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Johnson TF, Conti M, Iacoviello F, Shearing PR, Pullen J, Dimartino S, Bracewell DG. Evaluating 3D-printed bioseparation structures using multi-length scale tomography. Anal Bioanal Chem 2023; 415:5961-5971. [PMID: 37522918 PMCID: PMC10556175 DOI: 10.1007/s00216-023-04866-6] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023]
Abstract
X-ray computed tomography was applied in imaging 3D-printed gyroids used for bioseparation in order to visualize and characterize structures from the entire geometry down to individual nanopores. Methacrylate prints were fabricated with feature sizes of 500 µm, 300 µm, and 200 µm, with the material phase exhibiting a porous substructure in all cases. Two X-ray scanners achieved pixel sizes from 5 µm to 16 nm to produce digital representations of samples across multiple length scales as the basis for geometric analysis and flow simulation. At the gyroid scale, imaged samples were visually compared to the original computed-aided designs to analyze printing fidelity across all feature sizes. An individual 500 µm feature, part of the overall gyroid structure, was compared and overlaid between design and imaged volumes, identifying individual printed layers. Internal subvolumes of all feature sizes were segmented into material and void phases for permeable flow analysis. Small pieces of 3D-printed material were optimized for nanotomographic imaging at a pixel size of 63 nm, with all three gyroid samples exhibiting similar geometric characteristics when measured. An average porosity of 45% was obtained that was within the expected design range, and a tortuosity factor of 2.52 was measured. Applying a voidage network map enabled the size, location, and connectivity of pores to be identified, obtaining an average pore size of 793 nm. Using Avizo XLAB at a bulk diffusivity of 7.00 × 10-11 m2s-1 resulted in a simulated material diffusivity of 2.17 × 10-11 m2s-1 ± 0.16 × 10-11 m2s-1.
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Affiliation(s)
- Thomas F. Johnson
- Department of Biochemical Engineering, University College London, Bernard Katz, London, WC1E 6BT UK
| | - Mariachiara Conti
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL UK
| | - Francesco Iacoviello
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
| | - Paul R. Shearing
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
| | - James Pullen
- Fujifilm Diosynth Technologies, Belasis Avenue, Billingham, TS23 1LH UK
| | - Simone Dimartino
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL UK
| | - Daniel G. Bracewell
- Department of Biochemical Engineering, University College London, Bernard Katz, London, WC1E 6BT UK
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2
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Clark J, Moses A, Nankasi A, Faust CL, Moses A, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Carruthers LV, Francoeur R, Tukahebwa EM, Prada JM, Lamberton PHL. Reconciling Egg- and Antigen-Based Estimates of Schistosoma mansoni Clearance and Reinfection: A Modeling Study. Clin Infect Dis 2022; 74:1557-1563. [PMID: 34358299 PMCID: PMC9070857 DOI: 10.1093/cid/ciab679] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Despite decades of interventions, 240 million people have schistosomiasis. Infections cannot be directly observed, and egg-based Kato-Katz thick smears lack sensitivity, affected treatment efficacy and reinfection rate estimates. The point-of-care circulating cathodic antigen (referred to from here as POC-CCA+) test is advocated as an improvement on the Kato-Katz method, but improved estimates are limited by ambiguities in the interpretation of trace results. METHOD We collected repeated Kato-Katz egg counts from 210 school-aged children and scored POC-CCA tests according to the manufacturer's guidelines (referred to from here as POC-CCA+) and the externally developed G score. We used hidden Markov models parameterized with Kato-Katz; Kato-Katz and POC-CCA+; and Kato-Katz and G-Scores, inferring latent clearance and reinfection probabilities at four timepoints over six-months through a more formal statistical reconciliation of these diagnostics than previously conducted. Our approach required minimal but robust assumptions regarding trace interpretations. RESULTS Antigen-based models estimated higher infection prevalence across all timepoints compared with the Kato-Katz model, corresponding to lower clearance and higher reinfection estimates. Specifically, pre-treatment prevalence estimates were 85% (Kato-Katz; 95% CI: 79%-92%), 99% (POC-CCA+; 97%-100%) and 98% (G-Score; 95%-100%). Post-treatment, 93% (Kato-Katz; 88%-96%), 72% (POC-CCA+; 64%-79%) and 65% (G-Score; 57%-73%) of those infected were estimated to clear infection. Of those who cleared infection, 35% (Kato-Katz; 27%-42%), 51% (POC-CCA+; 41%-62%) and 44% (G-Score; 33%-55%) were estimated to have been reinfected by 9-weeks. CONCLUSIONS Treatment impact was shorter-lived than Kato-Katz-based estimates alone suggested, with lower clearance and rapid reinfection. At 3 weeks after treatment, longer-term clearance dynamics are captured. At 9 weeks after treatment, reinfection was captured, but failed clearance could not be distinguished from rapid reinfection. Therefore, frequent sampling is required to understand these important epidemiological dynamics.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Adriko Moses
- Vector Control Division, Ministry of Health, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Uganda
| | | | | | - Lauren V Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science & Engineering, University of Chester, Chester, United Kingdom
| | | | - Joaquin M Prada
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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3
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Kwon H, Basran J, Pathak C, Hussain M, Freeman SL, Fielding AJ, Bailey AJ, Stefanou N, Sparkes HA, Tosha T, Yamashita K, Hirata K, Murakami H, Ueno G, Ago H, Tono K, Yamamoto M, Sawai H, Shiro Y, Sugimoto H, Raven EL, Moody PCE. XFEL Crystal Structures of Peroxidase Compound II. Angew Chem Int Ed Engl 2021; 60:14578-14585. [PMID: 33826799 PMCID: PMC8251747 DOI: 10.1002/anie.202103010] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Indexed: 01/07/2023]
Abstract
Oxygen activation in all heme enzymes requires the formation of high oxidation states of iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and Compound II. The nature of the ferryl heme-and whether it is an FeIV =O or FeIV -OH species-is important for controlling reactivity across groups of heme enzymes. The most recent evidence for Compound I indicates that the ferryl heme is an unprotonated FeIV =O species. For Compound II, the nature of the ferryl heme is not unambiguously established. Here, we report 1.06 Å and 1.50 Å crystal structures for Compound II intermediates in cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX), collected using the X-ray free electron laser at SACLA. The structures reveal differences between the two peroxidases. The iron-oxygen bond length in CcP (1.76 Å) is notably shorter than in APX (1.87 Å). The results indicate that the ferryl species is finely tuned across Compound I and Compound II species in closely related peroxidase enzymes. We propose that this fine-tuning is linked to the functional need for proton delivery to the heme.
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Affiliation(s)
- Hanna Kwon
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Jaswir Basran
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Chinar Pathak
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Mahdi Hussain
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Samuel L. Freeman
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Alistair J. Fielding
- Centre for Natural Products Discovery, Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityJames Parsons Building, Byrom StreetLiverpoolL3 3AFUK
| | - Anna J. Bailey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Natalia Stefanou
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Hazel A. Sparkes
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | | | - Keitaro Yamashita
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
- Present address: MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB1 0QHUK
| | - Kunio Hirata
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hironori Murakami
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | - Go Ueno
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hideo Ago
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | | | - Hitomi Sawai
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | - Yoshitsugu Shiro
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | | | - Emma L. Raven
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Peter C. E. Moody
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
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4
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Lau S, Gasperini D, Webster RL. Amine-Boranes as Transfer Hydrogenation and Hydrogenation Reagents: A Mechanistic Perspective. Angew Chem Int Ed Engl 2021; 60:14272-14294. [PMID: 32935898 PMCID: PMC8248159 DOI: 10.1002/anie.202010835] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Indexed: 11/10/2022]
Abstract
Transfer hydrogenation (TH) has historically been dominated by Meerwein-Ponndorf-Verley (MPV) reactions. However, with growing interest in amine-boranes, not least ammonia-borane (H3 N⋅BH3 ), as potential hydrogen storage materials, these compounds have also started to emerge as an alternative reagent in TH reactions. In this Review we discuss TH chemistry using H3 N⋅BH3 and their analogues (amine-boranes and metal amidoboranes) as sacrificial hydrogen donors. Three distinct pathways were considered: 1) classical TH, 2) nonclassical TH, and 3) hydrogenation. Simple experimental mechanistic probes can be employed to distinguish which pathway is operating and computational analysis can corroborate or discount mechanisms. We find that the pathway in operation can be perturbed by changing the temperature, solvent, amine-borane, or even the substrate used in the system, and subsequently assignment of the mechanism can become nontrivial.
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Affiliation(s)
- Samantha Lau
- Department of ChemistryUniversity of BathClaverton DownBathUK
| | | | - Ruth L. Webster
- Department of ChemistryUniversity of BathClaverton DownBathUK
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5
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Grinter DC, Allan M, Yang HJ, Salcedo A, Murgida GE, Shaw B, Pang CL, Idriss H, Ganduglia‐Pirovano MV, Thornton G. Ce=O Terminated CeO 2. Angew Chem Int Ed Engl 2021; 60:13835-13839. [PMID: 33826220 PMCID: PMC8251574 DOI: 10.1002/anie.202101771] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/06/2021] [Indexed: 02/02/2023]
Abstract
Multiply bonded lanthanide oxo groups are rare in coordination compounds and have not previously been reported for a surface termination of a lanthanide oxide. Here we report the observation of a Ce=O terminated ceria surface in a CeO2 (111)-( 3 × 3 )R30° reconstruction of ≈3 nm thick ceria islands prepared on Pt(111). This is evidenced by scanning tunnelling microscopy (STM), low energy electron diffraction (LEED) and high-resolution electron energy loss spectroscopy (HREELS) measurements in conjunction with density functional theory (DFT) calculations. A Ce=O stretching frequency of 775 cm-1 is observed in HREELS, compared with 766 cm-1 calculated by DFT. The calculations also predict that the Ce=O bond is weak, with an oxygen vacancy formation energy of 0.85 eV. This could play an important role in the facile removal of lattice oxygen from CeO2 , accompanied by the reduction of CeIV to CeIII , which is a key attribute of ceria-based systems in connection with their unique catalytic properties.
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Affiliation(s)
- David C. Grinter
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
- Diamond Light SourceDiamond House, Harwell Science and Innovation CampusDidcotOX11 0DEUK
| | - Michael Allan
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Hyun Jin Yang
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Agustín Salcedo
- Departamento de Ingeniería Química, Facultad de IngenieríaUniversidad de Buenos AiresCiudad UniversitariaC1428EGABuenos AiresArgentina
| | - Gustavo E. Murgida
- Centro Atómico ConstituyentesGIyACNEASan MartínConsejo Nacional de Investigaciones Científicas y TecnicasC1033AAJBuenos AiresArgentina
| | - Bobbie‐Jean Shaw
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Chi L. Pang
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Hicham Idriss
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
- Surface Science and Advanced CharacterisationChemical Sciences DivisionSABIC-CRD at KaustThuwal23955Saudi Arabia
| | | | - Geoff Thornton
- Department of Chemistry and London Centre for NanotechnologyUniversity College London20 Gordon StreetLondonWC1H 0AJUK
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6
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Vornholt SM, Elliott CG, Rice CM, Russell SE, Kerr PJ, Rainer DN, Mazur M, Warren MR, Wheatley PS, Morris RE. Controlled Synthesis of Large Single Crystals of Metal-Organic Framework CPO-27-Ni Prepared by a Modulation Approach: In situ Single-Crystal X-ray Diffraction Studies. Chemistry 2021; 27:8537-8546. [PMID: 33783895 PMCID: PMC8251849 DOI: 10.1002/chem.202100528] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Indexed: 12/14/2022]
Abstract
The size of single crystals of the metal-organic framework CPO-27-Ni was incrementally increased through a series of modulated syntheses. A novel linker modulated synthesis using 2,5-dihydroxyterephthalic acid and the isomeric ligand 4,6-dihydroxyisophthalic acid yielded large single crystals of CPO-27-Ni (∼70 μm). All materials were shown to have high crystallinity and phase purity through powder X-ray diffraction, electron microscopy methods, thermogravimetry, and compositional analysis. For the first time single-crystal structure analyses were carried out on CPO-27-Ni. High BET surface areas and nitric oxide (NO) release efficiencies were recorded for all materials. Large single crystals of CPO-27-Ni showed a prolonged NO release and proved suitable for in situ single-crystal diffraction experiments to follow the NO adsorption. An efficient activation protocol was developed, leading to a dehydrated structure after just 4 h, which subsequently was NO-loaded, leading to a first NO loaded single-crystal structural model of CPO-27-Ni.
