acetonitrile or tetrahydrofuran (THF)) was tested as mobile phase using gradient elution. Once again, the strong influence of pH on the resolution was observed. The organic modifier nature was of critical importance, where only THF enabled baseline resolution for all amino acid derivatives. [less ▲]

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See detailSimultaneous analysis of nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry
Huang, Yang ULiege; Zhang, Tingting; Zhao, Yumei et al

in Journal of Pharmaceutical and Biomedical Analysis (2017), 144(213), 219

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ... [more ▼]

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ginseng extracts. Few analytical methods have been developed so far to simultaneously analyze these three classes of compounds with different polarities present in ginseng extracts. In the present study, a simple and efficient analytical method was successfully developed for the simultaneous separation of 17 nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The effect of various experimental factors on the separation performance, such as the column type, temperature and backpressure, the type of modifier and additive, and the concentration of make-up solvent were systematically investigated. Under the selected conditions, the developed method was successfully applied to the quality evaluation of 14 batches of ginseng extracts from different origins. The results obtained for the different batches indicate that this method could be employed for the quality assessment of ginseng extracts [less ▲]

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See detailDevelopment and validation of a fast SFC method for the analysis of flavonoids in plant extracts
Huang, Yang ULiege; Feng, Ying; Tang, Guangyun et al

in Journal of Pharmaceutical and Biomedical Analysis (2017), 140

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See detail(+) or (-)-1-(9-fluorenyl)ethyl chloroformate as chiral derivatizing agent: A review.
Moldovan, Radu-Cristian ULiege; Bodoki, Ede; Servais, Anne-Catherine ULiege et al

in Journal of Chromatography. A (2017), 1513

Over the last 30years, (+/-)-1-(9-fluorenyl)ethyl chloroformate ((+/-)-FLEC) was used as a chiral derivatizing agent in various analytical applications involving a wide range of endogenous, pharmaceutical ... [more ▼]

Over the last 30years, (+/-)-1-(9-fluorenyl)ethyl chloroformate ((+/-)-FLEC) was used as a chiral derivatizing agent in various analytical applications involving a wide range of endogenous, pharmaceutical and environmentally relevant molecules. This comprehensive review aims to present all the significant aspects related to the state of the art in FLEC labeling and subsequent chiral separation of the resulting diastereomers using LC, SFC and CE techniques. [less ▲]

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See detailSimultaneous analysis of nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry.
Huang, Yang; Zhang, Tingting; Zhao, Yumei et al

in Journal of Pharmaceutical and Biomedical Analysis (2017)

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ... [more ▼]

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ginseng extracts. Few analytical methods have been developed so far to simultaneously analyze these three classes of compounds with different polarities present in ginseng extracts. In the present study, a simple and efficient analytical method was successfully developed for the simultaneous separation of 17 nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The effect of various experimental factors on the separation performance, such as the column type, temperature and backpressure, the type of modifier and additive, and the concentration of make-up solvent were systematically investigated. Under the selected conditions, the developed method was successfully applied to the quality evaluation of 14 batches of ginseng extracts from different origins. The results obtained for the different batches indicate that this method could be employed for the quality assessment of ginseng extracts. [less ▲]

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See detailDevelopment and validation of a fast SFC method for the analysis of flavonoids in plant extracts.
Huang, Yang; Feng, Ying; Tang, Guangyun et al

in Journal of Pharmaceutical and Biomedical Analysis (2017), 140

Flavonoids from plants always show a wide range of biological activities. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the ... [more ▼]

Flavonoids from plants always show a wide range of biological activities. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the separation of 12 flavonoids. After careful optimization, the 12 flavonoids were baseline separated on a ZORBAX RX-SIL column using gradient elution. A 0.1% phosphoric acid solution in methanol was found to be the most suitable polar mobile phase component for the separation of flavonoids. From the viewpoint of retention and resolution, a backpressure of 200bar and a temperature of 40 degrees C were shown to give the best results. Compared with a previously developed reverse phase liquid chromatography method, the SFC method could provide flavonoid separations that were about three times faster, while maintaining good peak shape and comparable peak efficiency. This SFC method was validated and applied to the analysis of five flavonoids (kaempferol, luteolin, quercetin, luteoloside, buddleoside) present in Chrysanthemum morifolium Ramat. from different cultivars (Chuju, Gongju, Hangju, Boju). The results indicated a good repeatability and sensitivity for the quantification of the five analytes with RSDs for overall precision lower than 3%. The limits of detection ranged from 0.73 to 2.34mug/mL, while the limits of quantification were between 2.19 and 5.86mug/mL. The method showed that SFC could be employed as a useful tool for the quality assessment of Traditional Chinese medicines (TCMs) containing flavonoids as active components. [less ▲]

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See detailCapillary electrophoresis in the context of drug discovery.
Farcas, Elena ULiege; Pochet, Lionel; Crommen, Jacques ULiege et al

in Journal of Pharmaceutical and Biomedical Analysis (2017)

Capillary Electrophoresis is a very efficient and resolutive separation technique used for many years in the analytical field. Despite all its assets, CE remains poorly used in drug discovery. This can be ... [more ▼]

Capillary Electrophoresis is a very efficient and resolutive separation technique used for many years in the analytical field. Despite all its assets, CE remains poorly used in drug discovery. This can be explained by the relatively low number of experienced CE practitioners, the maturity of HPLC in the pharmaceutical industry and some intrinsic limitations of the technique. The objective of this review is to focus our attention on recent developments of this technique in three different drug discovery areas: bioassays, drug-plasma interactions and drug metabolism studies. These developments were based on two important abilities of CE: the capacity to measure non-covalent interactions in solution and the ability to use a portion of the capillary as a reactor while the rest of the capillary is used for the separation of the product of the reaction. [less ▲]

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