1
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Forson E, Parsons T, Caricato M. First Principles Simulations of Optical Rotation of Chiral Molecular Crystals. Chirality 2024; 36:e23709. [PMID: 39101242 DOI: 10.1002/chir.23709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 08/06/2024]
Abstract
In this work, we present simulations of the optical rotation (OR) for five molecular crystals at density functional theory level with periodic boundary conditions (DFT-PBC). Calculations are compared with experimental measurements and show semi-quantitative agreement with experimental data for three of the crystals: tartatic acid, benzil, and pentaerythritol. For the other two crystals, aspartic acid and glutamic acid, the calculated data are in qualitative agreement with, but two orders of magnitude smaller than, the experimental data. We provide some arguments that support the theoretical predictions and suggest that the experiments should be revisited. We also find that the position of H centers provided in experimental X-ray data is not sufficiently reliable for simulating OR, and better results are obtained when H atoms are allowed to relax while keeping heavier elements fixed at the experimental positions. Comparison with molecular cluster calculations with a better functional and a larger basis set indicate that the role of intermolecular interactions (reproduced with the PBC technique) is as or more important than the choice of model chemistry. Despite the current limitations in the level of theory that can be employed, these simulations provide a promising avenue to investigate the effect of intermolecular interactions on this sensitive electronic property of molecules and materials.
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Affiliation(s)
- Emmanuel Forson
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Taylor Parsons
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Marco Caricato
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
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2
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Mamatkulov K, Zavatski S, Arynbek Y, Esawii HA, Burko A, Bandarenka H, Arzumanyan G. Conformational analysis of lipid membrane mimetics modified with A β42 peptide by Raman spectroscopy and computer simulations. J Biomol Struct Dyn 2024:1-14. [PMID: 38520152 DOI: 10.1080/07391102.2024.2330706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/08/2024] [Indexed: 03/25/2024]
Abstract
Peptide-lipid interactions play an important role in maintaining the integrity and function of the cell membrane. Even slight changes in these interactions can induce the development of various diseases. Specifically, peptide misfolding and aggregation in the membrane is considered to be one of the triggers of Alzheimer's disease (AD), however its exact mechanism is still unclear. To this end, an increase of amyloid-beta (Aβ) peptide concentration in the human brain is widely accepted to gradually produce cytotoxic Aβ aggregates (plaques). These plaques initiate a sequence of pathogenic events ending up in observable symptoms of dementia. Understanding the mechanism of the Aβ interaction with cells is crucial for early detection and prevention of Alzheimer's disease. Hence, in this work, a comprehensive Raman analysis of the Aβ42 conformational dynamics in water and in liposomes and lipodiscs that mimic the membrane system is presented. The obtained results show that the secondary structure of Aβ42 in liposomes is dominated by the α-helix conformation, which remains stable over time. However, it comes as a surprise to reveal that the lipodisc environment induces the transformation of the Aβ42 secondary structure to a β-turn/random coil. Our Raman spectroscopy findings are supported with molecular dynamics (MD) and density functional theory (DFT) simulations, showing their good agreement.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kahramon Mamatkulov
- Laboratory of Neutron Physics, Sector of Raman Spectroscopy, Joint Institute for Nuclear Research, Dubna, Russia
| | - Siarhei Zavatski
- Applied Plasmonics Laboratory, Belarusian State University of Informatics and Radioelectronics, Minsk, Belarus
| | - Yersultan Arynbek
- Laboratory of Neutron Physics, Sector of Raman Spectroscopy, Joint Institute for Nuclear Research, Dubna, Russia
- Faculty of Physics and Technology, al-Farabi, Kazakh National University, Almaty, Kazakhstan
| | - Heba A Esawii
- Laboratory of Neutron Physics, Sector of Raman Spectroscopy, Joint Institute for Nuclear Research, Dubna, Russia
- Biophysics Department, Faculty of Science, Cairo University, Egypt
| | - Aliaksandr Burko
- Applied Plasmonics Laboratory, Belarusian State University of Informatics and Radioelectronics, Minsk, Belarus
| | - Hanna Bandarenka
- Applied Plasmonics Laboratory, Belarusian State University of Informatics and Radioelectronics, Minsk, Belarus
| | - Grigory Arzumanyan
- Laboratory of Neutron Physics, Sector of Raman Spectroscopy, Joint Institute for Nuclear Research, Dubna, Russia
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3
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Sepali C, Lafiosca P, Gómez S, Giovannini T, Cappelli C. Effective fully polarizable QM/MM approaches to compute Raman and Raman Optical Activity spectra in aqueous solution. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 305:123485. [PMID: 37827000 DOI: 10.1016/j.saa.2023.123485] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/22/2023] [Accepted: 10/01/2023] [Indexed: 10/14/2023]
Abstract
Raman and Raman Optical Activity (ROA) signals are amply affected by solvent effects, especially in the presence of strongly solute-solvent interactions such as Hydrogen Bonding (HB). In this work, we extend the fully atomistic polarizable Quantum Mechanics/Molecular Mechanics approach, based on the Fluctuating Charges and Fluctuating Dipoles force field to the calculation of Raman and ROA spectra. Such an approach is able to accurately describe specific HB interactions, by also accounting for anisotropic contributions due to the inclusion of fluctuating dipoles. To highlight the potentiality of the novel approach, Raman and ROA spectra of L-Serine and L-Cysteine dissolved in aqueous solution are computed and compared both with alternative theoretical approaches and experimental measurements.
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Affiliation(s)
- Chiara Sepali
- Scuola Normale Superiore, Piazza dei Cavalieri, 7, Pisa, 56126, Italy
| | - Piero Lafiosca
- Scuola Normale Superiore, Piazza dei Cavalieri, 7, Pisa, 56126, Italy
| | - Sara Gómez
- Scuola Normale Superiore, Piazza dei Cavalieri, 7, Pisa, 56126, Italy
| | | | - Chiara Cappelli
- Scuola Normale Superiore, Piazza dei Cavalieri, 7, Pisa, 56126, Italy.
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4
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Grassin C, Pollok CH, Kreienborg NM, Merten C. Matrix effects in MI-VCD spectra of two chiral oxiranes and their potential microscopic origin. Phys Chem Chem Phys 2023; 25:31995-32001. [PMID: 37975701 DOI: 10.1039/d3cp05023h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Combining vibrational circular dichroism (VCD) spectroscopy with the matrix isolation (MI) technique opens up interesting possibilities to study chiral molecules. MI involves the isolation of guest species in inert solid matrices at cryogenic temperatures. Hence, MI-VCD measures are solid-state VCD measurements, and as such, can suffer from mostly birefringance-related artefacts in the same way as common solid-state VCD measurements. In this contribution, we demonstrate that the sample preparation condition have tremendous impact on the quality and reliability of the recorded MI-VCD spectra. While MI-IR spectra are basically blind to these artefacts, the variation of deposition temperatures and host flow rates seem to control whether high quality MI-VCD spectra are obtained or if depolarization effects lead to completely obscured spectra. For two selected examples, styrene oxide (SO) and 1-phenyl propylene oxide (PPO), we discuss how the various experimental conditions may lead to the aforementioned effects and give a microscopic description of their origin.
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Affiliation(s)
- Corentin Grassin
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany.
| | - Corina H Pollok
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany.
| | - Nora M Kreienborg
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany.
| | - Christian Merten
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany.
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5
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Müller C, Scholten K, Engelage E, Merten C. Synthesis and VCD Spectroscopic Characterization of a Series of Azacryptands from a Chiral Valine-Based Derivative of Tris(2-aminoethyl)amine (TREN). Chemistry 2023; 29:e202302126. [PMID: 37556200 DOI: 10.1002/chem.202302126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/09/2023] [Accepted: 08/09/2023] [Indexed: 08/10/2023]
Abstract
Utilizing experimental and computational vibrational circular dichroism (VCD) spectroscopy, we explored the conformational preferences of a series of chiral C3 -symmetric octaazacryptands with tris(2-aminoethyl)-amine head groups derived from valine. While the spectra of the smallest azacryptand with p-phenyl linkers and its elongated derivative with p-biphenyls linker were found to match well with the computed spectra, the computed conformational preferences of the m-biphenyl-based azacryptand did not seem to reflect the conformations dominating in chloroform solution. A detailed analysis revealed that structural changes resulting in a collapsed cage structure gave a notably better match with the experiment. It could subsequently be concluded from the VCD analysis, that the octaazacryptands prefer a collapsed structure, which is not predicted by density functional theory (DFT) calculations as the global minimum structures. These findings are expected to have consequences also for future studies on inclusion complexes of such azacryptands.