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Affiliation(s)
| | | | - Cameron M. Rice
- University of St AndrewsNorth HaughKY16 9STSt AndrewsUnited Kingdom
| | | | - Peter J. Kerr
- University of St AndrewsNorth HaughKY16 9STSt AndrewsUnited Kingdom
| | - Daniel N. Rainer
- University of St AndrewsNorth HaughKY16 9STSt AndrewsUnited Kingdom
| | - Michal Mazur
- Department of Physical and Macromolecular ChemistryFaculty of SciencesCharles UniversityHlavova 8128 43Prague 2Czech Republic
| | - Mark R. Warren
- Diamond Light SourceHarwell Science and Innovation CampusDidcotOX11 0DEUnited Kingdom
| | - Paul S. Wheatley
- University of St AndrewsNorth HaughKY16 9STSt AndrewsUnited Kingdom
| | - Russell E. Morris
- University of St AndrewsNorth HaughKY16 9STSt AndrewsUnited Kingdom
- Department of Physical and Macromolecular ChemistryFaculty of SciencesCharles UniversityHlavova 8128 43Prague 2Czech Republic
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7
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Abstract
Over the last 30 years, genetically engineered DNA has been tested as novel vaccination strategy against various diseases, including human immunodeficiency virus (HIV), hepatitis B, several parasites, and cancers. However, the clinical breakthrough of the technique is confined by the low transfection efficacy and immunogenicity of the employed vaccines. Therefore, carrier materials were designed to prevent the rapid degradation and systemic clearance of DNA in the body. In this context, biopolymers are a particularly promising DNA vaccine carrier platform due to their beneficial biochemical and physical characteristics, including biocompatibility, stability, and low toxicity. This article reviews the applications, fabrication, and modification of biopolymers as carrier medium for genetic vaccines.
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Affiliation(s)
- Christoph O. Franck
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhillipa Fawcett DriveCambridgeCB3 0ASUK
| | - Luise Fanslau
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhillipa Fawcett DriveCambridgeCB3 0ASUK
| | - Andrea Bistrovic Popov
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhillipa Fawcett DriveCambridgeCB3 0ASUK
| | - Puneet Tyagi
- Dosage Form Design and DevelopmentBioPharmaceuticals DevelopmentR&DAstra ZenecaGaithersburgMD20878USA
| | - Ljiljana Fruk
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhillipa Fawcett DriveCambridgeCB3 0ASUK
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8
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Plajer AJ, Williams CK. Heterotrimetallic Carbon Dioxide Copolymerization and Switchable Catalysts: Sodium is the Key to High Activity and Unusual Selectivity. Angew Chem Int Ed Engl 2021; 60:13372-13379. [PMID: 33971064 PMCID: PMC8251569 DOI: 10.1002/anie.202101180] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/08/2021] [Indexed: 12/18/2022]
Abstract
A challenge in polymer synthesis using CO2 is to precisely control CO2 placement in the backbone and chain end groups. Here, a new catalyst class delivers unusual selectivity and is self-switched between different polymerization cycles to construct specific sequences and desirable chain-end chemistries. The best catalyst is a trinuclear dizinc(II)sodium(I) complex and it functions without additives or co-catalysts. It shows excellent rates across different ring-opening (co)polymerization catalytic cycles and allows precise control of CO2 incorporation within polyesters and polyethers, thereby allowing access to new polymer chemistries without requiring esoteric monomers, multi-reactor processes or complex post-polymerization procedures. The structures, kinetics and mechanisms of the catalysts are investigated, providing evidence for intermediate speciation and uncovering the factors governing structure and composition and thereby guiding future catalyst design.
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Affiliation(s)
- Alex J. Plajer
- Oxford ChemistryChemical Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
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9
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Lanyon‐Hogg T, Ritzefeld M, Zhang L, Andrei SA, Pogranyi B, Mondal M, Sefer L, Johnston CD, Coupland CE, Greenfield JL, Newington J, Fuchter MJ, Magee AI, Siebold C, Tate EW. Photochemical Probe Identification of a Small-Molecule Inhibitor Binding Site in Hedgehog Acyltransferase (HHAT)*. Angew Chem Int Ed Engl 2021; 60:13542-13547. [PMID: 33768725 PMCID: PMC8252026 DOI: 10.1002/anie.202014457] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/26/2021] [Indexed: 11/30/2022]
Abstract
The mammalian membrane-bound O-acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small-molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small-molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure-activity relationship investigation identified single enantiomer IMP-1575, the most potent HHAT inhibitor reported to-date, and guided design of photocrosslinking probes that maintained HHAT-inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small-molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed by kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP-1575 (Ki =38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.
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Affiliation(s)
| | | | - Leran Zhang
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | | | - Balazs Pogranyi
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Milon Mondal
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Lea Sefer
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | - Claire E. Coupland
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | | | | | - Anthony I. Magee
- National Heart & Lung InstituteImperial College LondonLondonSW7 2AZUK
| | - Christian Siebold
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | - Edward W. Tate
- Department of ChemistryImperial College LondonLondonW12 0BZUK
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10
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Lannelongue L, Grealey J, Inouye M. Green Algorithms: Quantifying the Carbon Footprint of Computation. Adv Sci (Weinh) 2021; 8:2100707. [PMID: 34194954 PMCID: PMC8224424 DOI: 10.1002/advs.202100707] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Climate change is profoundly affecting nearly all aspects of life on earth, including human societies, economies, and health. Various human activities are responsible for significant greenhouse gas (GHG) emissions, including data centers and other sources of large-scale computation. Although many important scientific milestones are achieved thanks to the development of high-performance computing, the resultant environmental impact is underappreciated. In this work, a methodological framework to estimate the carbon footprint of any computational task in a standardized and reliable way is presented and metrics to contextualize GHG emissions are defined. A freely available online tool, Green Algorithms (www.green-algorithms.org) is developed, which enables a user to estimate and report the carbon footprint of their computation. The tool easily integrates with computational processes as it requires minimal information and does not interfere with existing code, while also accounting for a broad range of hardware configurations. Finally, the GHG emissions of algorithms used for particle physics simulations, weather forecasts, and natural language processing are quantified. Taken together, this study develops a simple generalizable framework and freely available tool to quantify the carbon footprint of nearly any computation. Combined with recommendations to minimize unnecessary CO2 emissions, the authors hope to raise awareness and facilitate greener computation.
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Affiliation(s)
- Loïc Lannelongue
- Cambridge Baker Systems Genomics InitiativeDepartment of Public Health and Primary CareUniversity of CambridgeCambridgeCB1 8RNUK
- British Heart Foundation Cardiovascular Epidemiology UnitDepartment of Public Health and Primary CareUniversity of CambridgeCambridgeCB1 8RNUK
- Health Data Research UK CambridgeWellcome Genome Campus and University of CambridgeCambridgeCB10 1SAUK
| | - Jason Grealey
- Cambridge Baker Systems Genomics InitiativeBaker Heart and Diabetes InstituteMelbourneVictoria3004Australia
- Department of Mathematics and StatisticsLa Trobe UniversityMelbourne3086Australia
| | - Michael Inouye
- Cambridge Baker Systems Genomics InitiativeDepartment of Public Health and Primary CareUniversity of CambridgeCambridgeCB1 8RNUK
- British Heart Foundation Cardiovascular Epidemiology UnitDepartment of Public Health and Primary CareUniversity of CambridgeCambridgeCB1 8RNUK
- Health Data Research UK CambridgeWellcome Genome Campus and University of CambridgeCambridgeCB10 1SAUK
- Cambridge Baker Systems Genomics InitiativeBaker Heart and Diabetes InstituteMelbourneVictoria3004Australia
- British Heart Foundation Centre of Research ExcellenceUniversity of CambridgeCambridgeCB1 8RNUK
- National Institute for Health Research Cambridge Biomedical Research CentreUniversity of Cambridge and Cambridge University HospitalsCambridgeCB2 0QQUK
- The Alan Turing InstituteLondonNW1 2DBUK
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11
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Rymaruk MJ, O'Brien CT, György C, Darmau B, Jennings J, Mykhaylyk OO, Armes SP. Small-Angle X-Ray Scattering Studies of Block Copolymer Nano-Objects: Formation of Ordered Phases in Concentrated Solution During Polymerization-Induced Self-Assembly. Angew Chem Int Ed Engl 2021; 60:12955-12963. [PMID: 33725372 PMCID: PMC8252599 DOI: 10.1002/anie.202101851] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/12/2021] [Indexed: 01/13/2023]
Abstract
We report that polymerization-induced self-assembly (PISA) can be used to prepare lyotropic phases comprising diblock copolymer nano-objects in non-polar media. RAFT dispersion polymerization of benzyl methacrylate (BzMA) at 90 °C using a trithiocarbonate-capped hydrogenated polybutadiene (PhBD) steric stabilizer block in n-dodecane produces either spheres or worms that exhibit long-range order at 40 % w/w solids. NMR studies enable calculation of instantaneous copolymer compositions for each phase during the BzMA polymerization. As the PBzMA chains grow longer when targeting PhBD80 -PBzMA40 , time-resolved small-angle X-ray scattering reveals intermediate body-centered cubic (BCC) and hexagonally close-packed (HCP) sphere phases prior to formation of a final hexagonal cylinder phase (HEX). The HEX phase is lost on serial dilution and the aligned cylinders eventually form disordered flexible worms. The HEX phase undergoes an order-disorder transition on heating to 150 °C and a pure HCP phase forms on cooling to 20 °C.
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Affiliation(s)
- Matthew J. Rymaruk
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
- Present address: SyngentaJealott's HillBracknellBerkshireRG42 6EYUK
| | - Cate T. O'Brien
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
| | - Csilla György
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
| | - Bastien Darmau
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
| | - James Jennings
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
| | | | - Steven P. Armes
- Dainton BuildingDepartment of ChemistryThe University of SheffieldSheffieldS3 7HFUK
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12
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Lan Y, Liu Y, Li J, Chen D, He G, Parkin IP. Natural Clay-Based Materials for Energy Storage and Conversion Applications. Adv Sci (Weinh) 2021; 8:e2004036. [PMID: 34105287 PMCID: PMC8188194 DOI: 10.1002/advs.202004036] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/18/2021] [Indexed: 05/03/2023]
Abstract
Among various energy storage and conversion materials, functionalized natural clays display significant potentials as electrodes, electrolytes, separators, and nanofillers in energy storage and conversion devices. Natural clays have porous structures, tunable specific surface areas, remarkable thermal and mechanical stabilities, abundant reserves, and cost-effectiveness. In addition, natural clays deliver the advantages of high ionic conductivity and hydrophilicity, which are beneficial properties for solid-state electrolytes. This review article provides an overview toward the recent advancements in natural clay-based energy materials. First, it comprehensively summarizes the structure, classification, and chemical modification methods of natural clays to make them suitable in energy storage and conversion devices. Then, the particular attention is focused on the application of clays in the fields of lithium-ion batteries, lithium-sulfur batteries, zinc-ion batteries, chloride-ion batteries, supercapacitors, solar cells, and fuel cells. Finally, the possible future research directions are provided for natural clays as energy materials. This review aims at facilitating the rapid developments of natural clay-based energy materials through a fruitful discussion from inorganic and materials chemistry aspects, and also promotes the broad sphere of clay-based materials for other utilization, such as effluent treatment, heavy metal removal, and environmental remediation.
