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Brink A, Mokolokolo PP, Visser HG, Roodt A. Rhenium monomers versus manganese dimers – what is driving the linkage? Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s205327331609478x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Nkoe PI, Koen R, Brink A, Schutte-Smith M. Crystal structure of hexacarbonyl bis(μ2-2-methoxybenzenethiolato-κ2S)pyridine(triphenylphosphane)dirhenium(I), C43H34NO8PS2Re2. Z KRIST-NEW CRYST ST 2016. [DOI: 10.1515/ncrs-2015-0139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractC43H34NO8PS2Re2, monoclinic, P21/c (no. 14), a = 12.165(8) Å, b = 19.027(11) Å, c = 18.848(14) Å, β = 108.735(2)°, V = 4131(5) Å3, Z = 4, Rgt(F) = 0.0308, wRref(F2) = 0.0683, T = 100(2) K.
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Mokolokolo PP, Brink A, Visser HG. Crystal structure of bis(μ 2-2-((3-methylphenyl)imino)methylphenolato-κ 2
N, O: O)hexacarbonyldimanganese(I), C 34H 24Mn 2N 2O 8. Z KRIST-NEW CRYST ST 2016. [DOI: 10.1515/ncrs-2015-0210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C34H24Mn2N2O8, triclinic, P1̅ (no. 2) a = 7.737(5) Å, b = 9.483(5) Å, c = 11.309(5) Å, β = 102.514(5)°, V = 766.6(7) Å3, Z = 1, R
gt
(F) = 0.0478, wR
ref
(F
2
) = 0.1297, T = 100(2) K
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Tsosane MS, Visser HG, Brink A. Crystal structure of ( E)-2-(((1,10-phenanthrolin-5-yl)imino)methyl)-5-methylphenol monohydrate, C 20H 15N 3O·H 2O. Z KRIST-NEW CRYST ST 2016. [DOI: 10.1515/ncrs-2015-0103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C20H15N3O·H2O, triclinic, P1̅ (No. 2), a = 7.066(3) Å, b = 9.996(4) Å, c = 12.873(5) Å, α = 86.007(14)°, β = 74.861(14)°, γ = 69.596(13)°, V = 822.4(6) Å3, Z = 2, R
gt
(F) = 0.0424, wR
ref
(F
2
) = 0.1241, T = 100 K.
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Marake DT, Roodt A, Brink A. Crystal structure of fac-tricarbonyl(2-(isopropylimino)methyl-5-methylphenolatido-κ 2
N, O)(pyridine-κ N)rhenium(I), C 19H 19N 2O 4Re. Z KRIST-NEW CRYST ST 2016. [DOI: 10.1515/ncrs-2015-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C19H19N2O4Re, Monoclinic, P21/c (no. 14), a = 8.2805(3) Å, b = 13.7325(5) Å, c = 16.3560(6) Å, β = 92.431(2)°, V = 1858.2(2) Å3, Z = 4, R
gt
(F) = 0.0347, wR
ref
(F
2
) = 0.0930, T = 100 K.
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Schadt S, Simon S, Kustermann S, Boess F, McGinnis C, Brink A, Lieven R, Fowler S, Youdim K, Ullah M, Marschmann M, Zihlmann C, Siegrist Y, Cascais A, Di Lenarda E, Durr E, Schaub N, Ang X, Starke V, Singer T, Alvarez-Sanchez R, Roth A, Schuler F, Funk C. Minimizing DILI risk in drug discovery — A screening tool for drug candidates. Toxicol In Vitro 2015; 30:429-37. [DOI: 10.1016/j.tiv.2015.09.019] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 08/28/2015] [Accepted: 09/20/2015] [Indexed: 12/14/2022]
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57
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Esterhuysen M, van den Berg PCW, Visser HG, Brink A, Zbačnik M, Roodt A. Different compounds from the same reactants: serendipity, misfortune or different reaction conditions? Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315093110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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58
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Roodt A, Brink A, Schutte-Smith M, Visser HG. Structure and function of coordination compounds for radiopharmaceutical application. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315098344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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59
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Brink A. Through the looking glass: anomalies and packing. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315093572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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60
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Pretorius C, Brink A, Roodt A. Novel 1-D rhodium polymeric chain systems via rhodium-rhodium interactions. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315098289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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61
