References of "Crommen, Jacques"
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See detailSeparation of human, bovine, and porcine insulins, three very closely related proteins, by micellar electrokinetic chromatography.
Lamalle, Caroline ULg; Roland, Diane ULg; Crommen, Jacques ULg et al

in Electrophoresis (2015), 36(19), 2504-6

Human, bovine, and porcine insulins are small proteins with very closely related amino acid sequences, which makes their separation challenging. In this study, we took advantage of the high-resolution ... [more ▼]

Human, bovine, and porcine insulins are small proteins with very closely related amino acid sequences, which makes their separation challenging. In this study, we took advantage of the high-resolution power of CE, and more particularly of micellar electrokinetic chromatography, to separate those biomolecules. Among several surfactants, perfluorooctanoic acid ammonium salt was selected. Then, using a design of experiments approach, the optimal BGE composition was found to consist of 50 mM ammonium acetate pH 9.0, 65 mM perfluorooctanoic acid ammonium salt, and 4% MeOH. The three insulins could be separated within 12 min with a satisfactory resolution. This method could be useful to detect possible counterfeit pharmaceutical formulations. Indeed, it would be easy to determine if human insulin was replaced by bovine or porcine insulin. [less ▲]

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See detailComparative evaluation of a one-pot strategy for the preparation of beta-cyclodextrin-functionalized monoliths: Effect of the degree of amino substitution of beta-cyclodextrin on the column performance.
Zhang, Qiaoxuan; Guo, Jialiang; Xiao, Yuan et al

in Journal of separation science (2015), 38(11), 1813-21

To further evaluate the feasibility and applicability of the one-pot strategy in monolithic column preparation, two novel beta-cyclodextrin-functionalized organic polymeric monoliths were prepared using ... [more ▼]

To further evaluate the feasibility and applicability of the one-pot strategy in monolithic column preparation, two novel beta-cyclodextrin-functionalized organic polymeric monoliths were prepared using two beta-cyclodextrin derivatives, i.e. mono(6-amino-6-deoxy)-beta-cyclodextrin and heptakis(6-amino-6-deoxy)-beta-cyclodextrin. In this improved method, mono(6-amino-6-deoxy)-beta-cyclodextrin or heptakis(6-amino-6-deoxy)-beta-cyclodextrin reacted with glycidyl methacrylate to generate the corresponding functional monomers and were subsequently copolymerized with ethylene dimethacrylate. The polymerization conditions for both monoliths were carefully optimized to obtain satisfactory column performance with respect to column efficiency, reproducibility, permeability, and stability. The obtained poly(glycidyl methacrylate-mono(6-amino-6-deoxy)-beta-cyclodextrin-co-ethylene dimethacrylate) and poly(glycidyl methacrylate-heptakis(6-amino-6-deoxy)-beta-cyclodextrin-co-ethylene dimethacrylate) monoliths exhibited a uniform structure, good permeability, and mechanical stability as indicated by scanning electron microscopy and micro-high-performance liquid chromatography experimental results. Because of the probable existence of multi-glycidyl methacrylate linking spacers on the poly(glycidyl methacrylate-heptakis(6-amino-6-deoxy)-beta-cyclodextrin-co-ethylene dimethacrylate) monolith, the effect of the ratio of glycidyl methacrylate/heptakis(6-amino-6-deoxy)-beta-cyclodextrin was especially studied, and satisfactory reproducibility could still be achieved by strictly controlling the composition of the polymerization mixture. To investigate the effect of the degree of amino substitution of beta-cyclodextrin on column performance, a detailed comparison of the two monoliths was also carried out using series of analytes including small peptides and chiral acids. It was found that the beta-cyclodextrin-functionalized monolith with mono-glycidyl methacrylate linking spacers demonstrated better chiral separation performance than that with multi-glycidyl methacrylate linking spacers. [less ▲]

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See detailOne-pot preparation of a sulfamethoxazole functionalized affinity monolithic column for selective isolation and purification of trypsin.
Xiao, Yuan; Guo, Jialiang; Ran, Danni et al

in Journal of chromatography. A (2015), 1400

A facile and efficient "one-pot" copolymerization strategy was used for the preparation of sulfonamide drug (SA) functionalized monolithic columns. Two novel SA-immobilized methacrylate monolithic columns ... [more ▼]

