1
|
Guo X, Zhang L, Hu J, Szilágyi B, Yu M, Chen S, Tircsó G, Zhou X, Tao J. Improving the potential of paraCEST through magnetic-coupling induced line sharpening. Chem Sci 2023; 14:14157-14165. [PMID: 38098703 PMCID: PMC10717539 DOI: 10.1039/d3sc04770a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 11/17/2023] [Indexed: 12/17/2023] Open
Abstract
Magnetic coupling between paramagnetic centers is a crucial phenomenon in the design of efficient MRI contrast agents. In this study, we investigate the paraCEST properties and magnetic coupling effects of a novel homodinuclear Ni(ii) complex, 1, containing a Robson type macrocyclic ligand. A thorough analysis of the complex's electronic and magnetic properties revealed that the magnetic coupling effect reduces the transverse relaxation rate and enhances the sharpness of the proton resonances, leading to enhanced CEST efficiency. This novel mechanism, which we coined "magnetic-coupling induced line sharpening" (MILS), can be crucial for optimizing the performance of paramagnetic metal complexes in paraCEST imaging. Moreover, magnetic coupling plays a critical role in the relaxation properties of homodinuclear complexes. Our study not only paves the way for the creation of advanced paraCEST agents with enhanced CEST capabilities and sensitivity but also provides valuable guidance for the design of other MRI contrast agents utilizing dinuclear metal complexes.
Collapse
Affiliation(s)
- Xin Guo
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology Beijing 102488 China
| | - Lei Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan National Laboratory for Optoelectronics Wuhan 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jiesheng Hu
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology Beijing 102488 China
| | - Balázs Szilágyi
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen Egyetem tér 1 H-4032 Debrecen Hungary
- Doctoral School of Chemistry, University of Debrecen Egyetem tér 1 H-4032 Debrecen Hungary
| | - Meng Yu
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology Beijing 102488 China
| | - Shizhen Chen
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan National Laboratory for Optoelectronics Wuhan 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Gyula Tircsó
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen Egyetem tér 1 H-4032 Debrecen Hungary
| | - Xin Zhou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan National Laboratory for Optoelectronics Wuhan 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jun Tao
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology Beijing 102488 China
| |
Collapse
|
2
|
Trindade IB, Coelho A, Cantini F, Piccioli M, Louro RO. NMR of paramagnetic metalloproteins in solution: Ubi venire, quo vadis? J Inorg Biochem 2022; 234:111871. [DOI: 10.1016/j.jinorgbio.2022.111871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 10/18/2022]
|
3
|
Li R, Khan FST, Tapia M, Hematian S. Oxygenation of copper(I) complexes containing fluorine tagged tripodal tetradentate chelates: significant ligand electronic effects. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2107429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Runzi Li
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Firoz Shah Tuglak Khan
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Marcos Tapia
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Shabnam Hematian
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
| |
Collapse
|
4
|
Sureshbabu P, Upadhyay C, Sabiah S. Structural and Magnetic Properties of Dimeric and Tetrameric Copper (II) Complexes with Simple Bidentate Ligands and Phosphate Bridges. ChemistrySelect 2022. [DOI: 10.1002/slct.202200916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Popuri Sureshbabu
- Department of Chemistry Pondicherry University Pondicherry 605 014 India
| | - Chandan Upadhyay
- School of Materials Science and Technology Indian Institute of Technology (BHU) Varanasi 221005 India
| | | |
Collapse
|
5
|
Miao Q, Nitsche C, Orton H, Overhand M, Otting G, Ubbink M. Paramagnetic Chemical Probes for Studying Biological Macromolecules. Chem Rev 2022; 122:9571-9642. [PMID: 35084831 PMCID: PMC9136935 DOI: 10.1021/acs.chemrev.1c00708] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/11/2022]
Abstract
Paramagnetic chemical probes have been used in electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopy for more than four decades. Recent years witnessed a great increase in the variety of probes for the study of biological macromolecules (proteins, nucleic acids, and oligosaccharides). This Review aims to provide a comprehensive overview of the existing paramagnetic chemical probes, including chemical synthetic approaches, functional properties, and selected applications. Recent developments have seen, in particular, a rapid expansion of the range of lanthanoid probes with anisotropic magnetic susceptibilities for the generation of structural restraints based on residual dipolar couplings and pseudocontact shifts in solution and solid state NMR spectroscopy, mostly for protein studies. Also many new isotropic paramagnetic probes, suitable for NMR measurements of paramagnetic relaxation enhancements, as well as EPR spectroscopic studies (in particular double resonance techniques) have been developed and employed to investigate biological macromolecules. Notwithstanding the large number of reported probes, only few have found broad application and further development of probes for dedicated applications is foreseen.
Collapse
Affiliation(s)
- Qing Miao
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- School
of Chemistry &Chemical Engineering, Shaanxi University of Science & Technology, Xi’an710021, China
| | - Christoph Nitsche
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Henry Orton
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Mark Overhand
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Gottfried Otting
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Marcellus Ubbink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| |
Collapse
|
6
|
Prosser KE, Xie D, Chu A, MacNeil GA, Varju BR, Kadakia RT, Que EL, Walsby CJ. Copper(II) Pyridyl Aminophenolates: Hypoxia-Selective, Nucleus-Targeting Cytotoxins, and Magnetic Resonance Probes. Chemistry 2021; 27:9839-9849. [PMID: 33878230 DOI: 10.1002/chem.202100603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Indexed: 11/10/2022]
Abstract
Targeting the low-oxygen (hypoxic) environments found in many tumours by using redox-active metal complexes is a strategy that can enhance efficacy and reduce the side effects of chemotherapies. We have developed a series of CuII complexes with tridentate pyridine aminophenolate-based ligands for preferential activation in the reduction window provided by hypoxic tissues. Furthermore, ligand functionalization with a pendant CF3 group provides a 19 F spectroscopic handle for magnetic-resonance studies of redox processes at the metal centre and behaviour in cellular environments. The phenol group in the ligand backbone was substituted at the para position with H, Cl, and NO2 to modulate the reduction potential of the CuII centre, giving a range of values below the window expected for hypoxic tissues. The NO2 -substituted complex, which has the highest reduction potential, showed enhanced cytotoxic selectivity towards HeLa cells grown under hypoxic conditions. Cell death occurs by apoptosis, as determined by analysis of the cell morphology. A combination of 19 F NMR and ICP-OES indicates localization of the NO2 complex in HeLa cell nuclei and increased cellular accumulation under hypoxia. This correlates with DNA nuclease activity being the likely origin of cytotoxic activity, as demonstrated by cleavage of DNA plasmids in the presence of the CuII nitro complex and a reducing agent. Selective detection of the paramagnetic CuII complexes and their diamagnetic ligands by 19 F MRI suggests hypoxia-targeting theranostic applications by redox activation.
