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Kovács B, Földes T, Szabó M, Dorkó É, Kótai B, Laczkó G, Holczbauer T, Domján A, Pápai I, Soós T. Illuminating the multiple Lewis acidity of triaryl-boranes via atropisomeric dative adducts. Chem Sci 2024:d4sc00925h. [PMID: 39257854 PMCID: PMC11382148 DOI: 10.1039/d4sc00925h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 08/23/2024] [Indexed: 09/12/2024] Open
Abstract
Using the principle that constrained conformational spaces can generate novel and hidden molecular properties, we challenged the commonly held perception that a single-centered Lewis acid reacting with a single-centered Lewis base always forms a single Lewis adduct. Accordingly, the emergence of single-centered but multiple Lewis acidity among sterically hindered and non-symmetric triaryl-boranes is reported. These Lewis acids feature several diastereotopic faces providing multiple binding sites at the same Lewis acid center in the interaction with Lewis bases giving rise to adducts with diastereomeric structures. We demonstrate that with a proper choice of the base, atropisomeric adduct species can be formed that interconvert via the dissociative mechanism rather than conformational isomerism. The existence of this exotic and peculiar molecular phenomenon was experimentally confirmed by the formation of atropisomeric piperidine-borane adducts using state-of-the-art NMR techniques in combination with computational methods.
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Affiliation(s)
- Benjámin Kovács
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Tamás Földes
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Márk Szabó
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Éva Dorkó
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Bianka Kótai
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Gergely Laczkó
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University P. O. Box 32 Budapest H-1518 Hungary
| | - Tamás Holczbauer
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Attila Domján
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Imre Pápai
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Tibor Soós
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
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Wang M, Garrison N, Nguyen PM, Prasad A, Wang Y, Kwon HK, Kim G, Siegler MA, Lectka T. Can the -CF 3 Group Act as a Tight, Well-Defined Hydrogen Bond Acceptor? A Clear Crystallographic CF 2-F···H-N + Interaction Says Yes. J Org Chem 2024; 89:9681-9685. [PMID: 38965938 DOI: 10.1021/acs.joc.4c00873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
The CF3 group is well noted for being noninteractive with other functional groups. In this Note, we present a highly rigid model system containing a significant hydrogen bonding interaction between a charged N-H donor and a CF3 acceptor that challenges this accepted wisdom. Spectroscopic and single crystal X-ray crystallography data characterize this interaction, consistent with a weak to moderate hydrogen bond that would be difficult to observe in an intermolecular system.
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Affiliation(s)
- Muyuan Wang
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Nathaniel Garrison
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Phuong Minh Nguyen
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Aarush Prasad
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Yuang Wang
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Hyeok-Kyu Kwon
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Gina Kim
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
| | - Thomas Lectka
- Department of Chemistry, Johns Hopkins University, 3400 North Charles St., Baltimore, Maryland 21218, United States
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3
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β-Cyclodextrin Supramolecular Recognition of bis-Cationic Dithienylethenes. ORGANICS 2022. [DOI: 10.3390/org3020005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The supramolecular interactions in water between β-cyclodextrin and the open and closed photochromic forms of two bis-cationic dithienylethenes, characterized by different electronic properties, were investigated aiming at underlying the key aspects of the recognition process. The dithienylethene equipped with the cyclopentenyl unit showed a difference in binding free energies to the β-cyclodextrin between the open and closed photochromic forms of about 1 kJ/mol. Conversely, the dithienylethene equipped with the perfluorinated cyclopentenyl unit not only was a better guest but showed a three times higher difference in the binding of free energies between the open and closed isomers.
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4
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Ribeiro dos Santos JB, Ribeiro da Silva MR. Small molecule CGRP receptor antagonists for the preventive treatment of migraine: A review. Eur J Pharmacol 2022; 922:174902. [DOI: 10.1016/j.ejphar.2022.174902] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/10/2022] [Accepted: 03/17/2022] [Indexed: 01/29/2023]
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5
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Aro-Heinilä A, Lepistö A, Äärelä A, Lönnberg TA, Virta P. 2-Trifluoromethyl-6-mercurianiline Nucleotide, a Sensitive 19F NMR Probe for Hg(II)-mediated Base Pairing. J Org Chem 2022; 87:137-146. [PMID: 34905374 PMCID: PMC8749955 DOI: 10.1021/acs.joc.1c02056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 01/02/2023]
Abstract
A 2-trifluoromethylaniline C-nucleoside was synthesized, incorporated in the middle of an oligonucleotide, and mercurated. The affinity of the mercurated oligonucleotide toward complementary strands placing each of the canonical nucleobases opposite to the organomercury nucleobase analogue was examined by ultraviolet (UV), circular dichroism (CD), and 19F NMR spectroscopy analyses. According to the UV melting profile analysis, the organomercury nucleobase analogue showed increased affinities in the order T > G > C > A. The CD profiles indicated the typical B-type helix in each case. The 19F resonance signal proved sensitive for the local environmental changes, showing clearly distinct signals for the duplexes with different opposing nucleobases. Furthermore, valuable information on the mercurated oligonucleotide and its binding to complementary strands at varying temperature could be obtained by 19F NMR spectroscopy.