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Marake DT, Mokolokolo PP, Visser HG, Brink A. Structural comparison of group 7 tricarbonyl complexes of 2-{[2-(1H-imidazol-4-yl)ethyl]iminomethyl}-5-methylphenolate. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2015; 71:423-9. [PMID: 26044320 DOI: 10.1107/s2053229615008360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/28/2015] [Indexed: 11/10/2022]
Abstract
Two tricarbonyl complexes of rhenium(I) and manganese(I) coordinated by the ligand 2-{[2-(1H-imidazol-4-yl)ethyl]iminomethyl}-5-methylphenolate are reported, viz. fac-tricarbonyl(2-{[2-(1H-imidazol-4-yl-κN(3))ethyl]iminomethyl-κN}-5-methylphenolato-κO)rhenium(I) methanol monosolvate, [Re(C16H14N3O4)(CO)3]·CH3OH, (I), and fac-tricarbonyl(2-{[2-(1H-imidazol-4-yl-κN(3))ethyl]iminomethyl-κN}-5-methylphenolato-κO)manganese(I), fac-[Mn(C16H14N3O4)(CO)3], (II), display facial coordination in a distorted octahedral environment. The crystal structure of (I) is stabilized by O-H···O, N-H···O and C-H···O hydrogen-bond interactions, while that of (II) is stabilized by N-H...O hydrogen-bond interactions only. These interactions result in two-dimensional networks and π-π stacking for both structures.
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Mphure LT, Visser HG, Roodt A, Brink A. Crystal structure of dichloro-N,N-bis(pyridine-2-ylmethyl)cyclohexamino copper(II), C18H23Cl2CuN3. ACTA ACUST UNITED AC 2015. [DOI: 10.1515/ncrs-2014-9042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract C18H23Cl2CuN3, monoclinic, P21/c (no. 14), a = 8.291(2) Å, b = 13.970(3) Å, c = 15.330(3) Å, β = 90.328(5)°, V = 1775.6 Å3, Z = 4, Rgt(F) = 0.0272, wRref(F2) = 0.0736, T = 101 K.
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Martens-de Kemp S, Rietbergen M, Brink A, Walsum MSV, Bloemena E, van Wieringen W, Slijper M, Braakhuis B, Leemans C, Brakenhoff R. 6 CD98 identifies a clinically relevant subpopulation of head and neck squamous cell carcinoma cells with stem cell properties. Oral Oncol 2015. [DOI: 10.1016/j.oraloncology.2015.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Helliwell JR, Brink A, Kaenket S, Starkey VL, Tanley SWM. X-ray diffraction in temporally and spatially resolved biomolecular science. Faraday Discuss 2015; 177:429-41. [PMID: 25605312 DOI: 10.1039/c4fd00166d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Time-resolved Laue protein crystallography at the European Synchrotron Radiation Facility (ESRF) opened up the field of sub-nanosecond protein crystal structure analyses. There are a limited number of such time-resolved studies in the literature. Why is this? The X-ray laser now gives us femtosecond (fs) duration pulses, typically 10 fs up to ∼50 fs. Their use is attractive for the fastest time-resolved protein crystallography studies. It has been proposed that single molecules could even be studied with the advantage of being able to measure X-ray diffraction from a 'crystal lattice free' single molecule, with or without temporal resolved structural changes. This is altogether very challenging R&D. So as to assist this effort we have undertaken studies of metal clusters that bind to proteins, both 'fresh' and after repeated X-ray irradiation to assess their X-ray-photo-dynamics, namely Ta6Br12, K2PtI6 and K2PtBr6 bound to a test protein, hen egg white lysozyme. These metal complexes have the major advantage of being very recognisable shapes (pseudo spherical or octahedral) and thereby offer a start to (probably very difficult) single molecule electron density map interpretations, both static and dynamic. A further approach is to investigate the X-ray laser beam diffraction strength of a well scattering nano-cluster; an example from nature being the iron containing ferritin. Electron crystallography and single particle electron microscopy imaging offers alternatives to X-ray structural studies; our structural studies of crustacyanin, a 320 kDa protein carotenoid complex, can be extended either by electron based techniques or with the X-ray laser representing a fascinating range of options. General outlook remarks concerning X-ray, electron and neutron macromolecular crystallography as well as 'NMR crystallography' conclude the article.