A facile and efficient "one-pot" copolymerization strategy was used for the preparation of sulfonamide drug (SA) functionalized monolithic columns. Two novel SA-immobilized methacrylate monolithic columns, i.e. poly(GMA-SMX-co-EDMA) and poly(GMA-SAA-co-EDMA) were prepared by one-pot in situ copolymerization of the drug ligand (sulfamethoxazole (SMX) or sulfanilamide (SAA)), the monomer (glycidyl methacrylate, GMA) and the cross-linker (ethylene dimethacrylate, EDMA) within 100 mum i.d. capillaries under optimized polymerization conditions. The physicochemical properties and column performance of the fabricated monolithic columns were characterized by elemental analysis, scanning electron microscopy and micro-HPLC. Satisfactory column permeability, efficiency and separation performance were obtained on the optimized poly(GMA-SMX-co-EDMA) monolithic column for small molecules, such as a standard test mixture and eight aromatic ketones. Notably, it was found that the poly(GMA-SMX-co-EDMA) monolith showed a selective affinity to trypsin, while the poly(GMA-SAA-co-EDMA) monolith containing sulfanilamide did not exhibit such affinity at all. This research not only provides a novel monolith for the selective isolation and purification of trypsin, but it also offers the possibility to easily prepare novel drug functionalized methacrylate monoliths through a one-pot copolymerization strategy. [less ▲]

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See detailReply to "a model lacking relevant literature comparison".
Wang, T.; Feng, Y.; Zhao, X. et al

in Journal of pharmaceutical and biomedical analysis (2015), 104

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See detailSeparation of N-derivatized di- and tri-peptide stereoisomers by micro-liquid chromatography using a quinidine-based monolithic column - Analysis of l-carnosine in dietary supplements.
Wang, Qiqin; Sanchez-Lopez, Elena; Han, Hai et al

in Journal of chromatography. A (2015)

In the present study, a new analytical methodology was developed enabling the enantiomeric determination of N-derivatized di- and tri-peptides in dietary supplements using chiral micro-LC on a monolithic ... [more ▼]

In the present study, a new analytical methodology was developed enabling the enantiomeric determination of N-derivatized di- and tri-peptides in dietary supplements using chiral micro-LC on a monolithic column consisting of poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-2-hydroxy ethyl methacrylate-co-ethylene dimethacrylate) (poly(MQD-co-HEMA-co-EDMA)). After optimization of the mobile phase conditions, a baseline resolution of the stereoisomers of 24 out of 53 N-derivatized di- and tri-peptides was obtained. 3,5-Dinitrobenzoyl- and 3,5-dichlorobenzoyl-peptide stereoisomers were separated with exceptionally high selectivity and resolution. The monolithic column was then applied to the quantitative analysis of l-carnosine and its enantiomeric impurity in three different commercial dietary supplements. Method validation demonstrated satisfactory results in terms of linearity, precision, selectivity, accuracy and limits of detection and quantification. The determined amounts of l-carnosine in commercial formulations were in agreement with the labeled content for all analyzed samples, and the enantiomeric impurity was found to be below the limit of detection (LOD), showing the potential of the poly(MQD-co-HEMA-co-EDMA) monolithic column as a reliable tool for the quality control of l-carnosine in dietary supplements by micro-LC. [less ▲]

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See detailComparative enantiomer affinity pattern of beta-blockers in aqueous and nonaqueous CE using single-component anionic cyclodextrins.
Feng, Ying; Wang, Tingting; Jiang, Zhengjin et al

in Electrophoresis (2015), 36(11-12), 1358-64

A series of eight chiral beta-blocker drugs, acebutolol, atenolol, carazolol, carteolol, carvedilol, propranolol, sotalol, and talinolol, have been enantioseparated using two single-component anionic beta ... [more ▼]