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Affiliation(s)
- Asmo Aro-Heinilä
- Department of Chemistry, University
of Turku, Henrikinkatu 2, 20500 Turku, Finland
| | - Assi Lepistö
- Department of Chemistry, University
of Turku, Henrikinkatu 2, 20500 Turku, Finland
| | - Antti Äärelä
- Department of Chemistry, University
of Turku, Henrikinkatu 2, 20500 Turku, Finland
| | | | - Pasi Virta
- Department of Chemistry, University
of Turku, Henrikinkatu 2, 20500 Turku, Finland
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6
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Li W, Li F, Zhao Y, Liu C, Li Y, Yang H, Fan K, Zhang P, Shan Y, Sun L. Promotion of the oxygen evolution performance of Ni-Fe layered hydroxides via the introduction of a proton-transfer mediator anion. Sci China Chem 2021. [DOI: 10.1007/s11426-021-1178-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Exploration of 7-azaindole-coumaranone hybrids and their analogues as protein kinase inhibitors. Chem Biol Interact 2021; 343:109478. [PMID: 33905741 DOI: 10.1016/j.cbi.2021.109478] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 03/24/2021] [Accepted: 04/12/2021] [Indexed: 01/01/2023]
Abstract
7-Azaindole has been labelled a privileged scaffold for the design of new potent inhibitors of protein kinases. In this paper, we determined the inhibition profiles of novel mono- and disubstituted derivatives of 7-azaindole-coumaranone hybrids on various disease-related protein kinases. Eight hit compounds were identified, including a potent Haspin inhibitor with an IC50 value of 0.15 μM. An interesting observation was that all active monosubstituted compounds displayed dual inhibition for Haspin and GSK-3β, while disubstituted derivatives inhibited GSK-3β and LmCK1 from Leishmania major parasite. Analyses of structure activity relationships (SARs) also revealed that mono-substitution with para-fluorobenzyloxy ring produced an equipotent inhibition of Haspin and GSK-3β. Haspin and GSK-3β are relevant targets for developing new anticancer agents while LmCK1 is an innovative target for leishmanicidal drugs. Novel compounds reported in this paper constitute promising starting points for the development of new anticancer and leishmanicidal drugs.
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8
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Tiwari S, Arya N, Mishra SK, Suryaprakash N. Competing HB acceptors: an extensive NMR investigations corroborated by single crystal XRD and DFT calculations. RSC Adv 2021; 11:15195-15202. [PMID: 35424030 PMCID: PMC8698242 DOI: 10.1039/d1ra02538d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 04/11/2021] [Indexed: 11/21/2022] Open
Abstract
A series of N-benzoylanthranilamide derivatives have been synthesized with the substitution of competitive HB acceptors and investigated by NMR spectroscopy and single crystal XRD. The interesting rivalry for HB acceptance between [double bond splayed left]C[double bond, length as m-dash]O and X (F or OMe) is observed in the investigated molecules which leads to an unusual increase in the electron density at the site of one of the NH protons, reflecting in the high field resonance in the 1H NMR spectrum. The NMR experimental findings and single crystal XRD are further reinforced by the DFT studies.
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Affiliation(s)
- Surbhi Tiwari
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
| | - Neeru Arya
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
| | - Sandeep Kumar Mishra
- Department of Physics and NMR Research Centre, Indian Institute of Science Education and Research Pune 411008 India
| | - N Suryaprakash
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
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9
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Accorsi G, Capodilupo AL, Claramunt RM, Clarkson GJ, Farrán A, Gatti FG, León S, Venturi S. Studies of novel trifluoroacetylated diaryl hydrazone molecular photoswitches in solution and in the solid state. NEW J CHEM 2021. [DOI: 10.1039/d1nj01677f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Photoisomerization of trifluoroacetylated diaryl hydrazones induces a change in color due to the formation of a new hydrogen bond in solution and in the solid state.