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Tsosane M, Brink A. Crystal structure of 5-methyl-2-(cyclohexyliminomethyl)phenol, C14H19NO. Z KRIST-NEW CRYST ST 2014. [DOI: 10.1515/ncrs-2014-0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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66
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Pretorius C, Brink A, Roodt A. Crystal structure of acetopyruvato-κ2O,O'-dicarbonylrhodium(I), C8H7O6Rh. Z KRIST-NEW CRYST ST 2014. [DOI: 10.1515/ncrs-2014-0195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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67
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Brink A, Visser HG, Roodt A. Solid state isostructural behavior and quantified limiting substitution kinetics in Schiff-base bidentate ligand complexes fac-[Re(O,N-Bid)(CO)3(MeOH)](n). Inorg Chem 2014; 53:12480-8. [PMID: 25393647 DOI: 10.1021/ic5019168] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A range of N,O-donor atom salicylidene complexes of the type fac-[M(O,N-Bid)(CO)3(L)](n) (O,N-Bid = anionic N,O-bidentate ligands; L = neutral coordinated ligand) have been studied. The unique feature of the complexes which crystallize in a monoclinic isostructural space group for complexes containing methanol in the sixth position (L = MeOH) is highlighted. The reactivity and stability of the complexes were evaluated by rapid stopped-flow techniques, and the methanol substitution by a range of pyridine type ligands indicates significant activation by the N,O-salicylidene type of bidentate ligands as observed from the variation in the second-order rate constants. In particular, following the introduction of the sterically demanding and electron rich cyclohexyl salicylidene moiety on the bidentate ligand, novel limiting kinetic behavior is displayed by all entering ligands, thus enabling a systematic probe and manipulation of the limiting kinetic constants. Clear evidence of an interchange type of intimate mechanism for the methanol substitution is produced. The equilibrium and rate constants (25 °C) for the two steps in the dissociative interchange mechanism for methanol substitution in fac-[Re(Sal-Cy)(CO)3(MeOH)] (5) by the pyridine type ligands 3-chloropyridine, pyridine, 4-picoline, and DMAP are k3 (s(-1)), 40 ± 4, 13 ± 2, 10.4 ± 0.7, and 2.11 ± 0.09, and K2 (M(-1)), 0.13 ± 0.01, 0.21 ± 0.03, 0.26 ± 0.02, and 1.8 ± 0.1, respectively.
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68
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Brink A, Truedsson I, Fleckhaus A, Johnson MT, Norrby PO, Roodt A, Wendt OF. Fast and reversible insertion of carbon dioxide into zirconocene-alkoxide bonds. A mechanistic study. Dalton Trans 2014; 43:8894-8. [PMID: 24796283 DOI: 10.1039/c3dt53566e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In two consecutive equilibria the compound (Cp*)2Zr(OMe)2 undergoes insertion of CO2 to form the mono- and bis-hemicarbonates. Both equilibria are exothermic but entropically disfavoured. Magnetisation transfer experiments gave kinetic data for the first equilibrium showing that the rate of insertion is overall second order with a rate constant of 3.20 ± 0.12 M(-1) s(-1), which is substantially higher than those reported for other early transition metal alkoxides, which are currently the best homogeneous catalysts for dimethyl carbonate formation from methanol and CO2. Activation parameters for the insertion reaction point to a highly ordered transition state and we interpret that as there being a substantial interaction between the CO2 and the metal during the C-O bond formation. This is supported by DFT calculations showing the lateral attack by CO2 to have the lowest energy transition state.
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69
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70
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Brink A. Antibiotic use and the trends of gram-negative resistance around the world. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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71
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Badal R, Lob S, Hoban D, Bouchillon S, Hackel M, Brink A. Comparison of susceptibility trends of Escherichia coli from intra-abdominal infections in high- vs. low-to-middle-income countries: SMART 2008-2012. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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72
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Brink A. Implication of current resistance trends on community-acquired respiratory tract infection (CA-RTI) management. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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73
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Brink A, Mann MD, Rode H. The role of limb perfusion studies in the paediatric ischaemic limb. S AFR J SURG 2014; 52:13-17. [PMID: 24881133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVES To study the use of limb perfusion scans in children with limb-threatening ischaemia and determine whether such scans are helpful in making clinical decisions. METHODS This retrospective study compared the clinical, scan and surgical findings in children who had limb perfusion scans for critical limb ischaemia at Red Cross War Memorial Children's Hospital, Cape Town, South Africa, from July 2001 to December 2010. Records were reviewed and the data analysed for aetiology, clinical findings, limb perfusion results, operative findings and outcome. RESULTS There were complete clinical and scan records for 20/22 patients, aged 1 month to 12 years. The causes of limb ischaemia were meningococcal septicaemia (n = 9), septic shock (n = 6), hypovolaemic shock due to gastroenteritis (n = 4), and electrical burns (n = 1). The clinical, scan and surgical findings correlated in 40/48 imaged limbs. In one leg the findings did not correlate, but the perfusion scan results predicted the outcome. In the remaining seven cases the exact correlation was uncertain owing to technical difficulties or absent operative notes. CONCLUSION This study describes a method for performing limb perfusion studies in children. Limb perfusion studies correlated well with surgical findings. These studies were useful in treatment decisions, parent and patient counselling and surgical planning. They supplemented clinical examination in assessment of the children.