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Affiliation(s)
- Ye Lan
- Department of ChemistryUniversity College London20 Gordon Street, WC1H 0AJLondonUK
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620P. R. China
| | - Yiyang Liu
- Department of ChemistryUniversity College London20 Gordon Street, WC1H 0AJLondonUK
| | - Jianwei Li
- Department of ChemistryUniversity College London20 Gordon Street, WC1H 0AJLondonUK
| | - Dajun Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620P. R. China
| | - Guanjie He
- Department of ChemistryUniversity College London20 Gordon Street, WC1H 0AJLondonUK
- School of ChemistryUniversity of LincolnBrayford PoolLincolnLN6 7TSUK
| | - Ivan P. Parkin
- Department of ChemistryUniversity College London20 Gordon Street, WC1H 0AJLondonUK
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13
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Unal MA, Bayrakdar F, Nazir H, Besbinar O, Gurcan C, Lozano N, Arellano LM, Yalcin S, Panatli O, Celik D, Alkaya D, Agan A, Fusco L, Suzuk Yildiz S, Delogu LG, Akcali KC, Kostarelos K, Yilmazer A. Graphene Oxide Nanosheets Interact and Interfere with SARS-CoV-2 Surface Proteins and Cell Receptors to Inhibit Infectivity. Small 2021; 17:e2101483. [PMID: 33988903 PMCID: PMC8236978 DOI: 10.1002/smll.202101483] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Indexed: 05/19/2023]
Abstract
Nanotechnology can offer a number of options against coronavirus disease 2019 (COVID-19) acting both extracellularly and intracellularly to the host cells. Here, the aim is to explore graphene oxide (GO), the most studied 2D nanomaterial in biomedical applications, as a nanoscale platform for interaction with SARS-CoV-2. Molecular docking analyses of GO sheets on interaction with three different structures: SARS-CoV-2 viral spike (open state - 6VYB or closed state - 6VXX), ACE2 (1R42), and the ACE2-bound spike complex (6M0J) are performed. GO shows high affinity for the surface of all three structures (6M0J, 6VYB and 6VXX). When binding affinities and involved bonding types are compared, GO interacts more strongly with the spike or ACE2, compared to 6M0J. Infection experiments using infectious viral particles from four different clades as classified by Global Initiative on Sharing all Influenza Data (GISAID), are performed for validation purposes. Thin, biological-grade GO nanoscale (few hundred nanometers in lateral dimension) sheets are able to significantly reduce copies for three different viral clades. This data has demonstrated that GO sheets have the capacity to interact with SARS-CoV-2 surface components and disrupt infectivity even in the presence of any mutations on the viral spike. GO nanosheets are proposed to be further explored as a nanoscale platform for development of antiviral strategies against COVID-19.
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Affiliation(s)
| | - Fatma Bayrakdar
- Ministry of Health General Directorate of Public HealthMicrobiology References LaboratorySihhiyeAnkara06430Turkey
| | - Hasan Nazir
- Department of ChemistryAnkara UniversityTandoganAnkara06100Turkey
| | - Omur Besbinar
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Cansu Gurcan
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Neus Lozano
- Catalan Institute of Nanoscience and Nanotechnology (ICN2)UAB Campus BellaterraBarcelona08193Spain
| | - Luis M. Arellano
- Catalan Institute of Nanoscience and Nanotechnology (ICN2)UAB Campus BellaterraBarcelona08193Spain
| | - Süleyman Yalcin
- Ministry of Health General Directorate of Public HealthMicrobiology References LaboratorySihhiyeAnkara06430Turkey
| | - Oguzhan Panatli
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Dogantan Celik
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Damla Alkaya
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Aydan Agan
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
| | - Laura Fusco
- Department of Biomedical SciencesUniversity of PaduaPadua35122Italy
| | - Serap Suzuk Yildiz
- Ministry of Health General Directorate of Public HealthMicrobiology References LaboratorySihhiyeAnkara06430Turkey
| | | | - Kamil Can Akcali
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of BiophysicsFaculty of MedicineAnkara UniversitySihhiyeAnkara06230Turkey
| | - Kostas Kostarelos
- Catalan Institute of Nanoscience and Nanotechnology (ICN2)UAB Campus BellaterraBarcelona08193Spain
- Nanomedicine Lab National Graphene Institute and Faculty of Biology Medicine & HealthThe University of ManchesterAV Hill BuildingManchesterM13 9PTUnited Kingdom
| | - Açelya Yilmazer
- Stem Cell InstituteAnkara UniversityBalgatAnkara06520Turkey
- Department of Biomedical EngineeringAnkara UniversityGolbasiAnkara06830Turkey
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14
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Chen S, Renny MN, C. Tomé L, Olmedo‐Martínez JL, Udabe E, Jenkins EPW, Mecerreyes D, Malliaras GG, McLeod RR, Proctor CM. Reducing Passive Drug Diffusion from Electrophoretic Drug Delivery Devices through Co-Ion Engineering. Adv Sci (Weinh) 2021; 8:2003995. [PMID: 34194928 PMCID: PMC8224430 DOI: 10.1002/advs.202003995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 02/17/2021] [Indexed: 05/13/2023]
Abstract
Implantable electrophoretic drug delivery devices have shown promise for applications ranging from treating pathologies such as epilepsy and cancer to regulating plant physiology. Upon applying a voltage, the devices electrophoretically transport charged drug molecules across an ion-conducting membrane out to the local implanted area. This solvent-flow-free "dry" delivery enables controlled drug release with minimal pressure increase at the outlet. However, a major challenge these devices face is limiting drug leakage in their idle state. Here, a method of reducing passive drug leakage through the choice of the drug co-ion is presented. By switching acetylcholine's associated co-ion from chloride to carboxylate co-ions as well as sulfopropyl acrylate-based polyanions, steady-state drug leakage rate is reduced up to sevenfold with minimal effect on the active drug delivery rate. Numerical simulations further illustrate the potential of this method and offer guidance for new material systems to suppress passive drug leakage in electrophoretic drug delivery devices.
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Affiliation(s)
- Shao‐Tuan Chen
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Megan N. Renny
- Materials Science and Engineering ProgramUniversity of ColoradoBoulderCO80309USA
| | - Liliana C. Tomé
- POLYMAT, University of the Basque Country UPV/EHUAvenida Tolosa 72Donostia‐San Sebastian20018Gipuzkoa, Spain
| | - Jorge L. Olmedo‐Martínez
- POLYMAT, University of the Basque Country UPV/EHUAvenida Tolosa 72Donostia‐San Sebastian20018Gipuzkoa, Spain
| | - Esther Udabe
- POLYMAT, University of the Basque Country UPV/EHUAvenida Tolosa 72Donostia‐San Sebastian20018Gipuzkoa, Spain
| | - Elise P. W. Jenkins
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - David Mecerreyes
- POLYMAT, University of the Basque Country UPV/EHUAvenida Tolosa 72Donostia‐San Sebastian20018Gipuzkoa, Spain
- IkerbasqueBasque Foundation for ScienceBilbao48013Spain
| | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Robert R. McLeod
- Materials Science and Engineering ProgramUniversity of ColoradoBoulderCO80309USA
- Department of Electrical, Computer & Energy EngineeringUniversity of ColoradoBoulderCO80309USA
| | - Christopher M. Proctor
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
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15
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Abstract
This Minireview compares two distinct ink types, namely metal-organic decomposition (MOD) and nanoparticle (NP) formulations, for use in the printing of some of the most conductive elements: silver, copper and aluminium. Printing of highly conductive features has found purpose across a broad array of electronics and as processing times and temperatures reduce, the avenues of application expand to low-cost flexible substrates, materials for wearable devices and beyond. Printing techniques such as screen, aerosol jet and inkjet printing are scalable, solution-based processes that historically have employed NP formulations to achieve low resistivity coatings printed at high resolution. Since the turn of the century, the rise in MOD inks has vastly extended the range of potentially applicable compounds that can be printed, whilst simultaneously addressing shelf life and sintering issues. A brief introduction to the field and requirements of an ink will be presented followed by a detailed discussion of a wide array of synthetic routes to both MOD and NP inks. Unindustrialized materials will be discussed, with the challenges and outlook considered for the market leaders: silver and copper, in comparison with the emerging field of aluminium inks.
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Affiliation(s)
- Samuel P. Douglas
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Shreya Mrig
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Caroline E. Knapp
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
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16
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Rajamalli P, Rizzi F, Li W, Jinks MA, Gupta AK, Laidlaw BA, Samuel IDW, Penfold TJ, Goldup SM, Zysman‐Colman E. Using the Mechanical Bond to Tune the Performance of a Thermally Activated Delayed Fluorescence Emitter*. Angew Chem Int Ed Engl 2021; 60:12066-12073. [PMID: 33666324 PMCID: PMC8251797 DOI: 10.1002/anie.202101870] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Indexed: 12/12/2022]
Abstract
We report the characterization of rotaxanes based on a carbazole-benzophenone thermally activated delayed fluorescence luminophore. We find that the mechanical bond leads to an improvement in key photophysical properties of the emitter, notably an increase in photoluminescence quantum yield and a decrease in the energy difference between singlet and triplet states, as well as fine tuning of the emission wavelength, a feat that is difficult to achieve when using covalently bound substituents. Computational simulations, supported by X-ray crystallography, suggest that this tuning of properties occurs due to weak interactions between the axle and the macrocycle that are enforced by the mechanical bond. This work highlights the benefits of using the mechanical bond to refine existing luminophores, providing a new avenue for emitter optimization that can ultimately increase the performance of these molecules.
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Affiliation(s)
- Pachaiyappan Rajamalli
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
- Materials Research CentreIndian Institute of ScienceBangalore560012India
| | - Federica Rizzi
- ChemistryUniversity of SouthamptonHighfieldSouthamptonSO17 1BJUK
| | - Wenbo Li
- Organic Semiconductor CentreSUPA School of Physics and AstronomyUniversity of St AndrewsSt AndrewsFifeKY16 9SSUK
| | - Michael A. Jinks
- ChemistryUniversity of SouthamptonHighfieldSouthamptonSO17 1BJUK
| | - Abhishek Kumar Gupta
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
- Organic Semiconductor CentreSUPA School of Physics and AstronomyUniversity of St AndrewsSt AndrewsFifeKY16 9SSUK
| | - Beth A. Laidlaw
- Chemistry, School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneNE1 7RUUK
| | - Ifor D. W. Samuel
- Organic Semiconductor CentreSUPA School of Physics and AstronomyUniversity of St AndrewsSt AndrewsFifeKY16 9SSUK
| | - Thomas J. Penfold
- Chemistry, School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneNE1 7RUUK
| | | | - Eli Zysman‐Colman
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
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17
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Zhu J, Zhang D, Ronson TK, Wang W, Xu L, Yang H, Nitschke JR. A Cavity-Tailored Metal-Organic Cage Entraps Gases Selectively in Solution and the Amorphous Solid State. Angew Chem Int Ed Engl 2021; 60:11789-11792. [PMID: 33768657 PMCID: PMC8251750 DOI: 10.1002/anie.202102095] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Indexed: 01/24/2023]
Abstract
Here we report the subcomponent self-assembly of a truxene-faced Zn4 L4 tetrahedron, which is capable of binding the smallest hydrocarbons in solution. By deliberately incorporating inward-facing ethyl groups on the truxene faces, the resulting partially-filled cage cavity was tailored to encapsulate methane, ethane, and ethene via van der Waals interactions at atmospheric pressure in acetonitrile, and also in the amorphous solid state. Interestingly, gas capture showed divergent selectivities in solution and the amorphous solid state. The selective binding may prove useful in designing new processes for the purification of methane and ethane as feedstocks for chemical synthesis.
