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Orlandini G, Groppi J, Secchi A, Arduini A, Kilburn JD. Electrochemical Response of the Threading/de-threading Process of Calix[6]arene-based Pseudorotaxanes Anchored on Glassy Carbon Electrodes. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Perveen S, Kilburn JD, Al-Taweel AM, Light ME. Synthesis, Characterisation and Crystal Structure of a Novel Pyridyl Urea Macrocycle. JOURNAL OF CHEMICAL RESEARCH 2016. [DOI: 10.3184/174751916x14792878808106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A novel pyridyl urea based macrocycle has been synthesised and fully characterised including a single crystal X-ray structure determination. The synthetic approach first involves the reaction of benzyloxycarbonylaminopropyl-3-isocyanate with t-butyl 2-[(2-aminopyridin-3-yl)oxy]acetate resulting in a coupling product. After deprotection of the amine and acid moieties and coupling subsequent coupling in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), a macrocycle is formed. The structures of the compounds were confirmed by mass spectrometry and NMR spectroscopy. The X-ray crystal structure of the macrocycle reveals as expected a non-binding conformation with an intramolecular hydrogen bond between the urea NH and the pyridyl nitrogen.
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Groppi J, Bartlett PN, Kilburn JD. Toward the Control of the Creation of Mixed Monolayers on Glassy Carbon Surfaces by Amine Oxidation. Chemistry 2016; 22:1030-6. [PMID: 26637108 DOI: 10.1002/chem.201503120] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/08/2015] [Indexed: 11/12/2022]
Abstract
A versatile and simple methodology for the creation of mixed monolayers on glassy carbon (GC) surfaces was developed, using an osmium-bipyridyl complex and anthraquinone as model redox probes. The work consisted in the electrochemical grafting on GC of a mixture of mono-protected diamine linkers in varying ratios which, after attachment to the surface, allowed orthogonal deprotection. After optimisation of the deprotection conditions, it was possible to remove one of the protecting groups selectively, couple a suitable osmium complex and cap the residual free amines. The removal of the second protecting group allowed the coupling of anthraquinone. The characterisation of the resulting surfaces by cyclic voltammetry showed the variation of the surface coverage of the two redox centres in relation to the initial ratio of the linking amine in solution.
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Aillard B, Kilburn JD, Blaydes JP, Tizzard GJ, Findlow S, Werner JM, Bloodworth S. Synthesis and evaluation of a (3R,6S,9S)-2-oxo-1-azabicyclo[4.3.0]nonane scaffold as a mimic of Xaa-trans-Pro in poly-l-proline type II helix conformation. Org Biomol Chem 2015; 13:4562-9. [DOI: 10.1039/c5ob00180c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Stereoselective synthesis of a (3R,6S,9S)-2-oxo-1-azabicyclo[4.3.0]nonane mimic of Xaa-trans-Pro in poly-l-proline type II helix conformation is reported.
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Wright EJ, Sosna M, Bloodworth S, Kilburn JD, Bartlett PN. Design of Maleimide-Functionalised Electrodes for Covalent Attachment of Proteins through Free Surface Cysteine Groups. Chemistry 2014; 20:5550-4. [DOI: 10.1002/chem.201400246] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Indexed: 11/09/2022]
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Clark Still W, Kilburn JD, Sanderson PE, Liu R, Wiley MR, Hollinger FP, Hawley RC, Nakajima M, Bernardi A, Hong JI, Namgoong SK. Enantioselective Hosts for Neutral Derivatives of Amino Acids. Isr J Chem 2013. [DOI: 10.1002/ijch.199200006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Pinczewska A, Sosna M, Bloodworth S, Kilburn JD, Bartlett PN. High-throughput synthesis and electrochemical screening of a library of modified electrodes for NADH oxidation. J Am Chem Soc 2012; 134:18022-33. [PMID: 23046387 DOI: 10.1021/ja307390x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We report the combinatorial preparation and high-throughput screening of a library of modified electrodes designed to catalyze the oxidation of NADH. Sixty glassy carbon electrodes were covalently modified with ruthenium(II) or zinc(II) complexes bearing the redox active 1,10-phenanthroline-5,6-dione (phendione) ligand by electrochemical functionalization using one of four different linkers, followed by attachment of one of five different phendione metal complexes using combinatorial solid-phase synthesis methodology. This gave a library with three replicates of each of 20 different electrode modifications. This library was electrochemically screened in high-throughput (HTP) mode using cyclic voltammetry. The members of the library were evaluated with regard to the surface coverage, midpeak potential, and voltammetric peak separation for the phendione ligand, and their catalytic activity toward NADH oxidation. The surface coverage was found to depend on the length and flexibility of the linker and the geometry of the metal complex. The choices of linker and metal complex were also found to have significant impact on the kinetics of the reaction between the 1,10-phenanthroline-5,6-dione ligand and NADH. The rate constants for the reaction were obtained by analyzing the catalytic currents as a function of NADH concentration and scan rate, and the influence of the surface molecular architecture on the kinetics was evaluated.
