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Jacobs FJ, Helliwell JR, Brink A. Time-series analysis of rhenium(I) organometallic covalent binding to a model protein for drug development. IUCrJ 2024; 11:359-373. [PMID: 38639558 PMCID: PMC11067751 DOI: 10.1107/s2052252524002598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/19/2024] [Indexed: 04/20/2024]
Abstract
Metal-based complexes with their unique chemical properties, including multiple oxidation states, radio-nuclear capabilities and various coordination geometries yield value as potential pharmaceuticals. Understanding the interactions between metals and biological systems will prove key for site-specific coordination of new metal-based lead compounds. This study merges the concepts of target coordination with fragment-based drug methodologies, supported by varying the anomalous scattering of rhenium along with infrared spectroscopy, and has identified rhenium metal sites bound covalently with two amino acid types within the model protein. A time-based series of lysozyme-rhenium-imidazole (HEWL-Re-Imi) crystals was analysed systematically over a span of 38 weeks. The main rhenium covalent coordination is observed at His15, Asp101 and Asp119. Weak (i.e. noncovalent) interactions are observed at other aspartic, asparagine, proline, tyrosine and tryptophan side chains. Detailed bond distance comparisons, including precision estimates, are reported, utilizing the diffraction precision index supplemented with small-molecule data from the Cambridge Structural Database. Key findings include changes in the protein structure induced at the rhenium metal binding site, not observed in similar metal-free structures. The binding sites are typically found along the solvent-channel-accessible protein surface. The three primary covalent metal binding sites are consistent throughout the time series, whereas binding to neighbouring amino acid residues changes through the time series. Co-crystallization was used, consistently yielding crystals four days after setup. After crystal formation, soaking of the compound into the crystal over 38 weeks is continued and explains these structural adjustments. It is the covalent bond stability at the three sites, their proximity to the solvent channel and the movement of residues to accommodate the metal that are important, and may prove useful for future radiopharmaceutical development including target modification.
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Affiliation(s)
- Francois J.F. Jacobs
- Department of Chemistry, University of the Free State, Nelson Mandela Drive, Bloemfontein, 9301, South Africa
| | - John R. Helliwell
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Alice Brink
- Department of Chemistry, University of the Free State, Nelson Mandela Drive, Bloemfontein, 9301, South Africa
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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2
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Pierik AS, Poell JB, Brink A, Stigter-van Walsum M, de Roest RH, Poli T, Yaromin A, Lambin P, Leemans CR, Brakenhoff RH. Intratumor genetic heterogeneity and head and neck cancer relapse. Radiother Oncol 2024; 191:110087. [PMID: 38185257 DOI: 10.1016/j.radonc.2024.110087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/18/2023] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
BACKGROUND Head and neck squamous cell carcinomas are treated by surgery, radiotherapy (RT), chemoradiotherapy (CRT) or combinations thereof, but locoregional recurrences (LRs) occur in 30-40% of treated patients. We have previously shown that in approximately half of the LRs after CRT, cancer driver mutations are not shared with the index tumor. AIM To investigate two possible explanations for these genetically unrelated relapses, treatment-induced genetic changes and intratumor genetic heterogeneity. METHODS To investigate treatment-induced clonal DNA changes, we compared copy number alterations (CNAs) and mutations between primary and recurrent xenografted tumors after treatment with (C)RT. Intratumor genetic heterogeneity was studied by multi-region sequencing on DNA from 31 biopsies of 11 surgically treated tumors. RESULTS Induction of clonal DNA changes by (C)RT was not observed in the xenograft models. Multi-region sequencing demonstrated variations in CNA profiles between paired biopsies of individual tumors, with copy number heterogeneity scores varying from 0.027 to 0.333. In total, 32 cancer driver mutations could be identified and were shared in all biopsies of each tumor. Remarkably, multi-clonal mutations in these same cancer driver genes were observed in 6 of 11 tumors. Genetically distinct heterogeneous cell cultures could also be established from single tumors, with different biomarker profiles and drug sensitivities. CONCLUSION Intratumor genetic heterogeneity at the level of the cancer driver mutations might explain the discordant mutational profiles in LRs after CRT, while there are no indications in xenograft models that these changes are induced by CRT.
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Affiliation(s)
- A S Pierik
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands
| | - J B Poell
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands
| | - A Brink
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands
| | - M Stigter-van Walsum
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands
| | - R H de Roest
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands
| | - T Poli
- Maxillofacial Surgery Unit, Department of Medicine and Surgery - University of Parma, University Hospital of Parma, Via Gramsci 14, Parma, Italy
| | - A Yaromin
- Maastricht University, Department of Precision Medicine-UM & Radiology-MUMC, Universiteitssingel 40, Maastricht, the Netherlands
| | - P Lambin
- Maastricht University, Department of Precision Medicine-UM & Radiology-MUMC, Universiteitssingel 40, Maastricht, the Netherlands
| | - C R Leemans
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands
| | - R H Brakenhoff
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Biology and Immunology laboratory, De Boelelaan 1117, Amsterdam, the Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, De Boelelaan 1117, Amsterdam, the Netherlands.
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3
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Brink A, Bruno I, Helliwell JR, McMahon B. The interoperability of crystallographic data and databases. IUCrJ 2024; 11:9-15. [PMID: 38131388 PMCID: PMC10833386 DOI: 10.1107/s2052252523010424] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023]
Abstract
Interoperability of crystallographic data with other disciplines is essential for the smooth and rapid progress of structure-based science in the computer age. Within crystallography and closely related subject areas, there is already a high level of conformance to the generally accepted FAIR principles (that data be findable, accessible, interoperable and reusable) through the adoption of common information exchange protocols by databases, publishers, instrument vendors, experimental facilities and software authors. Driven by the success within these domains, the IUCr has worked closely with CODATA (the Committee on Data of the International Science Council) to help develop the latter's commitment to cross-domain integration of discipline-specific data. The IUCr has, in particular, emphasized the need for standards relating to data quality and completeness as an adjunct to the FAIR data landscape. This can ensure definitive reusable data, which in turn can aid interoperability across domains. A microsymposium at the IUCr 2023 Congress provided an up-to-date survey of data interoperability within and outside of crystallography, expounded using a broad range of examples.