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Affiliation(s)
- Clemens Müller
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany
| | - Kevin Scholten
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany
| | - Elric Engelage
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany
| | - Christian Merten
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801, Bochum, Germany
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6
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Merten C. Modelling solute-solvent interactions in VCD spectra analysis with the micro-solvation approach. Phys Chem Chem Phys 2023; 25:29404-29414. [PMID: 37881890 DOI: 10.1039/d3cp03408a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Vibrational circular dichroism (VCD) spectroscopy has become an important part of the (stereo-)chemists' toolbox as a reliable method for the determination of absolute configurations. Being the chiroptical version of infrared spectroscopy, it has also been recognized as being very sensitive to conformational changes and intermolecular interactions. This sensitivity originates from the fact that the VCD spectra of individual conformers are often more different than their IR spectra, so that changes in conformational distributions or band positions and intensities become more pronounced. What is an advantage for studies focussing on intermolecular interactions can, however, quickly turn into a major obstacle during AC determinations: solute-solvent interactions can have a strong influence on spectral signatures and they must be accurately treated when simulating VCD and IR spectra. In this perspective, we showcase selected examples which exhibit particularly pronounced solvent effects. It is demonstrated that it is typically sufficient to model solute-solvent interactions by placing single solvent molecules near hydrogen bonding sites of the solute and subsequently use the optimized structures for spectra simulations. This micro-solvation approach works reasonably well for medium-sized, not too conformationally flexible molecules. We thus also discuss its limitations and outline the next steps that method development needs to take in order to further improve the workflows for VCD spectra predictions.
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Affiliation(s)
- Christian Merten
- Ruhr Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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7
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Lemler PM, Craft CL, Pollok CH, Regan TP, Vaccaro PH. Isolated and solvated chiroptical behavior in conformationally flexible butanamines. Chirality 2023; 35:586-618. [PMID: 37550220 DOI: 10.1002/chir.23570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/15/2023] [Accepted: 04/17/2023] [Indexed: 08/09/2023]
Abstract
The nonresonant optical activity of two highly flexible aliphatic amines, (2R)-3-methyl-2-butanamine (R-MBA) and (2R)-(3,3)-dimethyl-2-butanamine (R-DMBA), has been probed under isolated and solvated conditions to examine the roles of conformational isomerism and to explore the influence of extrinsic perturbations. The optical rotatory dispersion (ORD) measured in six solvents presented uniformly negative rotatory powers over the 320-590 nm region, with the long-wavelength magnitude of chiroptical response growing nearly monotonically as the dielectric constant of the surroundings diminished. The intrinsic specific optical rotation,α λ T (in deg dm-1 [g/mL]-1 ), extracted for ambient vapor-phase samples of R-MBA [-11.031(98) and -2.29 (11)] and R-DMBA [-9.434 (72) and -1.350 (48)] at 355 and 633 nm were best reproduced by counterintuitive solvents of high polarity (yet low polarizability) like acetonitrile and methanol. Attempts to interpret observed spectral signatures quantitatively relied on the linear-response frameworks of density-functional theory (B3LYP, cam-B3LYP, and dispersion-corrected analogs) and coupled-cluster theory (CCSD), with variants of the polarizable continuum model (PCM) deployed to account for the effects of implicit solvation. Building on the identification of several low-lying equilibrium geometries (nine for R-MBA and three for R-DMBA), ensemble-averaged ORD profiles were calculated at T = 300 K by means of the independent-conformer ansatz, which enabled response properties predicted for the optimized structure of each isomer to be combined through Boltzmann-weighted population fractions derived from corresponding relative internal-energy or free-energy values, the latter of which stemmed from composite CBS-APNO and G4 analyses. Although reasonable accord between theory and experiment was realized for the isolated (vapor-phase) species, the solution-phase results were less satisfactory and tended to degrade progressively as the solvent polarity increased. These trends were attributed to solvent-mediated changes in structural parameters and energy metrics for the transition states that separate and putatively isolate the equilibrium conformations supported by the ground electronic potential-energy surface, with the resulting displacement of barrier locations and/or decrease of barrier heights compromising the underlying premise of the independent-conformer ansatz.
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Affiliation(s)
- Paul M Lemler
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Intel Corporation, Hillsboro, Oregon, USA
| | - Clayton L Craft
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- United States Air Force Research Laboratory, Rome, New York, USA
| | - Corina H Pollok
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Organische Chemie II, Ruhr-Universität Bochum, Bochum, Germany
| | - Thomas P Regan
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Patrick H Vaccaro
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
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8
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Ciogli A, Fochetti A, Sorato A, Fabrizi G, Matera N, Mazzanti A, Mancinelli M. Diaryl-Pyrano-Chromenes Atropisomers: Stereodynamics and Conformational Studies. Molecules 2023; 28:4915. [PMID: 37446580 DOI: 10.3390/molecules28134915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 07/15/2023] Open
Abstract
The dynamic scenario of di-aryls-pyrano-chromenes was investigated using DFT calculations. The symmetry of the chromene scaffold and the presence of two ortho-substituted aryls substituents can generate two syn/anti diastereoisomers and conformational enantiomers with different rotational barriers. The relative conformations and configurations were derived using NOESY-1D experiments. Depending on the energies related to the conformational exchange, the experimental energy barriers were determined through Dynamic NMR, Dynamic HPLC or kinetic studies. The atropisomeric pairs were resolved in the latter scenario, and their absolute configuration was assigned using the ECD/TD-DFT method.
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Affiliation(s)
- Alessia Ciogli
- Department of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Andrea Fochetti
- Department of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Andrea Sorato
- Department of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Giancarlo Fabrizi
- Department of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Nunzio Matera
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - Michele Mancinelli
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
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9
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Eikås KDR, Krupová M, Kristoffersen T, Beerepoot MTP, Ruud K. Can the absolute configuration of cyclic peptides be determined with vibrational circular dichroism? Phys Chem Chem Phys 2023; 25:14520-14529. [PMID: 37190985 DOI: 10.1039/d2cp04942b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Cyclic peptides show a wide range of biological activities, among others as antibacterial agents. These peptides are often large and flexible with multiple chiral centers. The determination of the stereochemistry of molecules with multiple chiral centers is a challenging and important task in drug development. Chiroptical spectroscopies such as vibrational circular dichroism (VCD) can distinguish between different stereoisomers. The absolute configuration (AC) of a stereoisomer can be determined by comparing its experimental spectra to computed spectra of stereoisomers with known AC. In this way, the AC of rigid molecules with up to seven chiral centers has been assigned (Bogaerts et al., Phys. Chem. Chem. Phys., 2020, 22, 18014). The question arises whether this is possible with more conformationally flexible molecules such as cyclic peptides. We here investigate to what extent the AC of cyclic peptides can be determined with VCD. More specifically, we investigate the maximum number of chiral centers a cyclic peptide can have in order to be able to unambiguously assign the AC with VCD. We present experimental and computed IR and VCD spectra for a series of eight tetrapeptides and hexapeptides with two, three and four chiral centers. We use our recently developed computational protocol with a conformational search based on sampling with meta-dynamics. We use visual inspection to compare the computed spectra of different stereoisomers with an experimental spectrum of the corresponding cyclic peptide with known AC. We find that the AC of the investigated cyclic peptides with two chiral centers can be unambiguously assigned with VCD. This is however not possible for all of the cyclic peptides with three chiral centers and for none of those with four chiral centers. At best, one can limit the number of possible stereoisomers in those cases. Our work shows that other techniques are needed to assign the AC of cyclic peptides with three or more chiral centers. Our study also constitutes a warning that the spectra of all stereoisomers should be computed before attempting to match to an experimental spectrum, to avoid an accidental erroneous match.