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Affiliation(s)
- Gianluca Accorsi
- CNR NANOTEC – Institute of Nanotechnology c/o Campus Ecotekne
- University of Salento
- 73100 Lecce
- Italy
| | - Agostina-Lina Capodilupo
- CNR NANOTEC – Institute of Nanotechnology c/o Campus Ecotekne
- University of Salento
- 73100 Lecce
- Italy
| | - Rosa María Claramunt
- Departamento de Química Orgánica y Bio-Orgánica
- Facultad de Ciencias
- Universidad Nacional de Educación a Distancia
- E-28040 Madrid
- Spain
| | | | - A. Farrán
- Departamento de Química Orgánica y Bio-Orgánica
- Facultad de Ciencias
- Universidad Nacional de Educación a Distancia
- E-28040 Madrid
- Spain
| | - Francesco G. Gatti
- Dipartimento di Chimica
- Materiali ed Ingegneria Chimica “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
| | - Salvador León
- Departamento de Ingeniería Química
- Universidad Politécnica de Madrid
- ETSIIM
- 28006 Madrid
- Spain
| | - Silvia Venturi
- Dipartimento di Chimica
- Materiali ed Ingegneria Chimica “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
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10
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Li C, Cao Y, Hu B, Li Y. Unraveling the effect of fluorine substitution on the hydrogen bonding interaction in the complexes of fluorosubstituted pyridines and acetic acid. J PHYS ORG CHEM 2020. [DOI: 10.1002/poc.4151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chaozheng Li
- School of Mechanical and Electrical Engineering Henan Institute of Science and Technology Xinxiang China
| | - Yonghua Cao
- School of Mechanical and Electrical Engineering Henan Institute of Science and Technology Xinxiang China
| | - Bo Hu
- School of Mechanical and Electrical Engineering Henan Institute of Science and Technology Xinxiang China
| | - Yongfeng Li
- School of Mechanical and Electrical Engineering Henan Institute of Science and Technology Xinxiang China
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11
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Liu P, Hao W, Bian X, Mei D. The shuttling mechanism of foldaxanes: more than just translocation and rotation. Phys Chem Chem Phys 2020; 22:12967-12972. [PMID: 32490445 DOI: 10.1039/d0cp01952f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tailoring the structures of nanomachines to achieve specific functions is one of the major challenges in chemistry. Disentangling the different movements of nanomachines is critical to characterize their functions. Here, the motions within one kind of molecular machine, a foldaxane, composed of a foldamer with a spring-like conformation on an axle have been examined at the molecular level. With the aid of molecular dynamics simulations and enhanced sampling methods, the free-energy landscape characterizing the shuttling of the foldaxane has been drawn. The calculated free-energy barrier, amounting to 20.7 kcal mol-1, is in good agreement with experiments. Further analysis reveals that the predominant contribution to the free-energy barrier stems from the disruption of the hydrogen bonds between the foldamer and the thread. In the absence of hydrogen bonding interactions between the terminals of the foldamer and the thread, shrinkage and swelling movements of the foldamer have been identified and investigated in detail. By deciphering the intricate mechanism of how the foldaxane shuttles, our understanding of motions within molecular machines is expected to be improved, which will, in turn, assist the construction of molecular machines with specific functions.
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Affiliation(s)
- Peng Liu
- School of Chemistry and Chemical Engineering, State Key Laboratory of Separation Membranes and Membrane Processes, Tiangong University, Tianjin, 300387, China.
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12
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Malinowski PJ, Jaroń T, Domańska M, Slattery JM, Schmitt M, Krossing I. Building blocks for the chemistry of perfluorinated alkoxyaluminates [Al{OC(CF 3) 3} 4] -: simplified preparation and characterization of Li +-Cs +, Ag +, NH 4+, N 2H 5+ and N 2H 7+ salts. Dalton Trans 2020; 49:7766-7773. [PMID: 32329763 DOI: 10.1039/d0dt00592d] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Advanced weakly coordinating anions (WCAs) significantly facilitate synthesis of various exotic chemical compounds and novel, potentially useful materials. One of such anions - [Al{OC(CF3)3}4]-, denoted [Al(ORF)4]-, appears particularly convenient, as it can be easily prepared from the commercially available alanates and HOC(CF3)3. Here we present a thorough characterization of a series of solvent-free M[Al(ORF)4] salts, M = Li-Cs, Ag, NH4, N2H5 and N2H7, and related compounds of monovalent cations, which are crucial starting materials for further work with these species. Notably, the corresponding synthetic protocols are updated by an improved method for fast, facile and easily scalable synthesis of Li[Al(ORF)4], which remains the most useful primary source of the anion. The physico-chemical properties of these salts including crystal structures, thermal stability by TG/DSC, vibrational spectra as well as solubility are discussed in a systematic fashion.