Collapse
Affiliation(s)
- Kathleen E Prosser
- Department of Chemistry, Simon Fraser University, 8888 University Dr., Burnaby, BC V5A 1S6, Canada.,Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street Stop A5300, Austin, TX 78712, USA
| | - Da Xie
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street Stop A5300, Austin, TX 78712, USA
| | - Annica Chu
- Department of Chemistry, Simon Fraser University, 8888 University Dr., Burnaby, BC V5A 1S6, Canada
| | - Gregory A MacNeil
- Department of Chemistry, Simon Fraser University, 8888 University Dr., Burnaby, BC V5A 1S6, Canada
| | - Bryton R Varju
- Department of Chemistry, Simon Fraser University, 8888 University Dr., Burnaby, BC V5A 1S6, Canada
| | - Rahul T Kadakia
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street Stop A5300, Austin, TX 78712, USA
| | - Emily L Que
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street Stop A5300, Austin, TX 78712, USA
| | - Charles J Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Dr., Burnaby, BC V5A 1S6, Canada
| |
Collapse
|
7
|
Dasgupta R, Gupta KBSS, de Groot HJM, Ubbink M. The Resting Oxidized State of Small Laccase Analyzed with Paramagnetic NMR Spectroscopy. Chemphyschem 2021; 22:733-740. [PMID: 33682979 PMCID: PMC8252789 DOI: 10.1002/cphc.202100063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/28/2021] [Indexed: 12/28/2022]
Abstract
The enzyme laccase catalyzes the reduction of dioxygen to water at the trinuclear copper center (TNC). The TNC comprises a type‐3 (T3) and a type‐2 (T2) copper site. The paramagnetic NMR spectrum of the small laccase from Streptomyces coelicolor (SLAC) without the substrate shows a mixture of two catalytic states, the resting oxidized (RO) state and the native intermediate (NI) state. An analysis of the resonances of the RO state is reported. In this state, hydrogen resonances only of the T3 copper ligands can be found, in the region of 12–22 ppm. Signals from all six histidine ligands are found and can be attributed to Hδ1, Hβ or backbone amide HN nuclei. Two sequence‐specific assignments are proposed on the basis of a second‐coordination shell variant that also lacks the copper ion at the T1 site, SLAC−T1D/Q291E. This double mutant is found to be exclusively in the RO state, revealing a subtle balance between the RO and the NI states.
Collapse
Affiliation(s)
- Rubin Dasgupta
- Leiden Institute of Chemistry, Leiden University, Gorlaeus Laboratory, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Karthick B S S Gupta
- Leiden Institute of Chemistry, Leiden University, Gorlaeus Laboratory, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Huub J M de Groot
- Leiden Institute of Chemistry, Leiden University, Gorlaeus Laboratory, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Leiden University, Gorlaeus Laboratory, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| |
Collapse
|
8
|
Pastor‐Ramírez C, Zamorano‐Ulloa R, Vazquez‐Lima H, Hernández‐Anzaldo S, Reyes‐Ortega Y. Synthesis and Magneto‐Structural Study of Distorted Octahedral Co
II
Complexes with Picolinamide and Azide (
μ
1,1
)‐Bridge. ChemistrySelect 2021. [DOI: 10.1002/slct.202004323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Cándida Pastor‐Ramírez
- Instituto de Ciencias Centro de Química Benemérita Universidad Autónoma de Puebla Edif. IC09, C. U., Jardines de San Manuel Puebla Pue., C.P. 72540 México
| | - Rafael Zamorano‐Ulloa
- Departamento de Física ESFM Instituto Politécnico Nacional Av. Politécnico Nacional S/N Edif. 9 Col. San Pedro Zacatenco, C. P. 07738, CDMX México
| | - Hugo Vazquez‐Lima
- Instituto de Ciencias Centro de Química Benemérita Universidad Autónoma de Puebla Edif. IC09, C. U., Jardines de San Manuel Puebla Pue., C.P. 72540 México
| | - Samuel Hernández‐Anzaldo
- Instituto de Ciencias Centro de Química Benemérita Universidad Autónoma de Puebla Edif. IC09, C. U., Jardines de San Manuel Puebla Pue., C.P. 72540 México
| | - Yasmi Reyes‐Ortega
- Instituto de Ciencias Centro de Química Benemérita Universidad Autónoma de Puebla Edif. IC09, C. U., Jardines de San Manuel Puebla Pue., C.P. 72540 México
| |
Collapse
|
9
|
Rios N, Fuentes F, Oliveros D, Mora JR, Garcia-Garfido JM, Otero Y. Synthesis, characterization, and photophysical properties of a new 2,5-di(aryl)phosphole derivative and their trigonal copper–phosphole complexes. J COORD CHEM 2021. [DOI: 10.1080/00958972.2021.1873959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Neskarlys Rios
- Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela
| | - Franmerly Fuentes
- Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela
| | - Deivi Oliveros
- Departamento de Ingeniería Química, Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito, Quito, Ecuador
| | - José R. Mora
- Departamento de Ingeniería Química, Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito, Quito, Ecuador
| | - Juan M. Garcia-Garfido
- Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela
- Departamento de Física, Universidad de Santiago de Chile, Santiago, Chile
| | - Yomaira Otero
- Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| |
Collapse
|
10
|
Gupta A, Caravan P, Price WS, Platas-Iglesias C, Gale EM. Applications for Transition-Metal Chemistry in Contrast-Enhanced Magnetic Resonance Imaging. Inorg Chem 2020; 59:6648-6678. [PMID: 32367714 DOI: 10.1021/acs.inorgchem.0c00510] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Contrast-enhanced magnetic resonance imaging (MRI) is an indispensable tool for diagnostic medicine. However, safety concerns related to gadolinium in commercial MRI contrast agents have emerged in recent years. For patients suffering from severe renal impairment, there is an important unmet medical need to perform contrast-enhanced MRI without gadolinium. There are also concerns over the long-term effects of retained gadolinium within the general patient population. Demand for gadolinium-free MRI contrast agents is driving a new wave of inorganic chemistry innovation as researchers explore paramagnetic transition-metal complexes as potential alternatives. Furthermore, advances in personalized care making use of molecular-level information have motivated inorganic chemists to develop MRI contrast agents that can detect pathologic changes at the molecular level. Recent studies have highlighted how reaction-based modulation of transition-metal paramagnetism offers a highly effective mechanism to achieve MRI contrast enhancement that is specific to biochemical processes. This Viewpoint highlights how recent advances in transition-metal chemistry are leading the way for a new generation of MRI contrast agents.