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Affiliation(s)
- Alice Brink
- Chemistry Department, University of the Free State, Nelson Mandela Drive, Bloemfontein, South Africa
| | - Ian Bruno
- Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, United Kingdom
| | - John R. Helliwell
- Department of Chemistry, University of Manchester, Oxford Road, Manchester, United Kingdom
| | - Brian McMahon
- International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, United Kingdom
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Motente MA, Venter J, Brink A. ( N-Benzoyl- N-phenyl-hydroxy-laminato)carbon-yl(tri-phenyl-arsine)rhodium(I). IUCrdata 2023; 8:x230355. [PMID: 37151208 PMCID: PMC10162025 DOI: 10.1107/s2414314623003553] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 04/18/2023] [Indexed: 05/09/2023] Open
Abstract
The mol-ecule of the title compound, [Rh(C13H10NO2){As(C6H5)3}(CO)] or [Rh(BPHA)(AsPh3)(CO)] (BPHA is the N-benzoyl-N-phenyl-hydroxy-laminate anion), comprises a bidentate N-benzoyl-N-phenyl-hydroxy-laminate anion coordinating through the O atoms to the soft Lewis acid, rhodium(I), and two monodentate ligands, viz. tri-phenyl-arsine and carbonyl. The resulting CO2As coordination environment around the central RhI atom is distorted square planar.=.
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Affiliation(s)
- Mokete A. Motente
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa
- Correspondence e-mail:
| | - Johan Venter
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa
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van Dyk H, Jacobs FJF, Kroon RE, Makhafola TJ, Brink A. Characterisation, structural investigations and biological activity of substituted salicylidene-based compounds. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Pierik A, Poell J, Brink A, Leemans R, Brakenhoff R. O4.2 Early detection of recurrent HPV-positive HNSCC by ctDNA analysis. Oral Oncol 2022. [DOI: 10.1016/j.oraloncology.2022.106179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brink A, Jacobs FJF, Helliwell JR. Trends in coordination of rhenium organometallic complexes in the Protein Data Bank. IUCrJ 2022; 9:180-193. [PMID: 35371500 PMCID: PMC8895017 DOI: 10.1107/s2052252522000665] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Radiopharmaceutical development has similar overall characteristics to any biomedical drug development requiring a compound's stability, aqueous solubility and selectivity to a specific disease site. However, organometallic complexes containing 188/186Re or 99mTc involve a d-block transition-metal radioactive isotope and therefore bring additional factors such as metal oxidation states, isotope purity and half life into play. This topical review is focused on the development of radiopharmaceuticals containing the radioisotopes of rhenium and technetium and, therefore, on the occurrence of these organometallic complexes in protein structures in the Worldwide Protein Data Bank (wwPDB). The purpose of incorporating the group 7 transition metals of rhenium/technetium in the protein and the reasons for study by protein crystallography are described, as certain PDB studies were not aimed at drug development. Technetium is used as a medical diagnostic agent and involves the 99mTc isotope which decays to release gamma radiation, thereby employed for its use in gamma imaging. Due to the periodic relationship among group 7 transition metals, the coordination chemistry of rhenium is similar (but not identical) to that of technetium. The types of reactions the potential model radiopharmaceutical would prefer to partake in, and by extension knowing which proteins and biomolecules the compound would react with in vivo, are needed. Crystallography studies, both small molecule and macromolecular, are a key aspect in understanding chemical coordination. Analyses of bonding modes, coordination to particular residues and crystallization conditions are presented. In our Forward look as a concluding summary of this topical review, the question we ask is: what is the best way for this field to progress?
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Affiliation(s)
- Alice Brink
- Chemistry Department, University of the Free State, Nelson Mandela Drive, Bloemfontein, South Africa
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, United Kingdom
| | - Francois J. F. Jacobs
- Chemistry Department, University of the Free State, Nelson Mandela Drive, Bloemfontein, South Africa
| | - John R. Helliwell
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, United Kingdom
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Kama DV, Frei A, Brink A, Braband H, Alberto R, Roodt A. New approach for the synthesis of water soluble fac-[M I(CO) 3] + bis(diarylphosphino)alkylamine complexes (M = 99Tc, Re). Dalton Trans 2021; 50:17506-17514. [PMID: 34747429 DOI: 10.1039/d1dt03234h] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel proof-of-concept is reported to modify the water solubility and potential biological effects of a bis(diphenylphosphino)alkylamine (PNP) ligand and the corresponding metal complex, by introducing an amine group on the outer periphery of the pendant ligand arm. Thus, a tertiary butoxycarbonyl protected N'-Boc-ethylenediamine-N,N-bis(diphenylphosphino) (N'-Boc-PNP) ligand (1) was synthesized by reacting the protected ethylenediamine and chlorodiphenylphosphine in a 1 : 2 molar ratio. The corresponding fac-[Re(CO)3(N'-Boc-PNP)Br] (1A) complex was then obtained by reacting N'-Boc-PNP (1) with (Et4N)2fac-[Re(CO)3Br3] in equimolar amounts in DCM at 50 °C. De-protection of the N'-Boc pendant amine group in 1A with TFA leads to fac-[Re(NH3+-PNP)(CO)3Br]·CF3COO- (1B) which is soluble in D2O (>0.05 M). Treating 1B with saturated aqueous NaHCO3 yields fac-[Re(NH2-PNP)(CO)3Br]·MeOH (1C) in near quantitative yield. Although both 1A and 1C are not soluble in D2O, addition of TFA easily generates 1B (31P NMR), confirming the formation of the protonated amine. Isolation of fac-[99Tc(CO)3(N-Boc-PNP)(Cl)] (1D) confirmed that the rhenium and technetium (99Tc) can be easily interchanged in this process. Reported are hence the unique rhenium series of compounds 1A, 1B and 1C and the corresponding technetium complex 1D, unequivocally characterized by single crystal XRD, as well as IR and 1H NMR spectroscopy. Preliminary antimicrobial evaluation indicates that ligand 1 and its respective rhenium complexes (1A-1C) were not active against selected fungi (Candida albicans and Cryptococcus neoformans) and bacteria (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus). These types of ligands and complexes therefore present themselves as excellent radio models for further evaluation using 186Re, 188Re and 99mTc to potentially study the radiotoxicity of appropriately designed complexes.