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Affiliation(s)
- Jun‐Long Zhu
- Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal University3663 N. Zhongshan RoadShanghai200062P. R. China
| | - Dawei Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal University3663 N. Zhongshan RoadShanghai200062P. R. China
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Tanya K. Ronson
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Wenjing Wang
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China
| | - Lin Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal University3663 N. Zhongshan RoadShanghai200062P. R. China
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Hai‐Bo Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal University3663 N. Zhongshan RoadShanghai200062P. R. China
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18
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Abstract
Due to their intrinsic rigidity, three-dimensionality and structural novelty, spirocyclic molecules have become increasingly sought-after moieties in drug discovery. Herein, we report a strain-release driven synthesis of azetidine-containing spirocycles by harnessing the inherent ring strain of the azabicyclo[1.1.0]butane (ABB) fragment. Novel ABB-ketone precursors bearing silyl-protected alcohols were synthesized in a single step and shown to engage in electrophile-induced spirocyclization-desilylation reactions. Primary, secondary and tertiary silyl ethers were effectively transformed into a library of new spiro-azetidines, with a range of substituents and ring sizes. In addition, the products are generated with synthetically useful ketone and protected-amine functional groups, which provides the potential for further elaboration and for this chemistry to be utilized in the rapid assembly of medicinally relevant compounds.
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Affiliation(s)
- Jasper L. Tyler
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Adam Noble
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
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19
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Street STG, Peñalver P, O'Hagan MP, Hollingworth GJ, Morales JC, Galan MC. Imide Condensation as a Strategy for the Synthesis of Core-Diversified G-Quadruplex Ligands with Anticancer and Antiparasitic Activity*. Chemistry 2021; 27:7712-7721. [PMID: 33780044 PMCID: PMC8251916 DOI: 10.1002/chem.202100040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Indexed: 11/22/2022]
Abstract
A facile imide coupling strategy for the one-step preparation of G-quadruplex ligands with varied core chemistries is described. The G-quadruplex stabilization of a library of nine compounds was examined using FRET melting experiments, and CD, UV-Vis, fluorescence and NMR titrations, identifying several compounds that were capable of stabilizing G-quadruplex DNA with interesting selectivity profiles. The best G4 ligand was identified as compound 3, which was based on a perylene scaffold and exhibited 40-fold selectivity for a telomeric G-quadruplex over duplex DNA. Surprisingly, a tetra-substituted flexible core, compound 11, also exhibited selective stabilization of G4 DNA over duplex DNA. The anticancer and antiparasitic activity of the library was also examined, with the lead compound 3 exhibiting nanomolar inhibition of Trypanosoma brucei with 78-fold selectivity over MRC5 cells. The cellular localization of this compound was also studied via fluorescence microscopy. We found that uptake was time dependant, with localization outside the nucleus and kinetoplast that could be due to strong fluorescence quenching in the presence of small amounts of DNA.
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Affiliation(s)
- Steven T. G. Street
- School of ChemistryUniversity of BristolCantocks CloseBristolBS8 1TSUK
- Department of ChemistryUniversity of VictoriaDr. S. T. G. StreetVictoriaBC V8P 5C2Canada
| | - Pablo Peñalver
- Instituto de Parasitología y Biomedicina López NeyraCSIC, PTS GranadaAvenida del Conocimiento, 1718016Armilla, GranadaSpain
| | | | | | - Juan C. Morales
- Instituto de Parasitología y Biomedicina López NeyraCSIC, PTS GranadaAvenida del Conocimiento, 1718016Armilla, GranadaSpain
| | - M. Carmen Galan
- School of ChemistryUniversity of BristolCantocks CloseBristolBS8 1TSUK
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20
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Cook XAF, de Gombert A, McKnight J, Pantaine LRE, Willis MC. The 2-Pyridyl Problem: Challenging Nucleophiles in Cross-Coupling Arylations. Angew Chem Int Ed Engl 2021; 60:11068-11091. [PMID: 32940402 PMCID: PMC8246887 DOI: 10.1002/anie.202010631] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Indexed: 12/22/2022]
Abstract
Azine-containing biaryls are ubiquitous scaffolds in many areas of chemistry, and efficient methods for their synthesis are continually desired. Pyridine rings are prominent amongst these motifs. Transition-metal-catalysed cross-coupling reactions have been widely used for their synthesis and functionalisation as they often provide a swift and tuneable route to related biaryl scaffolds. However, 2-pyridine organometallics are capricious coupling partners and 2-pyridyl boron reagents in particular are notorious for their instability and poor reactivity in Suzuki-Miyaura cross-coupling reactions. The synthesis of pyridine-containing biaryls is therefore limited, and methods for the formation of unsymmetrical 2,2'-bis-pyridines are scarce. This Review focuses on the methods developed for the challenging coupling of 2-pyridine nucleophiles with (hetero)aryl electrophiles, and ranges from traditional cross-coupling processes to alternative nucleophilic reagents and novel main group approaches.
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Affiliation(s)
- Xinlan A. F. Cook
- Chemistry Research LaboratoryOxford University12 Mansfield RoadOxfordOX1 3TAUK
| | - Antoine de Gombert
- Chemistry Research LaboratoryOxford University12 Mansfield RoadOxfordOX1 3TAUK
| | - Janette McKnight
- Chemistry Research LaboratoryOxford University12 Mansfield RoadOxfordOX1 3TAUK
| | - Loïc R. E. Pantaine
- Chemistry Research LaboratoryOxford University12 Mansfield RoadOxfordOX1 3TAUK
| | - Michael C. Willis
- Chemistry Research LaboratoryOxford University12 Mansfield RoadOxfordOX1 3TAUK
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21
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Abstract
Anion receptors can be used to transport ions across lipid bilayers, which has potential for therapeutic applications. Synthetic bicarbonate transporters are of particular interest, as defects in transmembrane transport of bicarbonate are associated with various diseases. However, no convenient method exists to directly observe bicarbonate transport and study the mechanisms involved. Here, an assay is presented that allows the kinetics of bicarbonate transport into liposomes to be monitored directly and with great sensitivity. The assay utilises an encapsulated europium(III) complex, which exhibits a large increase in emission intensity upon binding bicarbonate. Mechanisms involving CO2 diffusion and the dissipation of a pH gradient are shown to be able to lead to an increase in bicarbonate concentration within liposomes, without transport of the anion occurring at all. By distinguishing these alternative mechanisms from actual bicarbonate transport, this assay will inform the future development of bicarbonate transporters.
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Affiliation(s)
- Luis Martínez‐Crespo
- Université Libre de Bruxelles (ULB)Engineering of Molecular NanoSystems, Ecole polytechnique de BruxellesAvenue F.D. Roosevelt 50, CP165/641050BrusselsBelgium
| | - Sarah H. Hewitt
- Loughborough UniversityDepartment of ChemistryEpinal WayLoughboroughLE11 3TUUK
| | | | - Vladimír Šindelář
- Masaryk UniversityDepartment of Chemistry and RECETOX, Faculty of ScienceKamenice 5625 00BrnoCzech Republic
| | - Anthony P. Davis
- University of BristolSchool of ChemistryCantock's CloseBristolBS8 1TSUK
| | - Stephen Butler
- Loughborough UniversityDepartment of ChemistryEpinal WayLoughboroughLE11 3TUUK
| | - Hennie Valkenier
- Université Libre de Bruxelles (ULB)Engineering of Molecular NanoSystems, Ecole polytechnique de BruxellesAvenue F.D. Roosevelt 50, CP165/641050BrusselsBelgium
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22
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Biggs GS, Klein OJ, Maslen SL, Skehel JM, Rutherford TJ, Freund SMV, Hollfelder F, Boss SR, Barker PD. Controlled Ligand Exchange Between Ruthenium Organometallic Cofactor Precursors and a Naïve Protein Scaffold Generates Artificial Metalloenzymes Catalysing Transfer Hydrogenation. Angew Chem Int Ed Engl 2021; 60:10919-10927. [PMID: 33616271 PMCID: PMC8251807 DOI: 10.1002/anie.202015834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Indexed: 11/05/2022]
Abstract
Many natural metalloenzymes assemble from proteins and biosynthesised complexes, generating potent catalysts by changing metal coordination. Here we adopt the same strategy to generate artificial metalloenzymes (ArMs) using ligand exchange to unmask catalytic activity. By systematically testing RuII (η6 -arene)(bipyridine) complexes designed to facilitate the displacement of functionalised bipyridines, we develop a fast and robust procedure for generating new enzymes via ligand exchange in a protein that has not evolved to bind such a complex. The resulting metal cofactors form peptidic coordination bonds but also retain a non-biological ligand. Tandem mass spectrometry and 19 F NMR spectroscopy were used to characterise the organometallic cofactors and identify the protein-derived ligands. By introduction of ruthenium cofactors into a 4-helical bundle, transfer hydrogenation catalysts were generated that displayed a 35-fold rate increase when compared to the respective small molecule reaction in solution.
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Affiliation(s)
- George S. Biggs
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Oskar James Klein
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Department of BiochemistryUniversity of CambridgeTennis Court RoadCambridgeCB2 1GAUK
| | - Sarah L. Maslen
- MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB2 0QHUK
| | - J. Mark Skehel
- MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB2 0QHUK
| | - Trevor J. Rutherford
- MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB2 0QHUK
| | - Stefan M. V. Freund
- MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB2 0QHUK
| | - Florian Hollfelder
- Department of BiochemistryUniversity of CambridgeTennis Court RoadCambridgeCB2 1GAUK
| | - Sally R. Boss
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Paul D. Barker
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
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23
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Zhong X, Wade CA, Withers PJ, Zhou X, Cai C, Haigh SJ, Burke MG. Comparing Xe + pFIB and Ga + FIB for TEM sample preparation of Al alloys: Minimising FIB-induced artefacts. J Microsc 2021; 282:101-112. [PMID: 33210738 PMCID: PMC8246817 DOI: 10.1111/jmi.12983] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/02/2020] [Accepted: 11/10/2020] [Indexed: 11/30/2022]
Abstract
Recently, the dual beam Xe+ plasma focused ion beam (Xe+ pFIB) instrument has attracted increasing interest for site-specific transmission electron microscopy (TEM) sample preparation for a local region of interest as it shows several potential benefits compared to conventional Ga+ FIB milling. Nevertheless, challenges and questions remain especially in terms of FIB-induced artefacts, which hinder reliable S/TEM microstructural and compositional analysis. Here we examine the efficacy of using Xe+ pFIB as compared with conventional Ga+ FIB for TEM sample preparation of Al alloys. Three potential source of specimen preparation artefacts were examined, namely: (1) implantation-induced defects such as amophisation, dislocations, or 'bubble' formation in the near-surface region resulting from ion bombardment of the sample by the incident beam; (2) compositional artefacts due to implantation of the source ions and (3) material redeposition due to the milling process. It is shown that Xe+ pFIB milling is able to produce improved STEM/TEM samples compared to those produced by Ga+ milling, and is therefore the preferred specimen preparation route. Strategies for minimising the artefacts induced by Xe+ pFIB and Ga+ FIB are also proposed. LAY DESCRIPTION: FIB (focused ion beam) instruments have become one of the most important systems in the preparation of site-specific TEM specimens, which are typically 50-100 nm in thickness. TEM specimen preparation of Al alloys is particularly challenging, as convention Ga-ion FIB produces artefacts in these materials that make microstructural analysis difficult or impossible. Recently, the use of noble gas ion sources, such as Xe, has markedly improved milling speeds and is being used for the preparation of various materials. Hence, it is necessary to investigate the structural defects formed during FIB milling and assess the ion-induced chemical contamination in these TEM samples. Here we explore the feasibility and efficiency of using Xe+ PFIB as a TEM sample preparation route for Al alloys in comparison with the conventional Ga+FIB.