Collapse
Affiliation(s)
- Abhishek Gupta
- Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, New South Wales 2751, Australia.,Ingham Institute of Applied Medical Research, Liverpool, New South Wales 2170, Australia
| | | | - William S Price
- Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, New South Wales 2751, Australia.,Ingham Institute of Applied Medical Research, Liverpool, New South Wales 2170, Australia
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña, Galicia 15071, Spain
| | | |
Collapse
|
11
|
Pires AS, Batista J, Murtinho D, Nogueira C, Karamysheva A, Luísa Ramos M, Milne BF, Tavares NT, Gonçalves J, Gonçalves AC, Abrantes AM, Soares R, Gonçalves T, Botelho MF, Silva Serra ME. Synthesis, Characterization and Evaluation of the Antibacterial and Antitumor Activity of HalogenatedSalen Copper (II) Complexes derived from Camphoric Acid. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ana Salomé Pires
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
- CNC.IBILI Consortium/Center for Innovative Biomedicine and Biotechnology (CIBB)University of Coimbra 3000‐548 Coimbra Portugal
| | - João Batista
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
- Centro de Química, Department of ChemistryUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - Dina Murtinho
- Centro de Química, Department of ChemistryUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - Célia Nogueira
- CNC ‐ Centre for Neuroscience and Cell BiologyUniversity of Coimbra 3004‐535 Coimbra Portugal
- Institute of Microbiology, Faculty of MedicineUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - Anna Karamysheva
- Institute of Microbiology, Faculty of MedicineUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - M. Luísa Ramos
- Centro de Química, Department of ChemistryUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - Bruce F. Milne
- CFisUC, Department of PhysicsUniversity of Coimbra Rua Larga 3004‐516 Coimbra Portugal
- Nano‐Bio Spectroscopy Group and ETSF Scientific Development Centre, Departamento de Física de MaterialesUniversidad del País Vasco UPV/EHU E‐20018 San Sebastián Spain
| | - Nuno Tiago Tavares
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
| | - José Gonçalves
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
| | - Ana Cristina Gonçalves
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
- CNC.IBILI Consortium/Center for Innovative Biomedicine and Biotechnology (CIBB)University of Coimbra 3000‐548 Coimbra Portugal
- Laboratory of Oncobiology and Hematology and University Clinic of Hematology/Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
| | - Ana Margarida Abrantes
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
- CNC.IBILI Consortium/Center for Innovative Biomedicine and Biotechnology (CIBB)University of Coimbra 3000‐548 Coimbra Portugal
| | - Rui Soares
- Institute of Microbiology, Faculty of MedicineUniversity of Coimbra 3004‐535 Coimbra Portugal
- Department of Clinical Pathology ServiceInstituto Português de Oncologia de Coimbra Francisco Gentil EPE 3000‐075 Coimbra Portugal
| | - Teresa Gonçalves
- CNC ‐ Centre for Neuroscience and Cell BiologyUniversity of Coimbra 3004‐535 Coimbra Portugal
- Institute of Microbiology, Faculty of MedicineUniversity of Coimbra 3004‐535 Coimbra Portugal
| | - Maria Filomena Botelho
- Biophysics Institute, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Faculty of MedicineUniversity of Coimbra 3000‐548 Coimbra Portugal
- CNC.IBILI Consortium/Center for Innovative Biomedicine and Biotechnology (CIBB)University of Coimbra 3000‐548 Coimbra Portugal
| | - M. Elisa Silva Serra
- Centro de Química, Department of ChemistryUniversity of Coimbra 3004‐535 Coimbra Portugal
| |
Collapse
|
12
|
Anjana SS, Varghese B, Murthy NN. Coligand modulated oxidative O-demethylation of a methyl ether appended tetradentate N-ligand in Co(ii) complexes. Dalton Trans 2020; 49:3187-3197. [PMID: 31967148 DOI: 10.1039/c9dt04609g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Two Co(ii) complexes of the formula CoLOMeX2 (X = Cl- (1a); X = I- (1b)), where LOMe is 2-methoxy-N,N-bis(pyridin-2-ylmethyl) aniline, were synthesized and their structure, spectra and reactivity were studied. Upon oxidation of 1a and 1b, the ligand LOMe undergoes demethylation at the metal centre resulting in the formation of Co(iii) complexes with modified phenoxide ligands. This is the very first example of oxidative O-demethylation reported at a Co(ii) centre. The oxidative behaviour exhibits a striking dependence on the nature of coligands coordinated to the metal centre. The Co(ii) complex 1a with stronger chloro coligands requires a strong oxidising agent like t-BuOOH for oxidative demethylation and the subsequent formation of a mononuclear Co(iii) complex with a demethylated ligand, CoLO-Cl2 (2). On the other hand, complex 1b with weaker iodo coligands undergoes oxidation in the presence of the weak oxidant O2 to form a dihydroxo bridged binuclear Co(iii) complex [Co2(LO-)2(OH)2]2+ (3) with modified phenoxide ligands. The oxidation of 1b to 3 is monitored and the intermediate Co(ii) iodo aqua complex [CoLOMeI(H2O)]+ and Co(ii) diaqua complex [CoLOMe(H2O)2]2+ are isolated and characterised.
Collapse
Affiliation(s)
- S S Anjana
- Department of Chemistry, IIT Madras, Chennai 600 036, India.
| | | | | |
Collapse
|
13
|
Pettenuzzo N, Brustolin L, Coltri E, Gambalunga A, Chiara F, Trevisan A, Biondi B, Nardon C, Fregona D. Cu II and Au III Complexes with Glycoconjugated Dithiocarbamato Ligands for Potential Applications in Targeted Chemotherapy. ChemMedChem 2019; 14:1162-1172. [PMID: 31091012 DOI: 10.1002/cmdc.201900226] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/29/2019] [Indexed: 11/07/2022]
Abstract
This work is focused on the synthesis, characterization, and preliminary biological evaluation of bio-conjugated AuIII and CuII complexes with the aim of overcoming the well-known side effects of chemotherapy by improving the selective accumulation of an anticancer metal payload in malignant cells. For this purpose, carbohydrates were chosen as targeting agents, exploiting the Warburg effect that accounts for the overexpression of glucose-transporter proteins (in particular GLUTs) in the phospholipid bilayer of most neoplastic cells. We linked the dithiocarbamato moiety to the C1 position of three different monosaccharides: d-glucose, d-galactose, and d-mannose. Altogether, six complexes with a 1:2 metal-to-ligand stoichiometry were synthesized and in vitro tested as anticancer agents. One of them showed high cytotoxic activity toward the HCT116 colorectal human carcinoma cell line, paving the way to future in vivo studies aimed at evaluating the role of carbohydrates in the selective delivery of whole molecules into cancerous cells.