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Affiliation(s)
- Dumisani V Kama
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, South Africa, 9300.
| | - Angelo Frei
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
| | - Alice Brink
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, South Africa, 9300.
| | - Henrik Braband
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
| | - Roger Alberto
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
| | - Andreas Roodt
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, South Africa, 9300.
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van Dyk H, Jacobs FJF, Brink A. Catalytic development and medical application of transition metal complexes (Re, Co, Cu) containing novel salicylidene Schiff bases. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s010876732108973x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kama DV, Brink A, Alberto R, Roodt A. Exploring structural implications of diphosphinamine ligands in medicine and catalysis. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321086864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Mokolokolo PP, Schutte-Smith M, Brink A, Roodt A. Structure and reactivity of rhodium(I) carbonyl complexes as model nano-wired assemblies and catalysts. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321087171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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12
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Morerwa ZG, Roodt A, Brink A. Environmentally friendly rhodium(I) model catalysts tailored by various bidentate and monodentate (water-soluble) ligands. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321086219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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13
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Brink A. The harvesting of small-molecule structure and dynamic data for macromolecular and catalytic usage. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321094733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kama DV, Brink A, Alberto R, Roodt A. Exploring structural implications of diphosphinamine ligands in medicine and catalysis. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s010876732108764x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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15
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Motente M, Venter J, Brink A. Rhodium(I) N, O-hydroxamic acid complexes as model catalysts. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321086670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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16
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Jacobs FJF, Brink A. Understanding small rhenium molecules kinetically and structurally in a macromolecular setting. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321089728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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17
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Bosman L, Kama DV, Brink A. Halogenated rhodium(I) complexes as model catalysts for methanol carbonylation. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321087626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Van Heerden J, Kruger M, Esterhuizen TM, Hendricks M, Du Plessis J, Engelbrecht G, Janse van Vuuren M, van Emmenes B, Uys R, Burger C, Nyakale N, More S, Brink A. The Association between Tumour Markers and Meta-iodobenzylguanidine Scans in South African Children with High-risk Neuroblastoma. Clin Oncol (R Coll Radiol) 2021; 33:517-526. [PMID: 33781675 DOI: 10.1016/j.clon.2021.03.003] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/04/2021] [Accepted: 03/04/2021] [Indexed: 12/13/2022]
Abstract
AIMS Diagnostic and post-induction 123I-meta-iodobenzylguanidine (123I-mIBG) scans have prognostic significance in the treatment of neuroblastoma, but data from low- and middle-income countries are limited due to resource constraints. The aim of this study was to determine the association between neuroblastoma-associated tumour markers (lactate dehydrogenase [LDH], ferritin and MYCN amplification) and 123I-mIBG scans (modified Curie scores and metastatic disease patterns) in predicting complete metastatic response rates (mCR) and overall survival. MATERIALS AND METHODS Two hundred and ninety patients diagnosed with high-risk neuroblastoma in South Africa between January 2000 and May 2018 and a subanalysis of 78 patients with diagnostic 123I-mIBG scans were included. Data collection included LDH, ferritin and MYCN amplification at diagnosis. Two nuclear physicians independently determined the modified Curie scores and pattern of distribution for each diagnostic and post-induction 123I-mIBG scans with high inter-rater agreement (r = 0.952) and reliability (K = 0.805). The cut-off values for the diagnostic and post-induction modified Curie scores of ≥7.0 (P = 0.026) and 3 (P = 0.009), respectively, were generated. The association between the tumour markers and the modified Curie score of the 123I-mIBG scans was determined using post-induction mCR and 2-year overall survival. RESULTS Diagnostic LDH (P < 0.001), ferritin (P < 0.001) and the diagnostic modified Curie scores (P = 0.019) significantly predicted mCR. Only ferritin correlated with diagnostic modified Curie scores (P = 0.003) but had a low correlation coefficient of 0.353. On multivariable analysis, the only significant covariate for 2-year overall survival at diagnosis was LDH <750 U/l (P = 0.024). A post-induction chemotherapy modified Curie score ≤3.0 had a 2-year overall survival of 46.2% compared with 30.8% for a score >3.0 (P = 0.484). CONCLUSION LDH, ferritin and the diagnostic 123I-mIBG scans significantly predicted mCR, but only LDH predicted 2-year overall survival. Ferritin and the modified Curie scores correlated with each other. MYCN amplification neither correlated with any aspect of the 123I-mIBG scans nor significantly predicted mCR or 2-year overall survival. LDH and ferritin are therefore appropriate neuroblastoma tumour markers to be used in low- and middle-income countries with limited or no access to mIBG scans and/or MYCN amplification studies.
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Affiliation(s)
- J Van Heerden
- Paediatric Haematology and Oncology, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg Hospital, Cape Town, South Africa; Paediatric Haematology and Oncology, Department of Paediatrics, Antwerp University Hospital, Antwerp, Belgium.