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Affiliation(s)
- Karolina Di Remigio Eikås
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Monika Krupová
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Tone Kristoffersen
- Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | | | - Kenneth Ruud
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
- Norwegian Defence Research Establishment, P.O. Box 25, 2027 Kjeller, Norway
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10
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Pecorari D, Mazzanti A, Mancinelli M. Atropostatin: Design and Total Synthesis of an Atropisomeric Lactone–Atorvastatin Prodrug. Molecules 2023; 28:molecules28073176. [PMID: 37049939 PMCID: PMC10095771 DOI: 10.3390/molecules28073176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
Atorvastatins play an important role in the inhibition of HMG-CoA reductase, an enzyme present in the liver that takes part in the biosynthesis of cholesterol. In this article, we report the total synthesis of a lactone–atorvastatin prodrug with additional atropisomeric features. Conformational and experimental studies of model compounds were designed to test the stability of the chiral axis. Docking calculations were performed to evaluate the constant inhibition of a library of atorvastatins. Full synthesis of the best candidate was achieved and thermally stable atropisomeric lactone–atorvastatin was obtained. The absolute configuration of the chiral axis of the atropisomers was assigned by means of chiroptical ECD spectroscopy coupled with TD-DFT calculations.
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Affiliation(s)
- Daniel Pecorari
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - Michele Mancinelli
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
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11
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Kreienborg NM, Yang Q, Pollok CH, Bloino J, Merten C. Matrix-isolation and cryosolution-VCD spectra of α-pinene as benchmark for anharmonic vibrational spectra calculations. Phys Chem Chem Phys 2023; 25:3343-3353. [PMID: 36633064 DOI: 10.1039/d2cp04782a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The inclusion of anharmonicity in vibrational spectral analyis remains associated to small molecular systems with up to a dozen of atoms, with half a dozen of non-hydrogen atoms, typically thesize of propylene oxide. One may see two reasons for this: first of all, larger systems are often thought to be computationally too demanding (high computational costs) for a full anharmonic vibrational analysis. Second, the identification of resonances and their correction is often considered something only expert theoreticians could address because of the lack of unequivocal criteria. In this contribution, we illustrate that resonances can indeed become a complex problem, which can be handled almost transparently thanks to recent advances in vibrational perturbation theory (VPT2). The study also emphasizes the importance and the central role played by experiment in benchmarking novel theoretical approaches. In fact, we herein provide the currently highest resolution VCD spectra available for α- and β-pinene obtained under matrix-isolation conditions and in liquid Xenon as solvent. They are interpreted by VPT2 with novel tests for the identification of resonances. Hence, the study demonstrates the mutual stimulation of advances in both experimental techniques and computational models.
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Affiliation(s)
- Nora M Kreienborg
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
| | - Qin Yang
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
| | - Corina H Pollok
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
| | - Julien Bloino
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
| | - Christian Merten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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12
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Golub TP, Feßner M, Engelage E, Merten C. Dynamic Stereochemistry of a Biphenyl-Bisprolineamide Model Catalyst and its Imidazolidinone Intermediates. Chemistry 2022; 28:e202201317. [PMID: 35611719 PMCID: PMC9545261 DOI: 10.1002/chem.202201317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Indexed: 12/15/2022]
Abstract
In this study, we characterize the dynamic stereochemistry of a biphenyl-2,2'-bis(proline amide) catalyst in chloroform and DMSO as representative weakly and strongly hydrogen bonding solvents. Using vibrational circular dichroism (VCD) spectroscopy and density functional theory (DFT) based spectra calculations, we show that the preferred axial stereochemistry of the catalyst is determined by solute-solvent interactions. Explicitly considering solvation with DMSO molecules is found to be essential to correctly predict the conformational preferences of the catalyst. Furthermore, we investigate the stereochemistry of the corresponding enamines and imidazolidinones that are formed upon reaction with isovaleraldehyde. The enamines are found to rapidly convert to endo-imidazolidinones and the thermodynamically favored exo-imidazolidinones are formed only slowly. The present study demonstrates that the stereochemistry of these imidazolidinones can be deduced directly from the VCD spectra analysis without any further detailed analysis of NMR spectra. Hence, we herein exemplify the use of VCD spectroscopy for an in situ characterization of intermediates relevant in asymmetric catalysts.
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Affiliation(s)
- Tino P. Golub
- Ruhr Universität BochumFakultät für Chemie und BiochemieOrganische Chemie IIUniversitätsstraße 15044801BochumGermany
| | - Malte Feßner
- Ruhr Universität BochumFakultät für Chemie und BiochemieOrganische Chemie IIUniversitätsstraße 15044801BochumGermany
| | - Elric Engelage
- Ruhr Universität BochumFakultät für Chemie und BiochemieOrganische Chemie IIUniversitätsstraße 15044801BochumGermany
| | - Christian Merten
- Ruhr Universität BochumFakultät für Chemie und BiochemieOrganische Chemie IIUniversitätsstraße 15044801BochumGermany
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13
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Scholten K, Merten C. Solvation of the Boc-Val-Phe- nPr peptide characterized by VCD spectroscopy and DFT calculations. Phys Chem Chem Phys 2022; 24:3611-3617. [PMID: 35103263 DOI: 10.1039/d1cp05457k] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The conformational preferences of peptides are strongly determined by hydrogen bonding interactions. Intermolecular solute-solvent interactions compete with intramolecular interactions, which typically stabilize the secondary structure of the peptide. The analysis of vibrational circular dichroism (VCD) spectra can give insights into solvation-induced changes in the conformational distribution of small peptides. Here we describe the VCD spectroscopic characterization of the model peptide Boc-Val-Phe-nPr in chloroform as representative for a weakly interacting solvent and dimethyl sulfoxide (DMSO-d6) as a strongly hydrogen bonding solvent. We show that the conformational preferences of the peptide in chloroform are well-described by the computationally predicted distribution of the isolated molecule assuming only implicit solvation effects through a continuum solvation model. In order to simulate the spectra recorded in DMSO-d6, solvation was accounted for explicitly by computed microsolvated structures containing one to three solvent molecules. A good match of the computed spectra with the experimental data is obtained by this method. Comparing the conformational distributions in deuterated chloroform-d1 and DMSO-d6, structures with intramolecular hydrogen bonds such as the (δ,δ)-conformer family contribute to the conformational distribution only when there is no strong interaction with the solvent. This is in contrast to the results for the related Boc-Pro-Phe-nPr studied before, for which the intramolecular interaction was found to persist in DMSO-d6. Furthermore, we discuss the influence of hydrogen bonding to different numbers of solvent molecules on the spectral signatures and show that the structure of the peptide in DMSO-d6 is best described as a mixture of twofold-solvated (δ,β)- and threefold-solvated (β,β)-conformers.
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Affiliation(s)
- Kevin Scholten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
| | - Christian Merten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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14
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Xia Y, Wang X, Sun H, Huang X. Proton-coupled electron transfer of catechin in tea wine: the enhanced mechanism of anti-oxidative capacity. RSC Adv 2021; 11:39985-39993. [PMID: 35494161 PMCID: PMC9044537 DOI: 10.1039/d1ra07769d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/30/2021] [Indexed: 12/13/2022] Open
Abstract
Tea wine is a Chinese traditional alcoholic drink made by cereal and tea leaves. It is rich in tea polyphenols, caffeine, amino acids, and protons and possesses various healthcare functions. In this work, electrochemical methods, as well as density functional theory (DFT) calculations, were adopted to reveal the proton-coupled electron-transfer process of catechin in tea wine. The electrochemical results showed that the catechin preferred hydrogen-bonding with ethanol and formed molecular clusters. Thus, the direct electron-transfer process of catechin changed to proton-coupled electron transfer. This procedure reduced the energy barrier of the redox reaction and enhanced the anti-oxidative capacity. Subsequently, DFT calculations were employed to explore the bond length, bond energy, and HOMO-LUMO energy gap of catechin, which confirmed the above-mentioned mechanism. Our work offers some positive value for the scientific promotion of traditional food and a greater understanding of the health mechanisms in terms of chemistry.