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Brink A, Visser HG, Roodt A. Coordinated ligand manipulation of rhenium tricarbonyl reactivity. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313097602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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75
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Brink A, Visser HG, Roodt A. Coordinated ligand manipulation of rhenium tricarbonyl reactivity. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313094440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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76
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Brink A, Visser HG, Roodt A. Activation of rhenium(I) toward substitution in fac-[Re(N,O'-Bid)(CO)3(HOCH3)] by Schiff-base bidentate ligands (N,O'-Bid). Inorg Chem 2013; 52:8950-61. [PMID: 23883066 DOI: 10.1021/ic401115j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of fac-[Re(N,O'-Bid)(CO)3(L)] (N,O'-Bid = monoanionic bidentate Schiff-base ligands with N,O donor atoms; L = neutral monodentate ligand) has been synthesized, and the methanol substitution reactions have been investigated. The complexes were characterized by NMR, IR, and UV-vis spectroscopy. X-ray crystal structures of the compounds fac-[Re(Sal-mTol)(CO)3(HOCH3)], fac-[Re(Sal-pTol)(CO)3(HOCH3)], fac-[Re(Sal-Ph)(CO)3(HOCH3)], and fac-[Re(Sal-Ph)(CO)3(Py)] (Sal-mTol = 2-(m-tolyliminomethyl)phenolato; Sal-pTol = 2-(p-tolyliminomethyl)phenolato; Sal-Ph = 2-(phenyliminomethyl)phenolato; Py = pyridine) are reported. Significant activation for the methanol substitution is induced by the use of the N,O bidentate ligand as manifested by the second order rate constants, with limiting kinetics being observed for the first time. Rate constants (25 °C) (k1 or k3) and activation parameters (ΔHk‡, kJ mol(-1); ΔSk‡, J K(-1) mol(-1)) from Eyring plots for entering nucleophiles as indicated are as follows: fac-[Re(Sal-mTol)(CO)3(HOCH3)] 3-chloropyridine: (k1) 2.33 ± 0.01 M(-1) s(-1); 85.1 ± 0.6, 48 ± 2; fac-[Re(Sal-mTol)(CO)3(HOCH3)] pyridine: (k1) 1.29 ± 0.02 M(-1) s(-1); 92 ± 2, 66 ± 7; fac-[Re(Sal-mTol)(CO)3(HOCH3)] 4-picoline: (k1) 1.27 ± 0.05 M(-1) s(-1); 88 ± 2, 53 ± 6; (k3) 3.9 ± 0.03 s(-1); 78 ± 8, 30 ± 27; (kf) 1.7 ± 0.02 M(-1) s(-1); 86 ± 2, 49 ± 6; fac-[Re(Sal-mTol)(CO)3(HOCH3)] DMAP (k3) 1.15 ± 0.02 s(-1); 88 ± 2, 52 ± 7. An interchange dissociative mechanism is proposed.
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Venter GJS, Brink A, Steyl G, Roodt A. 4-(2-Chloro-phenyl-amino)-pent-3-en-2-one. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o3101-2. [PMID: 23284429 PMCID: PMC3515202 DOI: 10.1107/s1600536812042043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 10/08/2012] [Indexed: 11/10/2022]
Abstract
In the title compound, C11H12ClNO, intramolecular N—H⋯O hydrogen bonding is present. The dihedral angle between the benzene ring and the pentenone unit is 46.52 (5)°. In the crystal, C—H⋯O interactions between hydrogen atoms of the aryl moiety and two separate oxygen atoms occur, leading to a three-dimensional network.