| | - M Kruger
- Paediatric Haematology and Oncology, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg Hospital, Cape Town, South Africa
| | - T M Esterhuizen
- Division of Epidemiology and Biostatistics, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - M Hendricks
- Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Cape Town, Paediatric Haematology and Oncology Service, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - J Du Plessis
- Department of Paediatrics, Faculty of Health Sciences, University of the Free State, Division of Paediatric Haematology and Oncology, Universitas Hospital, Bloemfontein, South Africa
| | - G Engelbrecht
- Department of Nuclear Medicine, University of the Free State, Universitas Hospital, Bloemfontein, South Africa
| | - M Janse van Vuuren
- Drs B Vorster and M Janse van Vuuren Incorporated, Nuclear Physicians, Bloemfontein, South Africa
| | - B van Emmenes
- Division of Paediatric Haematology and Oncology Hospital, Department of Paediatrics, Frere Hospital, East London, South Africa
| | - R Uys
- Paediatric Haematology and Oncology, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg Hospital, Cape Town, South Africa
| | - C Burger
- Department of Nuclear Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg Hospital, Cape Town, South Africa
| | - N Nyakale
- Department of Nuclear Medicine, Faculty of Health Sciences, University of KwaZulu-Natal, Inkosi Albert Luthuli Academic Hospital, Durban, South Africa
| | - S More
- Department of Paediatrics and Child Health, Division of Nuclear Medicine, Faculty of Health Sciences, University of Cape Town, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - A Brink
- Department of Paediatrics and Child Health, Division of Nuclear Medicine, Faculty of Health Sciences, University of Cape Town, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
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Alexander OT, Duvenhage MM, Kroon RE, Brink A, Visser HG. Comparison of a dimeric and a monomeric indium-quinolinato complex: synthesis, structure and photoluminescence. NEW J CHEM 2021. [DOI: 10.1039/d0nj03865b] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Two indium(iii) complexes, mer-[In(Ox)3]·2H2O (1) and [In2(Ox)2Cl2-μ-[κ2-O,O′-(Ox)2]]·C7H8 (2) (Ox = 8-hydroxyquinolinate), were synthesized and characterised for comparison by NMR, X-ray diffraction and photoluminescence.
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Affiliation(s)
- Orbett T. Alexander
- Department of Chemistry
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Mart M. Duvenhage
- Department of Physics
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Robin E. Kroon
- Department of Physics
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Alice Brink
- Department of Chemistry
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Hendrik G. Visser
- Department of Chemistry
- University of the Free State
- Bloemfontein 9300
- South Africa
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Kama DV, Frei A, Schutte-Smith M, Brink A, Swart C, Braband H, Alberto R, Roodt A. Exploring preliminary structural relationships and mitochondrial targeting of fac-[MI(CO)3]-bis(diarylphosphino)alkylamine complexes (M = 99Tc, Re). NEW J CHEM 2021. [DOI: 10.1039/d1nj04273d] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Preliminary structural relationships in fac-[MI(CO)3]-bis(diarylphosphino)alkylamine complexes (M = 99Tc, Re), antimicrobial and mitochondrial targeting are reported.
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Affiliation(s)
- Dumisani V. Kama
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Angelo Frei
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Marietjie Schutte-Smith
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Chantel Swart
- Department of Biochemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Henrik Braband
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Roger Alberto
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Andreas Roodt
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
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21
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Jacobs FJF, Venter GJS, Fourie E, Kroon RE, Brink A. Substitution reactivity and structural variability induced by tryptamine on the biomimetic rhenium tricarbonyl complex. RSC Adv 2021; 11:24443-24455. [PMID: 35479015 PMCID: PMC9036643 DOI: 10.1039/d1ra03750a] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/02/2021] [Indexed: 01/28/2023] Open
Abstract
A series of seven fac-[Re(CO)3(5Me-Sal-Trypt)(L)] complexes containing tryptamine on the N,O 5-methyl-salicylidene bidentate ligand backbone and where L is MeOH, Py, Imi, DMAP, PPh3 coordinated to the 6th position have been studied, including the formation of a dinuclear Re2 cluster. The crystallographic solid state structures show marked similarity in structural tendency, in particular the rigidity of the Re core and the hydrogen bond interactions similar to those found in protein structures. The rates of formation and stability of the complexes were evaluated by rapid time-resolved stopped-flow techniques and the methanol substitution reaction indicates the significant activation induced by the use of the N,O salicylidene bidentate ligand as manifested by the second-order rate constants for the entering nucleophiles. Both linear and limiting kinetics were observed and a systematic evaluation of the kinetics is reported clearly indicating an interchange type of intimate mechanism for the methanol substitution. The anticancer activity of compounds 1–7 was tested on HeLa cells and it was found that all compounds showed similar cytotoxicity where solubility allowed. IC50-values between ca. 11 and 22 μM indicate that some cytotoxicity resides most likely on the salicylidene–tryptamine ligand. The photoluminescence of the seven complexes is similar in maximum emission wavelength with little variation despite the broad range of ligands coordinated to the 6th position on the metal centre. The biomimetic tryptamine rhenium tricarbonyl complex shows rapid substitution reactivity on the 6th position as well as cytotoxicity and photoluminescence capability induced by the salicylidene bidentate ligand.![]()
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Affiliation(s)
| | | | - Eleanor Fourie
- Department of Chemistry
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Robin E. Kroon
- Department of Physics
- University of the Free State
- Bloemfontein 9300
- South Africa
| | - Alice Brink
- Department of Chemistry
- University of the Free State
- Bloemfontein 9300
- South Africa
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22
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Brink A, Alsma J, Brink HS, de Gelder J, Lucke JA, Mooijaart SP, Zietse R, Schuit SCE, Lingsma HF. Prediction admission in the older population in the Emergency Department: the CLEARED tool. Neth J Med 2020; 78:357-367. [PMID: 33380533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND Length of stay (LOS) in the Emergency Department (ED) is correlated with an extended in-hospital LOS and may even increase 30-day mortality. Older patients represent a growing population in the ED and they are especially at risk of adverse outcomes. Screening tools that adequately predict admission could help reduce waiting times in the ED and reduce time to treatment. We aimed to develop and validate a clinical prediction tool for admission, applicable to the aged patient population in the ED. METHODS Data from 7,606 ED visits of patients aged 70 years and older between 2012 and 2014 were used to develop the CLEARED tool. Model performance was assessed with discrimination using logistic regression and calibration. The model was internally validated by bootstrap resampling in Erasmus Medical Center and externally validated at two other hospitals, Medisch Spectrum Twente (MST) and Leiden University Medical Centre (LUMC). RESULTS CLEARED contains 10 predictors: body temperature, heart rate, diastolic blood pressure, systolic blood pressure, oxygen saturation, respiratory rate, referral status, the Manchester Triage System category, and the need for laboratory or radiology testing. The internally validated area under the curve (AUC) was 0.766 (95% CI [0.759;0.781]). External validation in MST showed an AUC of 0.797 and in LUMC, an AUC of 0.725. CONCLUSIONS The developed CLEARED tool reliably predicts admission in elderly patients visiting the ED. It is a promising prompt, although further research is needed to implement the tool and to investigate the benefits in terms of reduction of crowding and LOS in the ED.