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Affiliation(s)
- Yirong Xia
- School of Food and Chemical Engineering, Shaoyang University Shaoyang 422000 China
| | - Xintong Wang
- School of Food and Chemical Engineering, Shaoyang University Shaoyang 422000 China
| | - Hechen Sun
- Shanxian Central Hospital Heze 274300 China
| | - Ximing Huang
- School of Food and Chemical Engineering, Shaoyang University Shaoyang 422000 China
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15
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Jähnigen S, Sebastiani D, Vuilleumier R. The important role of non-covalent interactions for the vibrational circular dichroism of lactic acid in aqueous solution. Phys Chem Chem Phys 2021; 23:17232-17241. [PMID: 34369531 DOI: 10.1039/d1cp03106f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We present a computational study of vibrational circular dichroism (VCD) in solutions of (S)-lactic acid, relying on ab initio molecular dynamics (AIMD) and full solvation with bulk water. We discuss the effect of the hydrogen bond network on the aggregation behaviour of the acid: while aggregates of the solute represent conditions encountered in a weakly interacting solvent, the presence of water drastically interferes with the clusters - more strongly than originally anticipated. For both scenarios we computed the VCD spectra by means of nuclear velocity perturbation theory (NVPT). The comparison with experimental data allows us to establish a VCD-structure relationship that includes the solvent network around the chiral solute. We suggest that fundamental modes with strong polarisation such as the carbonyl stretching vibration can borrow VCD from the chirally restructured solvent cage, which extends the common explanatory models of VCD generation in aqueous solution.
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Affiliation(s)
- Sascha Jähnigen
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France.
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16
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Craft CL, Lemler PM, Vaccaro PH. Optical Activity in Saturated Cyclic Amines: Untangling the Roles of Nitrogen-Inversion and Ring-Puckering Dynamics. J Phys Chem A 2021; 125:5562-5584. [PMID: 34142836 DOI: 10.1021/acs.jpca.1c03882] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dispersive optical activity of two saturated cyclic amines, (R)-2-methylpyrrolidine (R-2MPY) and (S)-2-methylpiperidine (S-2MPI), has been interrogated under isolated and solvated conditions to elucidate the roles of large-amplitude motion associated with nitrogen-center inversion and ring-puckering dynamics. Experimental optical rotatory dispersion profiles were almost mirror images of one another and displayed parallel solvent dependencies. Quantum-chemical analyses built on density-functional and coupled-cluster methods revealed four low-lying conformers for each molecule, which are distinguished by axial/equatorial orientations of their amino hydrogens and methyl substituents. Chiroptical signatures predicted for these species were combined through an independent-conformer ansatz to simulate the ensemble-averaged response, with a polarizable continuum model (PCM) being used to treat implicit solute-solvent interactions. The intrinsic behavior observed for isolated (gaseous) R-2MPY and S-2MPI was reproduced best by merging coupled-cluster (CCSD) estimates of rotatory powers with thermal population fractions deduced from complete basis set (CBS-APNO) free-energy calculations. Although prior claims of sizable chiroptical contributions arising from helically twisted (chiral) heterocyclic frameworks could be discounted, less satisfactory agreement between experiment and theory was realized for solution phases. Response properties sustained modest isomer-dependent changes in the presence of PCM solvation, but the corresponding energy metrics showed systematic trends, whereby structures having larger electric-dipole moments were stabilized preferentially in media of high polarity. Despite the fact that R-2MPY conformations were predicted to undergo a progressive reordering of their relative energies across the six solvents of interest, S-2MPI was found to exhibit more pronounced solvent-induced perturbations at long wavelengths (viz., in regions far removed from electronic resonances). Experimental results are discussed in terms of the distinct ring-puckering mechanisms for R-2MPY and S-2MPI, which are expected to be dominated by hindered pseudorotation among envelope/twist motifs and semi-inversion between chairlike antipodes, respectively.
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Affiliation(s)
- Clayton L Craft
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Paul M Lemler
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Patrick H Vaccaro
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
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17
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D'Cunha R, Crawford TD. Modeling Complex Solvent Effects on the Optical Rotation of Chiral Molecules: A Combined Molecular Dynamics and Density Functional Theory Study. J Phys Chem A 2021; 125:3095-3108. [PMID: 33829790 DOI: 10.1021/acs.jpca.1c00803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The challenge of assigning the absolute stereochemical configuration to a chiral compound can be overcome via accurate ab initio predictions of optical rotation, a sensitive molecular property that is further complicated by solvent effects. The solvent's "chiral imprint"-the transfer of the chirality from the solute to the surrounding achiral solvent-is explored here using conformational averaging and time-dependent density-functional theory. These complex solvent effects are taken into account via simple averaging over a molecular dynamics trajectory together with the explicit quantum mechanical consideration of the solvent molecules within the solute's cybotactic region and implicit modeling of the bulk solvent. We consider several axes along which the system's optical rotation varies, including the sampling of the dynamical trajectory, the quality of the one-electron basis set, and the use of continuum solvent models to account for bulk effects.
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Affiliation(s)
- Ruhee D'Cunha
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - T Daniel Crawford
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.,Molecular Sciences Software Institute, 1880 Pratt Drive, Suite 1100, Blacksburg, Virginia 24060, United States
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18
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Kaminský J, Andrushchenko V, Bouř P. Natural and magnetic circular dichroism spectra of nucleosides: effect of the dynamics and environment. RSC Adv 2021; 11:8411-8419. [PMID: 35423314 PMCID: PMC8695171 DOI: 10.1039/d1ra00076d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/16/2021] [Indexed: 12/30/2022] Open
Abstract
Chiroptical spectroscopic methods are excellent tools to study structure and interactions of biomolecules. However, their sensitivity to different structural aspects varies. To understand the dependence of absorption, electronic and magnetic circular dichroism (ECD, MCD) intensities on the structure, dynamics and environment, we measured and simulated spectra of nucleosides and other nucleic acid model components. The conformation space was explored by molecular dynamics (MD), the electronic spectra were generated using time dependent density functional theory (TDDFT). The sum over state (SOS) method was employed for MCD. The results show that accounting for the dynamics is crucial for reproduction of the experiment. While unpolarized absorption spectroscopy is relatively indifferent, ECD reflects the conformation and geometry dispersion more. MCD spectra provide variable response dependent on the wavelength and structural change. In general, MCD samples the structure more locally than ECD. Simple computational tests suggest that the optical spectroscopies coupled with the computational tools provide useful information about nucleic acid components, including base pairing and stacking.
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Affiliation(s)
- Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
| | - Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
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19
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Scholten K, Engelage E, Merten C. Basis set dependence of S[double bond, length as m-dash]O stretching frequencies and its consequences for IR and VCD spectra predictions. Phys Chem Chem Phys 2020; 22:27979-27986. [PMID: 33290469 DOI: 10.1039/d0cp05420h] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Benchmarking functionals and basis sets for the computational prediction of molecular properties is usually done on very small model systems. Larger organic molecules containing heavier second row atoms are not the typical model structures. We herein present the first survey of basis sets and functionals for the prediction of the IR and VCD spectra of chiral tosylates and sulfinates as we noted drastic deviations between computed harmonic frequencies obtained at B3LYP/6-311++G(2d,p) level of theory and those observed in experimental solution phase IR and VCD spectra. We show that the harmonic frequencies of the asymmetric and symmetric S[double bond, length as m-dash]O stretching modes of tosylates are predicted at significantly too low vibrational frequencies if the employed basis set does not provide higher order polarization functions. The results of our benchmarks show that at least the 6-311G(3df,2dp) basis (or equivalent Dunning and Ahlrichs variants) should be used.
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Affiliation(s)
- Kevin Scholten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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20
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Giovannini T, Egidi F, Cappelli C. Theory and algorithms for chiroptical properties and spectroscopies of aqueous systems. Phys Chem Chem Phys 2020; 22:22864-22879. [PMID: 33043930 DOI: 10.1039/d0cp04027d] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Chiroptical properties and spectroscopies are valuable tools to study chiral molecules and assign absolute configurations. The spectra that result from chiroptical measurements may be very rich and complex, and hide much of their information content. For this reason, the interplay between experiments and calculations is especially useful, provided that all relevant physico-chemical interactions that are present in the experimental sample are accurately modelled. The inherent difficulty associated to the calculation of chiral signals of systems in aqueous solutions requires the development of specific tools, able to account for the peculiarities of water-solute interactions, and especially its ability to form hydrogen bonds. In this perspective we discuss a multiscale approach, which we have developed and challenged to model the most used chiroptical techniques.