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Sosna M, Stoica L, Wright E, Kilburn JD, Schuhmann W, Bartlett PN. Mass transport controlled oxygen reduction at anthraquinone modified 3D-CNT electrodes with immobilized Trametes hirsuta laccase. Phys Chem Chem Phys 2012; 14:11882-5. [DOI: 10.1039/c2cp41588g] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Meng J, Light ME, Kilburn JD, Dixon S. Samarium diiodide mediated intramolecular cyclisation of mixed enone–enoate systems: a simple preparation of spirocyclic ethers. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2010.12.077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Irfan Ashiq M, Tesfatsion BF, Gaggini F, Dixon S, Kilburn JD. Dimeric Self‐Assembly of Pyridyl Guanidinium Carboxylates in Polar Solvents. Chemistry 2010; 16:12387-97. [DOI: 10.1002/chem.201001861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ashiq MI, Hussain I, Dixon S, Light ME, Kilburn JD. Dimeric supramolecular motifs of two carboxylate–guanidinium compounds. Acta Crystallogr C 2010; 66:o455-8. [PMID: 20814105 DOI: 10.1107/s0108270110029252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 07/22/2010] [Indexed: 11/10/2022] Open
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Thitilertdecha N, Teerawutgulrag A, Kilburn JD, Rakariyatham N. Identification of major phenolic compounds from Nephelium lappaceum L. and their antioxidant activities. Molecules 2010; 15:1453-65. [PMID: 20335993 PMCID: PMC6257335 DOI: 10.3390/molecules15031453] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 03/05/2010] [Accepted: 03/08/2010] [Indexed: 11/16/2022] Open
Abstract
Nephelium lappaceum is a tropical fruit whose peel possesses antioxidant properties. Experiments on the isolation and identification of the active constituents were conducted, and on their antioxidant activity using a lipid peroxidation inhibition assay. The methanolic extract of N. lappaceum peels exhibited strong antioxidant properties. Sephadex LH-20 chromatography was utilized in the isolation of each constituent and the antioxidant properties of each was studied. The isolated compounds were identified as ellagic acid (EA) (1), corilagin (2) and geraniin (3). These compounds accounted for 69.3% of methanolic extract, with geraniin (56.8%) as the major component, and exhibited much greater antioxidant activities than BHT in both lipid peroxidation (77-186 fold) and DPPH* (42-87 fold) assays. The results suggest that the isolated ellagitannins, as the principal components of rambutan peels, could be further utilized as both a medicine and in the food industry.
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Meng J, Jiang T, Aslam Bhatti H, Siddiqui BS, Dixon S, Kilburn JD. Synthesis of dihydrodehydrodiconiferyl alcohol: the revised structure of lawsonicin. Org Biomol Chem 2010; 8:107-13. [DOI: 10.1039/b918179b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sosna M, Chrétien JM, Kilburn JD, Bartlett PN. Monolayer anthracene and anthraquinone modified electrodes as platforms for Trametes hirsuta laccase immobilisation. Phys Chem Chem Phys 2010; 12:10018-26. [DOI: 10.1039/c0cp00305k] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Powell JR, Dixon S, Light ME, Kilburn JD. Samarium diiodide-mediated intramolecular cyclodimerisation of bis-α,β-unsaturated carbonyl compounds. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.03.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ghanem MA, Chrétien JM, Kilburn JD, Bartlett PN. Electrochemical and solid-phase synthetic modification of glassy carbon electrodes with dihydroxybenzene compounds and the electrocatalytic oxidation of NADH. Bioelectrochemistry 2009; 76:115-25. [PMID: 19346167 DOI: 10.1016/j.bioelechem.2009.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 02/04/2009] [Accepted: 02/27/2009] [Indexed: 10/21/2022]
Abstract
We report the preparation, using electrochemical and solid-phase synthesis, and characterisation of a 26 member library of 13 dihydroxybenzene derivatives covalently attached to glassy carbon through ethylenediamine (EDA) and C(6)H(4)CH(2)NH linkers. First, Boc-protected EDA or Boc-NHCH(2)C(6)H(4) were electrochemically attached to the GC surface. After Boc-deprotection, dimethoxybenzoyl chlorides were coupled to the EDA and C(6)H(4)CH(2)NH linkers using solid-phase synthesis followed by deprotection of the methoxy groups to give the corresponding dihydroxybenzene compounds. Surface coverage and electrochemical parameters of the dihydroxybenzene modified electrodes were evaluated in parallel using cyclic voltammetry. The mid-peak potentials, E(mp), and surface coverages for the 13 dihydroxybenzene derivatives were found to be independent of the choice of linker. The mid-peak potentials of the immobilised dihydroxybenzene derivatives varied between 0.0 and 260 mV vs. SCE and their surface coverages varied between 0.07 and 1.1 nmol cm(-2), depending on the pattern of substitution of the dihydroxybenzene ring. The electrocatalytic activities of the library were evaluated for mediation of NADH oxidation, and the ortho-dihydroxybenzene derivatives were found to have higher catalytic activity.