Collapse
Affiliation(s)
- Nicolò Pettenuzzo
- Department of Chemical Sciences (DISC), University of Padova, Via Marzolo 1, 35131, Padova, Italy.,Department of Surgical, Oncological and Gastroenterological Sciences (DISCOG), University of Padova, Via Giustiniani 2, 35128, Padova, Italy
| | - Leonardo Brustolin
- Department of Chemical Sciences (DISC), University of Padova, Via Marzolo 1, 35131, Padova, Italy.,Department of Surgical, Oncological and Gastroenterological Sciences (DISCOG), University of Padova, Via Giustiniani 2, 35128, Padova, Italy
| | - Elisa Coltri
- Department of Chemical Sciences (DISC), University of Padova, Via Marzolo 1, 35131, Padova, Italy
| | - Alberto Gambalunga
- Department of Cardio-Thoraco-Vascular Sciences and Public Health (DCTV), University of Padova, Via Giustiniani 2, 35128, Padova, Italy
| | - Federica Chiara
- Department of Cardio-Thoraco-Vascular Sciences and Public Health (DCTV), University of Padova, Via Giustiniani 2, 35128, Padova, Italy
| | - Andrea Trevisan
- Department of Cardio-Thoraco-Vascular Sciences and Public Health (DCTV), University of Padova, Via Giustiniani 2, 35128, Padova, Italy
| | - Barbara Biondi
- Institute of Biomolecular Chemistry, Padova Unit, CNR, Via Marzolo 1, 35131, Padova, Italy
| | - Chiara Nardon
- Department of Chemical Sciences (DISC), University of Padova, Via Marzolo 1, 35131, Padova, Italy
| | - Dolores Fregona
- Department of Chemical Sciences (DISC), University of Padova, Via Marzolo 1, 35131, Padova, Italy
| |
Collapse
|
14
|
Kupietz K, Białek MJ, Białońska A, Szyszko B, Latos-Grażyński L. Organocopper(III) Phenanthriporphyrin-Exocyclic Transformations. Inorg Chem 2019; 58:1451-1461. [PMID: 30600994 DOI: 10.1021/acs.inorgchem.8b02997] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
5,6-Dimethoxyphenanthriporphyrin 1 and 5,6-dioxophenanthriporphyrin 2 act as suitable organometallic ligands for copper(III), adopting trianionic [CCNN] coordination cores. Under oxidizing conditions, in the presence of methanol, copper(III) phenanthriporphyrin 1-Cu undergoes transformation to copper(III) phenanthriporphodimethene with methoxy substituents attached to two trans meso positions. Addition of acids to 1-Cu yields two isomeric copper(III) isophenanthriporphyrins protonated on one of the meso carbon atoms. Protonation of copper(III) 5,6-dioxophenanthriporphyrin 2-Cu yields the aromatic diprotonated complex 2-Cu-H22+. In the presence of HBF4 2-Cu undergoes borylation at the carbonyl oxygen atoms, forming an aromatic exocyclic boron(III) complex.
Collapse
Affiliation(s)
- Kamil Kupietz
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Michał J Białek
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Agata Białońska
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Bartosz Szyszko
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | | |
Collapse
|
15
|
Liu Y, Hua S, Cheng M, Yu L, Demeshko S, Dechert S, Meyer F, Lee G, Chiang M, Peng S. Electron Delocalization of Mixed‐Valence Diiron Sites Mediated by Group 10 Metal Ions in Heterotrimetallic Fe‐M‐Fe (M=Ni, Pd, and Pt) Chain Complexes. Chemistry 2018; 24:11649-11666. [DOI: 10.1002/chem.201801325] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/28/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Yu‐Chiao Liu
- Institute of ChemistryAcademia Sinica Taipei 11529 Taiwan
| | - Shao‐An Hua
- Department of Chemistry and Center for Emerging Material and Advanced DevicesNational Taiwan University Taipei 10617 Taiwan
- Present address: Institut für Anorganische ChemieUniversität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | | | - Li‐Chung Yu
- Department of Chemistry and Center for Emerging Material and Advanced DevicesNational Taiwan University Taipei 10617 Taiwan
- Present address: National Synchrotron Radiation Research Center Hsinchu 30076 Taiwan
| | - Serhiy Demeshko
- Institut für Anorganische ChemieUniversität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Sebastian Dechert
- Institut für Anorganische ChemieUniversität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Franc Meyer
- Institut für Anorganische ChemieUniversität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Gene‐Hsiang Lee
- Department of Chemistry and Center for Emerging Material and Advanced DevicesNational Taiwan University Taipei 10617 Taiwan
| | | | - Shie‐Ming Peng
- Institute of ChemistryAcademia Sinica Taipei 11529 Taiwan
- Department of Chemistry and Center for Emerging Material and Advanced DevicesNational Taiwan University Taipei 10617 Taiwan
| |
Collapse
|
16
|
Lilley LM, Du K, Krzyaniak MD, Parigi G, Luchinat C, Harris TD, Meade TJ. Effect of Magnetic Coupling on Water Proton Relaxivity in a Series of Transition Metal Gd III Complexes. Inorg Chem 2018; 57:5810-5819. [PMID: 29714477 DOI: 10.1021/acs.inorgchem.8b00120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A fundamental challenge in the design of bioresponsive (or bioactivated) GdIII-based magnetic resonance (MR) imaging probes is the considerable background signal present in the "preactivated" state that arises from outer-sphere relaxation processes. When sufficient concentrations of a bioresponsive agent are present (i.e., a detectable signal in the image), the inner- and outer-sphere contributions to r1 may be misinterpreted to conclude that the agent has been activated, when it has not. Of the several parameters that determine the observed MR signal of an agent, only the electron relaxation time ( T1e) impacts both the inner- and outer-sphere relaxation. Therefore, strategies to minimize this background signal must be developed to create a near zero-background (or truly "off" state) of the agent. Here, we demonstrate that intramolecular magnetic exchange coupling when GdIII is coupled to a paramagnetic transition metal provides a means to overcome the contribution of second- and outer-sphere contributions to the observed relaxivity. We have prepared a series of complexes with the general formula LMLn(μ-O2CCH3)(O2CCH3)2 (M = Co, Cu, Zn). Solid-state magnetic susceptibility measurements reveal significant magnetic coupling between GdIII and the transition metal ion. Nuclear magnetic relaxation dispersion (NMRD) analysis confirms that the observed differences in relaxivity are associated with the modulation of T1e at GdIII. These results clearly demonstrate that magnetic exchange coupling between GdIII and a transition metal ion can provide a significant decrease in T1e (and therefore the relaxivity of GdIII). This design strategy is being exploited to prepare new generations of preclinical bioresponsive MR imaging probes with near zero-background.
Collapse
Affiliation(s)
| | | | | | - Giacomo Parigi
- Department of Chemistry and Magnetic Resonance Center (CERM) , University of Florence , Via L. Sacconi 6 , 50019 Sesto Fiorentino , Italy
| | - Claudio Luchinat
- Department of Chemistry and Magnetic Resonance Center (CERM) , University of Florence , Via L. Sacconi 6 , 50019 Sesto Fiorentino , Italy
| | | | | |
Collapse
|
17
|
Suseelan AS, Varghese B, Edamana P, Murthy NN. Reagent‐Regulated Oxidative
O
‐Demethylation of a Ferrous Complex Stabilized by a Tetradentate N Ligand with a Methoxyphenyl Substituent. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201700946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - Babu Varghese
- Sophisticated Analytical Instruments Facility (SAIF) IIT Madras 600036 Chennai India
| | - Prasad Edamana
- Sophisticated Analytical Instruments Facility (SAIF) IIT Madras 600036 Chennai India
| | | |
Collapse
|
18
|
Brustolin L, Nardon C, Pettenuzzo N, Zuin Fantoni N, Quarta S, Chiara F, Gambalunga A, Trevisan A, Marchiò L, Pontisso P, Fregona D. Synthesis, chemical characterization and cancer cell growth-inhibitory activities of Cu(ii) and Ru(iii) aliphatic and aromatic dithiocarbamato complexes. Dalton Trans 2018; 47:15477-15486. [DOI: 10.1039/c8dt02965b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects mediated by different cyclic dithiocarbamic ligands on three classes of antiproliferative coordination compounds were studied.