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Affiliation(s)
- Xiangli Zhong
- Department of MaterialsUniversity of ManchesterManchesterUK
| | - C. Austin Wade
- Department of Materials, Materials Performance CentreUniversity of ManchesterManchesterUK
| | - Philip J. Withers
- Department of Materials, Henry Royce InstituteUniversity of ManchesterManchesterUK
| | - Xiaorong Zhou
- Department of MaterialsUniversity of ManchesterManchesterUK
| | - Changrun Cai
- Department of MaterialsUniversity of ManchesterManchesterUK
| | - Sarah J. Haigh
- Department of MaterialsUniversity of ManchesterManchesterUK
| | - M. Grace Burke
- Department of Materials, Materials Performance CentreUniversity of ManchesterManchesterUK
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24
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Abstract
Organolithium compounds have been at the forefront of synthetic chemistry for over a century, as they mediate the synthesis of myriads of compounds that are utilised worldwide in academic and industrial settings. For that reason, lithium has always been the most important alkali metal in organometallic chemistry. Today, that importance is being seriously challenged by sodium and potassium, as the alkali-metal mediation of organic reactions in general has started branching off in several new directions. Recent examples covering main-group homogeneous catalysis, stoichiometric organic synthesis, low-valent main-group metal chemistry, polymerization, and green chemistry are showcased in this Review. Since alkali-metal compounds are often not the end products of these applications, their roles are rarely given top billing. Thus, this Review has been written to alert the community to this rising unifying phenomenon of "alkali-metal mediation".
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Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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25
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Abstract
Supported bimetallic nanoparticles used for various chemical transformations appear to be more appealing than their monometallic counterparts, because of their unique properties mainly originating from the synergistic effects between the two different metals. Exsolution, a relatively new preparation method for supported nanoparticles, has earned increasing attention for bimetallic systems in the past decade, not only due to the high stability of the resulting nanoparticles but also for the potential to control key particle properties (size, composition, structure, morphology, etc.). In this review, we summarize the trends and advances on exsolution of bimetallic systems and provide prospects for future studies in this field.
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Affiliation(s)
- Chenyang Tang
- School of Engineering.Newcastle UniversityNewcastle upon TyneNE1 7RUUK
| | - Kalliopi Kousi
- School of Engineering.Newcastle UniversityNewcastle upon TyneNE1 7RUUK
| | - Dragos Neagu
- Department of Process and Chemical EngineeringUniversity of StrathclydeGlasgowG1 1XLUK
| | - Ian S. Metcalfe
- School of Engineering.Newcastle UniversityNewcastle upon TyneNE1 7RUUK
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26
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Wright IA, Danos A, Montanaro S, Batsanov AS, Monkman AP, Bryce MR. Conformational Dependence of Triplet Energies in Rotationally Hindered N- and S-Heterocyclic Dimers: New Design and Measurement Rules for High Triplet Energy OLED Host Materials. Chemistry 2021; 27:6545-6556. [PMID: 33560550 PMCID: PMC8251716 DOI: 10.1002/chem.202100036] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/08/2021] [Indexed: 12/22/2022]
Abstract
A series of four heterocyclic dimers has been synthesized, with twisted geometries imposed across the central linking bond by ortho-alkoxy chains. These include two isomeric bicarbazoles, a bis(dibenzothiophene-S,S-dioxide) and a bis(thioxanthene-S,S-dioxide). Spectroscopic and electrochemical methods, supported by density functional theory, have given detailed insights into how para- vs. meta- vs. broken conjugation, and electron-rich vs. electron-poor heterocycles impact the HOMO-LUMO gap and singlet and triplet energies. Crucially for applications as OLED hosts, the triplet energy (ET ) of these molecules was found to vary significantly between dilute polymer films and neat films, related to conformational demands of the molecules in the solid state. One of the bicarbazole species shows a variation in ET of 0.24 eV in the different media-sufficiently large to "make-or-break" an OLED device-with similar discrepancies found between neat films and frozen solution measurements of other previously reported OLED hosts. From consolidated optical and optoelectronic investigations of different host/dopant combinations, we identify that only the lower ET values measured in neat films give a reliable indicator of host/guest compatibility. This work also provides new molecular design rules for obtaining very high ET materials and controlling their HOMO and LUMO energies.
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Affiliation(s)
- Iain A. Wright
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
- Department of ChemistryLoughborough UniversityLoughboroughLeicestershireLE11 3TUUK
| | - Andrew Danos
- Department of PhysicsDurham UniversitySouth RoadDurhamDH1 3LEUK
| | - Stephanie Montanaro
- Department of ChemistryLoughborough UniversityLoughboroughLeicestershireLE11 3TUUK
| | | | | | - Martin R. Bryce
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
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27
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Abstract
Domino reactions involving nickel-catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary-alcohol-containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti-arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.
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Affiliation(s)
- Harley Green
- The GlaxoSmithKline Carbon Neutral Laboratories for, Sustainable ChemistryUniversity of NottinghamJubilee Campus, Triumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Stephen P. Argent
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Hon Wai Lam
- The GlaxoSmithKline Carbon Neutral Laboratories for, Sustainable ChemistryUniversity of NottinghamJubilee Campus, Triumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
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28
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Woof CR, Durand DJ, Fey N, Richards E, Webster RL. Iron Catalyzed Double Bond Isomerization: Evidence for an Fe I /Fe III Catalytic Cycle. Chemistry 2021; 27:5972-5977. [PMID: 33492679 PMCID: PMC8048803 DOI: 10.1002/chem.202004980] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/19/2021] [Indexed: 12/21/2022]
Abstract
Iron-catalyzed isomerization of alkenes is reported using an iron(II) β-diketiminate pre-catalyst. The reaction proceeds with a catalytic amount of a hydride source, such as pinacol borane (HBpin) or ammonia borane (H3 N⋅BH3 ). Reactivity with both allyl arenes and aliphatic alkenes has been studied. The catalytic mechanism was investigated by a variety of means, including deuteration studies, Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre-catalyst activation step that gives access to an η2 -coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.
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Affiliation(s)
- Callum R. Woof
- School of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
| | - Derek J. Durand
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Natalie Fey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Emma Richards
- School of ChemistryCardiff UniversityMain Building, Park PlaceCardiffCF10 3ATUK
| | - Ruth L. Webster
- School of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
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29
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Cuttaz EA, Chapman CAR, Syed O, Goding JA, Green RA. Stretchable, Fully Polymeric Electrode Arrays for Peripheral Nerve Stimulation. Adv Sci (Weinh) 2021; 8:2004033. [PMID: 33898185 PMCID: PMC8061359 DOI: 10.1002/advs.202004033] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/19/2021] [Indexed: 05/08/2023]
Abstract
There is a critical need to transition research level flexible polymer bioelectronics toward the clinic by demonstrating both reliability in fabrication and stable device performance. Conductive elastomers (CEs) are composites of conductive polymers in elastomeric matrices that provide both flexibility and enhanced electrochemical properties compared to conventional metallic electrodes. This work focuses on the development of nerve cuff devices and the assessment of the device functionality at each development stage, from CE material to fully polymeric electrode arrays. Two device types are fabricated by laser machining of a thick and thin CE sheet variant on an insulative polydimethylsiloxane substrate and lamination into tubing to produce pre-curled cuffs. Device performance and stability following sterilization and mechanical loading are compared to a state-of-the-art stretchable metallic nerve cuff. The CE cuffs are found to be electrically and mechanically stable with improved charge transfer properties compared to the commercial cuff. All devices are applied to an ex vivo whole sciatic nerve and shown to be functional, with the CE cuffs demonstrating superior charge transfer and electrochemical safety in the biological environment.
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Affiliation(s)
- Estelle A. Cuttaz
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | | | - Omaer Syed
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Josef A. Goding
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Rylie A. Green
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
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30
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Zhao H, Leonori D. Minimization of Back-Electron Transfer Enables the Elusive sp 3 C-H Functionalization of Secondary Anilines. Angew Chem Int Ed Engl 2021; 60:7669-7674. [PMID: 33459469 PMCID: PMC8048505 DOI: 10.1002/anie.202100051] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 01/14/2021] [Indexed: 02/02/2023]
Abstract
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C-H functionalization.
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Affiliation(s)
- Huaibo Zhao
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Daniele Leonori
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
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31
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Bell NL, Xu C, Fyfe JWB, Vantourout JC, Brals J, Chabbra S, Bode BE, Cordes DB, Slawin AMZ, McGuire TM, Watson AJB. Cu(OTf) 2 -Mediated Cross-Coupling of Nitriles and N-Heterocycles with Arylboronic Acids to Generate Nitrilium and Pyridinium Products*. Angew Chem Int Ed Engl 2021; 60:7935-7940. [PMID: 33449408 PMCID: PMC8048606 DOI: 10.1002/anie.202016811] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/14/2021] [Indexed: 12/25/2022]
Abstract
Metal-catalyzed C-N cross-coupling generally forms C-N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C-N cross-coupling that uses a dative N-ligand in the bond-forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a CuII complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative CuIII complex enables the oxidative C-N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp2 ) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.
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Affiliation(s)
- Nicola L. Bell
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Chao Xu
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - James W. B. Fyfe
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Julien C. Vantourout
- GlaxoSmithKlineMedicines Research CentreGunnels Wood RoadStevenageHertfordshireSG1 2NYUK
| | - Jeremy Brals
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Sonia Chabbra
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Bela E. Bode
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - David B. Cordes
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | | | - Thomas M. McGuire
- AstraZenecaDarwin Building, Unit 310, Cambridge Science Park, Milton RoadCambridgeCB4 0WGUK
| | - Allan J. B. Watson
- EaStCHEMSchool of ChemistryUniversity of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
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32
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Alkorbi F, Díaz‐Moscoso A, Gretton J, Chambrier I, Tizzard GJ, Coles SJ, Hughes DL, Cammidge AN. Complementary Syntheses Giving Access to a Full Suite of Differentially Substituted Phthalocyanine-Porphyrin Hybrids. Angew Chem Int Ed Engl 2021; 60:7632-7636. [PMID: 33428323 PMCID: PMC8048519 DOI: 10.1002/anie.202016596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Indexed: 01/31/2023]
Abstract
Phthalocyanines and porphyrins are often the scaffolds of choice for use in widespread applications. Synthetic advances allow bespoke derivatives to be made, tailoring their properties. The selective synthesis of unsymmetrical systems, particularly phthalocyanines, has remained a significant unmet challenge. Porphyrin-phthalocyanine hybrids offer the potential to combine the favorable features of both parent structures, but again synthetic strategies are poorly developed. Here we demonstrate strategies that give straightforward, controlled access to differentially substituted meso-aryl-tetrabenzotriazaporphyrins by reaction between an aryl-aminoisoindolene (A) initiator and a complementary phthalonitrile (B). The choice of precursors and reaction conditions allows selective preparation of 1:3 Ar-ABBB and, uniquely, 2:2 Ar-ABBA functionalized hybrids.
