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Zhu J, Tuo DH, Wang XD, Ao YF, Wang QQ, Wang DX. Anion-Carbonyl Interactions. Org Lett 2024; 26:5984-5988. [PMID: 38975861 DOI: 10.1021/acs.orglett.4c02060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Presented herein is the exploration of a novel non-covalent anion-carbonyl (X-···C═O) interaction using aromatic imides as receptors and halides as lone pair donors. Combined theoretical calculations and experimental methods including 13C NMR, IR, and crystallographic analyses were performed to provide the physical origin and experimental evidence of anion-carbonyl interactions. The EDA analysis (energy decomposition analysis) based on DFT calculation indicates that electrostatic terms are the dominant contributions for the binding energy while electron delocalization also significantly contributes alongside the electrostatic attraction. Orbital interaction (n → π*) involving the delocalization of halide lone pairs on the carbonyl antibonding orbitals was visualized with NBO (Natural Bond Orbital) analysis. 13C NMR and IR spectra demonstrated upfield chemical shifts and red-shift frequency of hosts upon the addition of halides, reflecting the effect of orbital overlap between the halide lone pairs and π* of carbonyl (n → π* contribution). The anion-carbonyl interactions were directly revealed by X-ray structural analysis of anion and benzene triimide complexes.
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Affiliation(s)
- Jun Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - De-Hui Tuo
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xu-Dong Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Fei Ao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qi-Qiang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - De-Xian Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Wang XD, Zhu J, Wang DX. Intermolecular n→π* Interactions in Supramolecular Chemistry and Catalysis. Chempluschem 2023; 88:e202300288. [PMID: 37609956 DOI: 10.1002/cplu.202300288] [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: 06/14/2023] [Revised: 08/19/2023] [Accepted: 08/21/2023] [Indexed: 08/24/2023]
Abstract
The n→π* interactions describing attractive force between lone pairs (lps) of nucleophile and carbonyl or polarized unsaturated bonds have recently attracted growing attentions in various disciplines. So far, such non-covalent driving force are mainly concentrated to intramolecular systems. Intermolecular n→π* interactions in principle could produce fascinated supramolecular systems or facilitate organic reactions, however, they remain largely underexplored due to the very weak energy of individual interaction. This review attempts to give an overview of the challenging intermolecular n→π* interactions, much efforts emphasize the supramolecular systems, catalytic processes and spectroscopic measurements.
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Affiliation(s)
- Xu-Dong Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jun Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - De-Xian Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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3
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Adhav V, Saikrishnan K. The Realm of Unconventional Noncovalent Interactions in Proteins: Their Significance in Structure and Function. ACS OMEGA 2023; 8:22268-22284. [PMID: 37396257 PMCID: PMC10308531 DOI: 10.1021/acsomega.3c00205] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 05/22/2023] [Indexed: 07/04/2023]
Abstract
Proteins and their assemblies are fundamental for living cells to function. Their complex three-dimensional architecture and its stability are attributed to the combined effect of various noncovalent interactions. It is critical to scrutinize these noncovalent interactions to understand their role in the energy landscape in folding, catalysis, and molecular recognition. This Review presents a comprehensive summary of unconventional noncovalent interactions, beyond conventional hydrogen bonds and hydrophobic interactions, which have gained prominence over the past decade. The noncovalent interactions discussed include low-barrier hydrogen bonds, C5 hydrogen bonds, C-H···π interactions, sulfur-mediated hydrogen bonds, n → π* interactions, London dispersion interactions, halogen bonds, chalcogen bonds, and tetrel bonds. This Review focuses on their chemical nature, interaction strength, and geometrical parameters obtained from X-ray crystallography, spectroscopy, bioinformatics, and computational chemistry. Also highlighted are their occurrence in proteins or their complexes and recent advances made toward understanding their role in biomolecular structure and function. Probing the chemical diversity of these interactions, we determined that the variable frequency of occurrence in proteins and the ability to synergize with one another are important not only for ab initio structure prediction but also to design proteins with new functionalities. A better understanding of these interactions will promote their utilization in designing and engineering ligands with potential therapeutic value.
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Affiliation(s)
- Vishal
Annasaheb Adhav
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Kayarat Saikrishnan
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
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4
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Panwaria P, Das A. Effect of Substituents on the Intramolecular n→π* Interaction in 3-[2-(Dimethylamino) phenyl] propanal: A Computational Study. J Phys Chem A 2023; 127:3339-3346. [PMID: 37036493 DOI: 10.1021/acs.jpca.2c08641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
n→π* non-covalent interaction (NCI) and hydrogen bond have similarity in terms of delocalization of the electron density between the two orbitals involved in the interaction. Hydrogen bond (X-H···Y) involves delocalization of the lone pair electrons (n) on the Y atom into the σ* orbital of the X-H bond. In contrast, the n→π* interaction deals with delocalizing the lone pair electrons (n) on the N, O, or S atom into the π* orbital of a C═O group or aromatic ring. Herein, we have shown a resemblance of this weak n→π* interaction with the relatively stronger hydrogen bond in terms of folding the side chains in flexible molecules. This work reports the study of folding of the flexible side-chain in 3-[2-(dimethylamino) phenyl] propanal (DMAPhP) through a N···C═O n→π* interaction using various computational approaches such as NBO, QTAIM, and NCI analyses. The folding of the molecule by the n→π* interaction observed in this study is found to be similar to that present in the secondary structures of peptides or proteins through hydrogen bonding interactions. Interestingly, the stabilization of the global minimum conformer of DMAPhP by the n→π* interaction demonstrates the importance of this NCI in providing conformational preferences in molecular systems. Another important finding of this study is that the theoretical redshift obtained in the C═O stretching frequency of the most stable conformer of the DMAPhP is contributed mostly by the n→π* interaction as the C═O group is not involved in hyperconjugation with any neighboring heteroatom, which is a common phenomenon in any ester or amide. We have also demonstrated here that the strength of the intramolecular n→π* interaction can be modulated by varying the electronic substituents at the para position of the donor group involved in the interaction.
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Affiliation(s)
- Prakash Panwaria
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - Aloke Das
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
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5
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Zhu J, Wang XD, Ao YF, Wang QQ, Wang DX. Intermolecular n→π* Interactions Based on a Tailored Multicarbonyl-Containing Macrocycle. Chemistry 2023; 29:e202203485. [PMID: 36445795 DOI: 10.1002/chem.202203485] [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: 11/09/2022] [Revised: 11/24/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022]
Abstract
Towards unexplored intermolecular n→π* interactions, presented herein are the synthesis, structure, self-assembly and function of a multicarbonyl-containing macrocycle calix[2]arene[2]barbiturate 1. X-ray single crystal diffraction reveals the presence of Cl⋅⋅⋅C=O interactions in CH2 Cl2 ⊂1 host-guest complex and multiple intermolecular C=O⋅⋅⋅C=O interactions between molecules 1 in crystalline state. The intermolecular C=O⋅⋅⋅C=O interactions as attractive driving force led to unprecedented self-assembly of nanotube with diameter around 1.4 nm and inner surface engineered by aromatic rings. SEM and TEM images of the self-assembly of 1 demonstrated temperature-dependent morphologies which allows the observation of spheres at 25 °C and rods at 0 °C, respectively. XRD analysis indicated consistent hexagonal patterns in the self-assembly and single crystal lattice, indicating the nanotubes driven by C=O⋅⋅⋅C=O interactions constitute the basic structural architectures of both aggregates. The nanoscopic tubes (pores) formed in the rodlike single crystal engendering the separation of moving dyes were preliminarily investigated by a single-crystal chromatography and crystal-packed column chromatography.