Collapse
|
19
|
Sasi D, Ramkumar V, Murthy NN. Bite-Angle-Regulated Coordination Geometries: Tetrahedral and Trigonal Bipyramidal in Ni(II) with Biphenyl-Appended (2-Pyridyl)alkylamine N, N'-Bidentate Ligands. ACS OMEGA 2017; 2:2474-2481. [PMID: 31457593 PMCID: PMC6640959 DOI: 10.1021/acsomega.7b00119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/17/2017] [Indexed: 06/10/2023]
Abstract
Two simple biphenyl-appended (2-pyridyl)alkylamine N-bidentate ligands, Le and Lm, having ethylene and methylene spacers between donor groups, with bite angles Le ≈ 100° and Lm ≈ 80°, dictate pseudotetrahedral and trigonal-bipyramidal geometries in six high-spin Ni(II)-halide complexes, [Ni(Le)X2] and [Ni(Lm)2X](ClO4) (where X = Cl-, Br-, I-), respectively. The structures in the solid state, determined using X-ray crystallography, and in solution, determined using spectroscopic methods (UV-vis-NIR and paramagnetic 1H NMR), which complement each other, are described.
Collapse
|
20
|
Bansal D, Gupta R. Hydroxide-bridged dicopper complexes: the influence of secondary coordination sphere on structure and catecholase activity. Dalton Trans 2017; 46:4617-4627. [DOI: 10.1039/c6dt04858g] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work illustrates the syntheses, structures and catecholase activities of dicopper(ii) complexes having a Cu(μ-OH)Cu core encased within a secondary coordination sphere intricately created by appended heterocyclic rings.
Collapse
Affiliation(s)
- Deepak Bansal
- Department of Chemistry
- University of Delhi
- Delhi 110 007
- India
| | - Rajeev Gupta
- Department of Chemistry
- University of Delhi
- Delhi 110 007
- India
| |
Collapse
|
21
|
Nisanci B, Sahinoglu S, Tuner E, Arik M, Kani İ, Dastan A, Bozdemir ÖA. Synthesis of an F-BODIPY [2]catenane using the chemistry of bis(dipyrrinato)metal complexes. Chem Commun (Camb) 2017; 53:12418-12421. [DOI: 10.1039/c7cc07021g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Towards highly fluorescent BODIPY based mechanically interlocked molecules via the chemistry of dipyrrins.
Collapse
Affiliation(s)
- Bilal Nisanci
- Department of Chemistry
- Faculty of Science
- Atatürk University
- Erzurum
- Turkey
| | - Sinem Sahinoglu
- Department of Chemistry
- Faculty of Science
- Atatürk University
- Erzurum
- Turkey
| | - Esra Tuner
- Department of Chemistry
- Faculty of Science
- Atatürk University
- Erzurum
- Turkey
| | - Mustafa Arik
- Department of Chemistry
- Faculty of Science
- Atatürk University
- Erzurum
- Turkey
| | - İbrahim Kani
- Department of Chemistry
- Anadolu University
- Eskisehir
- Turkey
| | - Arif Dastan
- Department of Chemistry
- Faculty of Science
- Atatürk University
- Erzurum
- Turkey
| | | |
Collapse
|
22
|
Anjana S, Donring S, Sanjib P, Varghese B, Murthy NN. Controlling the oxidation of bis-tridentate cobalt(ii) complexes having bis(2-pyridylalkyl)amines: ligand vs. metal oxidation. Dalton Trans 2017. [DOI: 10.1039/c7dt01792h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Two bis-tridentate chelated cobalt(ii) complexes, which differ in the ligand structure by a methylene group, activate molecular oxygen (O2), and give different oxidation products.
Collapse
Affiliation(s)
- S. Anjana
- Department of Chemistry
- IIT Madras
- Chennai 600 036
- India
| | - S. Donring
- Deptartment of Chemistry
- Ewha Womans University
- South Korea
| | - P. Sanjib
- Department of Chemistry
- IIT Bombay
- India
| | - B. Varghese
- Sophisticated Analytical Instruments Facility (SAIF)
- IIT Madras
- India
| | | |
Collapse
|
23
|
González-García J, Martínez-Camarena À, Verdejo B, Clares MP, Soriano C, García-España E, Jiménez HR, Doménech-Carbó A, Tejero R, Calvo E, Briansó-Llort L, Serena C, Trefler S, Garcia-España A. Oxidative stress protection by manganese complexes of tail-tied aza-scorpiand ligands. J Inorg Biochem 2016; 163:230-239. [DOI: 10.1016/j.jinorgbio.2016.04.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/25/2016] [Accepted: 04/12/2016] [Indexed: 11/26/2022]
|
24
|
Du K, Harris TD. A CuII2 Paramagnetic Chemical Exchange Saturation Transfer Contrast Agent Enabled by Magnetic Exchange Coupling. J Am Chem Soc 2016; 138:7804-7. [DOI: 10.1021/jacs.6b03060] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Kang Du
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - T. David Harris
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| |
Collapse
|
25
|
Bertini I, Felli IC, Luchinat C, Parigi G, Pierattelli R. Towards a protocol for solution structure determination of copper(II) proteins: the case of Cu(II)Zn(II) superoxide dismutase. Chembiochem 2016; 8:1422-9. [PMID: 17583552 DOI: 10.1002/cbic.200700006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We have developed an optimized protocol to solve the solution structure of copper(II) proteins. After assignment, proton-proton NOEs are used for the shell where 1H spectra are conveniently observed. In a shell closer to the metal ion, 13C NMR spectra with band-selective homonuclear decoupling provide the assignment of all nuclei except for those of the metal ligands. A convenient method for the measurement of 13C longitudinal-relaxation rates (R1) of carbonyls and carboxylate moieties is proposed. 1H NOEs and 1H and 13C R1 data are sufficient to produce a good/reasonable solution structure, as demonstrated for a monomeric species of superoxide dismutase, a 153-residue protein.
Collapse
Affiliation(s)
- Ivano Bertini
- CERM and Department of Chemistry, University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy.
| | | | | | | | | |
Collapse
|
26
|
Beyeh NK, Puttreddy R. Methylresorcinarene: a reaction vessel to control the coordination geometry of copper(II) in pyridine N-oxide copper(II) complexes. Dalton Trans 2015; 44:9881-6. [PMID: 25939967 DOI: 10.1039/c5dt01143d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pyridine and 2-picolinic acid N-oxides form 2 : 2 and 2 : 1 ligand : metal (L : M) discrete L2M2 and polymeric complexes with CuCl2 and Cu(NO3)2, respectively, with copper(ii) salts. The N-oxides also form 1 : 1 host-guest complexes with methylresorcinarene. In combination, the three components form a unique 2 : 2 : 1 host-ligand-metal complex. The methylresorcinarene acts as a reaction vessel/protecting group to control the coordination of copper(ii) from cis-see-saw to trans-square planar, and from octahedral to square planar coordination geometry. These processes were studied in solution and in the solid state via(1)H NMR spectroscopy and single crystal X-ray diffraction.
