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Francesco Gasparrini - One of the best experts on this subject based on the ideXlab platform.
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required. Graphical AbstractWord cloud of cutting edge applications of superficially porous particles in liquid Chromatography
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations.
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required.
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expanding the potential of Chiral Chromatography for high throughput screening of large compound libraries by means of sub 2μm whelk o 1 stationary phase in supercritical fluid conditions
Journal of Chromatography A, 2015Co-Authors: Luca Sciascera, Omar H. Ismail, Alberto Cavazzini, Alessia Ciogli, Dorina Kotoni, Lorenzo Botta, Ted Szczerba, Jelena Kocergin, Claudio Villani, Francesco GasparriniAbstract:Abstract With the aim of exploring the potential of ultra-fast Chiral Chromatography for high-throughput analysis, the new sub–2 micron Whelk-O 1 Chiral stationary phase (CSP) has been employed in supercritical fluid conditions to screen 129 racemates, mainly of pharmaceutical interest. By using a 5-cm long column (0.46 cm internal diameter), a single co-solvent (MeOH) and a 7-min gradient elution, 85% of acidic and neutral analytes considered in this work have been successfully resolved, with resolution (Rs) larger than 2 in more than 65% of cases. Moreover, almost a half of basic samples that, for their own characteristics, are known to be difficult to separate on Whelk–O 1 CSP, have shown Rs greater than 0.3. The screening of the entire library could be accomplished in less than 24 h (single run) with 63% of positive score. For well-resolved enantiomers (Rs roughly included between 1 and 3), we show that method transfer from gradient to isocratic conditions is straightforward. In many cases, isocratic ultra-fast separations (with analysis time smaller than 60 s) have been achieved by simply employing, as isocratic mobile phase, the eluent composition at which the second enantiomer was eluted in gradient mode. By considering the extension and variety of the library in terms of chemico-physical and structural properties of compounds and numerousness, we believe that this work demonstrates the real potential of the technique for high-throughput enantioselective screening.
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determination of the absolute configuration of a Chiral oxadiazol 3 one calcium channel blocker resolved using Chiral Chromatography via concerted density functional theory calculations of its vibrational circular dichroism electronic circular dichro
Journal of Organic Chemistry, 2007Co-Authors: P J Stephens, Francesco Gasparrini, F J Devlin, Alessia Ciogli, Domenico Spinelli, Barbara CosimelliAbstract:The Chiral oxadiazol-3-one 2 has recently been shown to exhibit myocardial calcium entry channel blocking activity, substantially higher than that of diltiazem. To determine the enantioselectivity of this activity, the enantiomers of 2 have been resolved using Chiral Chromatography. The absolute configuration (AC) of 2 has been determined by comparison of density functional theory (DFT) calculations of its vibrational circular dichroism (VCD) spectrum, electronic circular dichroism (ECD) spectrum, and optical rotation (OR) to experimental VCD, ECD, and OR data. All three chiroptical properties yield identical ACs; the AC of 2 is unambiguously determined to be S(+)/R(−).
Alberto Cavazzini - One of the best experts on this subject based on the ideXlab platform.
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required. Graphical AbstractWord cloud of cutting edge applications of superficially porous particles in liquid Chromatography
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations.
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required.
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expanding the potential of Chiral Chromatography for high throughput screening of large compound libraries by means of sub 2μm whelk o 1 stationary phase in supercritical fluid conditions
Journal of Chromatography A, 2015Co-Authors: Luca Sciascera, Omar H. Ismail, Alberto Cavazzini, Alessia Ciogli, Dorina Kotoni, Lorenzo Botta, Ted Szczerba, Jelena Kocergin, Claudio Villani, Francesco GasparriniAbstract:Abstract With the aim of exploring the potential of ultra-fast Chiral Chromatography for high-throughput analysis, the new sub–2 micron Whelk-O 1 Chiral stationary phase (CSP) has been employed in supercritical fluid conditions to screen 129 racemates, mainly of pharmaceutical interest. By using a 5-cm long column (0.46 cm internal diameter), a single co-solvent (MeOH) and a 7-min gradient elution, 85% of acidic and neutral analytes considered in this work have been successfully resolved, with resolution (Rs) larger than 2 in more than 65% of cases. Moreover, almost a half of basic samples that, for their own characteristics, are known to be difficult to separate on Whelk–O 1 CSP, have shown Rs greater than 0.3. The screening of the entire library could be accomplished in less than 24 h (single run) with 63% of positive score. For well-resolved enantiomers (Rs roughly included between 1 and 3), we show that method transfer from gradient to isocratic conditions is straightforward. In many cases, isocratic ultra-fast separations (with analysis time smaller than 60 s) have been achieved by simply employing, as isocratic mobile phase, the eluent composition at which the second enantiomer was eluted in gradient mode. By considering the extension and variety of the library in terms of chemico-physical and structural properties of compounds and numerousness, we believe that this work demonstrates the real potential of the technique for high-throughput enantioselective screening.
Omar H. Ismail - One of the best experts on this subject based on the ideXlab platform.