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Affiliation(s)
- Jun Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China)
| | - Xu-Dong Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yu-Fei Ao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China)
| | - Qi-Qiang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China)
| | - De-Xian Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China)
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6
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Lu Y, Sun M, Xi N. Effects of fluorine bonding and nonbonding interactions on 19F chemical shifts. RSC Adv 2022; 12:32082-32096. [PMID: 36415555 PMCID: PMC9644289 DOI: 10.1039/d2ra06660b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 11/03/2023] Open
Abstract
19F-NMR signals are sensitive to local electrostatic fields and are useful in probing protein structures and dynamics. Here, we used chemically identical ortho-F nuclei in N-phenyl γ-lactams to investigate the relationship between 19F NMR chemical shifts and local environments. By varying the structures at the C5- and C7-substituents, we demonstrated that 19F shifts and Hammett coefficients in Hammett plots follow typical relationships in bonding interactions, while manifesting reverse correlations in nonbonding contacts. Quantum mechanics calculations revealed that one of the ortho-F nuclei engages in n → π* orbital delocalization between F lone pair electrons (n) and a C[double bond, length as m-dash]O/Ar[double bond, length as m-dash]N antibonding orbital (π*), and the other ortho-F nucleus exhibits n ↔ σ orbital polarization between the n electrons and the C-H σ bonding orbital. As 19F NMR spectroscopy find increasing use in molecular sensors and biological sciences, our findings are valuable for designing sensitive probes, elucidating molecular structures, and quantifying analytes.
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Affiliation(s)
- Yang Lu
- Institute of Drug Discovery Technology, Ningbo University Ningbo Zhejiang 315211 P. R. China
| | - Mingming Sun
- Department of Chemistry, Nanchang University 999 Xuefu Avenue Nanchang 330031 P. R. China
| | - Ning Xi
- Institute of Drug Discovery Technology, Ningbo University Ningbo Zhejiang 315211 P. R. China
- School of Medicine, Ningbo University Ningbo Zhejiang 315211 P. R. China
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7
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Purushotham M, Paul B, Govindachar DM, Singh AK, Periyasamy G, Peter SC. Ortho-halogen effects: n→π* interactions, halogen bonding, and deciphering chiral attributes in N-aryl glycine peptoid foldamers. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Buljan A, Roje M. Application of Green Chiral Chromatography in Enantioseparation of Newly Synthesized Racemic Marinoepoxides. Mar Drugs 2022; 20:md20080530. [PMID: 36005533 PMCID: PMC9409916 DOI: 10.3390/md20080530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/13/2022] [Accepted: 08/14/2022] [Indexed: 11/16/2022] Open
Abstract
Enantioseparation of the newly synthesized series of novel quinoline-2(1H)-one epoxide structures rac-6a-c and rac-8a-c, named marinoepoxides, is described. Marinoepoxide rac-6a, the key intermediate in the total synthesis of natural products marinoaziridines A and B, as well as their structural analogues, was synthesized by addition of the achiral ylide generated in situ from the sulfonium salt 5 or 7, to the carbon-oxygen double bond of the corresponding quinoline-2(1H)-one-4-carbaldehyde 4a-c in good yield. Separation of enantiomers of (±)-2,3,3-trisubstituted marinoepoxides rac-6a-c and (±)-trans-2,3-disubstituted marinoepoxides rac-8a-c was studied using two immobilized polysaccharide type chiral stationary phases (CSPs); tris-(3,5-dichlorophenylcarbamoyl)cellulose stationary phase (CHIRAL ART Cellulose-SC) and tris-(3,5-dimethylphenylcarbamoyl)amylose stationary phase (CHIRAL ART Amylose-SA). Enantioseparation conditions were explored by high-performance liquid chromatography (HPLC) using dimethyl carbonate/alcohol mixtures and n-hexane/ethanol (80/20, v/v) as mobile phase, and by supercritical fluid chromatography (SFC) using CO2/alcohol mixtures as mobile phase. In all examined racemates, enantioseparation was successfully achieved, but its efficiency largely depended on the structure of chiral selector and type/composition of the mobile phase.
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Affiliation(s)
| | - Marin Roje
- Correspondence: ; Tel.: +385-1-45-71-283
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9
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Zondlo NJ. Solvation stabilizes intercarbonyl n→π* interactions and polyproline II helix. Phys Chem Chem Phys 2022; 24:13571-13586. [PMID: 35635541 DOI: 10.1039/d2cp00857b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
n→π* interactions between consecutive carbonyls stabilize the α-helix and polyproline II helix (PPII) conformations in proteins. n→π* interactions have been suggested to provide significant conformational biases to the disordered states of proteins. To understand the roles of solvation on the strength of n→π* interactions, computational investigations were conducted on a model n→π* interaction, the twisted-parallel-offset formaldehyde dimer, as a function of explicit solvation of the donor and acceptor carbonyls, using water and HF. In addition, the effects of urea, thiourea, guanidinium, and monovalent cations on n→π* interaction strength were examined. Solvation of the acceptor carbonyl significantly strengthens the n→π* interaction, while solvation of the donor carbonyl only modestly weakens the n→π* interaction. The n→π* interaction strength was maximized with two solvent molecules on the acceptor carbonyl. Urea stabilized the n→π* interaction via simultaneous engagement of both oxygen lone pairs on the acceptor carbonyl. Solvent effects were further investigated in the model peptides Ac-Pro-NMe2, Ac-Ala-NMe2, and Ac-Pro2-NMe2. Solvent effects in peptides were similar to those in the formaldehyde dimer, with solvation of the acceptor carbonyl increasing n→π* interaction strength and resulting in more compact conformations, in both the proline endo and exo ring puckers, as well as a reduction in the energy difference between these ring puckers. Carbonyl solvation leads to an energetic preference for PPII over both the α-helix and β/extended conformations, consistent with experimental data that protic solvents and protein denaturants both promote PPII. Solvation of the acceptor carbonyl weakens the intraresidue C5 hydrogen bond that stabilizes the β conformation.
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Affiliation(s)
- Neal J Zondlo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
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10
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Zephyr J, Nageswara Rao D, Vo SV, Henes M, Kosovrasti K, Matthew AN, Hedger AK, Timm J, Chan ET, Ali A, Kurt Yilmaz N, Schiffer CA. Deciphering the Molecular Mechanism of HCV Protease Inhibitor Fluorination as a General Approach to Avoid Drug Resistance. J Mol Biol 2022; 434:167503. [PMID: 35183560 PMCID: PMC9189784 DOI: 10.1016/j.jmb.2022.167503] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 02/07/2023]
Abstract
Third generation Hepatitis C virus (HCV) NS3/4A protease inhibitors (PIs), glecaprevir and voxilaprevir, are highly effective across genotypes and against many resistant variants. Unlike earlier PIs, these compounds have fluorine substitutions on the P2-P4 macrocycle and P1 moieties. Fluorination has long been used in medicinal chemistry as a strategy to improve physicochemical properties and potency. However, the molecular basis by which fluorination improves potency and resistance profile of HCV NS3/4A PIs is not well understood. To systematically analyze the contribution of fluorine substitutions to inhibitor potency and resistance profile, we used a multi-disciplinary approach involving inhibitor design and synthesis, enzyme inhibition assays, co-crystallography, and structural analysis. A panel of inhibitors in matched pairs were designed with and without P4 cap fluorination, tested against WT protease and the D168A resistant variant, and a total of 22 high-resolution co-crystal structures were determined. While fluorination did not significantly improve potency against the WT protease, PIs with fluorinated P4 caps retained much better potency against the D168A protease variant. Detailed analysis of the co-crystal structures revealed that PIs with fluorinated P4 caps can sample alternate binding conformations that enable adapting to structural changes induced by the D168A substitution. Our results elucidate molecular mechanisms of fluorine-specific inhibitor interactions that can be leveraged in avoiding drug resistance.