Collapse
Affiliation(s)
- Ngong Kodiah Beyeh
- University of Jyvaskyla, Department of Chemistry, P. O. Box 35, 40014 University of Jyvaskyla, Jyvaskyla, Finland.
| | | |
Collapse
|
27
|
Kong X, Terskikh VV, Khade RL, Yang L, Rorick A, Zhang Y, He P, Huang Y, Wu G. Solid-state ¹⁷O NMR spectroscopy of paramagnetic coordination compounds. Angew Chem Int Ed Engl 2015; 54:4753-7. [PMID: 25694203 PMCID: PMC4418630 DOI: 10.1002/anie.201409888] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Indexed: 11/09/2022]
Abstract
High-quality solid-state (17)O (I=5/2) NMR spectra can be successfully obtained for paramagnetic coordination compounds in which oxygen atoms are directly bonded to the paramagnetic metal centers. For complexes containing V(III) (S=1), Cu(II) (S=1/2), and Mn(III) (S=2) metal centers, the (17)O isotropic paramagnetic shifts were found to span a range of more than 10,000 ppm. In several cases, high-resolution (17)O NMR spectra were recorded under very fast magic-angle spinning (MAS) conditions at 21.1 T. Quantum-chemical computations using density functional theory (DFT) qualitatively reproduced the experimental (17)O hyperfine shift tensors.
Collapse
Affiliation(s)
- Xianqi Kong
- Department of Chemistry, Queen's University Kingston, Ontario, K7L 3N6 (Canada)
| | - Victor V. Terskikh
- Department of Chemistry, University of Ottawa Ottawa, Ontario, K1N 6N5 (Canada)
| | - Rahul L. Khade
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology Castle Point on Hudson, Hoboken, New Jersey 07030 (USA)
| | - Liu Yang
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology Castle Point on Hudson, Hoboken, New Jersey 07030 (USA)
| | - Amber Rorick
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology Castle Point on Hudson, Hoboken, New Jersey 07030 (USA)
| | - Yong Zhang
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology Castle Point on Hudson, Hoboken, New Jersey 07030 (USA)
| | - Peng He
- Department of Chemistry, University of Western Ontario London, Ontario, N6A 5B7 (Canada)
| | - Yining Huang
- Department of Chemistry, University of Western Ontario London, Ontario, N6A 5B7 (Canada)
| | - Gang Wu
- Department of Chemistry, Queen's University Kingston, Ontario, K7L 3N6 (Canada)
| |
Collapse
|
28
|
Kong X, Terskikh VV, Khade RL, Yang L, Rorick A, Zhang Y, He P, Huang Y, Wu G. Solid-State17O NMR Spectroscopy of Paramagnetic Coordination Compounds. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201409888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
29
|
Anbu S, Ravishankaran R, Guedes da Silva MFC, Karande AA, Pombeiro AJL. Differentially selective chemosensor with fluorescence off-on responses on Cu(2+) and Zn(2+) ions in aqueous media and applications in pyrophosphate sensing, live cell imaging, and cytotoxicity. Inorg Chem 2014; 53:6655-64. [PMID: 24999857 DOI: 10.1021/ic500313m] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A new benzoyl hydrazone based chemosensor R is synthesized by Schiff base condensation of 2,6-diformyl-4-methylphenol and phenyl carbohydrazide and acts as a highly selective fluorescence sensor for Cu(2+) and Zn(2+) ions in aqueous media. The reaction of R with CuCl2 or ZnCl2 forms the corresponding dimeric dicopper(II) [Cu2(R)(CH3O)(NO3)]2(CH3O)2 (R-Cu(2+)) and dizinc(II) [Zn2(R)2](NO3)2 (R-Zn(2+)) complexes, which are characterized, as R, by conventional techniques including single-crystal X-ray analysis. Electronic absorption and fluorescence titration studies of R with different metal cations in a CH3CN/0.02 M HEPES buffer medium (pH = 7.3) show a highly selective binding affinity only toward Cu(2+)and Zn(2+) ions even in the presence of other commonly coexisting ions such as Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Fe(2+), Fe(3+), Co(2+), Ni(2+), Cd(2+), and Hg(2+). Quantification of the fluorescence titration analysis shows that the chemosensor R can indicate the presence of Cu(2+)and Zn(2+) even at very low concentrations of 17.3 and 16.5 ppb, respectively. R-Zn(2+) acts as a selective metal-based fluorescent sensor for inorganic pyrophosphate ion (PPi) even in the presence of other common anions such as F(-), Cl(-), Br(-), I(-), CH3COO(-), CO3(2-), HCO3(-), N3(-), SO4(2-), PPi, AMP, ADP, and ATP in an aqueous medium. The propensity of R as a bioimaging fluorescent probe to detect Cu(2+) and Zn(2+) ions in human cervical HeLa cancer cell lines and their cytotoxicity against human cervical (HeLa), breast cancer (MCF7), and noncancer breast epithelial (MCF10a) cells have also been investigated. R-Cu(2+) shows better cytotoxicity and sensitivity toward cancer cells over noncancer cells than R and R-Zn(2+) under identical conditions, with the appearance of apoptotic bodies.
Collapse
Affiliation(s)
- Sellamuthu Anbu
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa , Avenida Rovisco Pais, 1049-001 Lisboa. Portugal
| | | | | | | | | |
Collapse
|
30
|
Haldar S, Patra A, Bera M. Exploring the catalytic activity of new water soluble dinuclear copper(ii) complexes towards the glycoside hydrolysis. RSC Adv 2014. [DOI: 10.1039/c4ra09800e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Water soluble dicopper(ii/ii) complexes of a new dinucleating ligand, H3phpda were synthesized and characterized for the investigation of glycoside hydrolysis.
