The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Jeffrey D. Schmitt - One of the best experts on this subject based on the ideXlab platform.
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Protonation-induced stereoisomerism in nicotine: Conformational studies using classical (AMBER) and ab initio (Car–Parrinello) molecular dynamics
Journal of Computer-Aided Molecular Design, 2005Co-Authors: Philip S Hammond, Yudong Wu, Todd J. Minehardt, Rebecca Harris, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
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protonation induced stereoisomerism in nicotine conformational studies using classical amber and ab initio car parrinello molecular dynamics
Journal of Computer-aided Molecular Design, 2005Co-Authors: Philip S Hammond, Todd J. Minehardt, Rebecca Harris, Roberto Car, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
Philip S Hammond - One of the best experts on this subject based on the ideXlab platform.
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Protonation-induced stereoisomerism in nicotine: Conformational studies using classical (AMBER) and ab initio (Car–Parrinello) molecular dynamics
Journal of Computer-Aided Molecular Design, 2005Co-Authors: Philip S Hammond, Yudong Wu, Todd J. Minehardt, Rebecca Harris, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
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protonation induced stereoisomerism in nicotine conformational studies using classical amber and ab initio car parrinello molecular dynamics
Journal of Computer-aided Molecular Design, 2005Co-Authors: Philip S Hammond, Todd J. Minehardt, Rebecca Harris, Roberto Car, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
Todd J. Minehardt - One of the best experts on this subject based on the ideXlab platform.
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Protonation-induced stereoisomerism in nicotine: Conformational studies using classical (AMBER) and ab initio (Car–Parrinello) molecular dynamics
Journal of Computer-Aided Molecular Design, 2005Co-Authors: Philip S Hammond, Yudong Wu, Todd J. Minehardt, Rebecca Harris, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
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protonation induced stereoisomerism in nicotine conformational studies using classical amber and ab initio car parrinello molecular dynamics
Journal of Computer-aided Molecular Design, 2005Co-Authors: Philip S Hammond, Todd J. Minehardt, Rebecca Harris, Roberto Car, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
Rebecca Harris - One of the best experts on this subject based on the ideXlab platform.
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Protonation-induced stereoisomerism in nicotine: Conformational studies using classical (AMBER) and ab initio (Car–Parrinello) molecular dynamics
Journal of Computer-Aided Molecular Design, 2005Co-Authors: Philip S Hammond, Yudong Wu, Todd J. Minehardt, Rebecca Harris, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
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protonation induced stereoisomerism in nicotine conformational studies using classical amber and ab initio car parrinello molecular dynamics
Journal of Computer-aided Molecular Design, 2005Co-Authors: Philip S Hammond, Todd J. Minehardt, Rebecca Harris, Roberto Car, Jeffrey D. SchmittAbstract:A variety of biologically active small molecules contain prochiral tertiary amines, which become chiral centers upon protonation. S-nicotine, the prototypical nicotinic acetylcholine receptor agonist, produces two Diastereomers on protonation. Results, using both classical (AMBER) and ab initio (Car–Parrinello) molecular dynamical studies, illustrate the significant differences in conformational space explored by each Diastereomer. As is expected, this phenomenon has an appreciable effect on nicotine’s energy hypersurface and leads to differentiation in molecular shape and divergent sampling. Thus, protonation induced isomerism can produce dynamic effects that may influence the behavior of a molecule in its interaction with a target protein. We also examine differences in the conformational dynamics for each Diastereomer as quantified by both molecular dynamics methods.
Prasad L Polavarapu - One of the best experts on this subject based on the ideXlab platform.
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Dissymmetry Factor Spectral Analysis Can Provide Useful Diastereomer Discrimination: Chiral Molecular Structure of an Analogue of (-)-Crispine A.