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Affiliation(s)
- A Brink
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
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23
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Jacobs FJF, Brink A. Crystal structure of fac-tricarbonyl-(nitrato-k1
O)-bis(pyridine-κN)-rhenium, C13H10O6N3Re. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2020-0475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C13H10O6N3Re, monoclinic, P21/c (no. 14), a = 7.9325(9) Å, b = 13.811(2) Å, c = 13.458(2) Å, β = 92.637(4)°, V = 1472.83(4) Å3, Z = 4, R
gt(F) = 0.0249, wR
ref(F
2) = 0.0568, T = 100(2) K. CCDC no.: 2024932
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Affiliation(s)
- Francois J. F. Jacobs
- Department of Chemistry , University of the Free State , P. O. Box 339 , Bloemfontein , 9300 , South Africa
| | - Alice Brink
- Department of Chemistry , University of the Free State , P. O. Box 339 , Bloemfontein , 9300 , South Africa
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24
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Mokolokolo PP, Alexander OT, Schutte-Smith M, Brink A, Roodt A. Crystal structure of monocarbonyl[2-((cyclopentylmethylene)amino)-5-methylphenolato-κ 2N,O] (tricyclohexylphosphine)rhodium(I), C 32H 48NO 2PRh. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2020-0248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C32H48NO2PRh, orthorhombic, P212121 (no. 19), a = 26.784(10) Å, b = 8.837(3) Å, c = 12.759(4) Å, V = 3020.0(18) Å3, Z = 4, R
gt(F) = 0.0400, wR
ref(F
2) = 0.0920, T = 100(2) K.
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Affiliation(s)
- Pennie P. Mokolokolo
- Department of Chemistry , University of the Free State , Bloemfontein 9301, South Africa
| | - Orbett T. Alexander
- Department of Chemistry , University of the Free State , Bloemfontein 9301, South Africa
| | | | - Alice Brink
- Department of Chemistry , University of the Free State , Bloemfontein 9301, South Africa
| | - Andreas Roodt
- Department of Chemistry , University of the Free State , Bloemfontein 9301, South Africa
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25
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Mokolokolo PP, Brink A, Roodt A, Schutte-Smith M. Subtle variation of stereo-electronic effects in rhodium(I) carbonyl Schiff base complexes and their iodomethane oxidative addition kinetics. J COORD CHEM 2020. [DOI: 10.1080/00958972.2020.1809657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Pennie P. Mokolokolo
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
| | - Andreas Roodt
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
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26
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Kama DV, Brink A, Roodt A. Crystal structure of dichlorido( N- o-tolyl-1,1-di- p-tolylphosphanamine–κ 1
P)-(methoxydi- p-tolylphosphane-κ 1
P)palladium(II), C 36H 39Cl 2NOP 2Pd. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C36H39Cl2NOP2Pd, orthorhombic, Pbca (no. 61), a = 19.209(13) Å, b = 15.144(11) Å, c = 24.011(19) Å, V = 6985(9) Å3, Z = 8, R
gt(F) = 0.0292, wR
ref(F
2) = 0.0867, T = 100 K.
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Affiliation(s)
- Dumisani V. Kama
- Department of Chemistry , University of the Free State , P.O. Box 339 , Bloemfontein 9300 , South Africa
- University of the Free State , Chemistry Department , Nelson Mandela Drive , Bloemfontein 9300 , South Africa
| | - Alice Brink
- Department of Chemistry , University of the Free State , P.O. Box 339 , Bloemfontein 9300 , South Africa
| | - Andreas Roodt
- Department of Chemistry , University of the Free State , P.O. Box 339 , Bloemfontein 9300 , South Africa
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27
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Kama DV, Brink A, Alberto R, Roodt A. Crystal structure of hexacarbonyl-(μ 2-methanoato-k 2
O: O′)-(μ 2–bis(di- p-tolylphosphino)cyclohexylamine-κ 2
P: P′)dirhenium(I), C 42H 45NO 8P 2Re 2. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C42H45NO8P2Re2, monoclinic, C2/c (no. 15), a = 24.1612(7) Å, b = 13.0229(3) Å, c = 14.9180(4) Å, β = 121.383(3)°, V = 4007.2(2) Å3, Z = 4, R
gt(F) = 0.0235, wR
ref(F
2) = 0.0596, T = 173(2) K.
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Affiliation(s)
- Dumisani V. Kama
- University of the Free State , Chemistry Department , Nelson Mandela Drive , Bloemfontein 9300 , South Africa
| | - Alice Brink
- Department of Chemistry , University of the Free State , P.O. Box 339 , Bloemfontein 9300 , South Africa
| | - Roger Alberto
- Department of Chemistry , University of Zürich , Winterthurerstrasse, 190, 8057 , Zürich , Switzerland
| | - Andreas Roodt
- Department of Chemistry , University of the Free State , P.O. Box 339 , Bloemfontein 9300 , South Africa
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28
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Alexander OT, Brink A, Visser HG. The crystal structure of bis(μ2-5,7-dichloroquinolin-8-olato-κ3N,O:O)-tetrakis(5,7-dichloroquinolin-8-olato-κ2N,O)bis(methanol-κ1O)dieuropium(III) — toluene (1/1), C63H39Cl12Eu2N6O8. Z KRIST-NEW CRYST ST 2019. [DOI: 10.1515/ncrs-2019-0606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractC63H39Cl12Eu2N6O8, triclinic, P1̄ (no. 2), a = 10.720(5) Å, b = 12.232(5) Å, c = 14.267(5) Å, α = 65.288(32)°, β = 71.325(5)°, γ = 88.067(5)°, V = 1599.1(11) Å3, Z = 1, Rgt(F) = 0.0358, wRref(F2) = 0.0785, T = 293(2) K.