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11
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Arcoria PJ, Ware RI, Makwana SV, Troya D, Etzkorn FA. Conformational Analysis of Fluoro-, Chloro-, and Proteo-Alkene Gly-Pro and Pro-Pro Isosteres to Mimic Collagen. J Phys Chem B 2021; 126:217-228. [PMID: 34968406 DOI: 10.1021/acs.jpcb.1c09180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Collagen is the most abundant human protein, with the canonical sequence (Gly-Pro-Hyp)n in its triple helix region. Cis-trans isomerization of the Xaa-Pro amide has made two of these amide bonds the target of alkene replacement: the Gly-Pro and the Pro-Hyp positions. The conformations of Gly-Pro and Pro-Pro (as a Pro-Hyp model) fluoro-, chloro-, and proteo-alkene mimic models were investigated computationally to determine whether these alkenes can stabilize the polyproline type II (PPII) conformation of collagen. Second-order Møller-Plesset (MP2) calculations with various basis sets were used to perform the conformational analyses and locate stationary points. The calculation results predict that fluoro- and chloro-alkene mimics of Gly-Pro and Pro-Pro can participate in n→π* donation to stabilize PPII conformations, yet they are poor n→π* acceptors, shifting the global minima away from PPII conformations. For the proteo-alkene mimics, the lack of significant n→π* interactions and unstable PPII-like geometries explains their known destabilization of the triple helix in collagen-like peptides.
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Affiliation(s)
- Paul J Arcoria
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Rachel I Ware
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Sunny V Makwana
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Diego Troya
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Felicia A Etzkorn
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
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12
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Sandrone G, Cukier CD, Zrubek K, Marchini M, Vergani B, Caprini G, Fossati G, Steinkühler C, Stevenazzi A. Role of Fluorination in the Histone Deacetylase 6 (HDAC6) Selectivity of Benzohydroxamate-Based Inhibitors. ACS Med Chem Lett 2021; 12:1810-1817. [PMID: 34795871 DOI: 10.1021/acsmedchemlett.1c00425] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/06/2021] [Indexed: 12/23/2022] Open
Abstract
Nonselective histone deacetylase (HDAC) inhibitors show dose-limiting side effects due to the inhibition of multiple, essential HDAC subtypes that can be limited or prevented by restricting their selectivity. We herein report the crystal structures of zebrafish HDAC6 catalytic domain 2 (zHDAC6-CD2) in complex with the selective HDAC6 inhibitors ITF3756 and ITF3985 and shed light on the role of fluorination in the selectivity of benzohydroxamate-based structures over class I isoforms. The reason for the enhancement in the selectivity of the benzohydroxamate-based compounds is the presence of specific interactions between the fluorinated linker and the key residues Gly582, Ser531, and His614 of zHDAC6, which are hindered in class I HDAC isoforms by the presence of an Aspartate that replaces Ser531. These results can be used in the design and development of novel, highly selective HDAC6 inhibitors.
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Affiliation(s)
- Giovanni Sandrone
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Cyprian D. Cukier
- Department of Biochemistry, Selvita S.A., ul. Bobrzyńskiego 14, Kraków30-348, Poland
| | - Karol Zrubek
- Department of Biochemistry, Selvita S.A., ul. Bobrzyńskiego 14, Kraków30-348, Poland
| | - Mattia Marchini
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Barbara Vergani
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Gianluca Caprini
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Gianluca Fossati
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Christian Steinkühler
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
| | - Andrea Stevenazzi
- Research & Development, Italfarmaco Group, Via dei Lavoratori 54, Cinisello Balsamo, Milan I-20092, Italy
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13
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Morioka K, Wakamatsu K, Tsurumaki E, Toyota S. Synthesis, Structures, and Properties of Helically Fused Anthraquinones with Unusually Close Carbonyl-Carbonyl Contacts. Chemistry 2021; 28:e202103694. [PMID: 34762325 DOI: 10.1002/chem.202103694] [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: 10/12/2021] [Indexed: 11/08/2022]
Abstract
Electron-deficient aromatic ketones consisting of three fused anthraquinone units were synthesized by oxidation of the corresponding fused anthracenes. X-ray analysis revealed that these compounds had nonplanar helical structures with unusual contacts, C=O⋅⋅⋅C=O 2.467 Å, between the inner carbonyl groups. The role of n⋅⋅⋅π* interactions in the short contacts was evaluated using a noncovalent interaction plot and natural bond orbital analysis. The dynamic process involving helical inversion was observed by the variable temperature 1 H NMR measurement of a derivative with 2,4,6-trimethylphenyl groups, and the barrier was estimated to be 77 kJ mol-1 . DFT calculations indicated that the helical inversion proceeded via a multistep mechanism. The characteristic spectroscopic and electrochemical data due to the electron-deficient anthraquinone units and the sterically congested carbonyl groups are discussed with the aid of DFT calculations.
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Affiliation(s)
- Kozue Morioka
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Kan Wakamatsu
- Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama, 700-0005, Japan
| | - Eiji Tsurumaki
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Shinji Toyota
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
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14
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Enabling three-dimensional porous architectures via carbonyl functionalization and molecular-specific organic-SERS platforms. Nat Commun 2021; 12:6119. [PMID: 34675208 PMCID: PMC8531383 DOI: 10.1038/s41467-021-26385-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/28/2021] [Indexed: 11/21/2022] Open
Abstract
Molecular engineering via functionalization has been a great tool to tune noncovalent intermolecular interactions. Herein, we demonstrate three-dimensional highly crystalline nanostructured D(C7CO)-BTBT films via carbonyl-functionalization of a fused thienoacene π-system, and strong Raman signal enhancements in Surface-Enhanced Raman Spectroscopy (SERS) are realized. The small molecule could be prepared on the gram scale with a facile synthesis-purification. In the engineered films, polar functionalization induces favorable out-of-plane crystal growth via zigzag motif of dipolar C = O···C = O interactions and hydrogen bonds, and strengthens π-interactions. A unique two-stage film growth behavior is identified with an edge-on-to-face-on molecular orientation transition driven by hydrophobicity. The analysis of the electronic structures and the ratio of the anti-Stokes/Stokes SERS signals suggests that the π-extended/stabilized LUMOs with varied crystalline face-on orientations provide the key properties in the chemical enhancement mechanism. A molecule-specific Raman signal enhancement is also demonstrated on a high-LUMO organic platform. Our results demonstrate a promising guidance towards realizing low-cost SERS-active semiconducting materials, increasing structural versatility of organic-SERS platforms, and advancing molecule-specific sensing via molecular engineering. Nanostructured films of organic semiconductors with low lying LUMO orbitals can enhance Raman signals via a chemical enhancement mechanism but currently the material choice is limited to fluorinated oligothiophenes. Here, the authors investigate the growth of a porous thienoacene film enabled by carbonyls and demonstrate molecular specific organic-SERS platforms.