ACS Omega, 2019Co-Authors: Jordan L. Johnson, Divya S. Nair, Sarath Muraleedharan Pillai, Didimos Johnson, Zabeera Kallingathodi, Ibrahim Ibnusaud, Prasad L PolavarapuAbstract:(1R,10bR)-1'-((R)-1,2-Dihydroxyethyl)-1-hydroxy-8,9-dimethoxy1,5,6,10b-tetrahydropyrrolo [2,1-a]isoquinolin-3(2H)-one, an analogue of (-)-crispine A, with three stereogenic centers is synthesized and its absolute configuration (AC) established using the combined information derived from the synthetic scheme and single crystal X-ray diffraction data. The experimental chiroptical spectra (namely, optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD)) and the corresponding quantum chemical (QC) predicted spectra for all Diastereomers are used to evaluate the AC. The AC of the synthesized compound could be correctly established using any one of the three chiroptical spectroscopic methods (ORD, ECD, or VCD) when the relative configuration is constrained to be that derived from X-ray data or when the ACs of two of the chiral centers are constrained to be those derived from the synthetic scheme. In the absence of this outside information, the QC predicted ORD, ECD, and VCD for incorrect Diastereomers are also found to satisfactorily reproduce the corresponding experimental spectra. Nevertheless, incorrect Diastereomers could be eliminated when combined electronic dissymmetry factor (EDF) and vibrational dissymmetry factor (VDF) spectral analyses are included, leaving the correct Diastereomer as the sole choice. Thus, the combined EDF and VDF spectral analysis is seen to be a helpful Diastereomer discrimination tool.
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Dissymmetry Factor Spectral Analysis Can Provide Useful Diastereomer Discrimination: Chiral Molecular Structure of an Analogue of (−)-Crispine A
2019Co-Authors: Jordan L. Johnson, Divya S. Nair, Sarath Muraleedharan Pillai, Didimos Johnson, Zabeera Kallingathodi, Ibrahim Ibnusaud, Prasad L PolavarapuAbstract:(1R,10bR)-1′-((R)-1,2-Dihydroxyethyl)-1-hydroxy-8,9-dimethoxy1,5,6,10b-tetrahydropyrrolo [2,1-a]isoquinolin-3(2H)-one, an analogue of (−)-crispine A, with three stereogenic centers is synthesized and its absolute configuration (AC) established using the combined information derived from the synthetic scheme and single crystal X-ray diffraction data. The experimental chiroptical spectra (namely, optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD)) and the corresponding quantum chemical (QC) predicted spectra for all Diastereomers are used to evaluate the AC. The AC of the synthesized compound could be correctly established using any one of the three chiroptical spectroscopic methods (ORD, ECD, or VCD) when the relative configuration is constrained to be that derived from X-ray data or when the ACs of two of the chiral centers are constrained to be those derived from the synthetic scheme. In the absence of this outside information, the QC predicted ORD, ECD, and VCD for incorrect Diastereomers are also found to satisfactorily reproduce the corresponding experimental spectra. Nevertheless, incorrect Diastereomers could be eliminated when combined electronic dissymmetry factor (EDF) and vibrational dissymmetry factor (VDF) spectral analyses are included, leaving the correct Diastereomer as the sole choice. Thus, the combined EDF and VDF spectral analysis is seen to be a helpful Diastereomer discrimination tool
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Diastereomers of N-α-Phenylethyl-t-butylsulfinamide: Absolute Configurations and Predominant Conformations
The Journal of organic chemistry, 2008Co-Authors: Ana G. Petrovic, Prasad L Polavarapu, Józef Drabowicz, Piotr Łyżwa, Marian Mikołajczyk, And Michał W. Wieczorek, Agnieszka BalińskaAbstract:N-α-Phenylethyl-t-butylsulfinamide is a complicated system for determining molecular stereochemistry because of numerous possibilities for assigning the absolute configuration and a predominant conformation. Two Diastereomers of N-α-phenylethyl-t-butylsulfinamide derived from (−)-(S)-α-phenylethyl amine, a (+)-Diastereomer and a (−)-Diastereomer, have been synthesized and their experimental chiroptical spectroscopic properties have been measured. These properties include vibrational circular dichroism, electronic circular dichroism and optical rotatory dispersion. Using these experimental data, in conjunction with corresponding density functional theoretical predictions, the absolute configuration and predominant conformations of these two Diastereomers have been determined. Also, the absolute configuration of (−)-Diastereomer has been independently confirmed by determining its structure from X-ray diffraction data.