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13
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Mido T, Iitsuka H, Kobayashi M, Noguchi K, Yonezawa N, Okamoto A. Fluoro Group Pivoting Dual Hydrogen Bonding Intramolecular Bridge for 1,2-Bis(2-fluorophenyl)acenaphthenediol Molecule in Solution: NMR Spectrometrical Confirmation of Simultaneous Participation of F–C(sp 2) Group to Through-space-couplings with Aromatic and Hydroxy Hydrogen Atoms. CHEM LETT 2020. [DOI: 10.1246/cl.190903] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Takahiro Mido
- Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
| | - Hiroaki Iitsuka
- Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
| | - Miyuki Kobayashi
- Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
| | - Keiichi Noguchi
- Instrumentation Analysis Center, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
| | - Noriyuki Yonezawa
- Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
| | - Akiko Okamoto
- Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan
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15
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The Role of Fluorinated IL as an Interfacial Agent in P(VDF-CTFE)/Graphene Composite Films. NANOMATERIALS 2019; 9:nano9081181. [PMID: 31430868 PMCID: PMC6724409 DOI: 10.3390/nano9081181] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/19/2019] [Accepted: 07/26/2019] [Indexed: 11/17/2022]
Abstract
The incorporation of graphene into a polymer matrix can endow composites with extended functions. However, it is difficult to well disperse pristine graphene into a polymer matrix in order to obtain polymer nanocomposites due to the lack of functional groups on the surface for bonding with a polymer matrix. Herein, we investigated the role of fluorinated ionic liquid (IL) as a new interfacial agent in poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE))/graphene composite films. First, a task-specific IL, perfluorooctyltriphenylphosphonium iodide (IL-C8F13), was synthesized and adsorbed on the surface of graphene oxide (GO) and reduced graphene oxide (rGO) for making functional nanofillers which were capable of being incorporated into the P(VDF-CTFE) matrix. The cation structure of IL combined three phenyls (potential π–π interactions with graphene) and a short fluorinated chain (enhanced miscibility with fluorinated matrix via dipolar interactions) to make a compatible graphene filler and P(VDF-CTFE) matrix at the interface among them. Second, two series of P(VDF-CTFE)/GO-IL and P(VDF-CTFE)/rGO-IL composites with different loading contents were prepared with the goal of providing an understanding of the mechanism of interfacial interactions. This paper investigated the difference in the interaction model between GO with IL and rGO with IL. Subsequently, the interfacial effect of IL on the properties of P(VDF-CTFE)/graphene composites, such as crystallization, chain segmental relaxation behavior, dispersion, and the final dielectric properties will be further studied.
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Brai A, Martelli F, Riva V, Garbelli A, Fazi R, Zamperini C, Pollutri A, Falsitta L, Ronzini S, Maccari L, Maga G, Giannecchini S, Botta M. DDX3X Helicase Inhibitors as a New Strategy To Fight the West Nile Virus Infection. J Med Chem 2019; 62:2333-2347. [PMID: 30721061 DOI: 10.1021/acs.jmedchem.8b01403] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Increased frequency of arbovirus outbreaks in the last 10 years represents an important emergence for global health. Climate warming, extensive urbanization of tropical regions, and human migration flows facilitate the expansion of anthropophilic mosquitos and the emerging or re-emerging of new viral infections. Only recently the human adenosinetriphosphatase/RNA helicase X-linked DEAD-box polypeptide 3 (DDX3X) emerged as a novel therapeutic target in the fight against infectious diseases. Herein, starting from our previous studies, a new family of DDX3X inhibitors was designed, synthesized, validated on the target enzyme, and evaluated against the West Nile virus (WNV) infection. Time of addition experiments after virus infection indicated that the compounds exerted their antiviral activities after the entry process, likely at the protein translation step of WNV replication. Finally, the most interesting compounds were then analyzed for their in vitro pharmacokinetic parameters, revealing favorable absorption, distribution, metabolism, and excretion values. The good safety profile together with a good activity against WNV for which no treatments are currently available, make this new class of molecules a good starting point for further in vivo studies.
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Affiliation(s)
- Annalaura Brai
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy.,Lead Discovery Siena S.r.l. , Castelnuovo Berardenga, I-53019 Siena , Italy
| | - Francesco Martelli
- Department of Experimental and Clinical Medicine , University of Florence , I-50134 Florence , Italy
| | - Valentina Riva
- Istituto di Genetica Molecolare, IGM-CNR , Via Abbiategrasso 207 , I-27100 Pavia , Italy
| | - Anna Garbelli
- Istituto di Genetica Molecolare, IGM-CNR , Via Abbiategrasso 207 , I-27100 Pavia , Italy
| | - Roberta Fazi
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy
| | - Claudio Zamperini
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy.,Lead Discovery Siena S.r.l. , Castelnuovo Berardenga, I-53019 Siena , Italy
| | - Alessandro Pollutri
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy
| | - Lucia Falsitta
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy
| | - Stefania Ronzini
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy
| | - Laura Maccari
- Lead Discovery Siena S.r.l. , Castelnuovo Berardenga, I-53019 Siena , Italy
| | - Giovanni Maga
- Istituto di Genetica Molecolare, IGM-CNR , Via Abbiategrasso 207 , I-27100 Pavia , Italy
| | - Simone Giannecchini
- Department of Experimental and Clinical Medicine , University of Florence , I-50134 Florence , Italy
| | - Maurizio Botta
- Dipartimento Biotecnologie, Chimica e Farmacia , Università degli Studi di Siena , Via A. De Gasperi 2 , I-53100 Siena , Italy.,Lead Discovery Siena S.r.l. , Castelnuovo Berardenga, I-53019 Siena , Italy.,Biotechnology College of Science and Technology , Temple University , BioLife Science Building, Suite 333, 1900 North 12th Street , Philadelphia , Pennsylvania 19122 , United States
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17
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Naito W, Urakawa K, Sato R, Shigeta Y, Yasuda N, Maeda H. Quadruply N-methylated octaphyrin: a helical macrocycle exhibiting chiroptical properties and dynamic conformation changes correlated with helical and inner N-methyl orientations. Org Biomol Chem 2019; 17:1163-1168. [PMID: 30644491 DOI: 10.1039/c8ob03161d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
[38]Octaphyrin(1.1.1.1.1.1.1.1) bearing four methyl moieties at the inner nitrogen sites has been synthesized. This expanded porphyrin has helical chirality as correlated with the orientations of the inner N-methyl groups, exhibiting chiroptical properties as observed in CD Cotton effects from the enantiomers through optical resolution. The chirality of the octaphyrin was retained at r.t. but the racemization occurred at higher temperature as examined by CD spectral changes. The dynamic conversion processes between the enantiomers were investigated by theoretical studies, suggesting the plausible pathways via the intermediates with appropriate conformations.