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Affiliation(s)
- Faeza Alkorbi
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | | | - Jacob Gretton
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Isabelle Chambrier
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Graham J. Tizzard
- UK National Crystallography ServiceChemistry University of SouthamptonSouthamptonSO17 1BJUK
| | - Simon J. Coles
- UK National Crystallography ServiceChemistry University of SouthamptonSouthamptonSO17 1BJUK
| | - David L. Hughes
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Andrew N. Cammidge
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
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33
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McMillan AJ, Sieńkowska M, Di Lorenzo P, Gransbury GK, Chilton NF, Salamone M, Ruffoni A, Bietti M, Leonori D. Practical and Selective sp 3 C-H Bond Chlorination via Aminium Radicals. Angew Chem Int Ed Engl 2021; 60:7132-7139. [PMID: 33458924 PMCID: PMC8048631 DOI: 10.1002/anie.202100030] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Indexed: 12/12/2022]
Abstract
The introduction of chlorine atoms into organic molecules is fundamental to the manufacture of industrial chemicals, the elaboration of advanced synthetic intermediates and also the fine-tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site-selective chlorination of sp3 C-H bonds. This process exploits the ability of protonated N-chloroamines to serve as aminium radical precursors and also radical chlorinating agents. Upon photochemical initiation, an efficient radical-chain propagation is established allowing the functionalization of a broad range of substrates due to the large number of compatible functionalities. The ability to synergistically maximize both polar and steric effects in the H-atom transfer transition state through appropriate selection of the aminium radical has provided the highest known selectivity in radical sp3 C-H chlorination.
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Affiliation(s)
| | - Martyna Sieńkowska
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Piero Di Lorenzo
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Gemma K. Gransbury
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Nicholas F. Chilton
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Michela Salamone
- Dipartimento di Scienze e Tecnologie ChimicheUniversità “Tor Vergata”Via della Ricerca Scientifica00133RomeItaly
| | - Alessandro Ruffoni
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Massimo Bietti
- Dipartimento di Scienze e Tecnologie ChimicheUniversità “Tor Vergata”Via della Ricerca Scientifica00133RomeItaly
| | - Daniele Leonori
- Department of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
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34
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Shoemark DK, Colenso CK, Toelzer C, Gupta K, Sessions RB, Davidson AD, Berger I, Schaffitzel C, Spencer J, Mulholland AJ. Molecular Simulations suggest Vitamins, Retinoids and Steroids as Ligands of the Free Fatty Acid Pocket of the SARS-CoV-2 Spike Protein*. Angew Chem Int Ed Engl 2021; 60:7098-7110. [PMID: 33469977 PMCID: PMC8013358 DOI: 10.1002/anie.202015639] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/18/2020] [Indexed: 12/15/2022]
Abstract
We investigate binding of linoleate and other potential ligands to the recently discovered fatty acid binding site in the SARS-CoV-2 spike protein, using docking and molecular dynamics simulations. Simulations suggest that linoleate and dexamethasone stabilize the locked spike conformation, thus reducing the opportunity for ACE2 interaction. In contrast, cholesterol may expose the receptor-binding domain by destabilizing the closed structure, preferentially binding to a different site in the hinge region of the open structure. We docked a library of FDA-approved drugs to the fatty acid site using an approach that reproduces the structure of the linoleate complex. Docking identifies steroids (including dexamethasone and vitamin D); retinoids (some known to be active in vitro, and vitamin A); and vitamin K as potential ligands that may stabilize the closed conformation. The SARS-CoV-2 spike fatty acid site may bind a diverse array of ligands, including dietary components, and therefore provides a promising target for therapeutics or prophylaxis.
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Affiliation(s)
- Deborah K. Shoemark
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
- Bristol Synthetic Biology Centre BrisSynBio24 Tyndall AveBristolBS8 1TQUK
| | - Charlotte K. Colenso
- School of Cellular and Molecular Medicine, Biomedical Sciences BuildingUniversity of BristolBristolBS8 1TDUK
| | - Christine Toelzer
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
- Bristol Synthetic Biology Centre BrisSynBio24 Tyndall AveBristolBS8 1TQUK
| | - Kapil Gupta
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
- Bristol Synthetic Biology Centre BrisSynBio24 Tyndall AveBristolBS8 1TQUK
| | - Richard B. Sessions
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
| | - Andrew D. Davidson
- School of Cellular and Molecular Medicine, Biomedical Sciences BuildingUniversity of BristolBristolBS8 1TDUK
| | - Imre Berger
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
- Bristol Synthetic Biology Centre BrisSynBio24 Tyndall AveBristolBS8 1TQUK
- Max Planck Bristol Centre for Minimal BiologyCantock's CloseBristolBS8 1TSUK
- School of ChemistryUniversity of BristolBristolBS8 1TSUK
| | - Christiane Schaffitzel
- School of BiochemistryUniversity of Bristol1 Tankard's CloseBristolBS8 1TDUK
- Bristol Synthetic Biology Centre BrisSynBio24 Tyndall AveBristolBS8 1TQUK
| | - James Spencer
- School of Cellular and Molecular Medicine, Biomedical Sciences BuildingUniversity of BristolBristolBS8 1TDUK
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35
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Bolitho EM, Coverdale JPC, Bridgewater HE, Clarkson GJ, Quinn PD, Sanchez‐Cano C, Sadler PJ. Tracking Reactions of Asymmetric Organo-Osmium Transfer Hydrogenation Catalysts in Cancer Cells. Angew Chem Int Ed Engl 2021; 60:6462-6472. [PMID: 33590607 PMCID: PMC7985874 DOI: 10.1002/anie.202016456] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/16/2020] [Indexed: 12/21/2022]
Abstract
Most metallodrugs are prodrugs that can undergo ligand exchange and redox reactions in biological media. Here we have investigated the cellular stability of the anticancer complex [OsII [(η6 -p-cymene)(RR/SS-MePh-DPEN)] [1] (MePh-DPEN=tosyl-diphenylethylenediamine) which catalyses the enantioselective reduction of pyruvate to lactate in cells. The introduction of a bromide tag at an unreactive site on a phenyl substituent of Ph-DPEN allowed us to probe the fate of this ligand and Os in human cancer cells by a combination of X-ray fluorescence (XRF) elemental mapping and inductively coupled plasma-mass spectrometry (ICP-MS). The BrPh-DPEN ligand is readily displaced by reaction with endogenous thiols and translocated to the nucleus, whereas the Os fragment is exported from the cells. These data explain why the efficiency of catalysis is low, and suggests that it could be optimised by developing thiol resistant analogues. Moreover, this work also provides a new way for the delivery of ligands which are inactive when administered on their own.
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Affiliation(s)
- Elizabeth M. Bolitho
- Department of ChemistryUniversity of WarwickCoventryCV4 7ALUK
- I14 Imaging BeamlineDiamond Light SourceOxfordOX11 0DEUK
| | | | | | - Guy J. Clarkson
- Department of ChemistryUniversity of WarwickCoventryCV4 7ALUK
| | - Paul D. Quinn
- I14 Imaging BeamlineDiamond Light SourceOxfordOX11 0DEUK
| | - Carlos Sanchez‐Cano
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE)Basque Research and Technology Alliance (BRTA)Paseo de Miramon 18220014San SebastiánSpain
| | - Peter J. Sadler
- Department of ChemistryUniversity of WarwickCoventryCV4 7ALUK
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36
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Exner RM, Cortezon‐Tamarit F, Pascu SI. Explorations into the Effect of meso-Substituents in Tricarbocyanine Dyes: A Path to Diverse Biomolecular Probes and Materials. Angew Chem Int Ed Engl 2021; 60:6230-6241. [PMID: 32959963 PMCID: PMC7985877 DOI: 10.1002/anie.202008075] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Polymethine cyanine dyes have been widely recognized as promising chemical tools for a range of life science and biomedical applications, such as fluorescent staining of DNA and proteins in gel electrophoresis, fluorescence guided surgery, or as ratiometric probes for probing biochemical pathways. The photophysical properties of such dyes can be tuned through the synthetic modification of the conjugated backbone, for example, by altering aromatic cores or by varying the length of the conjugated polymethine chain. Alternative routes to shaping the absorption, emission, and photostability of dyes of this family are centered around the chemical modifications on the polymethine chain. This Minireview aims to discuss strategies for the introduction of substituents in the meso-position, their effect on the photophysical properties of these dyes and some structure-activity correlations which could help overcome common limitations in the state of the art in the synthesis.
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Affiliation(s)
- Rüdiger M. Exner
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
| | | | - Sofia I. Pascu
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
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Bunce SJ, Wang Y, Radford SE, Wilson AJ, Hall CK. Structural insights into peptide self-assembly using photo-induced crosslinking experiments and discontinuous molecular dynamics. AIChE J 2021; 67:e17101. [PMID: 33776061 PMCID: PMC7988534 DOI: 10.1002/aic.17101] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/07/2020] [Indexed: 11/09/2022]
Abstract
Determining the structure of the (oligomeric) intermediates that form during the self-assembly of amyloidogenic peptides is challenging because of their heterogeneous and dynamic nature. Thus, there is need for methodology to analyze the underlying molecular structure of these transient species. In this work, a combination of fluorescence quenching, photo-induced crosslinking (PIC) and molecular dynamics simulation was used to study the assembly of a synthetic amyloid-forming peptide, Aβ16-22. A PIC amino acid containing a trifluormethyldiazirine (TFMD) group-Fmoc(TFMD)Phe-was incorporated into the sequence (Aβ*16-22). Electrospray ionization ion-mobility spectrometry mass-spectrometry (ESI-IMS-MS) analysis of the PIC products confirmed that Aβ*16-22 forms assemblies with the monomers arranged as anti-parallel, in-register β-strands at all time points during the aggregation assay. The assembly process was also monitored separately using fluorescence quenching to profile the fibril assembly reaction. The molecular picture resulting from discontinuous molecule dynamics simulations showed that Aβ16-22 assembles through a single-step nucleation into a β-sheet fibril in agreement with these experimental observations. This study provides detailed structural insights into the Aβ16-22 self-assembly processes, paving the way to explore the self-assembly mechanism of larger, more complex peptides, including those whose aggregation is responsible for human disease.
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Affiliation(s)
- Samuel J. Bunce
- School of ChemistryUniversity of LeedsLeedsUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
| | - Yiming Wang
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
- Department of Chemical and Biological EngineeringPrinceton UniversityPrincetonNew JerseyUSA
| | - Sheena E. Radford
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
- School of Molecular and Cellular BiologyUniversity of LeedsLeedsUK
| | - Andrew J. Wilson
- School of ChemistryUniversity of LeedsLeedsUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
| | - Carol K. Hall
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
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Quandelacy TM, Cummings DAT, Jiang CQ, Yang B, Kwok KO, Dai B, Shen R, Read JM, Zhu H, Guan Y, Riley S, Lessler J. Using serological measures to estimate influenza incidence in the presence of secular trends in exposure and immuno-modulation of antibody response. Influenza Other Respir Viruses 2021; 15:235-244. [PMID: 33108707 PMCID: PMC7902255 DOI: 10.1111/irv.12807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/24/2020] [Accepted: 08/30/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Influenza infection is often measured by a fourfold antibody titer increase over an influenza season (ie seroconversion). However, this approach may fail when influenza seasons are less distinct as it does not account for transient effects from recent infections. Here, we present a method to determine seroconversion for non-paired sera, adjusting for changes in individuals' antibody titers to influenza due to the transient impact of recent exposures, varied sampling times, and laboratory processes. METHODS We applied our method using data for five H3N2 strains collected from 942 individuals, aged 2-90 years, during the first two study visits of the Fluscape cohort study (2009-2012) in Guangzhou, China. RESULTS After adjustment, apparent seroconversion rates for non-circulating strains decreased while we observed a 20% increase in seroconversion rates to recently circulating strains. When examining seroconversion to the most recently circulating strain (A/Brisbane/20/2007) in our study, participants aged under 18, and over 64 had the highest seroconversion rates compared to other age groups. CONCLUSIONS Our results highlight the need for improved methods when using antibody titers as an endpoint in settings where there is no clear influenza "off" season. Methods, like those presented here, that use titers from circulating and non-circulating strains may be key.