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Affiliation(s)
- Orbett T. Alexander
- Department of Chemistry, University of the Free State, Bloemfontein 9301, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, Bloemfontein 9301, South Africa
| | - Hendrik G. Visser
- Department of Chemistry, University of the Free State, Bloemfontein 9301, South Africa
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29
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Alexander OT, Kroon RE, Brink A, Visser HG. Symmetry correlations between crystallographic and photoluminescence study of ternary β-diketone europium(iii) based complexes using 1,10-phenanthroline as the ancillary ligand. Dalton Trans 2019; 48:16074-16082. [PMID: 31616878 DOI: 10.1039/c9dt02580d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This work entails deep red emitting EuIII based complexes with a variety of ternary β-diketonate ligands and 1,10-phenanthroline as the ancillary ligand in the system. The solid state structure and spectroscopic analysis has been outlaid in terms of photoluminescence and crystallography. A luminescence quantum efficiency of 50% was obtained for the [tris-(4,4,4-trifluoro-1-chlorophenyl-butanedione)mono-(1,10-phenanthroline)europium(iii)] complexes. Moreover, complexes [tris-(2,2,6,6-tetramethyl-heptanedione)mono-(1,10-phenanthroline) europium(iii)] and {[hexa-(benzyl carboxylic acid) bis-(1,10-phenanthroline)di-europium(iii)]-μ-[κ2-O,O'-(benzyl carboxylic acid)]2} were found to also have quantum yields of 9% and 28% with respective sensitization efficiencies of 85%, 15% and 58%. These results were articulated with crystallographic details pertaining to the nature of coordination and the effect of steric and electronic properties thereof which somewhat impacts the Eu-N bond distances. A symmetry correlation was drawn between the crystallographic data and the photoluminescence data.
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Affiliation(s)
- Orbett T Alexander
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa.
| | - Robin E Kroon
- Department of Physics, University of the Free State, Bloemfontein, 9301, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa.
| | - Hendrik G Visser
- Department of Chemistry, University of the Free State, Bloemfontein, 9301, South Africa.
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30
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Brink A, Helliwell JR. Why is interoperability between the two fields of chemical crystallography and protein crystallography so difficult? IUCrJ 2019; 6:788-793. [PMID: 31576212 PMCID: PMC6760442 DOI: 10.1107/s2052252519010972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 08/06/2019] [Indexed: 05/06/2023]
Abstract
The interoperability of chemical and biological crystallographic data is a key challenge to research and its application to pharmaceutical design. Research attempting to combine data from the two disciplines, small-molecule or chemical crystallography (CX) and macromolecular crystallography (MX), will face unique challenges including variations in terminology, software development, file format and databases which differ significantly from CX to MX. This perspective overview spans the two disciplines and originated from the investigation of protein binding to model radiopharmaceuticals. The opportunities of interlinked research while utilizing the two databases of the CSD (Cambridge Structural Database) and the PDB (Protein Data Bank) will be highlighted. The advantages of software that can handle multiple file formats and the circuitous route to convert organometallic small-molecule structural data for use in protein refinement software will be discussed. In addition some pointers to avoid being shipwrecked will be shared, such as the care which must be taken when interpreting data precision involving small molecules versus proteins.
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Affiliation(s)
- Alice Brink
- Department of Chemistry, University of the Free State, Nelson Mandela Drive, Bloemfontein, Free State 9301, South Africa
- Department of Chemistry, University of Manchester, Brunswick Street, Manchester M13 9PL, UK
- Correspondence e-mail:
| | - John R. Helliwell
- Department of Chemistry, University of Manchester, Brunswick Street, Manchester M13 9PL, UK
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31
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Roodt A, Mokolokolo PP, Alexander OT, Kama DV, Brink A, Schutte Smith M. Structure/reactivity relationships from detailed reaction mechanisms. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319090697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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32
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Brink A, Helliwell JR. Formation of a highly dense tetra-rhenium cluster in a protein crystal and its implications in medical imaging. IUCrJ 2019; 6:695-702. [PMID: 31316813 PMCID: PMC6608631 DOI: 10.1107/s2052252519006651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/09/2019] [Indexed: 05/22/2023]
Abstract
The fact that a protein crystal can serve as a chemical reaction vessel is intrinsically fascinating. That it can produce an electron-dense tetranuclear rhenium cluster compound from a rhenium tri-carbonyl tri-bromo starting compound adds to the fascination. Such a cluster has been synthesized previously in vitro, where it formed under basic conditions. Therefore, its synthesis in a protein crystal grown at pH 4.5 is even more unexpected. The X-ray crystal structures presented here are for the protein hen egg-white lysozyme incubated with a rhenium tri-carbonyl tri-bromo compound for periods of one and two years. These reveal a completed, very well resolved, tetra-rhenium cluster after two years and an intermediate state, where the carbonyl ligands to the rhenium cluster are not yet clearly resolved, after one year. A dense tetranuclear rhenium cluster, and its technetium form, offer enhanced contrast in medical imaging. Stimulated by these crystallography results, the unusual formation of such a species directly in an in vivo situation has been considered. It offers a new option for medical imaging compounds, particularly when considering the application of the pre-formed tetranuclear cluster, suggesting that it may be suitable for medical diagnosis because of its stability, preference of formation and biological compatibility.
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Affiliation(s)
- Alice Brink
- Department of Chemistry, University of the Free State, Nelson Mandela Drive, Bloemfontein, 9301, South Africa
- School of Chemistry, University of Manchester, Brunswick Street, Manchester M13 9PL, UK
- Correspondence e-mail:
| | - John R. Helliwell
- School of Chemistry, University of Manchester, Brunswick Street, Manchester M13 9PL, UK
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34
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Brink A, Alsma J, Fortuin AW, Bramer WM, Zietse R, Lingsma HF, Schuit S. Prediction models for mortality in adult patients visiting the Emergency Department: a systematic review. Acute Med 2019; 18:171-183. [PMID: 31536055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We provide a systematic overview of literature on prediction models for mortality in the Emergency Department (ED). We searched various databases for observational studies in the ED or similar setting describing prediction models for short-term mortality (up to 30 days or in-hospital mortality) in a non-trauma population. We used the CHARMS-checklist for quality assessment. We found a total of 14.768 articles and included 17 articles, describing 22 models. Model performance ranged from AUC 0.63-0.93. Most articles had a moderate risk of bias in one or more domains. The full model and PARIS model performed best, but are not yet ready for implementation. There is a need for validation studies to compare multiple prediction models and to evaluate their accuracy.