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78
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Schutte M, Brink A, Visser HG, Roodt A. Tetra-μ(3)-hydroxido-tetra-kis-[tricarbonyl-rhenium(I)] pyridine tetra-solvate. Acta Crystallogr Sect E Struct Rep Online 2012; 68:m1208-m1209. [PMID: 22969493 PMCID: PMC3435620 DOI: 10.1107/s1600536812036033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 06/01/2023]
Abstract
The title compound, [Re(4)(μ(3)-OH)(4)(CO)(12)]·4C(5)H(5)N, crystallizes with one tetranuclear rhenium(I) cubane-like molecule and four pyridine mol-ecules in the asymmetric unit. The coordination environment of each Re(I) atom is distorted octahedral. Four intra-molecular O-H⋯N and four inter-molecular C-H⋯O hydrogen-bond inter-actions are observed. Relatively strong hydrogen bonds are found between the hydrogen-bond donor (μ(3)-OH) and acceptor (basic N atom of pyridine), with N⋯O distances between 2.586 (10) and 2.628 (10) Å. Inter-cube distances of 9.873 (2) and 12.376 (3) Å are observed.
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79
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Brink A, Visser HG, Roodt A. Unusual ligand coordination effects: crystallographic study of [Re(CO) 3] +complexes. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312095141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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80
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Brink A, Visser HG, Roodt A. 4-Fluoro-2-[(3-methyl-phen-yl)imino-meth-yl]phenol. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o1071. [PMID: 22589937 PMCID: PMC3344028 DOI: 10.1107/s1600536812010513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/09/2012] [Indexed: 11/29/2022]
Abstract
The title compound, C14H12FNO, crystallizes as the trans phenol–imine tautomer. The two benzene rings are essentially coplanar, being inclined to one another by 9.28 (7)°. This is at least in part due to the intramolecular O—H⋯N hydrogen bond between the hydroxy O atom and the imine N atom. The crystal structure is stabilized by an array of weak C—H⋯O and C—H⋯F interactions, which link the molecules into a stable three-dimensional network.
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Brink A, Visser HG, Roodt A. Under the microscope: crystallographic and spectroscopic study of Rh(I) complexes. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311085308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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82
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Visser A, Moore DP, Whitelaw A, Lowman W, Kantor G, Hoosen A, Madhi S, Brink A, van den Bergh D, Devenish L, Moodley P, Apalata T, Duse AG, Gelband H. Part VII. Interventions. S Afr Med J 2011; 101:587-595. [PMID: 21920138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 06/27/2011] [Indexed: 05/31/2023] Open
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83
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Crowther-Gibson P, Govender N, Lewis DA, Bamford C, Brink A, von Gottberg A, Klugman K, du Plessis M, Fali A, Harris B, Keddy K, Botha M. Part IV. Human infections and antibiotic resistance. S Afr Med J 2011; 101:567-578. [PMID: 21920135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 06/24/2011] [Indexed: 05/31/2023] Open
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Bamford C, Brink A, Govender N, Lewis DA, Perovic O, Botha M, Harris B, Keddy KH, Gelband H, Duse AG. Part V. Surveillance activities. S Afr Med J 2011; 101:579-582. [PMID: 21920136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 06/29/2011] [Indexed: 05/31/2023] Open
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85
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Roodt A, Visser HG, Brink A. Structure/reactivity relationships and mechanism from X-ray data and spectroscopic kinetic analysis. CRYSTALLOGR REV 2011. [DOI: 10.1080/0889311x.2011.593032] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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86
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Brink A, Visser HG, Roodt A. Tetraethylammonium dibromidotricarbonyl( o-toluidine)rhenate(I). Acta Crystallogr Sect E Struct Rep Online 2011; 67:m32-3. [PMID: 21522556 PMCID: PMC3050163 DOI: 10.1107/s1600536810050038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 11/30/2010] [Indexed: 11/10/2022]
Abstract
In the title compound, (C8H20N)[ReBr2(C7H9N)(CO)3], the ReI atom is octahedrally surrounded by three carbonyl ligands orientated in a facial arrangement, two bromide ligands and an o-toluidine ligand. The amine lies trans to the carbonyl ligand and is substitutionally disordered over two positions in a 0.66 (1):0.34 (1) ratio. An array of C—H⋯O, C—H⋯Br and N—H⋯Br hydrogen-bonding interactions between the cations and the surrounding rhenate anions stabilize the crystal structure.