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15
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Sahariah B, Sarma BK. Spectroscopic evidence of n → π* interactions involving carbonyl groups. Phys Chem Chem Phys 2021; 22:26669-26681. [PMID: 33226050 DOI: 10.1039/d0cp03557b] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
n → π* has emerged as an important noncovalent interaction that can affect the conformations of both small- and macromolecules including peptides and proteins. Carbonyl-carbonyl (COCO) n → π* interactions involving CO groups are well studied. Recent studies have shown that the COCO n → π* interactions are the most abundant secondary interactions in proteins with a frequency of 33 interactions per 100 residues and, among the various secondary interactions, n → π* interactions are expected to provide the highest enthalpic contributions to the conformational stability of globular proteins. However, n → π* interactions are relatively weak and provide an average stabilization of about 0.25 kcal mol-1 per interaction in proteins. The strongest n → π* interaction could be as strong as a moderate hydrogen bond. Therefore, it is challenging to detect and quantify these weak interactions, especially in solution in the presence of perturbation from other intermolecular interactions. Accordingly, spectroscopic investigations that can provide direct evidence of n → π* interaction are limited, and the majority of papers published in this area have relied on X-ray crystallography and/or theoretical calculations to establish the presence of this interaction. The aim of this perspective is to discuss the studies where a spectroscopic signature in support of n → π* interaction was observed. As the "n → π* interaction" is a relatively new terminology, there remains the possibility of there being earlier studies where spectroscopic evidence for n → π* interactions was obtained but it was not discussed in light of the n → π* terminology. We noticed several such studies and, as can be expected, these studies were often overlooked in the discussion of n → π* interactions in the recent literature. In this perspective, we have also discussed these studies and provided computational support for the presence of n → π* interaction.
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Affiliation(s)
- Biswajit Sahariah
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
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16
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Linclau B, Ardá A, Reichardt NC, Sollogoub M, Unione L, Vincent SP, Jiménez-Barbero J. Fluorinated carbohydrates as chemical probes for molecular recognition studies. Current status and perspectives. Chem Soc Rev 2021; 49:3863-3888. [PMID: 32520059 DOI: 10.1039/c9cs00099b] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This review provides an extensive summary of the effects of carbohydrate fluorination with regard to changes in physical, chemical and biological properties with respect to regular saccharides. The specific structural, conformational, stability, reactivity and interaction features of fluorinated sugars are described, as well as their applications as probes and in chemical biology.
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Affiliation(s)
- Bruno Linclau
- School of Chemistry, University of Southampton, Highfield, Southampton SO171BJ, UK
| | - Ana Ardá
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain.
| | | | - Matthieu Sollogoub
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232, 4 place Jussieu, 75005 Paris, France
| | - Luca Unione
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Stéphane P Vincent
- Department of Chemistry, Laboratory of Bio-organic Chemistry, University of Namur (UNamur), B-5000 Namur, Belgium
| | - Jesús Jiménez-Barbero
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain. and Ikerbasque, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain and Department of Organic Chemistry II, Faculty of Science and Technology, UPV/EHU, 48940 Leioa, Spain
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17
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Daicho K, Ozawa Y, Sugimoto K, Abe M. A pyrazine‐bridged trimer of oxo‐centered triruthenium–carbonyl clusters and the supramolecular assembly built from multiple noncovalent contacts. J CHIN CHEM SOC-TAIP 2020. [DOI: 10.1002/jccs.202000491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Keita Daicho
- Graduate School of Material Science University of Hyogo Ako‐gun Japan
| | - Yoshiki Ozawa
- Graduate School of Material Science University of Hyogo Ako‐gun Japan
| | - Kunihisa Sugimoto
- Diffraction & Scattering Division, Japan Synchrotron Radiation Research Institute (JASRI) Sayo‐gun Japan
| | - Masaaki Abe
- Graduate School of Material Science University of Hyogo Ako‐gun Japan
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18
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Dittrich J, Kather M, Holzberger A, Pich A, Gohlke H. Cumulative Submillisecond All-Atom Simulations of the Temperature-Induced Coil-to-Globule Transition of Poly(N-vinylcaprolactam) in Aqueous Solution. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Jonas Dittrich
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Michael Kather
- DWI-Leibniz-Institute for Interactive Materials, RWTH Aachen University, 52056 Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Anna Holzberger
- DWI-Leibniz-Institute for Interactive Materials, RWTH Aachen University, 52056 Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Andrij Pich
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, 52425 Jülich, Germany
- DWI-Leibniz-Institute for Interactive Materials, RWTH Aachen University, 52056 Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, 52425 Jülich, Germany
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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19
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Kilgore HR, Olsson CR, D’Angelo KA, Movassaghi M, Raines RT. n→π* Interactions Modulate the Disulfide Reduction Potential of Epidithiodiketopiperazines. J Am Chem Soc 2020; 142:15107-15115. [PMID: 32701272 PMCID: PMC7484275 DOI: 10.1021/jacs.0c06477] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Epithiodiketopiperazines (ETPs) are a structurally complex class of fungal natural products with potent anticancer activity. In ETPs, the diketopiperazine ring is spanned by a disulfide bond that is constrained in a high-energy eclipsed conformation. We employed computational, synthetic, and spectroscopic methods to investigate the physicochemical attributes of this atypical disulfide bond. We find that the disulfide bond is stabilized by two n→π* interactions, each with large energies (3-5 kcal/mol). The n→π* interactions in ETPs make disulfide reduction much more difficult, endowing stability in physiological environments in a manner that could impact their biological activity. These data reveal a previously unappreciated means to stabilize a disulfide bond and highlight the utility of the n→π* interaction in molecular design.
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Affiliation(s)
| | | | - Kyan A. D’Angelo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Mohammad Movassaghi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ronald T. Raines
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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20
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Muchowska KB, Pascoe DJ, Borsley S, Smolyar IV, Mati IK, Adam C, Nichol GS, Ling KB, Cockroft SL. Reconciling Electrostatic and n→π* Orbital Contributions in Carbonyl Interactions. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kamila B. Muchowska
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Dominic J. Pascoe
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Stefan Borsley
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Ivan V. Smolyar
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Ioulia K. Mati
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Catherine Adam
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Gary S. Nichol
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Kenneth B. Ling
- Syngenta Jealott's Hill International Research Centre Bracknell Berkshire RG42 6EY UK
| | - Scott L. Cockroft
- EaStCHEM School of Chemistry The University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
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21
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Muchowska KB, Pascoe DJ, Borsley S, Smolyar IV, Mati IK, Adam C, Nichol GS, Ling KB, Cockroft SL. Reconciling Electrostatic and n→π* Orbital Contributions in Carbonyl Interactions. Angew Chem Int Ed Engl 2020; 59:14602-14608. [PMID: 32485046 PMCID: PMC7496118 DOI: 10.1002/anie.202005739] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/29/2020] [Indexed: 12/16/2022]
Abstract
Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n→π* orbital delocalisation. Here these observations are reconciled. A combined experimental and computational approach confirmed the dominance of electrostatic interactions in a new series of synthetic molecular balances, while also highlighting the distance-dependent observation of inductive polarisation manifested by n→π* orbital delocalisation. Computational fiSAPT energy decomposition and natural bonding orbital analyses correlated with experimental data to reveal the contexts in which short-range inductive polarisation augment electrostatic dipolar interactions. Thus, we provide a framework for reconciling the context dependency of the dominance of electrostatic interactions and the occurrence of n→π* orbital delocalisation in C=O⋅⋅⋅C=O interactions.