A series of eight chiral beta-blocker drugs, acebutolol, atenolol, carazolol, carteolol, carvedilol, propranolol, sotalol, and talinolol, have been enantioseparated using two single-component anionic beta-CD derivatives, namely heptakis (2,3-di-O-methyl-6-sulfo)-beta-CD (HDMS-beta-CD) and heptakis (2,3-di-O-acetyl-6-sulfo)-beta-CD (HDAS-beta-CD), in aqueous CE and NACE. The influence of the nature of substituents (methyl or acetyl) in positions 2 and 3 on the CD derivatives and of the electrophoretic medium (water or methanol) on the enantioselectivity and enantiomer affinity pattern (EAP) of these structurally related compounds was systematically studied. All eight beta-blockers could be enantioseparated at least partially in the four CE systems, except sotalol with HDMS-beta-CD in NACE. In general, lower affinity and enantioselectivity were obtained in the presence of HDMS-beta-CD compared to HDAS-beta-CD. Reversals of EAPs were observed for all compounds. EAPs toward these two CDs were found to be opposite to each other in NACE for all compounds except carvedilol and in aqueous CE for atenolol, carteolol, talinolol, and sotalol. It is particularly noteworthy that opposite EAPs were also observed using the same CD derivative when the aqueous BGE was replaced with the methanolic one: for carazolol, carvedilol, and propranolol in the presence of HDMS-beta-CD and for acebutolol and carvedilol with HDAS-beta-CD. [less ▲]

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See detailPreparation and evaluation of novel zwitterionic HILIC monolithic columns
Liu, C; Li, H; Crommen, Jacques ULg et al

Conference (2015)

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See detailSimultaneous determination of insulin and its analogues in pharmaceutical formulations by micellar electrokinetic chromatography
Lamalle, Caroline ULg; Servais, Anne-Catherine ULg; RADERMECKER, Régis ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2015)

A simple and efficient MEKC method was developed to simultaneously determine human insulin, its five analogues, the main degradation products and the excipients usually present in injection formulations ... [more ▼]

A simple and efficient MEKC method was developed to simultaneously determine human insulin, its five analogues, the main degradation products and the excipients usually present in injection formulations. A very fast method with a total analysis time of 3 min was then successfully validated for the analysis of human insulin and the quality control of different commercial formulations was carried out. [less ▲]

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See detailDéveloppement de méthodes séparatives pour détecter la contrefaçon de molécules biosynthétiques comme l'insuline et les GHRP
Lamalle, Caroline ULg; Baptiste, Emeline; Marini Djang'Eing'A, Roland ULg et al

in Spectra Analyse (2014), 43

Counterfeiting is a widespread problem in the world. The medicines, like insulin or GHRP, need a strict quality control. Capillary electrophoresis and liquid chromatography methods were developed to ... [more ▼]

Counterfeiting is a widespread problem in the world. The medicines, like insulin or GHRP, need a strict quality control. Capillary electrophoresis and liquid chromatography methods were developed to analyze these peptides. The human insulin and its different analogues (lispro, aspart, glulisin, glargin and detemir) were separated by MEKC within 15 minutes. The GHRP-2 and -6 were separated by HPLC also in 15 minutes. Several samples of GHRP-6 were analyzed and non-compliances were reported. These analytical approaches seem to be promising to fight against the counterfeiting of such medicines. [less ▲]

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See detailStratégies analytiques pour la détection de contrefaçons de médicaments pour la dysfonction érectile
Sacre, Pierre-Yves ULg; Deconinck, Eric; Marini Djang'Eing'A, Roland ULg et al

in Spectra Analyse (2014), 43

Erectile dysfunction drugs are among the most counterfeit drug classes in industrialized countries. To fight against this plague, several analytical approaches are available for control laboratories. The ... [more ▼]

Erectile dysfunction drugs are among the most counterfeit drug classes in industrialized countries. To fight against this plague, several analytical approaches are available for control laboratories. The present article reviews the main used techniques and concludes presenting a general strategy for the detection and handling of drug counterfeits. [less ▲]

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See detailOne-step strategy for the synthesis of a derivatized cyclodextrin-based monolithic column.
Guo, Jialiang; Zhang, Qiaoxuan; Yao, Zhe et al

in Journal of separation science (2014), 37(14), 1720-7

Derivatized beta-cyclodextrin (beta-CD) functionalized monolithic columns were prepared by a "one-step" strategy using click chemistry. First, the intended derivatized beta-CD monomers were synthesized by ... [more ▼]

Derivatized beta-cyclodextrin (beta-CD) functionalized monolithic columns were prepared by a "one-step" strategy using click chemistry. First, the intended derivatized beta-CD monomers were synthesized by a click reaction between propargyl methacrylate and mono-6-azido-beta-CD and then sulfonation or methylation was carried out. Finally, monolithic columns were prepared through a one-step in situ copolymerization of the derivatized beta-CD monomer and ethylene glycol dimethacrylate. The sulfated beta-CD-based monolith was successfully applied to the hydrophilic interaction liquid chromatography separation of nucleosides and small peptides, while the methylated beta-CD-functionalized monolith was useful for the separation of nonpolar compounds and drug enantiomers in capillary reversed-phase liquid chromatography. The structures of the monomers were characterized by Fourier transform infrared spectroscopy and mass spectrometry. The physicochemical properties and column performance of monoliths were evaluated by scanning electron microscopy and micro high performance liquid chromatography. This strategy has considerable prospects for the preparation of other derivatized CD-functionalized methacrylate monoliths. [less ▲]