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Affiliation(s)
- Talia M. Quandelacy
- Department of EpidemiologyJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
- Present address:
Centers for Disease Control and PreventionSan JuanPuerto Rico
| | - Derek A. T. Cummings
- Department of EpidemiologyJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
- Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | | | - Bingyi Yang
- Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Kin On Kwok
- The Jockey Club School of Public Health and Primary CareThe Chinese University of Hong KongHong Kong Special Administrative RegionChina
- Stanley Ho Centre for Emerging Infectious DiseasesHong Kong Special Administrative RegionThe Chinese University of Hong KongShatin, Hong KongChina
- Shenzhen Research InstituteThe Chinese University of Hong KongShenzhenChina
| | - Byran Dai
- Department of EpidemiologyJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
| | | | - Jonathan M. Read
- Center for Health Informatics Computing and StatisticsLancaster Medical SchoolLancaster UniversityLancasterUK
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - Huachen Zhu
- State Key Laboratory of Emerging Infectious DiseasesSchool of Public HealthThe University of Hong KongHong KongChina
- Shantou University Medical CollegeShantouChina
| | - Yi Guan
- Shantou University Medical CollegeShantouChina
- School of Public HealthImperial College LondonLondonUK
| | - Steven Riley
- School of Public HealthImperial College LondonLondonUK
| | - Justin Lessler
- Department of EpidemiologyJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
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McGuire TM, Bowles J, Deane E, Farrar EHE, Grayson MN, Buchard A. Control of Crystallinity and Stereocomplexation of Synthetic Carbohydrate Polymers from d- and l-Xylose. Angew Chem Int Ed Engl 2021; 60:4524-4528. [PMID: 33225519 PMCID: PMC7986207 DOI: 10.1002/anie.202013562] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/11/2020] [Indexed: 01/24/2023]
Abstract
Manipulating the stereochemistry of polymers is a powerful method to alter their physical properties. Despite the chirality of monosaccharides, reports on the impact of stereochemistry in natural polysaccharides and synthetic carbohydrate polymers remain absent. Herein, we report the cocrystallisation of regio- and stereoregular polyethers derived from d- and l-xylose, leading to enhanced thermal properties compared to the enantiopure polymers. To the best of our knowledge, this is the first example of a stereocomplex between carbohydrate polymers of opposite chirality. In contrast, atactic polymers obtained from a racemic mixture of monomers are amorphous. We also show that the polymer hydroxyl groups are amenable to post-polymerisation functionalization. These strategies afford a family of carbohydrate polyethers, the physical and chemical properties of which can both be controlled, and which opens new possibilities for polysaccharide mimics in biomedical applications or as advanced materials.
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Affiliation(s)
- Thomas M. McGuire
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
| | - Jessica Bowles
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
| | - Edward Deane
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
| | - Elliot H. E. Farrar
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
| | - Matthew N. Grayson
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
| | - Antoine Buchard
- Department of ChemistryUniversity of BathCentre for Sustainable and Circular TechnologiesClaverton DownBathBA2 7AYUK
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40
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Abstract
Kinetic resolution using biocatalysis has proven to be an excellent complementary technique to traditional asymmetric catalysis for the production of enantioenriched compounds. Resolution using oxidative enzymes produces valuable oxygenated structures for use in synthetic route development. This Minireview focuses on enzymes which catalyse the insertion of an oxygen atom into the substrate and, in so doing, can achieve oxidative kinetic resolution. The Baeyer-Villiger rearrangement, epoxidation, and hydroxylation are included, and biological advancements in enzyme development, and applications of these key enantioenriched intermediates in natural product synthesis are discussed.
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Affiliation(s)
- Lucy A. Harwood
- Department of ChemistryUniversity of OxfordChemistry Research LaboratoryMansfield RoadOxfordOX1 3TAUK
| | - Luet L. Wong
- Department of ChemistryUniversity of OxfordInorganic Chemistry LaboratorySouth Parks RoadOxfordOX1 3QRUK
- Oxford Suzhou Centre for Advanced ResearchRuo Shui Road, Suzhou Industrial ParkJiangsu215123P. R. China
| | - Jeremy Robertson
- Department of ChemistryUniversity of OxfordChemistry Research LaboratoryMansfield RoadOxfordOX1 3TAUK
- Oxford Suzhou Centre for Advanced ResearchRuo Shui Road, Suzhou Industrial ParkJiangsu215123P. R. China
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41
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Furfari SK, Tegner BE, Burnage AL, Doyle LR, Bukvic AJ, Macgregor SA, Weller AS. Selectivity of Rh⋅⋅⋅H-C Binding in a σ-Alkane Complex Controlled by the Secondary Microenvironment in the Solid State. Chemistry 2021; 27:3177-3183. [PMID: 33112000 PMCID: PMC7898853 DOI: 10.1002/chem.202004585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/27/2020] [Indexed: 12/13/2022]
Abstract
Single-crystal to single-crystal solid-state molecular organometallic (SMOM) techniques are used for the synthesis and structural characterization of the σ-alkane complex [Rh(tBu2 PCH2 CH2 CH2 PtBu2 )(η2 ,η2 -C7 H12 )][BArF 4 ] (ArF =3,5-(CF3 )2 C6 H3 ), in which the alkane (norbornane) binds through two exo-C-H⋅⋅⋅Rh interactions. In contrast, the bis-cyclohexyl phosphine analogue shows endo-alkane binding. A comparison of the two systems, supported by periodic DFT calculations, NCI plots and Hirshfeld surface analyses, traces this different regioselectivity to subtle changes in the local microenvironment surrounding the alkane ligand. A tertiary periodic structure supporting a secondary microenvironment that controls binding at the metal site has parallels with enzymes. The new σ-alkane complex is also a catalyst for solid/gas 1-butene isomerization, and catalyst resting states are identified for this.
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Affiliation(s)
| | - Bengt E. Tegner
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | - Arron L. Burnage
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | | | - Alexander J. Bukvic
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
- Department of ChemistryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
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42
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Zheng X, Heilmann A, McManus C, Aldridge S. A Xanthene-Based Mono-Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry. Chemistry 2021; 27:3159-3165. [PMID: 33200850 PMCID: PMC7898390 DOI: 10.1002/chem.202004741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/16/2020] [Indexed: 12/05/2022]
Abstract
The synthesis of a novel mono-anionic phosphino-amide ligand based on a xanthene backbone is reported, togetherr with the corresponding GaI complex, (PON)Ga (PON = 4-(di(2,4,6-trimethylphenyl)phosphino)-5-(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). The solid-state structure of (PON)Ga (obtained from X-ray crystallography) reveals very weak O⋅⋅⋅Ga and P⋅⋅⋅Ga interactions, consistent with a R2 NGa fragment which closely resembles those found in one-coordinate amidogallium systems. Strong N-to-Ga π donation from the amido substituent is reflected in a very short N-Ga distance (1.961(2) Å), while the P⋅⋅⋅Ga contact (3.076(1) Å) is well outside the sum of the respective covalent radii. While the donor properties of the PON ligand towards GaI are highly unsymmetrical, oxidation to GaIII leads to much stronger coordination of the pendant phosphine as shown by P-Ga distances which are up to 20 % shorter. From a steric perspective, the PON ligand is shown to be significantly bulkier than related β-diketiminate systems, a finding consistent with reactions of (PON)Ga towards O-atom sources that proceed without oligomerization. Despite this, the enhanced P-donor properties brought about by oxidation at gallium are not sufficient to quench the reactivity of the highly polar Ga-O unit. Instead, intramolecular benzylic C-H activation is observed across the Ga-O bond of a transient gallanone intermediate.
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Affiliation(s)
- Xiongfei Zheng
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Andreas Heilmann
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Caitilín McManus
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Simon Aldridge
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
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43
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Wright JS, Scott PJH, Steel PG. Iridium-Catalysed C-H Borylation of Heteroarenes: Balancing Steric and Electronic Regiocontrol. Angew Chem Int Ed Engl 2021; 60:2796-2821. [PMID: 32202024 PMCID: PMC7894576 DOI: 10.1002/anie.202001520] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/09/2020] [Indexed: 12/19/2022]
Abstract
The iridium-catalysed borylation of aromatic C-H bonds has become the preferred method for the synthesis of aromatic organoboron compounds. The reaction is highly efficient, tolerant of a broad range of substituents and can be applied to both carbocyclic and heterocyclic substrates. The regioselectivity of C-H activation is dominated by steric considerations and there have been considerable efforts to develop more selective processes for less constrained substrates. However, most of these have focused on benzenoid-type substrates and in contrast, heteroarenes remain much desired but more challenging substrates with the position and/or nature of the heteroatom(s) significantly affecting reactivity and regioselectivity. This review will survey the borylation of heteroarenes, focusing on the influence of steric and electronic effects on regiochemical outcome and, by linking to current mechanistic understandings, will provide insights to what is currently possible and where further developments are required.
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Affiliation(s)
- Jay S. Wright
- Department of ChemistryUniversity of DurhamScience Laboratories, South Road DurhamDurhamDH1 3LEUK
- Department of RadiologyUniversity of MichiganAnn ArborMichiganUSA
| | | | - Patrick G. Steel
- Department of ChemistryUniversity of DurhamScience Laboratories, South Road DurhamDurhamDH1 3LEUK
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44
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Poulter JA, Gravett MSC, Taylor RL, Fujinami K, De Zaeytijd J, Bellingham J, Rehman AU, Hayashi T, Kondo M, Rehman A, Ansar M, Donnelly D, Toomes C, Ali M, De Baere E, Leroy BP, Davies NP, Henderson RH, Webster AR, Rivolta C, Zeitz C, Mahroo OA, Arno G, Black GCM, McKibbin M, Harris SA, Khan KN, Inglehearn CF. New variants and in silico analyses in GRK1 associated Oguchi disease. Hum Mutat 2021; 42:164-176. [PMID: 33252155 PMCID: PMC7898643 DOI: 10.1002/humu.24140] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 09/15/2020] [Accepted: 11/05/2020] [Indexed: 12/16/2022]
Abstract
Biallelic mutations in G-Protein coupled receptor kinase 1 (GRK1) cause Oguchi disease, a rare subtype of congenital stationary night blindness (CSNB). The purpose of this study was to identify disease causing GRK1 variants and use in-depth bioinformatic analyses to evaluate how their impact on protein structure could lead to pathogenicity. Patients' genomic DNA was sequenced by whole genome, whole exome or focused exome sequencing. Disease associated variants, published and novel, were compared to nondisease associated missense variants. The impact of GRK1 missense variants at the protein level were then predicted using a series of computational tools. We identified twelve previously unpublished cases with biallelic disease associated GRK1 variants, including eight novel variants, and reviewed all GRK1 disease associated variants. Further structure-based scoring revealed a hotspot for missense variants in the kinase domain. In addition, to aid future clinical interpretation, we identified the bioinformatics tools best able to differentiate disease associated from nondisease associated variants. We identified GRK1 variants in Oguchi disease patients and investigated how disease-causing variants may impede protein function in-silico.