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Affiliation(s)
- Kamila B. Muchowska
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Dominic J. Pascoe
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Stefan Borsley
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Ivan V. Smolyar
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Ioulia K. Mati
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Catherine Adam
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Gary S. Nichol
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
| | - Kenneth B. Ling
- SyngentaJealott's Hill International Research CentreBracknellBerkshireRG42 6EYUK
| | - Scott L. Cockroft
- EaStCHEM School of ChemistryThe University of EdinburghJoseph Black BuildingDavid Brewster RoadEdinburghEH9 3FJUK
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22
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Kia R, Kalaghchi A. Intra- and intermolecular interactions in a series of chlorido-tricarbonyl-diazabutadienerhenium(I) complexes: structural and theoretical studies. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2020; 76:417-426. [PMID: 32831260 DOI: 10.1107/s2052520620004333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
A series of new chlorido-tricarbonylrhenium(I) complexes bearing alkyl-substituted diazabutadiene (DAB) ligands, namely N,N'-bis(2,4-dimethylbenzene)-1,4-diazabutadiene (L1), N,N'-bis(2,4-dimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L2), N,N'-bis(2,4,6-trimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L3) and N,N'-bis(2,6-diisopropylbenzene)-1,4-diazabutadiene (L4), were synthesized and investigated. The crystal structures have been fully characterized by X-ray diffraction and spectroscopic methods. Density functional theory, natural bond orbital and non-covalent interaction index methods have been used to study the optimized geometry in the gas phase and intra- and intermolecular interactions in the complexes, respectively. The most important studied interactions in these metal carbonyl complexes are n→π*, n→σ* and π→π*. Among complexes 1-4, only 2 shows interesting intermolecular n→π* interactions due to lp(C[triple-bond]O)...π* and lp(Cl)...π* (lp = lone pair) contacts.
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Affiliation(s)
- Reza Kia
- Department of Chemistry, Sharif University of Technology, Tehran, 11155-3516, Iran
| | - Azadeh Kalaghchi
- Department of Chemistry, Sharif University of Technology, Tehran, 11155-3516, Iran
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23
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Sarkar S, Ramanathan N, Sruthi P, Sundararajan K. Computational and experimental evidence of N–H…π and cooperative πN…π∗ interactions in pyrrole…benzene and pyrrole…ethylene heterodimers at low temperatures. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.127983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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24
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Design and evaluation of polar-embedded stationary phases containing triacontyl group for liquid chromatography. J Chromatogr A 2020; 1621:461035. [DOI: 10.1016/j.chroma.2020.461035] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 02/06/2023]
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25
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Structural, Non-Covalent Interaction, and Natural Bond Orbital Studies on Bromido-Tricarbonyl Rhenium(I) Complexes Bearing Alkyl-Substituted 1,4-Diazabutadiene (DAB) Ligands. CRYSTALS 2020. [DOI: 10.3390/cryst10040267] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The synthesis, characterization, structural and computational studies of Re(I) tricarbonyl bromo complexes bearing alkyl-substituted 1,4-diazabutadiene ligands, [Re(CO)3(1,4-DAB)Br], where 1,4-DAB = N,N-bis(2,4-dimethylbenzene)-1,4-diazabutadiene, 2,4-Me2DAB (1); N,N-bis(2,4-dimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene, 2,4-Me2DABMe (2); N,N-bis(2,4,6-trimethylbenzene)-1,4-diazabutadiene, 2,4,6-Me3DAB (3); and N,N-bis(2,6-diisopropylbenzene)-1,4-diazabutadiene, 2,6-ipr2DAB (4) are reported. The complexes were characterized by different spectroscopic methods such as FT-IR, 1H-NMR, 13C-NMR, and elemental analyses and their solid-state structures were confirmed by X-ray diffraction. In each complex, the Re(I) centre shows a distorted octahedral shape with a facial geometry of carbonyl groups. The gas phase geometry of the complexes was identified by density functional theory. Interesting intermolecular n…π* interactions of complexes 1 and 3 were investigated by non-covalent interaction index (NCI), and natural bond orbital (NBO) analyses. The intramolecular n…σ*, σ…π*, π…σ* interactions were also studied in complexes 3 and 4.
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26
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Wang S, Cai SL, Zhang J, Wan XH. Tunable Cis-cisoid Helical Conformation of Poly(3,5-disubstibuted phenylacetylene)s Stabilized by n→π* Interaction. CHINESE JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1007/s10118-020-2376-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Kia R, Taghavi T, Raithby PR. Supramolecular assembly through intermolecular n → π* interactions through a coordinated perrhenate formed via superoxidation of Re( i) to Re( vii) in the formation of substituted Re(CO) 3 complexes bearing Diimine ligands. CrystEngComm 2020. [DOI: 10.1039/d0ce01073a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Two Re(i) tricarbonyl complexes bearing Ph4TAP and dafone ligands and having a coordinated perrhenate group obtained via in situ superoxidation of Re(i) to Re(vii) have been characterized.
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Affiliation(s)
- Reza Kia
- Chemistry Department
- Sharif University of Technology
- Tehran
- Iran
| | - Tahereh Taghavi
- Chemistry Department
- Sharif University of Technology
- Tehran
- Iran
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28
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Deka JKR, Sahariah B, Baruah K, Bar AK, Sarma BK. Conformational control of N-methyl-N,N′-diacylhydrazines by noncovalent carbon bonding in solution. Chem Commun (Camb) 2020; 56:4874-4877. [DOI: 10.1039/d0cc00943a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unusual N(amide)⋯C–X noncovalent carbon bonding interactions stabilize the trans–cis (t–c) amide bond rotamers of N-methyl-N,N′-diacylhydrazines over the expected trans–trans (t–t) rotamers in solution.
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Affiliation(s)
| | - Biswajit Sahariah
- Department of Chemistry
- School of Natural Sciences
- Shiv Nadar University
- Dadri
- India
| | - Kalpita Baruah
- Department of Chemistry
- School of Natural Sciences
- Shiv Nadar University
- Dadri
- India
| | - Arun Kumar Bar
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER) Tirupati
- Tirupati 517507
- India
| | - Bani Kanta Sarma
- New Chemistry Unit
- Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR)
- Bangalore 560064
- India
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29
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Zhang Z. An X-shaped cyano–carbonyl interaction on the polar surface of (cyanoacetyl)hydrazones. CrystEngComm 2020. [DOI: 10.1039/d0ce00359j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An X-shaped CN⋯CO interaction, which plays a critical role in dictating the molecule conformation and crystal packing patterns, has been found to occur on the polar surface of (cyanoacetyl)hydrazones, and is rationalized by density functional theory calculations.
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Affiliation(s)
- Zhenfeng Zhang
- School of Chemistry and Chemical Engineering
- Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals
- Henan Key Laboratory of Organic Functional Molecule and Drug Innovation
- Key Laboratory of Green Chemical Media and Reactions
- Ministry of Education
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30
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Rees GJ, Day SP, Barnsley KE, Iuga D, Yates JR, Wallis JD, Hanna JV. Measuring multiple 17O–13C J-couplings in naphthalaldehydic acid: a combined solid state NMR and density functional theory approach. Phys Chem Chem Phys 2020; 22:3400-3413. [DOI: 10.1039/c9cp03977e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combined multinuclear solid-state NMR and a density functional theory computational approach, with SIMPSON simulations, is evaluated to determine the four heteronuclear 1J(13C,17O) couplings in naphthalaldehydic acid.