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Mammoliti O, Allasia S, Dixon S, Kilburn JD. Synthesis and anion-binding properties of new disulfonamide-based receptors. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.01.070] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lamberto M, Kilburn JD. Synthesis of indolizidines from dialkylated isocyanides: a novel radical cyclisation/N-alkylation/ring closing metathesis approach. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.08.088] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bartoli S, Mahmood T, Malik A, Dixon S, Kilburn JD. Selective binding of l-glutamate derivative in aqueous solvents. Org Biomol Chem 2008; 6:2340-5. [DOI: 10.1039/b803089h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ghanem MA, Chrétien JM, Pinczewska A, Kilburn JD, Bartlett PN. Covalent modification of glassy carbon surface with organic redox probes through diamine linkers using electrochemical and solid-phase synthesis methodologies. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b809040h] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ragusa A, Hayes JM, Light ME, Kilburn JD. A Combined Computational and Experimental Approach for the Analysis of the Enantioselective Potential of a New Macrocyclic Receptor for N-Protected α-Amino Acids. Chemistry 2007; 13:2717-28. [PMID: 17200922 DOI: 10.1002/chem.200601289] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A new macrocyclic receptor incorporating a thiourea moiety has been synthesised. Crystal structures of the macrocycle showed that the receptor has a rigid backbone but the thiourea moiety can orientate itself to bind to a DMSO solvent molecule. Force-field (MMFFs) calculations were performed to model the macrocycle and its binding properties with respect to N-protected amino acids, which were measured experimentally by NMR titration. Binding free energies were calculated by using the mode integration algorithm (MINTA) or free-energy perturbation (FEP). Excellent qualitative agreement with experiment was obtained. To further exploit the accuracy of the free-energy predictions for this system, the faster free-energy algorithm MINTA was used as a prediction tool to test the binding affinity of the macrocycle towards a series of several other amino acid derivatives, which speeded up considerably the screening process and reduced laboratory costs.
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Shepherd J, Langley GJ, Herniman JM, Kilburn JD. Rapid Sequencing of Split-and-Mix Peptide Receptor Libraries – Identification of Binding Partners for Val-Val-Ile-Ala in Aqueous Solution. European J Org Chem 2007. [DOI: 10.1002/ejoc.200601004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chanwitheesuk A, Teerawutgulrag A, Kilburn JD, Rakariyatham N. Antimicrobial gallic acid from Caesalpinia mimosoides Lamk. Food Chem 2007. [DOI: 10.1016/j.foodchem.2005.11.008] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Fitzmaurice RJ, Gaggini F, Srinivasan N, Kilburn JD. Carboxylate binding in polar solvents using pyridylguanidinium salts. Org Biomol Chem 2007; 5:1706-14. [PMID: 17520138 DOI: 10.1039/b700988g] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of thiourea and guanidinium derivatives have been prepared and their ability to bind a carboxylate group has been investigated. Guanidinium 33, featuring two additional amides and a pyridine moiety, proved to be the most potent carboxylate binding site and was able to bind acetate in aqueous solvent systems (K(ass) = 480 M(-1) in 30% H(2)O-DMSO). The pyridine moiety is critical to obtaining strong binding, and comparison with the binding properties of analogous compounds in which the pyridine is replaced by a benzene ring provides a striking example of enthalpy-entropy compensation.
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Underhill AE, Robertson N, Ziegenbalg J, Narvor NL, Kilburn JD, Awaga K. Molecular Complexes of Extended Sulphur Donor Ligands. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259608037909] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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