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Affiliation(s)
- James A. Poulter
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
| | | | - Rachel L. Taylor
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicines and HealthUniversity of ManchesterManchesterUK
| | - Kaoru Fujinami
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical CentreTokyoJapan
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyLondonUK
- Keio University School of MedicineTokyoJapan
| | | | | | - Atta Ur Rehman
- Division of Genetic Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)University of LausanneLausanneSwitzerland
| | | | - Mineo Kondo
- Mie University Graduate School of MedicineMieJapan
| | - Abdur Rehman
- Department of Genetics, Faculty of ScienceHazara University MansehraDhodialPakistan
| | - Muhammad Ansar
- Clinical Research Center, Institute of Molecular and Clinical Ophthalmology Basel (IOB)BaselSwitzerland
| | - Dan Donnelly
- School of Biomedical Sciences, University of LeedsLeedsUK
| | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
| | | | | | - Bart P. Leroy
- Ghent UniversityGhentBelgium
- Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | | | | | - Andrew R. Webster
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyLondonUK
| | - Carlo Rivolta
- Department of Genetics and Genome BiologyUniversity of LeicesterLeicesterUK
- Clinical Research Center, Institute of Molecular and Clinical Ophthalmology Basel (IOB)BaselSwitzerland
- Department of OphthalmologyUniversity Hospital BaselBaselSwitzerland
| | - Christina Zeitz
- Sorbonne UniversitéINSERM, CNRS, Institut de la VisionParisFrance
| | - Omar A. Mahroo
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyLondonUK
| | - Gavin Arno
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical CentreTokyoJapan
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyLondonUK
| | - Graeme C. M. Black
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicines and HealthUniversity of ManchesterManchesterUK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation TrustManchesterUK
| | - Martin McKibbin
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
- Leeds Teaching Hospitals NHS Trust, St James’ University HospitalLeedsUK
| | | | - Kamron N. Khan
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation TrustManchesterUK
| | - Chris F. Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical ResearchUniversity of LeedsLeedsUK
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Paun LM, Husmeier D. Markov chain Monte Carlo with Gaussian processes for fast parameter estimation and uncertainty quantification in a 1D fluid-dynamics model of the pulmonary circulation. Int J Numer Method Biomed Eng 2021; 37:e3421. [PMID: 33249755 PMCID: PMC7901000 DOI: 10.1002/cnm.3421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 11/07/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
The past few decades have witnessed an explosive synergy between physics and the life sciences. In particular, physical modelling in medicine and physiology is a topical research area. The present work focuses on parameter inference and uncertainty quantification in a 1D fluid-dynamics model for quantitative physiology: the pulmonary blood circulation. The practical challenge is the estimation of the patient-specific biophysical model parameters, which cannot be measured directly. In principle this can be achieved based on a comparison between measured and predicted data. However, predicting data requires solving a system of partial differential equations (PDEs), which usually have no closed-form solution, and repeated numerical integrations as part of an adaptive estimation procedure are computationally expensive. In the present article, we demonstrate how fast parameter estimation combined with sound uncertainty quantification can be achieved by a combination of statistical emulation and Markov chain Monte Carlo (MCMC) sampling. We compare a range of state-of-the-art MCMC algorithms and emulation strategies, and assess their performance in terms of their accuracy and computational efficiency. The long-term goal is to develop a method for reliable disease prognostication in real time, and our work is an important step towards an automatic clinical decision support system.
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Affiliation(s)
- L. Mihaela Paun
- School of Mathematics and StatisticsUniversity of GlasgowGlasgowUK
| | - Dirk Husmeier
- School of Mathematics and StatisticsUniversity of GlasgowGlasgowUK
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Abstract
The chemistry of dirhodium(II) catalysts is highly diverse, and can enable the synthesis of many different molecular classes. A tool to aid in catalyst selection, independent of mechanism and reactivity, would therefore be highly desirable. Here, we describe the development of a database for dirhodium(II) catalysts that is based on the principal component analysis of DFT-calculated parameters capturing their steric and electronic properties. This database maps the relevant catalyst space, and may facilitate exploration of the reactivity landscape for any process catalysed by dirhodium(II) complexes. We have shown that one of the principal components of these catalysts correlates with the outcome (e.g. yield, selectivity) of a transformation used in a molecular discovery project. Furthermore, we envisage that this approach will assist the selection of more effective catalyst screening sets, and, hence, the data-led optimisation of a wide range of rhodium-catalysed transformations.
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Affiliation(s)
- Adam I. Green
- School of Chemistry and Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsLS29JTUK
| | | | - Stuart Warriner
- School of Chemistry and Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsLS29JTUK
| | - Adam Nelson
- School of Chemistry and Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsLS29JTUK
| | - Natalie Fey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS81TSUK
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47
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Rood SC, Pastor‐Algaba O, Tosca‐Princep A, Pinho B, Isaacs M, Torrente‐Murciano L, Eslava S. Synergistic Effect of Simultaneous Doping of Ceria Nanorods with Cu and Cr on CO Oxidation and NO Reduction. Chemistry 2021; 27:2165-2174. [PMID: 33210814 PMCID: PMC7898804 DOI: 10.1002/chem.202004623] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Indexed: 11/27/2022]
Abstract
Ceria particles play a key role in catalytic applications such as automotive three-way catalytic systems in which toxic CO and NO are oxidized and reduced to safe CO2 and N2 , respectively. In this work, we explore the incorporation of Cu and Cr metals as dopants in the crystal structure of ceria nanorods prepared by a single-step hydrothermal synthesis. XRD, Raman and XPS confirm the incorporation of Cu and Cr in the ceria crystal lattices, offering ceria nanorods with a higher concentration of oxygen vacancies. XPS also confirms the presence of Cr and Cu surface species. H2 -TPR and XPS analysis show that the simultaneous Cu and Cr co-doping results in a catalyst with a higher surface Cu concentration and a much-enhanced surface reducibility, in comparison with either undoped or singly doped (Cu or Cr) ceria nanorods. While single Cu doping enhances catalytic CO oxidation and Cr doping improves catalytic NO reduction, co-doping with both Cu and Cr enhances the benefits of both dopants in a synergistic manner employing roughly a quarter of dopant weight.
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Affiliation(s)
- Shawn C. Rood
- Centre for Sustainable Chemical TechnologiesDepartment of Chemical EngineeringUniversity of BathClaverton DownBathBA2 7AYUK
| | - Oriol Pastor‐Algaba
- Departament d'Enginyeria Química, Biològica i AmbientalUniversitat Autònoma de BarcelonaBellaterra08193Spain
| | - Albert Tosca‐Princep
- Departament d'Enginyeria Química, Biològica i AmbientalUniversitat Autònoma de BarcelonaBellaterra08193Spain
| | - Bruno Pinho
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhilippa Fawcett DriveCambridgeCB3 0ASUK
| | - Mark Isaacs
- Department of ChemistryUniversity College LondonLondonWC1H 0AJUK
| | - Laura Torrente‐Murciano
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhilippa Fawcett DriveCambridgeCB3 0ASUK
| | - Salvador Eslava
- Centre for Sustainable Chemical TechnologiesDepartment of Chemical EngineeringUniversity of BathClaverton DownBathBA2 7AYUK
- Department of Chemical EngineeringImperial College LondonLondonSW7 2AZUK
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48
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Marsh AV, Little M, Cheetham NJ, Dyson MJ, Bidwell M, White AJP, Warriner CN, Swain AC, McCulloch I, Stavrinou PN, Heeney M. Highly Deformed o-Carborane Functionalised Non-linear Polycyclic Aromatics with Exceptionally Long C-C Bonds. Chemistry 2021; 27:1970-1975. [PMID: 33044792 PMCID: PMC7898797 DOI: 10.1002/chem.202004517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 11/16/2022]
Abstract
The effect of substituting o-carborane into the most sterically hindered positions of phenanthrene and benzo(k)tetraphene is reported. Synthesised via a Bull-Hutchings-Quayle benzannulation, the crystal structures of these non-linear acenes exhibited the highest aromatic deformation parameters observed for any reported carborane compound to date, and among the largest carboranyl C-C bond length of all organo-substituted o-carboranes. Photoluminescence studies of these compounds demonstrated efficient intramolecular charge-transfer, leading to aggregation induced emission properties. Additionally, an unusual low-energy excimer was observed for the phenanthryl compound. These are two new members of the family of carborane-functionalised non-linear acenes, notable for their peculiar structures and multi-luminescent properties.
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Affiliation(s)
- Adam V. Marsh
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Mark Little
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Nathan J. Cheetham
- Department of Physics and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Matthew J. Dyson
- Molecular Materials and Nanosystems and Institute for Complex Molecular SystemsEindhoven University of Technology5600 MBEindhovenNetherlands
| | - Matthew Bidwell
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Andrew J. P. White
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | | | | | - Iain McCulloch
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUK
| | - Paul N. Stavrinou
- Department of Engineering ScienceUniversity of OxfordOxfordOX1 3PJUK
| | - Martin Heeney
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
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Protchenko AV, Vasko P, Fuentes MÁ, Hicks J, Vidovic D, Aldridge S. Approaching a "Naked" Boryl Anion: Amide Metathesis as a Route to Calcium, Strontium, and Potassium Boryl Complexes. Angew Chem Int Ed Engl 2021; 60:2064-2068. [PMID: 33026153 PMCID: PMC7894291 DOI: 10.1002/anie.202011839] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Indexed: 11/08/2022]
Abstract
Amide metathesis has been used to generate the first structurally characterized boryl complexes of calcium and strontium, {(Me3 Si)2 N}M{B(NDippCH)2 }(thf)n (M=Ca, n=2; M=Sr, n=3), through the reactions of the corresponding bis(amides), M{N(SiMe3 )2 }2 (thf)2 , with (thf)2 Li- {B(NDippCH)2 }. Most notably, this approach can also be applied to the analogous potassium amide K{N(SiMe3 )2 }, leading to the formation of the solvent-free borylpotassium dimer [K{B(NDippCH)2 }]2 , which is stable in the solid state at room temperature for extended periods (48 h). A dimeric structure has been determined crystallographically in which the K+ cations interact weakly with both the ipso-carbons of the flanking Dipp groups and the boron centres of the diazaborolyl heterocycles, with K⋅⋅⋅B distances of >3.1 Å. These structural features, together with atoms in molecules (QTAIM) calculations imply that the boron-containing fragment closely approaches a limiting description as a "free" boryl anion in the condensed phase.
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Affiliation(s)
- Andrey V. Protchenko
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Petra Vasko
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
- Department of Chemistry, Nanoscience CenterUniversity of JyväskyläP. O. Box 3540014JyväskyläFinland
| | - M. Ángeles Fuentes
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Jamie Hicks
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Dragoslav Vidovic
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Simon Aldridge
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
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Rees GJ, Spencer Jolly D, Ning Z, Marrow TJ, Pavlovskaya GE, Bruce PG. Imaging Sodium Dendrite Growth in All-Solid-State Sodium Batteries Using 23 Na T 2 -Weighted Magnetic Resonance Imaging. Angew Chem Int Ed Engl 2021; 60:2110-2115. [PMID: 33022833 PMCID: PMC7894568 DOI: 10.1002/anie.202013066] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Indexed: 11/07/2022]
Abstract
Two-dimensional, Knight-shifted, T2 -contrasted 23 Na magnetic resonance imaging (MRI) of an all-solid-state cell with a Na electrode and a ceramic electrolyte is employed to directly observe Na microstructural growth. A spalling dendritic morphology is observed and confirmed by more conventional post-mortem analysis; X-ray tomography and scanning electron microscopy. A significantly larger 23 Na T2 for the dendritic growth, compared with the bulk metal electrode, is attributed to increased sodium ion mobility in the dendrite. 23 Na T2 -contrast MRI of metallic sodium offers a clear, routine method for observing and isolating microstructural growths and can supplement the current suite of techniques utilised to analyse dendritic growth in all-solid-state cells.
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Affiliation(s)
- Gregory J. Rees
- Department of MaterialsUniversity of OxfordParks RoadOxfordOX1 3PHUK
- The Faraday InstitutionHarwell CampusDidcotOX11 0RAUK
| | | | - Ziyang Ning
- Department of MaterialsUniversity of OxfordParks RoadOxfordOX1 3PHUK
| | - T. James Marrow
- Department of MaterialsUniversity of OxfordParks RoadOxfordOX1 3PHUK
| | - Galina E. Pavlovskaya
- Sir Peter Mansfield Imaging CentreSchool of MedicineUniversity of NottinghamNottinghamNG7 2RDUK
- NIHR Nottingham Biomedical Research CentreUniversity of NottinghamNottinghamNG7 2RDUK
| | - Peter G. Bruce
- Department of MaterialsUniversity of OxfordParks RoadOxfordOX1 3PHUK
- Department of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QZUK
- The Henry Royce InstituteParks RoadOxfordOX1 3PHUK
- The Faraday InstitutionHarwell CampusDidcotOX11 0RAUK
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