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Affiliation(s)
- Tommaso Giovannini
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
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21
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Vermeyen T, Merten C. Solvation and the secondary structure of a proline-containing dipeptide: insights from VCD spectroscopy. Phys Chem Chem Phys 2020; 22:15640-15648. [PMID: 32617548 DOI: 10.1039/d0cp02283g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this study we investigate the IR and VCD spectra of the diastereomeric dipeptide Boc-Pro-Phe-(n-propyl) 1 in chloroform-d1 (CDCl3) and the strongly hydrogen bonding solvent dimethylsulfoxide-d6 (DMSO-d6). From comparison of the experimental spectra, the amide II spectral region is identified as marker signature for the stereochemistry of the dipeptide: the homochiral LL-1 features a (+/-)-pattern in the amide II region of the VCD spectrum, while the amide II signature of the diastereomer LD-1 is inverted. Computational analysis of the IR and VCD spectra of LL-1 reveals that the experimentally observed amide II signature is characteristic for a βI-turn structure of the peptide. Likewise, the inverted pattern found for LD-1 arises from a βII-turn structure of the dipeptide. Following a micro-solvation approach, the experimental spectra recorded in DMSO-d6 are computationally well reproduced by considering only a single solvent molecule in a hydrogen bond with N-H groups. Considering a second solvent molecule, which would lead to a cleavage of intramolecular hydrogen bonds in 1, is found to give a significantly worse match with the experiment. Hence, the detailed computational analysis of the spectra of LL- and LD-1 recorded in DMSO-d6 confirms that the intramolecular hydrogen bonding pattern, that stabilizes the β-turns and other conformations of LL- and LD-1 in apolar solvents, remains intact. Our findings also show that it is essential to consider solvation explicitly in the analysis of the IR and VCD spectra of dipeptides in strongly hydrogen bonding solvents. As the solute-solvent interactions affect both conformational preferences and spectral signatures, it is also demonstrated that this inclusion of solvent molecules cannot be circumvented by applying fitting procedures to non-solvated structures.
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Affiliation(s)
- Tom Vermeyen
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany. and University of Antwerp, Department of Chemistry, MolSpec Group, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Christian Merten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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22
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Niemeyer N, Tölle J, Neugebauer J. Approximate versus Exact Embedding for Chiroptical Properties: Reconsidering Failures in Potential and Response. J Chem Theory Comput 2020; 16:3104-3120. [PMID: 32301613 DOI: 10.1021/acs.jctc.0c00125] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigate the suitability of subsystem time-dependent density-functional theory (sTDDFT) for describing chiroptical properties with a focus on optical rotation parameters. Our starting point is a new implementation of the recently proposed projection-based, coupled frozen-density embedding (FDEc) framework. We adapt the generalized, non-Hermitian formulation of TDDFT and derive corresponding expressions for regular and damped response properties from subsystem TDDFT. We verify that our implementation of this "exact" formulation allows to reproduce supermolecular results of electronic circular dichroism (ECD) spectra, of optical rotatory dispersion, and of polarizabilities. We present a systematic test of the main approximations typically introduced in practical frozen-density embedding (FDE) calculations of response properties: (i) the use of approximate nonadditive kinetic-energy (NAKE) functionals, which can be avoided through projection techniques, (ii) the use of monomer (subsystem) basis sets rather than supersystem basis sets, and (iii) the neglect of intersubsystem response coupling within the so-called uncoupled FDE (or FDEu) approximation. While approximation (i) is known to generally lead to large errors for covalently bound subsystems, we present cases in which either the basis set or the coupling step are similarly or even (much) more important. In particular, we explicitly demonstrate by comparison to a fully coupled calculation that missing intersubsystem response couplings are responsible for the failure of FDE reported in a previous study [ J. Chem. Theory Comput. 2015, 11, 5305-5315]. We show that good agreement with reference results can be obtained in this case even with standard NAKE approximations for the FDE potentials and efficient monomer basis sets, making calculations for larger systems well accessible.
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Affiliation(s)
- Niklas Niemeyer
- Theoretische Organische Chemie, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität Münster Corrensstraße 40, 48149 Münster, Germany
| | - Johannes Tölle
- Theoretische Organische Chemie, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität Münster Corrensstraße 40, 48149 Münster, Germany
| | - Johannes Neugebauer
- Theoretische Organische Chemie, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität Münster Corrensstraße 40, 48149 Münster, Germany
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23
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Ozcelik A, Pereira-Cameselle R, Poklar Ulrih N, Petrovic AG, Alonso-Gómez JL. Chiroptical Sensing: A Conceptual Introduction. SENSORS (BASEL, SWITZERLAND) 2020; 20:E974. [PMID: 32059394 PMCID: PMC7071115 DOI: 10.3390/s20040974] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/07/2020] [Accepted: 02/09/2020] [Indexed: 12/21/2022]
Abstract
Chiroptical responses have been an essential tool over the last decades for chemical structural elucidation due to their exceptional sensitivity to geometry and intermolecular interactions. In recent times, there has been an increasing interest in the search for more efficient sensing by the rational design of tailored chiroptical systems. In this review article, advances made in chiroptical systems towards their implementation in sensing applications are summarized. Strategies to generate chiroptical responses are illustrated. Theoretical approaches to assist in the design of these systems are discussed. The development of efficient chiroptical reporters in different states of matter, essential for the implementation in sensing devises, is reviewed. In the last part, remarkable examples of chiroptical sensing applications are highlighted.
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Affiliation(s)
- Ani Ozcelik
- Department of Organic Chemistry, University of Vigo, 36310 Vigo, Spain; (A.O.); (R.P.-C.)
| | | | - Natasa Poklar Ulrih
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Kongresni trg 12, 1000 Ljubljana, Slovenia;
| | - Ana G. Petrovic
- Department of Biological & Chemical Sciences, New York Institute of Technology, New York, NY 10023, USA
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24
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Weirich L, Blanke K, Merten C. More complex, less complicated? Explicit solvation of hydroxyl groups for the analysis of VCD spectra. Phys Chem Chem Phys 2020; 22:12515-12523. [DOI: 10.1039/d0cp01656j] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With increasing size of the molecules, hydrogen bonding induced solvent effects on the IR and VCD spectra become more negligible.
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Affiliation(s)
- Luisa Weirich
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- Organische Chemie II
- 44801 Bochum
- Germany
| | - Katharina Blanke
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- Organische Chemie II
- 44801 Bochum
- Germany
| | - Christian Merten
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- Organische Chemie II
- 44801 Bochum
- Germany
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25
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Weirich L, Magalhães de Oliveira J, Merten C. How many solvent molecules are required to solvate chiral 1,2-diols with hydrogen bonding solvents? A VCD spectroscopic study. Phys Chem Chem Phys 2020; 22:1525-1533. [DOI: 10.1039/c9cp06030h] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A VCD spectroscopic analysis of selected model systems for solute–solvent interactions of chiral diols with hydrogen bonding solvents DMSO and ACN.
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Affiliation(s)
- Luisa Weirich
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- Organische Chemie II
- 44801 Bochum
- Germany
| | | | - Christian Merten
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- Organische Chemie II
- 44801 Bochum
- Germany
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26
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Le Barbu-Debus K, Bowles J, Jähnigen S, Clavaguéra C, Calvo F, Vuilleumier R, Zehnacker A. Assessing cluster models of solvation for the description of vibrational circular dichroism spectra: synergy between static and dynamic approaches. Phys Chem Chem Phys 2020; 22:26047-26068. [DOI: 10.1039/d0cp03869e] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Solvation effects are essential for defining the shape of vibrational circular dichroism (VCD) spectra.