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See detailA novel mixed phospholipid functionalized monolithic column for early screening of drug induced phospholipidosis risk.
Zhao, Xianglong; Chen, Weijia; Liu, Zhenghua et al

in Journal of chromatography. A (2014), 1367

Drug-induced phospholipidosis (PLD) is characterized by the excessive accumulation of phospholipids, resulting in multilamellar vesicle structure within lysosomes. In the present study, a novel mixed ... [more ▼]

Drug-induced phospholipidosis (PLD) is characterized by the excessive accumulation of phospholipids, resulting in multilamellar vesicle structure within lysosomes. In the present study, a novel mixed phospholipid functionalized monolithic column was developed for the first time through a facile one-step co-polymerization approach. The phospholipid composition of the monolith can be adjusted quantitatively and accurately to mimic the mixed phospholipid environment of different biomembranes on a solid matrix. The mixed phospholipid functionalized monolith as a promising immobilized artificial membrane technique was used to study drug-phospholipid interaction. Scanning electron microscopy, elemental analysis, FT-IR spectra, zeta-potential analysis and micro-HPLC were carried out to characterize the physicochemical properties and separation performance of the monolith. Mechanism studies revealed that both hydrophobic and electrostatic interactions play an important role in the retention of analytes. The ratio of their contributions to retention can be easily manipulated by adjusting the composition of the mixed phospholipids, in order to better mimic the interaction between drugs and cell membrane. The obtained mixed phospholipid functionalized monolithic columns were applied to the screening of drug-induced PLD potency. Data from 79 drugs on the market demonstrated that the chromatographic hydrophobicity index referring to the mixed phospholipid functionalized monolith at pH 7.4 (CHI IAM7.4) for the selected drugs were highly correlated with the drug-induced PLD potency data obtained from other in vivo or in vitro assays. Moreover, the effect of the acidic phospholipid phosphatidylserine proportion on prediction accuracy was also investigated. The monolith containing 20% phosphatidylserine and 80% phosphatidylcholine exhibited the best prediction ability for the drug-induced PLD potency of the tested compounds. This research has led to the successful development of a novel and facile approach to prepare a mixed phospholipids functionalized monolith, which offers a reliable, cost-effective and high-throughput screening tool for early prediction of the PLD potency of drug candidates. [less ▲]

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See detailPreparation of a beta-cyclodextrin functionalized monolith via a novel and simple one-pot approach and application to enantioseparations.
Zhang, Qiaoxuan; Guo, Jialiang; Wang, Feng et al

in Journal of chromatography. A (2014), 1325

A novel and facile one-pot copolymerization approach was developed for the preparation of a beta-cyclodextrin (beta-CD) functionalized organic polymer monolith. The proposed one-pot process involved two ... [more ▼]

A novel and facile one-pot copolymerization approach was developed for the preparation of a beta-cyclodextrin (beta-CD) functionalized organic polymer monolith. The proposed one-pot process involved two major reactions occurring in sequence in the same vial: (1) the ring opening reaction between the epoxy groups of glycidyl methacrylate (GMA) and the primary amino groups of ethylenediamine-beta-CD (EDA-beta-CD); (2) the copolymerization of glycidyl methacrylate-ethylenediamine-beta-CD (GMA-EDA-beta-CD) and ethylene dimethacrylate (EDMA) using 2,2'-azobisisobutyronitrile (AIBN) as the polymerization initiator. This approach avoids the time-consuming post-polymerization derivatization of the traditional two-step strategy. Compared to the previously reported two-step strategy, the monolith prepared by this one-pot method exhibited higher beta-CD ligand density and better column efficiency in HPLC. Satisfactory column permeability and separation selectivity were also obtained on the optimized poly(GMA-EDA-beta-CD-co-EDMA) monolithic column. Additionally, the column was also applied to the enantioseparation of some racemic acidic compounds with promising results. [less ▲]