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Affiliation(s)
| | | | | | - Dinu Iuga
- Department of Physics
- University of Warwick
- Coventry
- UK
| | | | - John D. Wallis
- School of Science and Technology
- Nottingham Trent University
- Nottingham
- UK
| | - John V. Hanna
- Department of Physics
- University of Warwick
- Coventry
- UK
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31
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Wang Y, Yang Y, Wang C. Rhenium‐Catalyzed Decarboxylative Tri‐/Difluoromethylation of Styrenes with Fluorinated Carboxylic Acid‐Derived Hypervalent Iodine Reagents. CHINESE J CHEM 2019. [DOI: 10.1002/cjoc.201900296] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yin Wang
- Radiochemistry Laboratory, School of Nuclear Science and TechnologyLanzhou University Lanzhou Gansu 730000 China
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Yunhui Yang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Physical Science LaboratoryHuairou National Comprehensive Science Center Beijing 101400 China
| | - Congyang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Physical Science LaboratoryHuairou National Comprehensive Science Center Beijing 101400 China
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32
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Takkalkar P, Tobin MJ, Vongsvivut J, Mukherjee T, Nizamuddin S, Griffin G, Kao N. Structural, thermal, rheological and optical properties of poly(lactic acid) films prepared through solvent casting and melt processing techniques. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2019.08.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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33
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Abstract
A complete inventory of the forces governing protein folding is critical for productive protein modeling, including structure prediction and de novo design, as well as understanding protein misfolding diseases of clinical significance. The dominant contributors to protein folding include the hydrophobic effect and conventional hydrogen bonding, along with Coulombic and van der Waals interactions. Over the past few decades, important additional contributors have been identified, including C-H···O hydrogen bonding, n→π* interactions, C5 hydrogen bonding, chalcogen bonding, and interactions involving aromatic rings (cation-π, X-H···π, π-π, anion-π, and sulfur-arene). These secondary contributions fall into two general classes: (1) weak but abundant interactions of the protein main chain and (2) strong but less frequent interactions involving protein side chains. Though interactions with high individual energies play important roles in specifying nonlocal molecular contacts and ligand binding, we estimate that weak but abundant interactions are likely to make greater overall contributions to protein folding, particularly at the level of secondary structure. Further research is likely to illuminate additional roles of these noncanonical interactions and could also reveal contributions yet unknown.
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Affiliation(s)
| | - Ronald T. Raines
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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34
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Xu Z, Li Y. Triel bonds in RZH 2···NH 3: hybridization, solvation, and substitution. J Mol Model 2019; 25:219. [PMID: 31300929 DOI: 10.1007/s00894-019-4089-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 06/04/2019] [Indexed: 12/19/2022]
Abstract
The influence of hybridization, substitution, and solvation on the triel bond has been investigated in the complexes of RZH2···NH3 (Z = B and Al). The magnitude of the π-hole on the triel atom is related to the nature of the Z atom and the hybridization of R. CH3BH2 has the largest π-hole among RBH2, while for RAlH2 the largest π-hole is found in CH≡CAlH2. The interaction energy is partly inconsistent with the magnitude of the π-hole on the triel atom and the orbital interaction from the N lone pair of NH3 into the empty p orbital of the triel atom. The strongest B···N triel bond is found in CH≡CBH2···NH3, while the weakest Al···N triel bond is in CH3AlH2···NH3. The strength of the triel bond is increased in solvents, and its enhancement is prominent with the increase of solvent polarity. Solvents also change the nature of the Al···N triel bond from an electrostatic interaction to a partially covalent one. The F substituent in the triel donor strengthens the triel bond, depending on the substitution position and number. Graphical Abstract The π-hole triel bonded complexes between RZH2 (Z =B and Al) and NH3 have been investigated. We focused on the effects of hybridization, solvent, and substitution on the strength and nature of π-hole triel bond.
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Affiliation(s)
- Zhefeng Xu
- Department of Chemical Engineering, Inner Mongolia Vocational College of Chemical Engineering, Hohhot, 010070, People's Republic of China
| | - Yan Li
- Department of Chemical Engineering, Inner Mongolia Vocational College of Chemical Engineering, Hohhot, 010070, People's Republic of China.
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35
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Taylor R, Wood PA. A Million Crystal Structures: The Whole Is Greater than the Sum of Its Parts. Chem Rev 2019; 119:9427-9477. [PMID: 31244003 DOI: 10.1021/acs.chemrev.9b00155] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The founding in 1965 of what is now called the Cambridge Structural Database (CSD) has reaped dividends in numerous and diverse areas of chemical research. Each of the million or so crystal structures in the database was solved for its own particular reason, but collected together, the structures can be reused to address a multitude of new problems. In this Review, which is focused mainly on the last 10 years, we chronicle the contribution of the CSD to research into molecular geometries, molecular interactions, and molecular assemblies and demonstrate its value in the design of biologically active molecules and the solid forms in which they are delivered. Its potential in other commercially relevant areas is described, including gas storage and delivery, thin films, and (opto)electronics. The CSD also aids the solution of new crystal structures. Because no scientific instrument is without shortcomings, the limitations of CSD research are assessed. We emphasize the importance of maintaining database quality: notwithstanding the arrival of big data and machine learning, it remains perilous to ignore the principle of garbage in, garbage out. Finally, we explain why the CSD must evolve with the world around it to ensure it remains fit for purpose in the years ahead.
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Affiliation(s)
- Robin Taylor
- Cambridge Crystallographic Data Centre , 12 Union Road , Cambridge CB2 1EZ , United Kingdom
| | - Peter A Wood
- Cambridge Crystallographic Data Centre , 12 Union Road , Cambridge CB2 1EZ , United Kingdom
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36
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Pisa R, Cupido T, Kapoor TM. Designing Allele-Specific Inhibitors of Spastin, a Microtubule-Severing AAA Protein. J Am Chem Soc 2019; 141:5602-5606. [PMID: 30875216 DOI: 10.1021/jacs.8b13257] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The bump-hole approach is a powerful chemical biology strategy to specifically probe the functions of closely related proteins. However, for many protein families, such as the ATPases associated with diverse cellular activities (AAA), we lack structural data for inhibitor-protein complexes to design allele-specific chemical probes. Here we report the X-ray structure of a pyrazolylaminoquinazoline-based inhibitor bound to spastin, a microtubule-severing AAA protein, and characterize the residues involved in inhibitor binding. We show that an inhibitor analogue with a single-atom hydrogen-to-fluorine modification can selectively target a spastin allele with an engineered cysteine mutation in its active site. We also report an X-ray structure of the fluoro analogue bound to the spastin mutant. Furthermore, analyses of other mutant alleles suggest how the stereoelectronics of the fluorine-cysteine interaction, rather than sterics alone, contribute to the inhibitor-allele selectivity. This approach could be used to design allele-specific probes for studying cellular functions of spastin isoforms. Our data also suggest how tuning stereoelectronics can lead to specific inhibitor-allele pairs for the AAA superfamily.