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Affiliation(s)
- Katia Le Barbu-Debus
- Institut des Sciences Moléculaires d’Orsay (ISMO)
- CNRS
- Université Paris-Saclay
- F-91405 Orsay
- France
| | - Jessica Bowles
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- UMR8000
- 91405 Orsay
| | - Sascha Jähnigen
- PASTEUR
- Département de Chimie
- Ecole Normale Supérieure
- PSL University
- Sorbonne Université
| | - Carine Clavaguéra
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- UMR8000
- 91405 Orsay
| | - Florent Calvo
- Université Grenoble Alpes
- CNRS
- LiPhy
- F-38000 Grenoble
- France
| | - Rodolphe Vuilleumier
- PASTEUR
- Département de Chimie
- Ecole Normale Supérieure
- PSL University
- Sorbonne Université
| | - Anne Zehnacker
- Institut des Sciences Moléculaires d’Orsay (ISMO)
- CNRS
- Université Paris-Saclay
- F-91405 Orsay
- France
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27
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Merten C, Golub TP, Kreienborg NM. Absolute Configurations of Synthetic Molecular Scaffolds from Vibrational CD Spectroscopy. J Org Chem 2019; 84:8797-8814. [PMID: 31046276 DOI: 10.1021/acs.joc.9b00466] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Vibrational circular dichroism (VCD) spectroscopy is one of the most powerful techniques for the determination of absolute configurations (AC), as it does not require any specific UV/vis chromophores, no chemical derivatization, and no growth of suitable crystals. In the past decade, it has become increasingly recognized by chemists from various fields of synthetic chemistry such as total synthesis and drug discovery as well as from developers of asymmetric catalysts. This perspective article gives an overview about the most important experimental aspects of a VCD-based AC determination and explains the theoretical analysis. The comparison of experimental and computational spectra that leads to the final conclusion about the AC of the target molecules is described. In addition, the review summarizes unique VCD studies carried out in the period 2008-2018 that focus on the determination of unknown ACs of new compounds, which were obtained in its enantiopure form either through direct asymmetric synthesis or chiral chromatography.
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Affiliation(s)
- Christian Merten
- Ruhr Universität Bochum , Organische Chemie II , Universitätsstraße 150 , 44780 Bochum , Germany
| | - Tino P Golub
- Ruhr Universität Bochum , Organische Chemie II , Universitätsstraße 150 , 44780 Bochum , Germany
| | - Nora M Kreienborg
- Ruhr Universität Bochum , Organische Chemie II , Universitätsstraße 150 , 44780 Bochum , Germany
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28
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Egidi F, Giovannini T, Del Frate G, Lemler PM, Vaccaro PH, Cappelli C. A combined experimental and theoretical study of optical rotatory dispersion for (R)-glycidyl methyl ether in aqueous solution. Phys Chem Chem Phys 2019; 21:3644-3655. [PMID: 30383044 DOI: 10.1039/c8cp04445g] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The dispersive optical activity for aqueous solutions of non-rigid (R)-glycidyl methyl ether (R-GME) has been explored synergistically from experimental and theoretical perspectives. Density functional theory analyses performed with the polarizable continuum model for implicit solvation identified nine low-lying stable conformers that are interconverted by rotation about two large-amplitude torsional coordinates. The antagonistic chiroptical signatures predicted for these structural isomers were averaged under a Boltzmann-weighting ansatz to estimate the behavior expected for a thermally equilibrated ensemble. This led to optical rotatory dispersion profiles that reproduced the overall shape of observations but failed to achieve uniform agreement with measured specific-rotation values even when anharmonic vibrational corrections were applied. A mixed QM/FQ paradigm, whereby quantum-mechanical (QM) calculations of optical activity were combined with classical molecular dynamics simulations of explicit solvation that included mutual-polarization effects by means of fluctuating charges (FQ), was enlisted to elucidate the microsolvation environment and gauge its impact upon conformer distributions and response properties. Although quantitative accord with experiments remained elusive, this approach revealed strong variations in the magnitude and sign of rotatory powers for R-GME as the configuration of surrounding water molecules evolved, thereby highlighting the inherently dynamical nature of the solvated chiroptical response, calling into question the validity of "static" descriptions based on the presumption of distinct energy minima, and giving insight into the inherent complexity posed by the modeling of such properties for solvated systems.
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Affiliation(s)
- Franco Egidi
- Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy
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29
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Górecki M, Zullo V, Iuliano A, Pescitelli G. On the Absolute Stereochemistry of Tolterodine: A Circular Dichroism Study. Pharmaceuticals (Basel) 2019; 12:ph12010021. [PMID: 30691175 PMCID: PMC6469158 DOI: 10.3390/ph12010021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 02/06/2023] Open
Abstract
Tolterodine (1) is a potent muscarinic receptor antagonist used in the treatment of overactive urinary bladder (OAB) syndrome. Tolterodine is chiral and it was patented, and is currently marketed, as the l-tartrate salt of the (R)-enantiomer. However, the existing literature does not offer an ultimate proof of a stereoselective mode of action of 1. A second open stereochemical issue concerns the absolute configuration (AC) of 1. Neither the original patents nor subsequent studies have established the AC of 1 in an unambiguous way, although the AC of the l-tartrate salt of 1 was assigned by X-ray diffractometry. Finally, neither electronic nor vibrational circular dichroism (ECD and VCD) spectra of 1 are reported so far. We performed a thorough ECD/VCD study of 1 in different solvents and at variable temperatures. Solvent and temperature dependence highlighted the existence of moderate flexibility which was confirmed by molecular modelling. ECD calculations with time-dependent density functional theory (TDDFT) accurately reproduced the experimental spectra and allowed us to confirm the AC of 1 in an independent way.
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Affiliation(s)
- Marcin Górecki
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy.
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 St., 01-224 Warsaw, Poland.
| | - Valerio Zullo
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy.
| | - Anna Iuliano
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy.
| | - Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy.
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30
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Kessler J, Andrushchenko V, Kapitán J, Bouř P. Insight into vibrational circular dichroism of proteins by density functional modeling. Phys Chem Chem Phys 2018; 20:4926-4935. [PMID: 29384537 DOI: 10.1039/c7cp08016f] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Vibrational circular dichroism (VCD) spectroscopy is an excellent method to determine the secondary structure of proteins in solution. Comparison of experimental spectra with quantum-chemical simulations represents a convenient and objective way to extract information on the structure. This has been difficult for such large molecules where approximate theoretical models have to be used. In the present study we applied the Cartesian-coordinate based tensor transfer (CCT) making it possible to extend the density functional theory (DFT) and model spectral intensities of large globular proteins nearly at quantum-chemical precision. Indeed, comparison with experiment provided a better understanding of the dependence of VCD spectral shapes on the geometry, their sensitivity to fine structural details and interactions with the environment. On a model set of globular proteins the simulated spectra correlated well with experimental data and revealed which structural information can (and cannot) be obtained from this kind of spectroscopy. Although the VCD technique has been regarded as being rather insensitive to side-chain variations, we found that the spectra of human and hen lysozyme differing by a few amino acids only are quite distinct. This has been explained by long-distance coupling of the amide vibrations. Likewise, the modeling reproduced some spectral changes caused by protein deuteration even when the protein structure was conserved.
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Affiliation(s)
- Jiří Kessler
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
| | - Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
| | - Josef Kapitán
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
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31
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Kuksenok VY, Shtrykova VV, Filimonov VD, Druganov AG, Bondarev AA, Stankevich KS. The determination of enantiomer composition of 1-((3-chlorophenyl)-(phenyl)methyl) amine and 1-((3-chlorophenyl)(phenyl)-methyl) urea (Galodif) by NMR spectroscopy, chiral HPLC, and polarimetry. Chirality 2018; 30:1135-1143. [PMID: 30075486 DOI: 10.1002/chir.23005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/28/2018] [Accepted: 07/09/2018] [Indexed: 11/06/2022]
Abstract
For the first time, a method for enantiomer resolution of the anticonvulsant Galodif (1-((3-chlorophenyl)(phenyl)methyl) urea) by chiral HPLC was developed, whereas the enantiomeric composition of 1-((3-chlorophenyl)(phenyl)methyl) amine-precursor in Galodif synthesis-cannot be resolved by this method. However, starting 1-((3-chlorophenyl)(phenyl)methyl) amine quantitatively forms diastereomeric N-((3-chlorophenyl)(phenyl)methyl)-1-camphorsulfonamides in reaction with chiral (1R)-(+)- or (1S)-(-)-camphor-10-sulfonyl chlorides. The diastereomeric ratio of obtained camphorsulfonamides can be easily determined by NMR 1 H and 13 C spectroscopy. The DFT calculations of specific rotation of Galodif enantiomers showed good agreement with experimental data. The absolute configuration of enantiomers was proposed for the first time.