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required. Graphical AbstractWord cloud of cutting edge applications of superficially porous particles in liquid Chromatography
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New frontiers and cutting edge applications in ultra high performance liquid Chromatography through latest generation superficially porous particles with particular emphasis to the field of Chiral separations.
Analytical and Bioanalytical Chemistry, 2018Co-Authors: Martina Catani, Simona Felletti, Omar H. Ismail, Chiara De Luca, Francesco Gasparrini, Valentina Costa, Nicola Marchetti, Luisa Pasti, Alberto CavazziniAbstract:About ten years after their introduction to the market (happened in 2006), the so-called second generation superficially porous particles (SPPs) have undoubtedly become the benchmark as well as, very often, the preferred choice for many applications in liquid Chromatography (LC), when high efficiency and fast separations are required. This trend has interested practically all kinds of separations, with the only exception of Chiral Chromatography (at least so far). The technology of production of base SPPs is advanced, relatively simple and widely available. The deep investigation of mass transfer mechanisms under reversed-phase (RP) and normal-phase (NP) conditions for aChiral separations has shown the advantages in the use of these particles over their fully porous counterparts. In addition, it has been demonstrated that SPPs are extremely suitable for the preparation of efficient packed beds through slurry packing techniques. However, the research in this field is in continual evolution. In this article, some of the most advanced concepts and modern applications based on the use of SPPs, embracing in particular ultrafast Chiral Chromatography and the design of SPPs with engineered pore structures or very reduced particle diameter, are revised. We describe modern trends in these fields and focus on those aspect where further innovation and research will be required.
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expanding the potential of Chiral Chromatography for high throughput screening of large compound libraries by means of sub 2μm whelk o 1 stationary phase in supercritical fluid conditions
Journal of Chromatography A, 2015Co-Authors: Luca Sciascera, Omar H. Ismail, Alberto Cavazzini, Alessia Ciogli, Dorina Kotoni, Lorenzo Botta, Ted Szczerba, Jelena Kocergin, Claudio Villani, Francesco GasparriniAbstract:Abstract With the aim of exploring the potential of ultra-fast Chiral Chromatography for high-throughput analysis, the new sub–2 micron Whelk-O 1 Chiral stationary phase (CSP) has been employed in supercritical fluid conditions to screen 129 racemates, mainly of pharmaceutical interest. By using a 5-cm long column (0.46 cm internal diameter), a single co-solvent (MeOH) and a 7-min gradient elution, 85% of acidic and neutral analytes considered in this work have been successfully resolved, with resolution (Rs) larger than 2 in more than 65% of cases. Moreover, almost a half of basic samples that, for their own characteristics, are known to be difficult to separate on Whelk–O 1 CSP, have shown Rs greater than 0.3. The screening of the entire library could be accomplished in less than 24 h (single run) with 63% of positive score. For well-resolved enantiomers (Rs roughly included between 1 and 3), we show that method transfer from gradient to isocratic conditions is straightforward. In many cases, isocratic ultra-fast separations (with analysis time smaller than 60 s) have been achieved by simply employing, as isocratic mobile phase, the eluent composition at which the second enantiomer was eluted in gradient mode. By considering the extension and variety of the library in terms of chemico-physical and structural properties of compounds and numerousness, we believe that this work demonstrates the real potential of the technique for high-throughput enantioselective screening.
Christopher J Welch - One of the best experts on this subject based on the ideXlab platform.
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Factors influencing the interconversion of a new class of dibenzodiazepine sulfonamide atropisomers.
Chirality, 2020Co-Authors: Christopher J Welch, Mirlinda Biba, Xiaoyi Gong, Wes Schafer, Harry Chobanian, Adam BeardAbstract:A novel family of atropisomers based on a conformationally constrained seven membered ring system is investigated using a combination of preparative Chiral Chromatography, circular dichroism, and other analytical techniques. The influence of structure on the rate of atropisomer interconversion was explored with a series of analogs showing a range of interconversion rates ranging from very fast (undetectable on the HPLC timescale) to very slow (half life of many days).
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ultrafast Chiral Chromatography as the second dimension in two dimensional liquid Chromatography experiments
Analytical Chemistry, 2017Co-Authors: Chandan L Barhate, Erik L Regalado, Nathan D Contrella, Junyong Jo, Alexey A Makarov, Daniel W Armstrong, Christopher J WelchAbstract:Chromatographic separation and analysis of complex mixtures of closely related species is one of the most challenging tasks in modern pharmaceutical analysis. In recent years, two-dimensional liquid Chromatography (2D-LC) has become a valuable tool for improving peak capacity and selectivity. However, the relatively slow speed of Chiral separations has limited the use of Chiral stationary phases (CSPs) as the second dimension in 2D-LC, especially in the comprehensive mode. Realizing that the recent revolution in the field of ultrafast enantioselective Chromatography could now provide significantly faster separations, we herein report an investigation into the use of ultrafast Chiral Chromatography as a second dimension for 2D chromatographic separations. In this study, excellent selectivity, peak shape, and repeatability were achieved by combining aChiral and Chiral narrow-bore columns (2.1 mm × 100 mm and 2.1 mm × 150 mm, sub-2 and 3 μm) in the first dimension with 4.6 mm × 30 mm and 4.6 mm × 50 mm colum...