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Affiliation(s)
- A Brink
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - J Alsma
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - A W Fortuin
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - W M Bramer
- Medical Library, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - R Zietse
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - H F Lingsma
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - Sce Schuit
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
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Nkoe PI, Visser HG, Swart C, Brink A, Schutte-Smith M. Synthesis of Re I tricarbonyl complexes with various sulfur- and oxygen-donating ligands: crystal structures of two Re I dinuclear structures bridged by S atoms. Acta Crystallogr C Struct Chem 2018; 74:1116-1122. [PMID: 30284976 DOI: 10.1107/s205322961801207x] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/24/2018] [Indexed: 11/10/2022]
Abstract
The synthesis and characterization of two dinuclear complexes, namely fac-hexacarbonyl-1κ3C,2κ3C-(pyridine-1κN)[μ-2,2'-sulfanediyldi(ethanethiolato)-1κ2S1,S3:2κ3S1,S2,S3]dirhenium(I), [Re2(C4H8S3)(C5H5N)(CO)6], (1), and tetraethylammonium fac-tris(μ-2-methoxybenzenethiolato-κ2S:S)bis[tricarbonylrhenium(I)], (C8H20N)[Re2(C7H7OS)3(CO)6], (2), together with two mononuclear complexes, namely (2,2'-bithiophene-5-carboxylic acid-κ2S,S')bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene-2-carboxylate-κ2O,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X-ray diffraction. The crystal structure of (1) revealed two Re-S-Re bridges. The thioether S atom only bonds to one of the ReI metal centres, while the geometry of the second ReI metal centre is completed by a pyridine ligand. The structure of (2) is characterized by three S-atom bridges and an Re...Re nonbonding distance of 3.4879 (5) Å, which is shorter than the distance found for (1) [3.7996 (6)/3.7963 (6) Å], but still clearly a nonbonding distance. Complex (1) is stabilized by six intermolecular hydrogen-bond interactions and an O...O interaction, while (2) is stabilized by two intermolecular hydrogen-bond interactions and two O...π interactions.
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Affiliation(s)
- Pheello I Nkoe
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, Free State, 9301, South Africa
| | - Hendrik G Visser
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, Free State, 9301, South Africa
| | - Chantel Swart
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, PO Box 339, Bloemfontein, Free State, 9301, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, Free State, 9301, South Africa
| | - Marietjie Schutte-Smith
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, Free State, 9301, South Africa
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Brink A. Modifying the RheManTec triad – a small molecule meanders into the macromolecular world. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318089489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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37
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Frei A, Mokolokolo PP, Bolliger R, Braband H, Tsosane MS, Brink A, Roodt A, Alberto R. Self-Assembled Multinuclear Complexes Incorporating 99m Tc. Chemistry 2018; 24:10397-10402. [PMID: 29672957 DOI: 10.1002/chem.201800600] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/18/2018] [Indexed: 12/30/2022]
Abstract
Multinuclear complexes or clusters are rarely investigated in medicinal inorganic chemistry although they represent structural intermediates between molecules and nanomaterials. We present in this report two strategies towards 99m Tc-containing clusters. In a pre-assembly approach, the preformed but incomplete cluster fragment [Re3 (μ2 -OH)3 (μ3 -OH)(CO)9 ]- reacts with [99m Tc(CO)3 ]+ to the highly stable [99m TcRe3 (μ3 -OH)4 (CO)12 ] cube. The same structure self-assembles when reacting the mononuclear Re and 99m Tc precursors in one pot. Integrating the coordinating OH groups from Schiff bases in this concept leads straight to dinuclear, mixed-metal complexes of the type [99m TcRe(μ2 -O^N-R1 )2 (CO)6 ] in quantitative yields. Both strategies are unprecedented and open a future path towards clusters, incorporating a 99m Tc radiolabel while being decorated with targeting or cytotoxic moieties.
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Affiliation(s)
- Angelo Frei
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057, Zurich, Switzerland
| | - Pennie P Mokolokolo
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Robin Bolliger
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057, Zurich, Switzerland
| | - Henrik Braband
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057, Zurich, Switzerland
| | - Mampotso S Tsosane
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Andreas Roodt
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Roger Alberto
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057, Zurich, Switzerland
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Brink A, Sheridan C, Harding K. Combined biological and advance oxidation processes for paper and pulp effluent treatment. South African Journal of Chemical Engineering 2018. [DOI: 10.1016/j.sajce.2018.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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39
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Brink A, Kroon RE, Visser HG, van Rensburg CEJ, Roodt A. Designing model imino bifunctional chelators for radiopharmaceuticals – in vitro antitumor activity, photoluminescence and structural analysis. NEW J CHEM 2018. [DOI: 10.1039/c7nj04208f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Designed bifunctional chelators for the radionuclides of 188/186Re or 99mTc. Structure, DFT calculations, antitumor and imaging properties are described.
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Affiliation(s)
- Alice Brink
- Department of Chemistry, University of the Free State
- Bloemfontein 9300
- South Africa
| | - Robin E. Kroon
- Department of Physics, University of the Free State
- Bloemfontein 9300
- South Africa
| | - Hendrik G. Visser
- Department of Chemistry, University of the Free State
- Bloemfontein 9300
- South Africa
| | | | - Andreas Roodt
- Department of Chemistry, University of the Free State
- Bloemfontein 9300
- South Africa
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Alexander O, Brink A, Kroon R, Duvenhage MM, Swart H, Visser H. The fluoretic difference in homoleptic mononuclear and dinuclear indium species. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s2053273317086429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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41
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Kama DV, Schutte-Smith M, Brink A, Visser HG, Roodt A. Diphosphinoamine (PNP) ligand effects in homogeneous catalysis and radiopharmaceuticals. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s2053273317093573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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42
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Oosthuizen R, Brink A, Venter GJS. The crystal structure of tetrakis(1,3,5-triaza-7-phosphatricyclo[3.3.1.1 3,7]decane-κ P)silver(I) chloride dihydrate, C 24H 60AgClN 12O 6P 4. Z KRIST-NEW CRYST ST 2017. [DOI: 10.1515/ncrs-2017-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C24H60AgClN12O6P4, tetragonal, P42/nmc (no. 137), a = 14.1874(3) Å, c = 9.8721(3) Å, V = 1987.08(1) Å3, Z = 2, R
gt(F) = 0.0148, wR
ref(F
2) = 0.0417, T = 100 K.
