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Veeraprakash B, Shanavas AKJ, Reddy GSM, Lobo NP, Ramanathan KV, Narasimhaswamy T. Molecular Conformations of Shape Anisometrically Variant Mesogens in Liquid Crystalline Phase Studied by 13 C NMR Spectroscopy. Chemphyschem 2023:e202300353. [PMID: 37725408 DOI: 10.1002/cphc.202300353] [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: 05/18/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 09/21/2023]
Abstract
Mesogens that vary in shape anisometry have been investigated by 13 C solid-state NMR in the liquid crystalline phase to inspect the conformations. The molecules examined comprise of (i) rod-like mesogen with three-phenyl ring core and terminal hexyloxy chains, (ii) three-ring core linked to the fourth phenyl ring via a spacer, and (iii) trimesic acid connected to three side arms core units through a spacer. The order parameter (Szz ) values for the phenyl rings of the rod-like mesogen are 0.65-0.68, while the mesogen with a three-ring core linked to a phenyl ring via spacer showed dissimilarity. Consequently, for the core unit phenyl rings, Szz is ~0.70, and the terminal phenyl ring showed a low value of 0.12. For the trimesic acid based mesogen, the Szz value for the side arm phenyl rings is ~0.53, and for the central phenyl ring, a very low value of 0.11 is witnessed. By considering the ordering of the rod-like mesogen as a yardstick and employing the ratios of Szz values of the phenyl rings, the average conformations of other mesogens are arrived. Accordingly, for the trimesic acid based mesogen, a tripod-like conformation instead of λ shape is proposed in the liquid crystalline phase.
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Affiliation(s)
- Bathini Veeraprakash
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India
| | - Abdul K J Shanavas
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India
| | - Goddeti S M Reddy
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India
| | - Nitin P Lobo
- Centre for Analysis, Testing, Evaluation & Reporting Services (CATERS), CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | | | - Tanneru Narasimhaswamy
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai, 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Bavo F, Pallavicini M, Pucci S, Appiani R, Giraudo A, Oh H, Kneisley DL, Eaton B, Lucero L, Gotti C, Clementi F, Whiteaker P, Bolchi C. Subnanomolar Affinity and Selective Antagonism at α7 Nicotinic Receptor by Combined Modifications of 2-Triethylammonium Ethyl Ether of 4-Stilbenol (MG624). J Med Chem 2022; 66:306-332. [PMID: 36526469 PMCID: PMC9841521 DOI: 10.1021/acs.jmedchem.2c01256] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Modifications of the cationic head and the ethylene linker of 2-(triethylammonium)ethyl ether of 4-stilbenol (MG624) have been proved to produce selective α9*-nAChR antagonism devoid of any effect on the α7-subtype. Here, single structural changes at the styryl portion of MG624 lead to prevailing α7-nAChR antagonism without abolishing α9*-nAChR antagonism. Nevertheless, rigidification of the styryl into an aromatic bicycle, better if including a H-bond donor NH, such as 5-indolyl (31), resulted in higher and more selective α7-nAChR affinity. Hybridization of this modification with the constraint of the 2-triethylammoniumethyloxy portion into (R)-N,N-dimethyl-3-pyrrolidiniumoxy substructure, previously reported as the best modification for the α7-nAChR affinity of MG624 (2), was a winning strategy. The resulting hybrid 33 had a subnanomolar α7-nAChR affinity and was a potent and selective α7-nAChR antagonist, producing at the α7-, but not at the α9*-nAChR, a profound loss of subsequent ACh function.