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Factors influencing the interconversion of a new class of dibenzodiazepine sulfonamide atropisomers
Chirality, 2009Co-Authors: Christopher J Welch, Mirlinda Biba, Xiaoyi Gong, Wes Schafer, Harry Chobanian, Adam BeardAbstract:A novel family of atropisomers based on a conformationally constrained seven membered ring system is investigated using a combination of preparative Chiral Chromatography, circular dichroism, and other analytical techniques. The influence of structure on the rate of atropisomer interconversion was explored with a series of analogs showing a range of interconversion rates ranging from very fast (undetectable on the HPLC timescale) to very slow (half life of many days). Chirality 21:E105–E109, 2009. © 2009 Wiley-Liss, Inc.
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serendipitous discovery of a ph dependant atropisomer bond rotation toward a write protectable Chiral molecular switch
Journal of Chromatography B, 2008Co-Authors: Christopher J Welch, Mirlinda Biba, Remy Angelaud, Melissa S EgbertsonAbstract:Abstract Owing to slow rotation of a sterically constrained dimethylamide substituent, two slowly interconverting enantiomers of a preclinical candidate for pharmaceutical development, 1, (6-(3-Chloro-4-fluoro-benzyl)-4-hydroxy-2-methyl-3,5-dioxo-2,3,5,6,7,8-hexahydro-[2,6]naphthyridine-1-carboxylic acid dimethylamide) are observed by Chiral Chromatography. Isolation of pure enantiomer by preparative Chiral Chromatography followed by enantiopurity analysis over time allowed for a study of the kinetics of enantiomer interconversion under a variety of conditions. Relatively slow racemization was observed in alcohol solvents, with a half life on the order of 5–10 h. A dramatic influence of aqueous buffer pH on racemization was noted, with higher pH leading to rapid racemization within a few minutes, and lower pH leading to essentially no racemization for periods up to a week. A hypothesis explaining this unusual effect of pH on carboxamide bond rotation is offered, and some suggestions for potential utility of such a system are considered.
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Preparative Enantioselective Chromatography - Chiral Chromatography in Support of Pharmaceutical Process Research
Preparative Enantioselective Chromatography, 2007Co-Authors: Christopher J WelchAbstract:Preparative Chiral Chromatography has recently become a preferred method for rapidly accessing enantiopure compounds in the pharmaceutical industry [1–8]. While preparative chromatographic enantioseparation has been practiced for a number of years by specialized researchers, the current widespread interest in the approach can be attributed in part to advances in equipment and stationary phases, but more importantly, to an increasingly widespread realization of the cost-effectiveness of this technique. In many instances, developing and executing a chromatographic enantioseparation is faster and less labour-intensive than more traditional approaches for accessing enantiopurity. Consequently, preparative Chiral Chromatography is increasingly used in place of, or in conjunction with, the more traditional methods of organic synthesis. We herein present a general introduction that focuses on some of the current areas of interest in the field of preparative chromatographic enantioseparation, which we hope will be useful to newcomers and experienced practitioners alike.
Weiming Li - One of the best experts on this subject based on the ideXlab platform.
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and petromyroxols antipodal tetrahydrofurandiols from larval sea lamprey petromyzon marinus l that elicit enantioselective olfactory responses
Organic Letters, 2015Co-Authors: Ke Li, Mar Huertas, Cory O Brant, Yu Wen Chungdavidson, Ugo Bussy, Thomas R Hoye, Weiming LiAbstract:(+)- and (−)-Petromyroxol [(+)-1 and (−)-1, respectively], two novel tetrahydrofuran (THF)-diol fatty acid enantiomers, were isolated from water conditioned with larval sea lamprey. We herein describe their isolation and subsequent resolution using Chiral Chromatography. The absolute configuration of each enantiomer was determined by a combination of Mosher ester analysis and comparison with related natural and synthetic products. Electro-olfactogram (EOG) assays indicated that (+)-petromyroxol (1) possesses potent olfactory activity for sea lamprey.
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(+)- and (-)-petromyroxols: antipodal tetrahydrofurandiols from larval sea lamprey (Petromyzon marinus L.) that elicit enantioselective olfactory responses.
Organic Letters, 2014Co-Authors: Ke Li, Mar Huertas, Cory O Brant, Ugo Bussy, Thomas R Hoye, Yu Wen Chung-davidson, Weiming LiAbstract:(+)- and (−)-Petromyroxol [(+)-1 and (−)-1, respectively], two novel tetrahydrofuran (THF)-diol fatty acid enantiomers, were isolated from water conditioned with larval sea lamprey. We herein describe their isolation and subsequent resolution using Chiral Chromatography. The absolute configuration of each enantiomer was determined by a combination of Mosher ester analysis and comparison with related natural and synthetic products. Electro-olfactogram (EOG) assays indicated that (+)-petromyroxol (1) possesses potent olfactory activity for sea lamprey.