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Affiliation(s)
- Wakana Naito
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
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18
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Patel AK, Mishra SK, Krishnamurthy K, Suryaprakash N. Retention of strong intramolecular hydrogen bonds in high polarity solvents in binaphthalene–benzamide derivatives: extensive NMR studies. RSC Adv 2019; 9:32759-32770. [PMID: 35529738 PMCID: PMC9073135 DOI: 10.1039/c9ra07299c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/07/2019] [Indexed: 11/21/2022] Open
Abstract
Advanced multidimensional NMR techniques have been employed to investigate the intramolecular hydrogen bonds (HBs) in a series of N,N′-([1,1′-binaphthalene]-2,2′-diyl)bis(benzamide) derivatives, with the site-specific substitution of different functional groups. The existence of intramolecular HBs and the elimination of any molecular aggregation and possible intermolecular HBs are ascertained by various experimental NMR techniques, including solvent polarity dependent modifications of HB strengths. In the fluorine substituted derivative, direct evidence for the engagement of organic fluorine in HB is obtained by the detection of heteronuclear through-space correlation and the coupling between two NMR active nuclei where the transmission of spin polarization is mediated through HBs (1hJFH). The extent of reduction in the strength of 1hJFH on dilution with high polarity solvents directly provided the qualitative measure of HB strength. The HB, although becoming weakened, does not get nullified even in pure high polarity solvent, which is attributed to the structural constraints. The rate of exchange of a labile hydrogen atom with the deuterium of the solvent permitted the measurement of their half-lives, that are correlated to the relative strengths of HBs. The experimental NMR findings are further validated by XRD and DFT-based theoretical computations, such as, NCI and QTAIM. NMR studies reveal very strong hydrogen bond unbreakable even in high polarity solvents.![]()
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Affiliation(s)
- Arun Kumar Patel
- Solid State and Structural Chemistry Unit and NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- NMR Research Centre
| | | | | | - N. Suryaprakash
- Solid State and Structural Chemistry Unit and NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- NMR Research Centre
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19
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Ravindra M, Wilson MR, Tong N, O'Connor C, Karim M, Polin L, Wallace-Povirk A, White K, Kushner J, Hou Z, Matherly LH, Gangjee A. Fluorine-Substituted Pyrrolo[2,3- d]Pyrimidine Analogues with Tumor Targeting via Cellular Uptake by Folate Receptor α and the Proton-Coupled Folate Transporter and Inhibition of de Novo Purine Nucleotide Biosynthesis. J Med Chem 2018; 61:4228-4248. [PMID: 29701475 DOI: 10.1021/acs.jmedchem.8b00408] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Novel fluorinated 2-amino-4-oxo-6-substituted pyrrolo[2,3- d]pyrimidine analogues 7-12 were synthesized and tested for selective cellular uptake by folate receptors (FRs) α and β or the proton-coupled folate transporter (PCFT) and for antitumor efficacy. Compounds 8, 9, 11, and 12 showed increased in vitro antiproliferative activities (∼11-fold) over the nonfluorinated analogues 2, 3, 5, and 6 toward engineered Chinese hamster ovary and HeLa cells expressing FRs or PCFT. Compounds 8, 9, 11, and 12 also inhibited proliferation of IGROV1 and A2780 epithelial ovarian cancer cells; in IGROV1 cells with knockdown of FRα, 9, 11, and 12 showed sustained inhibition associated with uptake by PCFT. All compounds inhibited glycinamide ribonucleotide formyltransferase, a key enzyme in the de novo purine biosynthesis pathway. Molecular modeling studies validated in vitro cell-based results. NMR evidence supports the presence of an intramolecular fluorine-hydrogen bond. Potent in vivo efficacy of 11 was established with IGROV1 xenografts in severe compromised immunodeficient mice.