Collapse
Affiliation(s)
| | - Ayan Patra
- Department of Chemistry
- University of Kalyani
- Kalyani, India
| | | |
Collapse
|
31
|
Reger DL, Pascui AE, Pellechia PJ, Ozarowski A. NMR Investigations of Dinuclear, Single-Anion Bridged Copper(II) Metallacycles: Structure and Antiferromagnetic Behavior in Solution. Inorg Chem 2013; 52:12741-8. [DOI: 10.1021/ic402016m] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Daniel L. Reger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrea E. Pascui
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Perry J. Pellechia
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| |
Collapse
|
32
|
Postsynthetic modification of a coordination compound with a paddlewheel motif via click reaction: DOSY and ESR studies. INORG CHEM COMMUN 2012. [DOI: 10.1016/j.inoche.2011.09.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
33
|
Siluvai GS, Vargheese B, Murthy NN. H2O2 reactivity of a dinuclear copper(II) complex incorporating a constrained binucleating polyaminopyridyl ligand and a phosphodiester coligand. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.04.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
34
|
Tsui EY, Day MW, Agapie T. Trinucleating Copper: Synthesis and Magnetostructural Characterization of Complexes Supported by a Hexapyridyl 1,3,5-Triarylbenzene Ligand. Angew Chem Int Ed Engl 2011; 50:1668-72. [DOI: 10.1002/anie.201005232] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Revised: 10/24/2010] [Indexed: 11/10/2022]
|
35
|
Tsui EY, Day MW, Agapie T. Trinucleating Copper: Synthesis and Magnetostructural Characterization of Complexes Supported by a Hexapyridyl 1,3,5-Triarylbenzene Ligand. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201005232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
36
|
Tromp M, van Strijdonck GPF, van Berkel SS, van den Hoogenband A, Feiters MC, de Bruin B, Fiddy SG, van der Eerden AMJ, van Bokhoven JA, van Leeuwen PWNM, Koningsberger DC. Multitechnique Approach to Reveal the Mechanism of Copper(II)-Catalyzed Arylation Reactions. Organometallics 2010. [DOI: 10.1021/om9010643] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Moniek Tromp
- Debye Institute, Department of Inorganic Chemistry and Catalysis, Utrecht, The Netherlands
| | | | - Sander S. van Berkel
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Martinus C. Feiters
- IMM, Department of Organic Chemistry, Faculty of Science, University of Nijmegen, Nijmegen, The Netherlands
| | - Bas de Bruin
- IMM, Department of Inorganic Chemistry, Faculty of Science, University of Nijmegen, Nijmegen, The Netherlands
| | | | | | - Jeroen A. van Bokhoven
- Debye Institute, Department of Inorganic Chemistry and Catalysis, Utrecht, The Netherlands
| | | | | |
Collapse
|
37
|
Striegler S, Dunaway NA, Gichinga MG, Barnett JD, Nelson AGD. Evaluating Binuclear Copper(II) Complexes for Glycoside Hydrolysis. Inorg Chem 2010; 49:2639-48. [DOI: 10.1021/ic9014064] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Susanne Striegler
- Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, Alabama 36849
| | - Natasha A. Dunaway
- Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, Alabama 36849
| | - Moses G. Gichinga
- Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, Alabama 36849
| | - James D. Barnett
- Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, Alabama 36849
| | - Anna-Gay D. Nelson
- Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, Alabama 36849
| |
Collapse
|
38
|
Synthesis, X-ray powder structure analysis and biological properties of a mononuclear Cu(II) complex of N-2-hydroxyhippuric acid. Appl Organomet Chem 2009. [DOI: 10.1002/aoc.1565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
39
|
Sabiah S, Varghese B, Murthy NN. Mononuclear [(BP)(2)MX](n+) (M = Cu(2+), Co(2+), Zn(2+); X = OH(2), Cl(-)) complexes with a new biphenyl appended N-bidentate ligand: structural, spectroscopic, solution equilibrium and ligand dynamic studies. Dalton Trans 2009:9770-80. [PMID: 19885522 DOI: 10.1039/b910519k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new series of five-coordinate [(BP)2MX]n+ complexes, (where X = OH2, M = Zn(II) (1), Cu(II) (2); X = Cl-, M = Cu(II) (3), Co(II) (4)) with a new bidentate chelating ligand [{N,N(1,1'-biphenyl-2,2'-dimethylene)-N(2-pyridyl methyl)} amine] with a biphenyl group (BP), have been synthesized and characterized by X-ray crystal structure and combined spectroscopic methods. They display unique trigonal bipyramidal (TBP) geometry, influenced by the bidentate ligand. The Zn(II) complex 1 reveals ligand dynamics due to an atropisomeric biphenyl moiety as indicated by variable temperature (VT) proton NMR spectroscopy. The calculated free energy for the inversion of the bridged biphenyl is approximately 13.08 kcal mol-1 (Tc = 273 K, Delta(nu) = 82.8 Hz, J = 8.7 Hz). The absorption spectra of Cu(II) complexes 2 and 3, in CH2Cl2 display greatly enhanced d-d bands (800-950 nm, epsilon>500 M-1 cm-1). On the other hand, complex 2 in N,N-dimethylformamide (DMF) showed almost 50% reduction in absorption intensity as DMF, a coordinating solvent, displaces the weakly-coordinated tertiary amine-nitrogens of the ligand and this competitive binding was studied by electronic absorption spectroscopy. When the mononuclear copper aqua complex 2 was treated with a base, a dicopper dihydroxide complex, [{(BP)Cu}2(mu-OH)2]2+, (2a) was obtained. The same phenomenon was also observed with chloro complex 3 when treated with a base. This mono-dicopper equilibrium and conversion of 2 --> 2a was monitored by UV-vis spectroscopy. Copper(II) complexes 2 and 3 displayed reverse EPR spectra consistent with the TBP geometry. Cyclic voltammetry of 2 and 3 in DMF showed an irreversible redox wave owing to Cu(II)/Cu(I) of five and four-coordinate species. The solution magnetic moment values of 1.76, 1.81 and 4.47 microB for 2, 3 and 4, respectively, are in agreement with Cu(II) (S = 1/2) and Co(II) (S = 3/2) high-spin configurations. The 1H NMR of 4 displays sharp but hyperfine shifted signals for the ligand protons between -30 to +220 ppm. The ESI-mass data complement the data obtained from X-ray structure.
Collapse
|
40
|
Ray A, Sadhukhan D, Rosair GM, Gómez-García CJ, Mitra S. An unprecedented CuII–Schiff base complex existing as two different trinuclear units with strong antiferromagnetic couplings. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.07.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
41
|
González-Alvarez A, Alfonso I, Cano J, Díaz P, Gotor V, Gotor-Fernández V, García-España E, García-Granda S, Jiménez H, Lloret F. A Ferromagnetic [Cu3(OH)2]4+Cluster Formed inside a Tritopic Nonaazapyridinophane: Crystal Structure and Solution Studies. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200901888] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
42
|
González-Alvarez A, Alfonso I, Cano J, Díaz P, Gotor V, Gotor-Fernández V, García-España E, García-Granda S, Jiménez H, Lloret F. A Ferromagnetic [Cu3(OH)2]4+Cluster Formed inside a Tritopic Nonaazapyridinophane: Crystal Structure and Solution Studies. Angew Chem Int Ed Engl 2009; 48:6055-8. [DOI: 10.1002/anie.200901888] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
43
|
X-ray structure and spectroscopic characterization of divalent dinuclear cobalt complexes containing carboxylate- and phosphodiester- auxiliary bridges. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
44
|
Siluvai GS, Murthy NN. X-ray structure and spectroscopic characterization of doubly-bridged binuclear copper(II) complexes in symmetric and asymmetric coordination environments. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
45
|
Ray A, Rizzoli C, Pilet G, Desplanches C, Garribba E, Rentschler E, Mitra S. Two New Supramolecular Architectures of Singly Phenoxo-Bridged Copper(II) and Doubly Phenoxo-Bridged Manganese(II) Complexes Derived from an Unusual ONOO Donor Hydrazone Ligand: Syntheses, Structural Variations, Cryomagnetic, DFT, and EPR Studies. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900188] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
46
|
Abriata LA, Ledesma GN, Pierattelli R, Vila AJ. Electronic structure of the ground and excited states of the Cu(A) site by NMR spectroscopy. J Am Chem Soc 2009; 131:1939-46. [PMID: 19146411 DOI: 10.1021/ja8079669] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic properties of Thermus thermophilus Cu(A) in the oxidized form were studied by (1)H and (13)C NMR spectroscopy. All of the (1)H and (13)C resonances from cysteine and imidazole ligands were observed and assigned in a sequence-specific fashion. The detection of net electron spin density on a peptide moiety is attributed to the presence of a H-bond to a coordinating sulfur atom. This hydrogen bond is conserved in all natural Cu(A) variants and plays an important role for maintaining the electronic structure of the metal site, rendering the two Cys ligands nonequivalent. The anomalous temperature dependence of the chemical shifts is explained by the presence of a low-lying excited state located about 600 cm(-1) above the ground state. The room-temperature shifts can be described as the thermal average of a sigma(u)* ground state and a pi(u) excited state. These results provide a detailed description of the electronic structure of the Cu(A) site at atomic resolution in solution at physiologically relevant temperature.