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Affiliation(s)
- Vera Yu Kuksenok
- The Kizhner Research Center, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Victoria V Shtrykova
- The Kizhner Research Center, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Victor D Filimonov
- The Kizhner Research Center, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Alexandr G Druganov
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | | | - Ksenia S Stankevich
- The Kizhner Research Center, National Research Tomsk Polytechnic University, Tomsk, Russia
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32
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Polyoxygenated cyathane diterpenoids from the mushroom Cyathus africanus, and their neurotrophic and anti-neuroinflammatory activities. Sci Rep 2018; 8:2175. [PMID: 29391558 PMCID: PMC5794895 DOI: 10.1038/s41598-018-20472-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/19/2018] [Indexed: 11/08/2022] Open
Abstract
In a previous study, we reported ten new polyoxygenated cyathane diterpenoids, neocyathins A-J, and their anti-neuroinflammatory effects from the liquid culture of the medicinal Basidiomycete Cyathus africanus. In the present study, eight new highly polyoxygenated cyathane diterpenoids, named neocyathins K-R (1-8), were isolated from the solid culture of C. africanus cultivated on cooked rice, together with three known congeners (9-11). The structures and the absolute configurations of the new compounds were elucidated through comprehensive NMR and HRESIMS spectroscopic data, electronic circular dichroism (ECD) data, and chemical conversion. Compounds 1 and 2 represent the first reported naturally occurring compounds with 4,9-seco-cyathane carbon skeleton incorporating an unprecedented medium-sized 9/7 fused ring system, while the 3,4-seco-cyathane derivative (3) was isolated from Cyathus species for the first time. All compounds were evaluated for their neurotrophic and anti-neuroinflammatory activity. All the isolates at 1-25 μM displayed differential nerve growth factor (NGF)-induced neurite outgrowth-promoting activity in PC-12 cells, while one of the compounds, allocyathin B2 (11), inhibited NO production in lipopolysaccharide (LPS)-stimulated microglia BV-2 cells. In addition, molecular docking studies showed that compound 11 generated interactions with the inducible nitric oxide synthase (iNOS) protein.
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33
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Nakanishi S, Hara N, Kuroda N, Tajima N, Fujiki M, Imai Y. Solvent-sensitive signs and magnitudes of circularly polarised luminescence and circular dichroism spectra: probing two phenanthrenes as emitters endowed with BINOL derivatives. Org Biomol Chem 2018; 16:1093-1100. [DOI: 10.1039/c7ob02308a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A C2-symmeric binaphthyl framework bearing phenanthrene as the emitter exhibited circularly polarised luminescence (CPL) in dilute solutions.
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Affiliation(s)
- Shoma Nakanishi
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Kindai University
- Higashi-Osaka
- Japan
| | - Nobuyuki Hara
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Kindai University
- Higashi-Osaka
- Japan
| | - Natsuki Kuroda
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Kindai University
- Higashi-Osaka
- Japan
| | - Nobuo Tajima
- Computational Materials Science Center
- National Institute for Materials Science 1-2-1 Sengen
- Tsukuba
- Japan
| | - Michiya Fujiki
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Ikoma
- Japan
| | - Yoshitane Imai
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Kindai University
- Higashi-Osaka
- Japan
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34
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Giovannini T, Del Frate G, Lafiosca P, Cappelli C. Effective computational route towards vibrational optical activity spectra of chiral molecules in aqueous solution. Phys Chem Chem Phys 2018; 20:9181-9197. [DOI: 10.1039/c8cp00487k] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A polarizable QM/MM approach to accurately compute the Vibrational Optical Activity (VOA) spectra of chiral systems is proposed and applied to aqueous solutions of (l)-methyl lactate and (S)-glycidol.
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35
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Gatto P, Lipparini F, Stamm B. Computation of forces arising from the polarizable continuum model within the domain-decomposition paradigm. J Chem Phys 2017; 147:224108. [DOI: 10.1063/1.5008329] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Paolo Gatto
- Mathematics Division, Center for Computational Engineering Science, RWTH Aachen University, Aachen, Germany
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Benjamin Stamm
- Mathematics Division, Center for Computational Engineering Science, RWTH Aachen University, Aachen, Germany
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36
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Górecki M, Capozzi MAM, Albano G, Cardellicchio C, Di Bari L, Pescitelli G. Stereochemical analysis of β-keto sulfoxides by circular dichroism. Chirality 2017; 30:29-42. [DOI: 10.1002/chir.22773] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/15/2017] [Accepted: 09/15/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Marcin Górecki
- Dipartimento di Chimica e Chimica Industriale; Università di Pisa; Pisa Italy
- Institute of Organic Chemistry; Polish Academy of Sciences; Warsaw Poland
| | | | - Gianluigi Albano
- Dipartimento di Chimica e Chimica Industriale; Università di Pisa; Pisa Italy
| | | | - Lorenzo Di Bari
- Dipartimento di Chimica e Chimica Industriale; Università di Pisa; Pisa Italy
| | - Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale; Università di Pisa; Pisa Italy
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37
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Lahiri P, Wiberg KB, Vaccaro PH. Dispersive Optical Activity of (R)-Methylene Norbornene: Intrinsic Response and Solvation Effects. J Phys Chem A 2017; 121:8251-8266. [DOI: 10.1021/acs.jpca.7b08193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Priyanka Lahiri
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Kenneth B. Wiberg
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Patrick H. Vaccaro
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
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38
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Raghavan V, Polavarapu PL. Specific optical rotation is a versatile tool for the identification of critical micelle concentration and micellar growth of tartaric acid-based diastereomeric amphiphiles. Chirality 2017; 29:836-846. [PMID: 28991388 DOI: 10.1002/chir.22767] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/14/2017] [Accepted: 08/29/2017] [Indexed: 11/09/2022]
Abstract
Four novel tartaric acid-based diastereomeric chiral amphiphiles, two being enantiomers of the other two, have been synthesized and investigated using chiroptical spectroscopic methods, along with tensiometry and dynamic light scattering experiments. We found that an inflection point in specific optical rotation (SOR) values at ~0.32 mM corresponds to the critical micelle concentration (CMC). The increase in magnitude of SOR values beyond CMC corresponds to the growth of aggregates. For enantiomers, oppositely signed SOR values were observed, ruling out the possibility for the presence of aggregation size mediated artefacts. SOR values did not exhibit concentration dependence for a chiral tartaric acid based non-aggregating analogue further establishing the absence of artefacts or anomalous interaction of tartaric acid based head group with solvent. Electronic circular dichroism spectra showed no significant changes in band positions or intensities with concentration. Due to the requirement for higher concentrations (~200 mM) needed to obtain vibrational circular dichroism spectra, these measurements are not found to be useful for studying concentration dependent properties of chiral amphiphiles.
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Affiliation(s)
- Vijay Raghavan
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
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39
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Pescitelli G, Bruhn T. Comment on “Cocaine Hydrochloride Structure in Solution Revealed by Three Chiroptical Methods”. Chemphyschem 2017; 18:2549-2551. [DOI: 10.1002/cphc.201700765] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale; Università di Pisa; Via G. Moruzzi 13 56124 Pisa Italy
| | - Torsten Bruhn
- German Federal Institute for Risk Assessment; Department Chemicals and Product Safety; Max-Dohrn-Str. 8-10 10589 Berlin Germany
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40
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Górecki M, Groszek G, Frelek J. Chirality sensing of bioactive compounds with amino alcohol unit via circular dichroism. Chirality 2017; 29:589-598. [PMID: 28771833 DOI: 10.1002/chir.22736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/24/2017] [Accepted: 06/26/2017] [Indexed: 12/31/2022]
Abstract
The aim of the present work was to test various chiroptical techniques, including in particular the in situ dirhodium methodology, to assign the absolute configuration of 1,2- and 1,3-amino alcohols. As models, we selected mainly compounds that have both an additional strongly absorbing and interfering chromophoric system and application in medicinal chemistry. Determination of the absolute configuration (AC) of the tested molecules such as cinchona alkaloids, Tamiflu, and others was carried out using a combination of electronic and vibrational circular dichroism (ECD, VCD) spectroscopy. It has been demonstrated that both 1,2- and 1,3-aminol moieties are subject to the same sector rule correlating stereostructure of formed Rh2 -complex with chiroptical properties, and that the changes in the position of the stereogenic center do not affect its proper use.