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Affiliation(s)
- Manasa Ravindra
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Mike R Wilson
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Nian Tong
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Carrie O'Connor
- Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Mohammad Karim
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Lisa Polin
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Adrianne Wallace-Povirk
- Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Kathryn White
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Juiwanna Kushner
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Zhanjun Hou
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Larry H Matherly
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States.,Department of Pharmacology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Aleem Gangjee
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
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20
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Bouza AA, Swanson HC, Smolen KA, VanDine AL, Taracila MA, Romagnoli C, Caselli E, Prati F, Bonomo RA, Powers RA, Wallar BJ. Structure-Based Analysis of Boronic Acids as Inhibitors of Acinetobacter-Derived Cephalosporinase-7, a Unique Class C β-Lactamase. ACS Infect Dis 2018; 4:325-336. [PMID: 29144724 DOI: 10.1021/acsinfecdis.7b00152] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Acinetobacter baumannii is a multidrug resistant pathogen that infects more than 12 000 patients each year in the US. Much of the resistance to β-lactam antibiotics in Acinetobacter spp. is mediated by class C β-lactamases known as Acinetobacter-derived cephalosporinases (ADCs). ADCs are unaffected by clinically used β-lactam-based β-lactamase inhibitors. In this study, five boronic acid transition state analog inhibitors (BATSIs) were evaluated for inhibition of the class C cephalosporinase ADC-7. Our goal was to explore the properties of BATSIs designed to probe the R1 binding site. Ki values ranged from low micromolar to subnanomolar, and circular dichroism (CD) demonstrated that each inhibitor stabilizes the β-lactamase-inhibitor complexes. Additionally, X-ray crystal structures of ADC-7 in complex with five inhibitors were determined (resolutions from 1.80 to 2.09 Å). In the ADC-7/CR192 complex, the BATSI with the lowest Ki (0.45 nM) and greatest Δ Tm (+9 °C), a trifluoromethyl substituent, interacts with Arg340. Arg340 is unique to ADCs and may play an important role in the inhibition of ADC-7. The ADC-7/BATSI complexes determined in this study shed light into the unique recognition sites in ADC enzymes and also offer insight into further structure-based optimization of these inhibitors.
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Affiliation(s)
- Alexandra A. Bouza
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
| | - Hollister C. Swanson
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
| | - Kali A. Smolen
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
| | - Alison L. VanDine
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
| | - Magdalena A. Taracila
- Research
Service, Louis Stokes Cleveland Department of Veterans Affairs Medical
Center, 10701 East Boulevard, Cleveland, Ohio 44106, United States
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Chiara Romagnoli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Emilia Caselli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Fabio Prati
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Robert A. Bonomo
- Research
Service, Louis Stokes Cleveland Department of Veterans Affairs Medical
Center, 10701 East Boulevard, Cleveland, Ohio 44106, United States
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Rachel A. Powers
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
| | - Bradley J. Wallar
- Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States
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21
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Lakshmipriya A, Chaudhary M, Mogurampelly S, Klein ML, Suryaprakash N. Intramolecular Hydrogen Bonding Appetency for Conformational Penchants in Oxalohydrazide Fluoro Derivatives: NMR, MD, QTAIM, and NCI Studies. J Phys Chem A 2018; 122:2703-2713. [PMID: 29488767 DOI: 10.1021/acs.jpca.8b00913] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformational stability of synthesized diphenyloxalohydrazide and dibenzoyloxalohydrazide fluoro derivatives has been investigated by extensive NMR studies that are ascertained by various levels of theoretical calculations. Two-dimensional 1H-19F HOESY NMR experiments revealed the close spatial proximity between two NMR-active nuclei, confirming the hydrogen bond (HB)-mediated interaction between them, further aiding in establishing the probable stable conformations of these molecules. The relaxed potential energy scan disclosed the energy-minimized most stable structure among the several possible multiple conformations, which is in concurrence with NMR interpretations. Atomistic molecular dynamics simulations have been employed to unequivocally establish the conformational stability and the nature of HB formation at varied temperatures. With the possibility of occurrence of a number of probable conformations, the percentage of occurrences of different types of HBs in them was determined by MD simulations. Their population analysis was carried out using a Boltzmann distribution, in addition to deriving their Gibbs free energies. The molecular interactions governing the stable conformations have not only been ascertained by experimental NMR interpretations but also corroborated by other theoretical computations, viz., quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI).