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See detailLiposome electrokinetic chromatography based in vitro model for early screening of the drug-induced phospholipidosis risk.
Wang, Tingting; Feng, Ying; Jin, Xiaohan et al

in Journal of pharmaceutical and biomedical analysis (2014), 96

Drug-induced phospholipidosis (PLD) is a storage disorder of lysosomes characterized by the excessive accumulation of phospholipids as a result of improper medical treatments. Although few evidences have ... [more ▼]

Drug-induced phospholipidosis (PLD) is a storage disorder of lysosomes characterized by the excessive accumulation of phospholipids as a result of improper medical treatments. Although few evidences have supported that PLD can induce significant pathological consequences, this potential toxicity indeed can put off the drug discovery process. In this research, a high-throughput liposome electrokinetic chromatography (LEKC) method was validated to evaluate the PLD risk of drug candidates by screening drug-phospholipid interaction, which correlates to the phospholipidosis inducing risk. A statistical analysis based on the Spearman's correlation test showed that the retention factors (log k) of the tested drugs in the LEKC system and the literature reported in vivo and in vitro PLD data were highly correlated. In order to investigate the predictability of LEKC, the effect of liposome composition such as the molar ratio of phospholipids and the addition of cholesterol were also discussed in this study. The results indicated that the LEKC method could offer a fast, reliable and cost-effective screening tool for early prediction of the PLD inducing potential of drug candidates. [less ▲]

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See detailEnantioseparation of N-derivatized amino acids by micro-liquid chromatography using carbamoylated quinidine functionalized monolithic stationary phase.
Wang, Qiqin; Feng, Jun; Han, Hai et al

in Journal of chromatography. A (2014), 1363

In order to obtain satisfactory column permeability, efficiency and selectivity for micro-HPLC, a capillary monolithic column containing O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine ... [more ▼]

In order to obtain satisfactory column permeability, efficiency and selectivity for micro-HPLC, a capillary monolithic column containing O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD) as chiral selector was re-optimized. The monolithic column was used to successfully enantioresolve a wide range of N-derivatized amino acids including alanine, leucine, methionine, threonine, phenylalanine, valine, serine, isoleucine, tryptophan, and cysteine. The influence of mobile phase parameters, such as the organic solvent type and concentration, the apparent pH, and buffer concentration, on retention and enantioseparation of N-derivatized amino acids has been investigated. 3,5-dinitrobenzoyl-amino acids and 3,5-dichlorobenzoyl-amino acids were resolved into enantiomers with exceptionally high selectivity and resolution. The chemoselectivity of the monolithic column for a multicomponent mixture of N-derivatized amino acids was also investigated. A mixture of three pairs of 3,5-dichlorobenzoyl-amino acids could be fully resolved in 22.5 min. [less ▲]

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See detailInfluence of the crosslinker type on the chromatographic properties of hydrophilic sulfoalkylbetaine-type monolithic columns.
Liu, Chusheng; Chen, Weijia; Yuan, Guangxin et al

in Journal of chromatography. A (2014), 1373

In order to investigate the effects of the crosslinker on the separation performance of polar zwitterionic sulfoalkylbetaine-type monolithic columns, three crosslinkers, i.e. 1,4-bis(acryloyl)piperazine ... [more ▼]

In order to investigate the effects of the crosslinker on the separation performance of polar zwitterionic sulfoalkylbetaine-type monolithic columns, three crosslinkers, i.e. 1,4-bis(acryloyl)piperazine (PDA), ethylene dimethacrylate (EDMA) and N,N'-methylenebisacrylamide (MBA), were copolymerized with the hydrophilic monomer N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)ammonium betaine (SPDA). The chromatographic properties of the three hydrophilic sulfoalkylbetaine-type monolithic columns, including column efficiency, permeability, porosity and separation mechanism, were systematically compared using scanning electron microscopy or micro-HPLC. Good selectivity in micro-HPLC separations was achieved on all three monolithic columns. The results indicate that the polarity of sulfoalkylbetaine-type monolithic columns may be related to the polarity of the crosslinker, which further affects column selectivity and efficiency. A particularly high column efficiency (100,000 plates/m) was obtained on the novel poly(SPDA-co-PDA) monolithic column at a linear velocity of 1mm/s using thiourea as test analyte. A higher resolution was also observed for nucleobases, nucleosides and hydrophilic organic acids on this novel poly(SPDA-co-PDA) monolithic column compared to the other two columns. [less ▲]

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