Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, Jan 12, 2016
The effect of different kosmotropic/chaotropic salt systems on retention characteristics of intac... more The effect of different kosmotropic/chaotropic salt systems on retention characteristics of intact proteins has been examined in hydrophobic interaction chromatography (HIC). The performance was assessed using different column chemistries, i.e., polyalkylamide, alkylamine incorporating hydrophobic moieties, and a butyl chemistry. Selectivity in HIC is mainly governed by the salt concentration and by the molal surface tension increment of the salt. Typically, a linear relationship between the natural logarithm of the retention factor and the salt concentration is obtained. Using a 250mm long column packed with 5μm polyalkylamide functionalized silica particles and applying a 30min linear salt gradient, a peak capacity of 78 was achieved, allowing the baseline separation of seven intact proteins. The hydrophobicity index appeared to be a good indicator to predict the elution order of intact proteins in HIC mode. Furthermore, the effect of adding additives in the mobile phase, such as ...
... a, Carole Bressonb, Arnaud Boisdenghienb, Frédéric Pierardb, Andrée Kirsch-De Mesmaekerb, Jér... more ... a, Carole Bressonb, Arnaud Boisdenghienb, Frédéric Pierardb, Andrée Kirsch-De Mesmaekerb, Jérôme Lacourc and Kristin Bartik*a. ... The authors would also like to thank David Monchaud, Jonathan Jodry and France Favarger for the preparation of the TRISPHAT salts and ...
The association of a concave macrocyclic compound to one or multiple fluorophores is an appealing... more The association of a concave macrocyclic compound to one or multiple fluorophores is an appealing strategy for the design of chemosensors. Indeed, as with biological systems, a cavity-based selectivity can be expected with such fluorescent receptors. Examples of calix[6]arene-based systems using this strategy are rare in the literature, and to our knowledge, no examples of fluorescent receptors that can bind organic contact ion pairs have been reported. This report describes the straightforward synthesis of fluorescent calix[6]arene-based receptors 4a and 4b bearing three pyrenyl subunits and the study of their binding properties toward anions and ammonium salts using different spectroscopies. It was found that receptor 4a exhibits a remarkable selectivity for the sulfate anion in DMSO, enabling its selective sensing by fluorescence spectroscopy. In CDCl3, the receptor is able to bind ammonium ions efficiently only in association with the sulfate anion. Interestingly, this cooperative binding of ammonium sulfate salts was also evidenced in a protic environment. Finally, a cavity-based selectivity in terms of size and shape of the guest was observed with both receptors 4a and 4b, opening interesting perspectives on the elaboration of fluorescent cavity-based systems for the selective sensing of biologically relevant ammonium salts such as neurotransmitters.
129Xe NMR has been used to investigate intermolecular interactions between xenon and α-cyclodextr... more 129Xe NMR has been used to investigate intermolecular interactions between xenon and α-cyclodextrin in H2O and in DMSO. Nuclear Overhauser enhancement effects confirmed the formation of a xenon–cyclodextrin complex. Chemical shifts were measured in solutions containing different concentrations of α-cyclodextrin and in solutions containing linear oligosaccharides. The experimental data are interpreted on the basis of a three-site model for xenon.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, Jan 12, 2016
The effect of different kosmotropic/chaotropic salt systems on retention characteristics of intac... more The effect of different kosmotropic/chaotropic salt systems on retention characteristics of intact proteins has been examined in hydrophobic interaction chromatography (HIC). The performance was assessed using different column chemistries, i.e., polyalkylamide, alkylamine incorporating hydrophobic moieties, and a butyl chemistry. Selectivity in HIC is mainly governed by the salt concentration and by the molal surface tension increment of the salt. Typically, a linear relationship between the natural logarithm of the retention factor and the salt concentration is obtained. Using a 250mm long column packed with 5μm polyalkylamide functionalized silica particles and applying a 30min linear salt gradient, a peak capacity of 78 was achieved, allowing the baseline separation of seven intact proteins. The hydrophobicity index appeared to be a good indicator to predict the elution order of intact proteins in HIC mode. Furthermore, the effect of adding additives in the mobile phase, such as ...
... a, Carole Bressonb, Arnaud Boisdenghienb, Frédéric Pierardb, Andrée Kirsch-De Mesmaekerb, Jér... more ... a, Carole Bressonb, Arnaud Boisdenghienb, Frédéric Pierardb, Andrée Kirsch-De Mesmaekerb, Jérôme Lacourc and Kristin Bartik*a. ... The authors would also like to thank David Monchaud, Jonathan Jodry and France Favarger for the preparation of the TRISPHAT salts and ...
The association of a concave macrocyclic compound to one or multiple fluorophores is an appealing... more The association of a concave macrocyclic compound to one or multiple fluorophores is an appealing strategy for the design of chemosensors. Indeed, as with biological systems, a cavity-based selectivity can be expected with such fluorescent receptors. Examples of calix[6]arene-based systems using this strategy are rare in the literature, and to our knowledge, no examples of fluorescent receptors that can bind organic contact ion pairs have been reported. This report describes the straightforward synthesis of fluorescent calix[6]arene-based receptors 4a and 4b bearing three pyrenyl subunits and the study of their binding properties toward anions and ammonium salts using different spectroscopies. It was found that receptor 4a exhibits a remarkable selectivity for the sulfate anion in DMSO, enabling its selective sensing by fluorescence spectroscopy. In CDCl3, the receptor is able to bind ammonium ions efficiently only in association with the sulfate anion. Interestingly, this cooperative binding of ammonium sulfate salts was also evidenced in a protic environment. Finally, a cavity-based selectivity in terms of size and shape of the guest was observed with both receptors 4a and 4b, opening interesting perspectives on the elaboration of fluorescent cavity-based systems for the selective sensing of biologically relevant ammonium salts such as neurotransmitters.
129Xe NMR has been used to investigate intermolecular interactions between xenon and α-cyclodextr... more 129Xe NMR has been used to investigate intermolecular interactions between xenon and α-cyclodextrin in H2O and in DMSO. Nuclear Overhauser enhancement effects confirmed the formation of a xenon–cyclodextrin complex. Chemical shifts were measured in solutions containing different concentrations of α-cyclodextrin and in solutions containing linear oligosaccharides. The experimental data are interpreted on the basis of a three-site model for xenon.
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Papers by Kristin Bartik