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Affiliation(s)
- A Lakshmipriya
- NMR Research Centre , Indian Institute of Science , Bangalore , Karnataka 560012 , India.,Solid State and Structural Chemistry Unit , Indian Institute of Science , Bangalore , Karnataka 560012 , India
| | - Madhusudan Chaudhary
- NMR Research Centre , Indian Institute of Science , Bangalore , Karnataka 560012 , India
| | - Santosh Mogurampelly
- Institute for Computational Molecular Science , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Michael L Klein
- Institute for Computational Molecular Science , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - N Suryaprakash
- NMR Research Centre , Indian Institute of Science , Bangalore , Karnataka 560012 , India.,Solid State and Structural Chemistry Unit , Indian Institute of Science , Bangalore , Karnataka 560012 , India
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22
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Dhanishta P, Mishra SK, Suryaprakash N. Intramolecular HB Interactions Evidenced in Dibenzoyl Oxalamide Derivatives: NMR, QTAIM, and NCI Studies. J Phys Chem A 2017; 122:199-208. [DOI: 10.1021/acs.jpca.7b10598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Dhanishta
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Sandeep Kumar Mishra
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - N. Suryaprakash
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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23
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Investigation of conventional and non-conventional hydrogen bonds: a comparison of fluorine-substituted and non-fluorine substituted compounds. MONATSHEFTE FUR CHEMIE 2017. [DOI: 10.1007/s00706-017-2044-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Mishra SK, Suryaprakash N. Intramolecular Hydrogen Bonding Involving Organic Fluorine: NMR Investigations Corroborated by DFT-Based Theoretical Calculations. Molecules 2017; 22:E423. [PMID: 28272370 PMCID: PMC6155419 DOI: 10.3390/molecules22030423] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/02/2017] [Indexed: 01/24/2023] Open
Abstract
The combined utility of many one and two dimensional NMR methodologies and DFT-based theoretical calculations have been exploited to detect the intramolecular hydrogen bond (HB) in number of different organic fluorine-containing derivatives of molecules, viz. benzanilides, hydrazides, imides, benzamides, and diphenyloxamides. The existence of two and three centered hydrogen bonds has been convincingly established in the investigated molecules. The NMR spectral parameters, viz., coupling mediated through hydrogen bond, one-bond NH scalar couplings, physical parameter dependent variation of chemical shifts of NH protons have paved the way for understanding the presence of hydrogen bond involving organic fluorine in all the investigated molecules. The experimental NMR findings are further corroborated by DFT-based theoretical calculations including NCI, QTAIM, MD simulations and NBO analysis. The monitoring of H/D exchange with NMR spectroscopy established the effect of intramolecular HB and the influence of electronegativity of various substituents on the chemical kinetics in the number of organic building blocks. The utility of DQ-SQ technique in determining the information about HB in various fluorine substituted molecules has been convincingly established.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India.
| | - N Suryaprakash
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India.
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25
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Zhang W, Yang H, Liu F, Chen T, Hu G, Guo D, Hou Q, Wu X, Su Y, Wang J. Molecular interactions between DOPA and surfaces with different functional groups: a chemical force microscopy study. RSC Adv 2017. [DOI: 10.1039/c7ra04228k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The adhesion of mussel foot proteins (Mfps) to a variety of surfaces has been widely investigated, but the mechanisms behind the mussel adhesion to surfaces with different properties are far from being understood.
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26
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Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions. Nat Chem 2016; 8:768-77. [PMID: 27442282 PMCID: PMC4957664 DOI: 10.1038/nchem.2523] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/30/2016] [Indexed: 12/25/2022]
Abstract
Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium-organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities.
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27
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Mishra SK, Suryaprakash N. Intramolecular hydrogen bonds involving organic fluorine in the derivatives of hydrazides: an NMR investigation substantiated by DFT based theoretical calculations. Phys Chem Chem Phys 2016; 17:15226-35. [PMID: 25993543 DOI: 10.1039/c5cp01505g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rare examples of intramolecular hydrogen bonds (HB) of the type the N-H∙∙∙F-C, detected in a low polarity solvent in the derivatives of hydrazides, by utilizing one and two-dimensional solution state multinuclear NMR techniques, are reported. The observation of through-space couplings, such as, (1h)JFH, and (1h)JFN, provides direct evidence for the existence of intra-molecular HB. Solvent induced perturbations and the variable temperature NMR experiments unambiguously establish the presence of intramolecular HB. The existence of multiple conformers in some of the investigated molecules is also revealed by two dimensional HOESY and (15)N-(1)H HSQC experiments. The (1)H DOSY experimental results discard any possibility of self or cross dimerization of the molecules. The derived NMR experimental results are further substantiated by Density Function Theory (DFT) based Non Covalent Interaction (NCI), and Quantum Theory of Atom in Molecule (QTAIM) calculations. The NCI calculations served as a very sensitive tool for detection of non-covalent interactions and also confirm the presence of bifurcated HBs.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, India.
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28
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The strengths and weaknesses of NMR spectroscopy and mass spectrometry with particular focus on metabolomics research. Methods Mol Biol 2015; 1277:161-93. [PMID: 25677154 DOI: 10.1007/978-1-4939-2377-9_13] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mass spectrometry (MS) and nuclear magnetic resonance (NMR) have evolved as the most common techniques in metabolomics studies, and each brings its own advantages and limitations. Unlike MS spectrometry, NMR spectroscopy is quantitative and does not require extra steps for sample preparation, such as separation or derivatization. Although the sensitivity of NMR spectroscopy has increased enormously and improvements continue to emerge steadily, this remains a weak point for NMR compared with MS. MS-based metabolomics provides an excellent approach that can offer a combined sensitivity and selectivity platform for metabolomics research. Moreover, different MS approaches such as different ionization techniques and mass analyzer technology can be used in order to increase the number of metabolites that can be detected. In this chapter, the advantages, limitations, strengths, and weaknesses of NMR and MS as tools applicable to metabolomics research are highlighted.