Collapse
Affiliation(s)
- Luciano A Abriata
- IBR (Instituto de Biologia Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Suipacha 531, Argentina
| | | | | | | |
Collapse
|
47
|
Mathrubootham V, Addison AW, Holman KT, Sinn E, Thompson LK. A novel copper(II) complex of a tripodal ligand with phenolate-phenol interligand, intramolecular hydrogen bonding. Dalton Trans 2009:8111-6. [DOI: 10.1039/b910188h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
48
|
Verdejo B, Blasco S, García-España E, Lloret F, Gaviña P, Soriano C, Tatay S, Jiménez HR, Doménech A, Latorre J. Imidazolate bridged Cu(II)-Cu(II) and Cu(II)-Zn(II) complexes of a terpyridinophane azamacrocycle: a solution and solid state study. Dalton Trans 2007:4726-37. [PMID: 17940655 DOI: 10.1039/b708186c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dinuclear Cu2+ and Zn2+ as well as the mixed Cu2+-Zn2+ complexes of a 5,5''-pentaazaterpyridinophane ligand (L) are able to incorporate imidazolate (Im-) as a bridging ligand. The crystal structure of [Cu(2)L(Im)(Br)(H2O)](CF(3)SO(3))(2).3H2O (1) shows one copper coordinated by the three pyridine nitrogens of the terpyridine unit, one nitrogen of the imidazolate bridge (Im-) and one bromide anion occupying the axial position of a distorted square pyramid. The second copper atom is coordinated by the remaining imidazolate nitrogen, the three secondary nitrogens at the centre of the polyamine bridge and one water molecule that occupies the axial position. Magnetic measurements have been performed in the 2.0-300.0 K temperature range. Experimental data could be satisfactorily reproduced by using an isotropic exchange model H = -JS(1)S(2) with J = -52.3 cm(-1) and g = 2.09. Potentiometric studies have provided details of the speciation and stability constants for the mixed Cu2+-L-HIm, Zn2+-L-HIm (HIm = imidazole) and Cu2+-Zn2+-L-HIm systems. The apparent stability constant obtained at pH = 9 for the addition of imidazole to the dinuclear Cu2+ complexes is one of the highest so far reported (log K = 7.5). UV-Vis spectroscopy and paramagnetic NMR data show that imidazole coordinates to the Cu2+ ions as a bridging imidazolate ligand from pH 5 to 10. Electrochemical reduction of the Cu2+-Zn2+-L complex occurs in two successive one-electron per copper ion quasi-reversible steps. The formal potential of the Cu2+-Zn2+-L/Cu+-Zn2+-L couple is close to that of SOD. The IC50 values measured at pH 7.8 by means of the nitro blue tetrazolium method show significant SOD activity for the dinuclear Cu2+ complexes (IC50 = 2.5 microM) and moderate activity for the Cu2+-Zn2+ mixed systems (IC50 = 30 microM).
Collapse
Affiliation(s)
- Begoña Verdejo
- Departament de Química Inorgànica, Institut de Ciència Molecular (ICMOL), Universitat de València. Edificio de Institutos de Paterna, Apartado de Correos 22085, 46071 Valencia, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Tepper AWJW, Bubacco L, Canters GW. Paramagnetic properties of the halide-bound derivatives of oxidised tyrosinase investigated by 1H NMR spectroscopy. Chemistry 2007; 12:7668-75. [PMID: 16927257 DOI: 10.1002/chem.200501494] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The (1)H NMR relaxation characteristics of the histidines in the oxidised type-3 copper site of tyrosinase (Ty(met)) from the bacterium Streptomyces antibioticus in the halide-bound forms (Ty(met)X with X = F(-), Cl(-), Br(-)) have been determined and analysed. The (1)H NMR spectra of the Ty(met)X species display remarkably sharp, well-resolved, paramagnetically shifted (1)H signals, which originate from the protons of the six His residues coordinated to the two Cu(II) ions in the type-3 centre. From the temperature-dependence of the (1)H paramagnetic shifts the following values for the exchange-coupling parameter -2J were determined: 260 (Ty(met)F), 200 (Ty(met)Cl) and 162 cm(-1) (Ty(met)Br). The (1)H T(1) relaxation is dipolar in origin and correlates with the Cu--H distances. Electronic relaxation times tau(S) derived from the (1)H T(1) data amount to about 10(-11) s and follow the order Ty(met)F>Ty(met)Cl>Ty(met)Br. They are two orders of magnitude shorter than the tau(S) values reported for mononuclear copper systems, in accordance with the sharpness of the (1)H signals. The results corroborate the Cu(2) bridging mode of the halide ions. On the basis of the measured hyperfine interaction constants for the ligand histidine nuclei, it is concluded that 70-80 % of the spin density in the excited triplet state resides on the two copper ions and the bridging atoms.
Collapse
Affiliation(s)
- Armand W J W Tepper
- Leiden Institute of Chemistry Gorlaeus Laboratories, Leiden University Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | | | | |
Collapse
|
50
|
Foxon S, Xu JY, Turba S, Leibold M, Hampel F, Heinemann FW, Walter O, Würtele C, Holthausen M, Schindler S. Syntheses, Characterization and Reactivity of Iron(II), Nickel(II), Copper(II) and Zinc(II) Complexes of the LigandN,N,N′,N′-Tetrakis(2-pyridylmethyl)benzene-1,3-diamine (1,3-tpbd) and Its Phenol Derivative 2,6-Bis[bis(2-pyridylmethyl)amino]-p-cresol (2,6-tpcd). Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200600944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|