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Affiliation(s)
- Rudolf Pisa
- Laboratory of Chemistry and Cell Biology , The Rockefeller University , New York , New York 10065 , United States
| | - Tommaso Cupido
- Laboratory of Chemistry and Cell Biology , The Rockefeller University , New York , New York 10065 , United States
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology , The Rockefeller University , New York , New York 10065 , United States
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37
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Etzkorn FA, Ware RI, Pester AM, Troya D. Conformational Analysis of n→π* Interactions in Collagen Triple Helix Models. J Phys Chem B 2019; 123:496-503. [PMID: 30525631 DOI: 10.1021/acs.jpcb.8b08384] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio calculations of three models of collagen at positions Pro-Pro-Gly (1), Pro-Gly-Pro (2), and Gly-Pro-Pro (3) were performed to assess the conformational variation of n→π* contributions to the stability of the collagen triple helix. Full conformational analyses by relaxed potential-energy scans of the Ψ dihedral angle of the central residue in models 1, 2, and 3 revealed the presence of several n→π* interactions. In model 2, with Gly as the central residue, both the Φ and Ψ dihedral angles of Gly were scanned. Most minima of each model contained one or two n→π* interactions, with pyramidalization at the π* carbon. We also observed pyramidalization at the n→π* donor amide nitrogens. Minima with hydrogen-bond or non-native n→π* interactions compete with the collagen stabilizing n→π* interactions. The collagen-like n→ re-π* conformation was found as the global minimum only in model 3. The global minimum of 1 had a 5-membered ring hydrogen bond with an additional weak n→ si-π* interaction. The global minimum of 2 was in the extended conformation. We predict that the n→π* interactions found in native collagen, while individually small, cumulatively contribute to the stability of the triple helix conformation of collagen.
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Affiliation(s)
- Felicia A Etzkorn
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Rachel I Ware
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Amanda M Pester
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Diego Troya
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
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38
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de la Torre AF, Ali A, Concepcion O, Montero-Alejo AL, Muñiz FM, Jiménez CA, Belmar J, Velázquez-Libera JL, Hernández-Rodríguez EW, Caballero J. A study of the cis–trans isomerization preference of N-alkylated peptides containing phosphorus in the side chain and backbone. NEW J CHEM 2019. [DOI: 10.1039/c9nj02234a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The current work provides a study on the cis–trans isomerization behaviour of N-alkylated peptides decorated with phosphonate ester groups.
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Affiliation(s)
- Alexander F. de la Torre
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Akbar Ali
- Department of Chemistry
- University of Sargodha
- Pakistan
| | - Odette Concepcion
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | | | - Francisco M. Muñiz
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Claudio A. Jiménez
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Julio Belmar
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | | | | | - Julio Caballero
- Centro de Bioinformática y Simulación Molecular (CBSM)
- Universidad de Talca
- Talca
- Chile
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Singh SK, More S, Kumar S, Mishra KK, Ganesh KN, Das A. A conformation-specific IR spectroscopic signature for weak CO⋯CO n→π* interaction in capped 4R-hydroxyproline. Phys Chem Chem Phys 2019; 21:4755-4762. [DOI: 10.1039/c8cp07660j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CO⋯CO n→π*-amide interaction in the monomeric building block of collagen is probed using conformation-specific IR spectroscopy.
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Affiliation(s)
- Santosh K. Singh
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune-411008
- India
| | - Shahaji More
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Tirupati-517507
- India
| | - Satish Kumar
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune-411008
- India
| | - Kamal K. Mishra
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune-411008
- India
| | - Krishna N. Ganesh
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Tirupati-517507
- India
| | - Aloke Das
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune-411008
- India
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40
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Fayzullin RR, Shteingolts SA, Lodochnikova OA, Mamedova VL, Korshin DE, Mamedov VA. Intermolecular head-to-head interaction of carbonyl groups in bicyclic hydrogen-bonded synthon based on β-hydroxy ketones. CrystEngComm 2019. [DOI: 10.1039/c8ce02132e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we report a counterintuitive carbonyl–carbonyl interaction explored for crystalline (2RS,3RS)-1-aryl-2-bromo-3-hydroxy-3-(2-nitrophenyl)-propan-1-ones.
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Affiliation(s)
- Robert R. Fayzullin
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
| | - Sergey A. Shteingolts
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
| | - Olga A. Lodochnikova
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
| | - Vera L. Mamedova
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
| | - Dmitry E. Korshin
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
| | - Vakhid A. Mamedov
- Arbuzov Institute of Organic and Physical Chemistry
- FRC Kazan Scientific Center of Russian Academy of Sciences
- Kazan 420088
- Russian Federation
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Sahariah B, Sarma BK. Relative orientation of the carbonyl groups determines the nature of orbital interactions in carbonyl-carbonyl short contacts. Chem Sci 2018; 10:909-917. [PMID: 30774885 PMCID: PMC6346288 DOI: 10.1039/c8sc04221g] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 10/27/2018] [Indexed: 12/13/2022] Open
Abstract
Carbonyl-carbonyl (CO···CO) interactions are emerging noncovalent interactions found in many small molecules, polyesters, peptides and proteins. However, little is known about the effect of the relative orientation of the two carbonyl groups on the nature of these interactions. Herein, we first show that simple homodimers of acetone and formaldehyde can serve as models to understand the effect of relative orientations of the two carbonyl groups on the nature of CO···CO interactions. Further, from a comprehensive statistical analysis of molecules having inter- or intramolecular CO···CO interactions, we show that the molecules can be broadly categorized into six different structural motifs (I-VI). The analysis of pyramidality of the acceptor carbon atoms in these motifs and natural bond orbital (NBO) analysis suggest that the relative orientation of the two interacting carbonyl groups determines whether the orbital interaction between the two carbonyl groups would be n → π* or π → π* or a combination of both.
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Affiliation(s)
- Biswajit Sahariah
- Department of Chemistry , School of Natural Sciences , Shiv Nadar University , Dadri , Uttar Pradesh-201314 , India .
| | - Bani Kanta Sarma
- Department of Chemistry , School of Natural Sciences , Shiv Nadar University , Dadri , Uttar Pradesh-201314 , India .
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42
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Kale RD, Gorade VG, Madye N, Chaudhary B, Bangde PS, Dandekar PP. Preparation and characterization of biocomposite packaging film from poly(lactic acid) and acylated microcrystalline cellulose using rice bran oil. Int J Biol Macromol 2018; 118:1090-1102. [DOI: 10.1016/j.ijbiomac.2018.06.076] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/03/2018] [Accepted: 06/13/2018] [Indexed: 11/29/2022]
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Kaufman RH, Law CM, Simanis JA, Woodall EL, Zwick CR, Wedler HB, Wendelboe P, Hamaker CG, Goodell JR, Tantillo DJ, Mitchell TA. Oxidopyrylium-Alkene [5 + 2] Cycloaddition Conjugate Addition Cascade (C3) Sequences: Scope, Limitation, and Computational Investigations. J Org Chem 2018; 83:9818-9838. [DOI: 10.1021/acs.joc.8b01322] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Riley H. Kaufman
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Chunyin M. Law
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Justin A. Simanis
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Erica L. Woodall
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Christian R. Zwick
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Henry B. Wedler
- Department of Chemistry, University of California, Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Paul Wendelboe
- Department of Chemistry, University of California, Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Christopher G. Hamaker
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - John R. Goodell
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Dean J. Tantillo
- Department of Chemistry, University of California, Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - T. Andrew Mitchell
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
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44
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Oligoacetylacetones as shapable carbon chains and their transformation to oligoimines for construction of metal-organic architectures. Commun Chem 2018. [DOI: 10.1038/s42004-018-0021-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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45
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Echeverría J. Intermolecular Carbonyl···Carbonyl Interactions in Transition-Metal Complexes. Inorg Chem 2018; 57:5429-5437. [PMID: 29664621 DOI: 10.1021/acs.inorgchem.8b00392] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We performed a comprehensive analysis of intermolecular carbonyl-carbonyl interactions in transition-metal complexes. Those interactions can be classified in two main types depending on the organometallic or organic nature of the donor carbonyl: M-CO···CO and R-CO···CO, respectively. By means of a combined structural and computational study we unraveled their geometrical features and strength. Moreover, electronic structure, natural bond orbitals, energy decomposition analysis, and quantum theory of atoms in molecules calculations were performed to try to understand their nature. Remarkably, we discovered that these carbonyl-carbonyl contacts have several features of the n → π* interaction. The charge transfer from an oxygen lone pair to an empty antibonding π orbital of the acceptor carbonyl is also accompanied by an electrostatic Oδ-···Cδ+ interaction. To the best of our knowledge this is the first report of an intermolecular n → π* interaction in metal complexes. These results might be significant, for instance, for the catalytic activation of carbonyl-containing small molecules with metal compounds or in the design of hybrid organic-inorganic materials, metal-organic frameworks, and other extended structures.