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29
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Mishra SK, Suryaprakash N. Organic fluorine involved intramolecular hydrogen bonds in the derivatives of imides: NMR evidence corroborated by DFT based theoretical calculations. RSC Adv 2015. [DOI: 10.1039/c5ra19537c] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The rare occurrence of intramolecular hydrogen bonds (HBs) of the type N–H⋯F–C is detected in the derivatives of imides in a low polarity solvent by using multi-dimensional and multinuclear NMR experiments.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012
- India
| | - N. Suryaprakash
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012
- India
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30
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Lakshmipriya A, Rama Chaudhari S, Shahi A, Arunan E, Suryaprakash N. Three centered hydrogen bonds of the type CO⋯H(N)⋯X–C in diphenyloxamide derivatives involving halogens and a rotating CF3 group: NMR, QTAIM, NCI and NBO studies. Phys Chem Chem Phys 2015; 17:7528-36. [DOI: 10.1039/c4cp05917d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The existence of three centered CO⋯H(N)⋯X–C hydrogen bonds (H-bonds) involving organic fluorine and other halogens in diphenyloxamide derivatives has been explored by NMR spectroscopy and quantum theoretical studies.
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Affiliation(s)
- A. Lakshmipriya
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
| | - Sachin Rama Chaudhari
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
| | - Abhishek Shahi
- Inorganic and Physical Chemistry Department
- Indian Institute of Science
- Bangalore 560012
- India
| | - E. Arunan
- Inorganic and Physical Chemistry Department
- Indian Institute of Science
- Bangalore 560012
- India
| | - N. Suryaprakash
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
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31
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Langseth E, Nova A, Tråseth EA, Rise F, Øien S, Heyn RH, Tilset M. A Gold Exchange: A Mechanistic Study of a Reversible, Formal Ethylene Insertion into a Gold(III)–Oxygen Bond. J Am Chem Soc 2014; 136:10104-15. [DOI: 10.1021/ja504554u] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | | | | | | | | | - Richard H. Heyn
- SINTEF
Materials and Chemistry, P.O. Box 124, Blindern, N-0314 Oslo, Norway
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32
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RES-TOCSY: A facile approach for accurate determination of magnitudes, and relative signs of nJHF. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Abstract
![]()
This review will summarize our structural
and kinetic studies of
RB69 DNA polymerase (RB69pol) as well as selected variants of the
wild-type enzyme that were undertaken to obtain a deeper understanding
of the exquisitely high fidelity of B family replicative DNA polymerases.
We discuss how the structures of the various RB69pol ternary complexes
can be used to rationalize the results obtained from pre-steady-state
kinetic assays. Our main findings can be summarized as follows. (i)
Interbase hydrogen bond interactions can increase catalytic efficiency
by 5000-fold; meanwhile, base selectivity is not solely determined
by the number of hydrogen bonds between the incoming dNTP and the
templating base. (ii) Minor-groove hydrogen bond interactions at positions n – 1 and n – 2 of the primer
strand and position n – 1 of the template
strand in RB69pol ternary complexes are essential for efficient primer
extension and base selectivity. (iii) Partial charge interactions
among the incoming dNTP, the penultimate base pair, and the hydration
shell surrounding the incoming dNTP modulate nucleotide insertion
efficiency and base selectivity. (iv) Steric clashes between mismatched
incoming dNTPs and templating bases with amino acid side chains in
the nascent base pair binding pocket (NBP) as well as weak interactions
and large gaps between the incoming dNTPs and the templating base
are some of the reasons that incorrect dNTPs are incorporated so inefficiently
by wild-type RB69pol. In addition, we developed a tC°–tCnitro Förster resonance energy transfer assay to monitor
partitioning of the primer terminus between the polymerase and exonuclease
subdomains.
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Affiliation(s)
- Shuangluo Xia
- Department of Molecular Biophysics and Biochemistry, Yale University , New Haven, Connecticut 06520-8024, United States
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34
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Chaudhari SR, Suryaprakash N. Pure shift NMR approach for fast and accurate extraction of heteronuclear couplings. RSC Adv 2014. [DOI: 10.1039/c4ra01436g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An NMR experiment for the direct determination of heteronuclear couplings from the severely overlapped 1H NMR spectrum.
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Affiliation(s)
- Sachin Rama Chaudhari
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012, India
| | - N. Suryaprakash
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012, India
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35
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Struble MD, Strull J, Patel K, Siegler MA, Lectka T. Modulating “Jousting” C–F---H–C Interactions with a Bit of Hydrogen Bonding. J Org Chem 2013; 79:1-6. [DOI: 10.1021/jo4018205] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mark D. Struble
- Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Jessica Strull
- Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Kishan Patel
- Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A. Siegler
- Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Thomas Lectka
- Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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36
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Giuffredi GT, Gouverneur V, Bernet B. Intramolecular OH⋅⋅⋅FC Hydrogen Bonding in Fluorinated Carbohydrates: CHF is a Better Hydrogen Bond Acceptor than CF2. Angew Chem Int Ed Engl 2013; 52:10524-8. [DOI: 10.1002/anie.201303766] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/11/2013] [Indexed: 11/08/2022]
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37
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Intramolecular OH⋅⋅⋅FC Hydrogen Bonding in Fluorinated Carbohydrates: CHF is a Better Hydrogen Bond Acceptor than CF2. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201303766] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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