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Affiliation(s)
- Runé Oosthuizen
- Department of Chemistry , University of the Free State , P. O. Box 339 , Bloemfontein , 9300, South Africa
| | - Alice Brink
- Department of Chemistry , University of the Free State , P. O. Box 339 , Bloemfontein , 9300, South Africa
| | - Gertruida J. S. Venter
- Department of Chemistry , University of the Free State , P. O. Box 339 , Bloemfontein , 9300, South Africa
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Al-Rubaye BK, Brink A, Miller GJ, Potgieter H, Al-Jeboori MJ. Crystal structure of ( E)-4-benzyl-idene-6-phenyl-1,2,3,4,7,8,9,10-octa-hydro-phenanthridine. Acta Crystallogr E Crystallogr Commun 2017; 73:1092-1096. [PMID: 28775890 PMCID: PMC5499298 DOI: 10.1107/s2056989017009537] [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] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/26/2017] [Indexed: 11/28/2022]
Abstract
The title compound was synthesized using a novel one-pot method under mild conditions and fully characterized using NMR, ESI–MS and SXRD. The supramolecular structure of the title compound is defined by a combination of C—H⋯N and π–π interactions. The preparation of the title compound, C26H25N, was achieved by the condensation of an ethanolic mixture of benzaldehyde, cyclohexanone and ammonium acetate in a 2:1:1 molar ratio. There are two crystallographically independent molecules in the asymmetric unit. The two cyclohexyl rings adopt an anti-envelope conformation with the benzyl moiety adopting a cis conformation with respect to the nitrogen atom of the phenanthridine segment. In the crystal, molecules are linked through C—H⋯N interactions into hydrogen-bonded chains that are further arranged into distinct layers by weak offset π–π interactions.
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Affiliation(s)
- Baidaa K Al-Rubaye
- Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Iraq
| | - Alice Brink
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, South Africa
| | - Gary J Miller
- Analytical Sciences, Manchester Metropolitan University, Chester Street M1 5GD, UK
| | - Herman Potgieter
- School of Research, Enterprise & Innovation, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK.,School of Chemical & Metallurgical Engineering, University of the Witwatersr, Private Bag X3, Wits 2050, South Africa
| | - Mohamad J Al-Jeboori
- Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Iraq
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Brink A, Visser HG, Roodt A. Rhenium reactivity – manipulation by ligand development. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s0108767317099779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Brink A, Helliwell JR. New leads for fragment-based design of rhenium/technetium radiopharmaceutical agents. IUCrJ 2017; 4:283-290. [PMID: 28512575 PMCID: PMC5414402 DOI: 10.1107/s2052252517003475] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/03/2017] [Indexed: 05/22/2023]
Abstract
Multiple possibilities for the coordination of fac-[Re(CO)3(H2O)3]+ to a protein have been determined and include binding to Asp, Glu, Arg and His amino-acid residues as well as to the C-terminal carboxylate in the vicinity of Leu and Pro. The large number of rhenium metal complex binding sites that have been identified on specific residues thereby allow increased target identification for the design of future radiopharmaceuticals. The core experimental concept involved the use of state-of-art tuneable synchrotron radiation at the Diamond Light Source to optimize the rhenium anomalous dispersion signal to a large value (f'' of 12.1 electrons) at its LI absorption edge with a selected X-ray wavelength of 0.9763 Å. At the Cu Kα X-ray wavelength (1.5418 Å) the f'' for rhenium is 5.9 electrons. The expected peak-height increase owing to the optimization of the Re f'' was therefore 2.1. This X-ray wavelength tuning methodology thereby showed the lower occupancy rhenium binding sites as well as the occupancies of the higher occupancy rhenium binding sites.
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Affiliation(s)
- Alice Brink
- Department of Chemistry, University of the Free State, Nelson Mandela Drive, Bloemfontein, Free State 9301, South Africa
| | - John R. Helliwell
- School of Chemistry, University of Manchester, Brunswick Street, Manchester M13 9PL, England
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Affiliation(s)
| | - S. Marx
- North-West University, South Africa
| | - A. Brink
- North-West University, South Africa
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47
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Alexander OT, Duvenhage MM, Brink A, Swart HC, Müller P, Kroon RE, Visser HG. Synthesis, structures and luminescence properties of two gallium(III) complexes with 5,7-dimethyl-8-hydroxyquinoline. J COORD CHEM 2017. [DOI: 10.1080/00958972.2017.1303487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Orbett T. Alexander
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
| | - Mart M. Duvenhage
- Department of Physics, University of the Free State, Bloemfontein, South Africa
| | - Alice Brink
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
| | - Hendrik C. Swart
- Department of Physics, University of the Free State, Bloemfontein, South Africa
| | - Peter Müller
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - R. E. Kroon
- Department of Physics, University of the Free State, Bloemfontein, South Africa
| | - Hendrik G. Visser
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
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Esterhuysen M, Brink A, Roodt A, Zbačnik M, Slabbert J, Beukes P. P21. Synthesis, structure and biological study of Gallium(III) complexes as model radiopharmaceuticals. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.07.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Roodt A, Visser HG, Brink A, Schutte-Smith M, Mokolokolo P, Kama DV, Frei A, Alberto RA. Single-crystal structures and spectroscopic analysis in metal complex dynamics. Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s2053273316094316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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50
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Alexander OT, Alexander OT, Duvenhage MM, Brink A, Muller P, Swart HC, Visser HG. Synthesis, structures and luminescence properties of two gallium(III) complexes containing 5,7-dimethyl-8-hydroxyquinoline. Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s2053273316095498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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