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Affiliation(s)
- Jorge Echeverría
- Departament de Química Inorgànica i Orgànica and Institut de Química Teòrica i Computacional IQTC-UB , Universitat de Barcelona , Martí i Franquès 1-11 , 08028 Barcelona , Spain
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46
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Kubyshkin V, Budisa N. Exploring hydrophobicity limits of polyproline helix with oligomeric octahydroindole-2-carboxylic acid. J Pept Sci 2018; 24:e3076. [PMID: 29582506 DOI: 10.1002/psc.3076] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/24/2018] [Accepted: 02/26/2018] [Indexed: 12/12/2022]
Abstract
The polyproline-II helix is the most extended naturally occurring helical structure and is widely present in polar, exposed stretches and "unstructured" denatured regions of polypeptides. Can it be hydrophobic? In this study, we address this question using oligomeric peptides formed by a hydrophobic proline analogue, (2S,3aS,7aS)-octahydroindole-2-carboxylic acid (Oic). Previously, we found the molecular principles underlying the structural stability of the polyproline-II conformation in these oligomers, whereas the hydrophobicity of the peptide constructs remains to be examined. Therefore, we investigated the octan-1-ol/water partitioning and inclusion in detergent micelles of the oligo-Oic peptides. The results showed that the hydrophobicity is remarkably enhanced in longer oligomeric sequences, and the oligo-Oic peptides with 3 to 4 residues and higher are specific towards hydrophobic environments. This contrasts significantly to the parent oligoproline peptides, which were moderately hydrophilic. With these findings, we have demonstrated that the polyproline-II structure is compatible with nonpolar media, whereas additional manipulations of the terminal functionalities feature solubility in extremely nonpolar solvents such as hexane.
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Affiliation(s)
- Vladimir Kubyshkin
- Institute of Chemistry, Technical University of Berlin, Müller-Breslau-Str. 10, Berlin, 10623, Germany
| | - Nediljko Budisa
- Institute of Chemistry, Technical University of Berlin, Müller-Breslau-Str. 10, Berlin, 10623, Germany
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47
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Abstract
We report here, for the first time, the existence of n →π* interactions in transition metal complexes containing carbonyl ligands. This interaction has been observed to be surprisingly abundant and to stabilize precise molecular conformations that maximize the overlap between the donor and acceptor orbitals.
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Affiliation(s)
- Jorge Echeverría
- Departament de Química Inorgànica i Orgànica and Institut de Química Teòrica i Computacional IQTC-UB, Universitat de Barcelona, Martí i Franquès 1-11 08028, Barcelona, Spain.
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48
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Wang S, Shi G, Guan X, Zhang J, Wan X. Cis-Cisoid Helical Structures of Poly(3,5-disubstituted phenylacetylene)s Stabilized by Intramolecular n → π* Interactions. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00078] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Sheng Wang
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics
of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Ge Shi
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics
of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiaoyan Guan
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics
of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jie Zhang
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics
of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xinhua Wan
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics
of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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Meanwell NA. Fluorine and Fluorinated Motifs in the Design and Application of Bioisosteres for Drug Design. J Med Chem 2018; 61:5822-5880. [PMID: 29400967 DOI: 10.1021/acs.jmedchem.7b01788] [Citation(s) in RCA: 1365] [Impact Index Per Article: 227.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The electronic properties and relatively small size of fluorine endow it with considerable versatility as a bioisostere and it has found application as a substitute for lone pairs of electrons, the hydrogen atom, and the methyl group while also acting as a functional mimetic of the carbonyl, carbinol, and nitrile moieties. In this context, fluorine substitution can influence the potency, conformation, metabolism, membrane permeability, and P-gp recognition of a molecule and temper inhibition of the hERG channel by basic amines. However, as a consequence of the unique properties of fluorine, it features prominently in the design of higher order structural metaphors that are more esoteric in their conception and which reflect a more sophisticated molecular construction that broadens biological mimesis. In this Perspective, applications of fluorine in the construction of bioisosteric elements designed to enhance the in vitro and in vivo properties of a molecule are summarized.
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Affiliation(s)
- Nicholas A Meanwell
- Discovery Chemistry and Molecular Technologies Bristol-Myers Squibb Research and Development P.O. Box 4000, Princeton , New Jersey 08543-4000 , United States
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50
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Cieplak AS. Protein folding, misfolding and aggregation: The importance of two-electron stabilizing interactions. PLoS One 2017; 12:e0180905. [PMID: 28922400 PMCID: PMC5603215 DOI: 10.1371/journal.pone.0180905] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 06/22/2017] [Indexed: 12/17/2022] Open
Abstract
Proteins associated with neurodegenerative diseases are highly pleiomorphic and may adopt an all-α-helical fold in one environment, assemble into all-β-sheet or collapse into a coil in another, and rapidly polymerize in yet another one via divergent aggregation pathways that yield broad diversity of aggregates’ morphology. A thorough understanding of this behaviour may be necessary to develop a treatment for Alzheimer’s and related disorders. Unfortunately, our present comprehension of folding and misfolding is limited for want of a physicochemical theory of protein secondary and tertiary structure. Here we demonstrate that electronic configuration and hyperconjugation of the peptide amide bonds ought to be taken into account to advance such a theory. To capture the effect of polarization of peptide linkages on conformational and H-bonding propensity of the polypeptide backbone, we introduce a function of shielding tensors of the Cα atoms. Carrying no information about side chain-side chain interactions, this function nonetheless identifies basic features of the secondary and tertiary structure, establishes sequence correlates of the metamorphic and pH-driven equilibria, relates binding affinities and folding rate constants to secondary structure preferences, and manifests common patterns of backbone density distribution in amyloidogenic regions of Alzheimer’s amyloid β and tau, Parkinson’s α-synuclein and prions. Based on those findings, a split-intein like mechanism of molecular recognition is proposed to underlie dimerization of Aβ, tau, αS and PrPC, and divergent pathways for subsequent association of dimers are outlined; a related mechanism is proposed to underlie formation of PrPSc fibrils. The model does account for: (i) structural features of paranuclei, off-pathway oligomers, non-fibrillar aggregates and fibrils; (ii) effects of incubation conditions, point mutations, isoform lengths, small-molecule assembly modulators and chirality of solid-liquid interface on the rate and morphology of aggregation; (iii) fibril-surface catalysis of secondary nucleation; and (iv) self-propagation of infectious strains of mammalian prions.
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Affiliation(s)
- Andrzej Stanisław Cieplak
- Department of Chemistry, Bilkent University, Ankara, Turkey
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Chemistry, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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