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Gartshore CJ, Wang X, Su Y, Molinski TF. Petrosamine Revisited. Experimental and Computational Investigation of Solvatochromism, Tautomerism and Free Energy Landscapes of a Pyridoacridinium Quaternary Salt. Mar Drugs 2023; 21:446. [PMID: 37623727 PMCID: PMC10455967 DOI: 10.3390/md21080446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/26/2023] Open
Abstract
Petrosamine (1)-a colored pyridoacridine alkaloid from the Belizean sponge, Petrosia sp., that is also a potent inhibitor of acetylcholine esterase (AChE)-was investigated by spectroscopic and computational methods. Analysis of the petrosamine-free energy landscapes, pKa and tautomerism, revealed an accurate electronic depiction of the molecular structure of 1 as the di-keto form, with a net charge of q = +1, rather than a dication (q = +2) under ambient conditions of isolation-purification. The pronounced solvatochromism (UV-vis) reported for 1, and related analogs were investigated in detail and is best explained by charge delocalization and stabilization of the ground state (HOMO) of 1 rather than an equilibrium of competing tautomers. Refinement of the molecular structure 1 by QM methods complements published computational docking studies to define the contact points in the enzyme active site that may improve the design of new AChE inhibitors based on the pyridoacridine alkaloid molecular skeleton.
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Affiliation(s)
- Christopher J. Gartshore
- Department of Chemistry and Biochemistry, University of California, 9500 Gilman Drive MC3568, La Jolla, San Diego, CA 92093, USA; (C.J.G.); (X.W.); (Y.S.)
| | - Xiao Wang
- Department of Chemistry and Biochemistry, University of California, 9500 Gilman Drive MC3568, La Jolla, San Diego, CA 92093, USA; (C.J.G.); (X.W.); (Y.S.)
| | - Yongxuan Su
- Department of Chemistry and Biochemistry, University of California, 9500 Gilman Drive MC3568, La Jolla, San Diego, CA 92093, USA; (C.J.G.); (X.W.); (Y.S.)
| | - Tadeusz F. Molinski
- Department of Chemistry and Biochemistry, University of California, 9500 Gilman Drive MC3568, La Jolla, San Diego, CA 92093, USA; (C.J.G.); (X.W.); (Y.S.)
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC3568, La Jolla, San Diego, CA 92093, USA
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2
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Langley SK, Vignesh KR, Gupta T, Gartshore CJ, Rajaraman G, Forsyth CM, Murray KS. New examples of triangular terbium(iii) and holmium(iii) and hexagonal dysprosium(iii) single molecule toroics. Dalton Trans 2019; 48:15657-15667. [PMID: 31482898 DOI: 10.1039/c9dt02419k] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural, magnetic and theoretical aspects are described for three triangular lanthanide complexes, [Tb(OH)(teaH2)3(paa)3]Cl2 (1), [Dy(OH)(teaH2)3(paa)3]Cl2 (2) and [Ho(OH)(teaH2)3(paa)3]Cl2 (3), and a hexanuclear wheel of formula [Dy(pdeaH)6(NO3)6] (4) [teaH3 = triethanolamine, paaH = N-(2-pyridyl)-acetoacetamide and pdeaH3 = 3-[bis(2-hydroxyethyl)amino]propan-1-ol]. Each complex displays single molecule toroidal behaviour as rationalised using high-level ab initio calculations. Complexes 2 and 3 are the first examples of mixed moment single molecule toroidal complexes featuring non-Kramers ions.