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Affiliation(s)
- Marcin Górecki
- Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Grażyna Groszek
- Faculty of Chemistry, Rzeszów University of Technology, Rzeszów, Poland
| | - Jadwiga Frelek
- Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
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41
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Bose S, Ghosh D. An interaction energy driven biased sampling technique: A faster route to ionization spectra in condensed phase. J Comput Chem 2017; 38:2248-2257. [DOI: 10.1002/jcc.24875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/06/2017] [Accepted: 06/19/2017] [Indexed: 01/09/2023]
Affiliation(s)
- Samik Bose
- Physical and Materials Chemistry Division; CSIR-National Chemical Laboratory; Pune 411008 India
| | - Debashree Ghosh
- Department of Physical Chemistry; Indian Association for the Cultivation of Science; Kolkata 700032 India
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42
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Haghdani S, Hoff BH, Koch H, Åstrand PO. Solvent Effects on Optical Rotation: On the Balance between Hydrogen Bonding and Shifts in Dihedral Angles. J Phys Chem A 2017; 121:4765-4777. [DOI: 10.1021/acs.jpca.6b12149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shokouh Haghdani
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Bård Helge Hoff
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Henrik Koch
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Per-Olof Åstrand
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
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43
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Srebro-Hooper M, Autschbach J. Calculating Natural Optical Activity of Molecules from First Principles. Annu Rev Phys Chem 2017; 68:399-420. [DOI: 10.1146/annurev-physchem-052516-044827] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260
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44
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Ma W, Xu L, de Moura AF, Wu X, Kuang H, Xu C, Kotov NA. Chiral Inorganic Nanostructures. Chem Rev 2017; 117:8041-8093. [DOI: 10.1021/acs.chemrev.6b00755] [Citation(s) in RCA: 485] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | - André F. de Moura
- Department
of Chemistry, Federal University of São Carlos, CP 676, CEP 13.565-905, São Carlos, SP, Brazil
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45
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Padula D, Cerezo J, Pescitelli G, Santoro F. The shape of the electronic circular dichroism spectrum of (2,6-dimethylphenyl)(phenyl)methanol: interplay between conformational equilibria and vibronic effects. Phys Chem Chem Phys 2017; 19:32349-32360. [DOI: 10.1039/c7cp06369e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Analysis of the interplay between conformational equilibria, solvent effects and vibronic contributions in the ECD spectra.
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Affiliation(s)
- Daniele Padula
- Department of Chemistry
- University of Liverpool
- Liverpool L69 7ZD
- UK
| | - Javier Cerezo
- Departamento de Química Física
- Universidad de Murcia
- 30100 Murcia
- Spain
| | - Gennaro Pescitelli
- Università di Pisa
- Dipartimento di Chimica e Chimica Industriale
- I-56124 Pisa
- Italy
| | - Fabrizio Santoro
- Consiglio Nazionale delle Ricerche – CNR
- Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR)
- Pisa
- Italy
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46
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Kononov LO, Fedina KG, Orlova AV, Kondakov NN, Abronina PI, Podvalnyy NM, Chizhov AO. Bimodal concentration-dependent reactivity pattern of a glycosyl donor: Is the solution structure involved? Carbohydr Res 2016; 437:28-35. [PMID: 27883907 DOI: 10.1016/j.carres.2016.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 11/30/2022]
Abstract
Changes in concentration (0.001-0.1 M) of an arabinofuranosyl donor (1) have been shown to modulate the temperature T at which activation of 1 occurs (from -23 °C to +7 °C), the reaction time (from 1.5 h to 3 days) and the yield of the disaccharide formed (from 14% to 82%). At concentrations exceeding 0.01 M, these parameters, as well as the specific optical rotation of the solution of 1, virtually do not depend on concentration suggesting formation of reacting species (supramers) of glycosyl donor with similar structures, hence reactivities, but considerably different from those formed in more dilute solutions. The found critical concentration (0.01 M) separates two concentration ranges of reaction solutions corresponding to two types of solution structure that are featured by the presence of fundamentally different supramers of glycosyl donor, which have distinct chemical properties. These results allow a fresh look at the problems of reactivity of chemical compounds and selectivity of the reactions in which they participate.
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Affiliation(s)
- Leonid O Kononov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation.
| | - Ksenia G Fedina
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Anna V Orlova
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Nikolay N Kondakov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Polina I Abronina
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Nikita M Podvalnyy
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Alexander O Chizhov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
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47
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Haghdani S, Hoff BH, Koch H, Åstrand PO. Optical Rotation Calculations for Fluorinated Alcohols, Amines, Amides, and Esters. J Phys Chem A 2016; 120:7973-7986. [DOI: 10.1021/acs.jpca.6b08899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shokouh Haghdani
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Bård Helge Hoff
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Henrik Koch
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Per-Olof Åstrand
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
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48
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Haghdani S, Gautun OR, Koch H, Åstrand PO. Optical Rotation Calculations for a Set of Pyrrole Compounds. J Phys Chem A 2016; 120:7351-60. [PMID: 27571252 DOI: 10.1021/acs.jpca.6b07004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Optical rotation of 14 molecules containing the pyrrole group is calculated by employing both time-dependent density functional theory (TDDFT) with the CAM-B3LYP functional and the second-order approximate coupled-cluster singles and doubles (CC2) method. All optical rotations have been provided using the aug-cc-pVDZ basis set at λ = 589 nm. The two methods predict similar results for both sign and magnitude for the optical rotation of all molecules. The obtained signs are consistent with experiments as well, although several conformers for four molecules needed to be studied to reproduce the experimental sign. We have also calculated excitation energies and rotatory strengths for the six lowest lying electronic transitions for several conformers of the two smallest molecules and found that each rotatory strength has various contributions for each conformer which can cause different optical rotations for different conformers of a molecule. Our results illustrate that both methods are able to reproduce the experimental optical rotations, and that the CAM-B3LYP functional, the least computationally expensive method used here, is an applicable and reliable method to predict the optical rotation for these molecules in line with previous studies.
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Affiliation(s)
- Shokouh Haghdani
- Department of Chemistry, Norwegian University of Science and Technology (NTNU) , N-7491 Trondheim, Norway
| | - Odd R Gautun
- Department of Chemistry, Norwegian University of Science and Technology (NTNU) , N-7491 Trondheim, Norway
| | - Henrik Koch
- Department of Chemistry, Norwegian University of Science and Technology (NTNU) , N-7491 Trondheim, Norway
| | - Per-Olof Åstrand
- Department of Chemistry, Norwegian University of Science and Technology (NTNU) , N-7491 Trondheim, Norway
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49
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Bünnemann K, Merten C. Solvation of N,C-Protected Valine: Interactions with DMSO and a Chiral Solvating Agent. J Phys Chem B 2016; 120:9434-42. [DOI: 10.1021/acs.jpcb.6b05897] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Christian Merten
- Organische
Chemie 2, Ruhr Universität Bochum, 44801 Bochum, Germany
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50
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Padula D, Di Bari L, Pescitelli G. The “Case of Two Compounds with Similar Configuration but Nearly Mirror Image CD Spectra” Refuted. Reassignment of the Absolute Configuration of N-Formyl-3′,4′-dihydrospiro[indan-1,2′(1′H)-pyridine]. J Org Chem 2016; 81:7725-32. [DOI: 10.1021/acs.joc.6b01416] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniele Padula
- Dipartimento
di Chimica e Chimica Industriale, Università di Pisa, via Moruzzi
13, 56124 Pisa, Italy
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, U.K
| | - Lorenzo Di Bari
- Dipartimento
di Chimica e Chimica Industriale, Università di Pisa, via Moruzzi
13, 56124 Pisa, Italy
| | - Gennaro Pescitelli
- Dipartimento
di Chimica e Chimica Industriale, Università di Pisa, via Moruzzi
13, 56124 Pisa, Italy
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