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Affiliation(s)
- Francesco Bavo
- Dipartimento
di Scienze Farmaceutiche, Università
degli Studi di Milano, via Mangiagalli 25, I-20133 Milano, Italy,Department
of Drug Design and Pharmacology, University
of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Marco Pallavicini
- Dipartimento
di Scienze Farmaceutiche, Università
degli Studi di Milano, via Mangiagalli 25, I-20133 Milano, Italy
| | - Susanna Pucci
- Institute
of Neuroscience, CNR, via Vanvitelli 32, I-20129 Milano, Italy,NeuroMi
Milan Center for Neuroscience, University
of Milano Bicocca, piazza
Ateneo Nuovo 1, I-20126 Milano, Italy
| | - Rebecca Appiani
- Dipartimento
di Scienze Farmaceutiche, Università
degli Studi di Milano, via Mangiagalli 25, I-20133 Milano, Italy
| | - Alessandro Giraudo
- Dipartimento
di Scienze Farmaceutiche, Università
degli Studi di Milano, via Mangiagalli 25, I-20133 Milano, Italy
| | - Hyoungil Oh
- Department
of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Dana L. Kneisley
- Department
of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Brek Eaton
- Division
of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona 85013, United States
| | - Linda Lucero
- Division
of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona 85013, United States
| | - Cecilia Gotti
- Institute
of Neuroscience, CNR, via Vanvitelli 32, I-20129 Milano, Italy
| | - Francesco Clementi
- Institute
of Neuroscience, CNR, via Vanvitelli 32, I-20129 Milano, Italy
| | - Paul Whiteaker
- Department
of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Cristiano Bolchi
- Dipartimento
di Scienze Farmaceutiche, Università
degli Studi di Milano, via Mangiagalli 25, I-20133 Milano, Italy,. Phone: +390250319347
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Mehreen S, Ullah A, Nadeem H, Dege N, Naseer MM. Synthesis, solid state self-assembly driven by antiparallel π⋯π stacking and {⋯H-C-C-F} 2 dimer synthons, and in vitro acetyl cholinesterase inhibition activity of phenoxy pendant isatins. RSC Adv 2022; 12:1788-1796. [PMID: 35425213 PMCID: PMC8979220 DOI: 10.1039/d1ra08286h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/03/2022] [Indexed: 12/12/2022] Open
Abstract
A series of novel phenoxy pendant isatins PI1-12 have been synthesized in excellent yields by a simple nucleophilic substitution reaction involving isatins and 1-(2-bromoethoxy)-4-substituted benzenes, and characterized by their FT-IR, 1H NMR, 13C NMR and GC-MS data, and in the case of PI4 by its single crystal X-ray analysis. The solid-state structure of PI4 showed an intriguing and unique 1D-supramolecular chain-based self-assembled structure, the driving force of which is mainly the strong antiparallel π⋯π stacking and {⋯H-C-C-F}2 dimer synthons. This compound not only highlights the potential of the isatin moiety in forming strong antiparallel π⋯π stacking interactions but also provides a platform to have considerable insight into the nature, strength and directionality of much debated π-π and C-H⋯F-C interactions. The in vitro biological studies revealed that three phenoxy pendant isatins PI1, PI2 and PI4 are highly potent inhibitors of acetylcholinesterase enzyme with IC50 values of 0.52 ± 0.073 μg ml-1, 0.72 ± 0.012 μg ml-1 and 0.68 ± 0.011 μg ml-1, respectively, showing comparable activity to the standard drug, donepezil (IC50 = 0.73 ± 0.015 μg ml-1). A simple and efficient synthesis of phenoxy pendant isatins PI1-12 from inexpensive and commercially available starting materials, and their high potential of acetyl cholinesterase inhibition provide an attractive opportunity to find more effective medication for Alzheimer's disease (AD).
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Affiliation(s)
- Saba Mehreen
- Department of Chemistry, Quaid-i-Azam University Islamabad 45320 Pakistan
| | - Aman Ullah
- Department of Agricultural, Food and Nutritional Science, 4-10 Agriculture/Forestry Centre, University of Alberta Edmonton AB T6G 2P5 Canada
| | - Humaira Nadeem
- Department of Pharmaceutical Chemistry, Riphah Institute of Pharmaceutical Sciences, Riphah International University G-7/4 Islamabad Pakistan
| | - Necmi Dege
- Ondokuz Mayıs University, Faculty of Arts and Sciences, Department of Physics Kurupelit 55139 Samsun Turkey
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