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Affiliation(s)
- Stuart K Langley
- School of science and the environment, Division of Chemistry, Manchester Metropolitan University, Manchester, M15 6BH, UK.
| | - Kuduva R Vignesh
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | - Tulika Gupta
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | | | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | - Craig M Forsyth
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
| | - Keith S Murray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
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3
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Vignesh KR, Langley SK, Gartshore CJ, Borilović I, Forsyth CM, Rajaraman G, Murray KS. Rationalizing the sign and magnitude of the magnetic coupling and anisotropy in dinuclear manganese(iii) complexes. Dalton Trans 2018; 47:11820-11833. [PMID: 29951677 DOI: 10.1039/c8dt01410h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We have synthesised twelve manganese(iii) dinuclear complexes, 1-12, in order to understand the origin of magnetic exchange (J) between the metal centres and the magnetic anisotropy (D) of each metal ion using a combined experimental and theoretical approach. All twelve complexes contain the same bridging ligand environment of one μ-oxo and two μ-carboxylato, that helped us to probe how the structural parameters, such as bond distance, bond angle and especially Jahn-Teller dihedral angle affect the magnetic behaviour. Among the twelve complexes, we found ferromagnetic coupling for five and antiferromagnetic coupling for seven. DFT computed the J and ab initio methods computed the D parameter, and are in general agreement with the experimentally determined values. The dihedral angle between the two Jahn-Teller axes of the constituent MnIII ions are found to play a key role in determining the sign of the magnetic coupling. Magneto-structural correlations are developed by varying the Mn-O distance and the Mn-O-Mn angle to understand how the magnetic coupling changes upon these structural changes. Among the developed correlations, the Mn-O distance is found to be the most sensitive parameter that switches the sign of the magnetic coupling from negative to positive. The single-ion zero-field splitting of the MnIII centres is found to be negative for complexes 1-11 and positive for complex 12. However, the zero-field splitting of the S = 4 state for the ferromagnetic coupled dimers is found to be positive, revealing a significant contribution from the exchange anisotropy - a parameter which has long been ignored as being too small to be effective.
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Gartshore CJ, Salib MN, Renshaw AA, Molinski TF. Isolation of bastadin-6-O-sulfate and expedient purifications of bastadins-4, -5 and -6 from extracts of Ianthella basta. Fitoterapia 2017; 126:16-21. [PMID: 29221701 DOI: 10.1016/j.fitote.2017.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/29/2017] [Accepted: 12/04/2017] [Indexed: 11/17/2022]
Abstract
Bastadin-6-34-O-sulfate ester (8) was isolated from methanol extracts of Ianthella basta. The structure of 8 was characterized by analysis of MS and NMR data, and conversion through acid hydrolysis, to the parent compound, bastadin-6, which was identical by HPLC, MS and NMR with an authentic sample. An improved procedure for procurement of pure samples of bastadins-4 (4), -5 (5) and -6 (6) is described.
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Affiliation(s)
- Christopher J Gartshore
- Department of Chemistry and Biochemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC0358, La Jolla, San Diego, CA 92093, United States
| | - Mariam N Salib
- Department of Chemistry and Biochemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC0358, La Jolla, San Diego, CA 92093, United States
| | - August A Renshaw
- Department of Chemistry and Biochemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC0358, La Jolla, San Diego, CA 92093, United States
| | - Tadeusz F Molinski
- Department of Chemistry and Biochemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC0358, La Jolla, San Diego, CA 92093, United States; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, 9500 Gilman Drive MC0358, La Jolla, San Diego, CA 92093, United States.
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5
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Vignesh KR, Langley SK, Gartshore CJ, Moubaraki B, Murray KS, Rajaraman G. What Controls the Magnetic Exchange and Anisotropy in a Family of Tetranuclear {Mn2IIMn2III} Single-Molecule Magnets? Inorg Chem 2017; 56:1932-1949. [PMID: 28156106 DOI: 10.1021/acs.inorgchem.6b02527] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Stuart K. Langley
- School of Science and the Environment, Chemistry Division, Manchester Metropolitan University, Manchester, United Kingdom
| | | | - Boujemaa Moubaraki
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Keith S. Murray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
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6
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Scott HS, Gartshore CJ, Guo SX, Moubaraki B, Bond AM, Batten SR, Murray KS. Ferrocene-appended ligands for use in spin crossover-redox “hybrid” complexes of iron(ii) and cobalt(ii). Dalton Trans 2014; 43:15212-20. [DOI: 10.1039/c4dt02126f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Structural, magnetic and electrochemical data are described for trans-[FeII(FTP)2(NCS)2], [CoII(FTTP)2](ClO4)2·2(MeCN) and [FeII(FTTP)2](ClO4)2·Et2O where FTP and FTTP are ferrocene-appended chelators.
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Affiliation(s)
| | | | - Si-Xuan Guo
- School of Chemistry
- Monash University
- Clayton, Australia
| | | | - Alan M. Bond
- School of Chemistry
- Monash University
- Clayton, Australia
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7
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Gass IA, Tewary S, Nafady A, Chilton NF, Gartshore CJ, Asadi M, Lupton DW, Moubaraki B, Bond AM, Boas JF, Guo SX, Rajaraman G, Murray KS. Observation of Ferromagnetic Exchange, Spin Crossover, Reductively Induced Oxidation, and Field-Induced Slow Magnetic Relaxation in Monomeric Cobalt Nitroxides. Inorg Chem 2013; 52:7557-72. [DOI: 10.1021/ic400565h] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Ian A. Gass
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Subrata Tewary
- Department
of Chemistry, Indian Institute of Technology—Bombay, Powai, Mumbai, India
| | - Ayman Nafady
- Department of Chemistry, King Saud University, P.O. Box 2455, Riyadh−11451, Kingdom of Saudi Arabia
| | | | | | - Mousa Asadi
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - David W. Lupton
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Boujemaa Moubaraki
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Alan M. Bond
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - John F. Boas
- School of Physics, Monash University,
Clayton, Victoria 3800, Australia
| | - Si-Xuan Guo
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Gopalan Rajaraman
- Department
of Chemistry, Indian Institute of Technology—Bombay, Powai, Mumbai, India
| | - Keith S. Murray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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8
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Gartshore CJ, Lupton DW. Enantioselective Palladium-Catalyzed Decarboxylative Allylation of Carbazolones and Indolones: Formal Synthesis of (+)-Kopsihainanine A. Angew Chem Int Ed Engl 2013; 52:4113-6. [DOI: 10.1002/anie.201209069] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Indexed: 11/10/2022]
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9
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Gartshore CJ, Lupton DW. Enantioselective Palladium-Catalyzed Decarboxylative Allylation of Carbazolones and Indolones: Formal Synthesis of (+)-Kopsihainanine A. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201209069] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Gartshore CJ, Lupton DW. Studies on the Enantioselective Synthesis of Carbazolones as Intermediates in Aspidosperma and Kopsia Alkaloid Synthesis. Aust J Chem 2013. [DOI: 10.1071/ch13287] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Two strategies for the assembly of homochiral carbazolones have been investigated. The first exploited desymmetrisation of 1,3-cyclohexadione derivatives however this failed to deliver satisfactory outcomes. An orthogonal route exploiting palladium catalysed decarboxylative allylation of racemic carbazolone β-ketoesters has been developed. Herein we report full details on the development of this reaction and clarify apparent discrepancies between our preliminary reports and those of Shao.
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Gass IA, Gartshore CJ, Lupton DW, Moubaraki B, Nafady A, Bond AM, Boas JF, Cashion JD, Milsmann C, Wieghardt K, Murray KS. Anion Dependent Redox Changes in Iron Bis-terdentate Nitroxide {NNO} Chelates. Inorg Chem 2011; 50:3052-64. [DOI: 10.1021/ic102588h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Gartshore CJ, Lupton DW. Readily Accessible Oxazolidine Nitroxyl Radicals: Bifunctional Cocatalysts for Simplified Copper Based Aerobic Oxidation. Adv Synth Catal 2010. [DOI: 10.1002/adsc.201000627] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Ngatimin M, Gartshore CJ, Kindler JP, Naidu S, Lupton DW. The α-halogenation of α,β-unsaturated carbonyls and dihalogenation of alkenes using bisacetoxyiodobenzene/pyridine hydrohalides. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.08.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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