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87
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Brink A, Visser HG, Roodt A. Synthesis, crystallographic, and theoretical investigation of fac-[ReI(salen)(CO)3(S)] complexes, salen = monocharged bidentate Schiff-base and S = pyridine, CH3OH. J COORD CHEM 2010. [DOI: 10.1080/00958972.2010.538050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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88
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Brink A, Visser HG, Roodt A. Tetra-ethyl-ammonium (acetyl-acetonato)bromidotricarbonyl-rhenate(I). Acta Crystallogr Sect E Struct Rep Online 2010; 67:m34-5. [PMID: 21522557 PMCID: PMC3050364 DOI: 10.1107/s1600536810050105] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 11/30/2010] [Indexed: 11/15/2022]
Abstract
In the title compound, (C8H20N)[ReBr(C5H7O2)(CO)3], the ReI atom in the rhenate anion is surrounded by three carbonyl ligands orientated in a facial arrangement, a bromide ligand and an acetylacetonate ligand, leading to a distorted octahedral ReC3BrO2 coordination with a O—Re—O bite angle of 85.66 (7)°. An array of C—H⋯O and C—H⋯Br hydrogen-bonding interactions between the cations and the surrounding rhenate anions stabilize the crystal structure.
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89
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Visser HG, Roodt A, Brink A, Kemp G, Schutte M. When crystallography meets kinetics. A study of rhenium(I) tricarbonyls. Acta Crystallogr A 2010. [DOI: 10.1107/s0108767310098144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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90
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Brink A, Roodt A, Visser HG. Crystallographic study of N-O Schiff bidentate rhenium and copper complexes. Acta Crystallogr A 2010. [DOI: 10.1107/s0108767310094122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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91
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van Zeeburg HJT, Huizenga A, Brink A, van den Doel PB, Zhu ZB, McCormick F, Brakenhoff RH, van Beusechem VW. Comparison of oncolytic adenoviruses for selective eradication of oral cancer and pre-cancerous lesions. Gene Ther 2010; 17:1517-24. [PMID: 20686507 DOI: 10.1038/gt.2010.99] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oncolytic adenoviruses are being investigated as potential anti-cancer agents. Selective lytic replication in cancer cells is essential for an effective and safe treatment. In this study, we compared 11 oncolytic adenoviruses in relevant cell cultures to assess their use for treating oral cancer and pre-cancerous lesions. We determined the cytotoxicity of oncolytic adenovirus infection and calculated selectivity indices for cytotoxicity to cancer cells compared with normal oral keratinocytes and fibroblasts. Keratinocytes were very sensitive to wild-type adenovirus serotype 5 (Ad5); 1- to 3-log more than head and neck squamous cell carcinoma (HNSCC) cells. The potencies of oncolytic adenoviruses to kill HNSCC cells within 7 days after infection ranged from approximately 10 times less potent to approximately 10 times more potent than Ad5. The selectivity indices determined on fibroblasts and keratinocytes differed markedly. Two oncolytic adenoviruses were more selective than Ad5 for HNSCC cells compared with fibroblasts; and five viruses showed selective replication on HNSCC cells compared with keratinocytes. Overall, CRAd-S.RGD with E1A driven by the survivin promoter and an infectivity-enhancing capsid modification showed the most favourable cytotoxicity pattern; being very potent in killing HNSCC cells, only slightly less effective than Ad5 in killing pre-neoplastic keratinocytes and the least toxic to normal keratinocytes.
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92
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Brink A, Roodt A, Steyl G, Visser HG. Steric vs. electronic anomaly observed from iodomethane oxidative addition to tertiary phosphine modified rhodium(i) acetylacetonato complexes following progressive phenyl replacement by cyclohexyl [PR3 = PPh3, PPh2Cy, PPhCy2 and PCy3]. Dalton Trans 2010; 39:5572-8. [PMID: 20480082 DOI: 10.1039/b922083f] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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93
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Brink A, Roodt A, Visser HG. 2-(m-Tolyl-imino-meth-yl)phenol. Acta Crystallogr Sect E Struct Rep Online 2009; 65:o3175-6. [PMID: 21578890 PMCID: PMC2972180 DOI: 10.1107/s1600536809049307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 11/18/2009] [Indexed: 11/10/2022]
Abstract
The title compound, C(14)H(13)NO, is non-planar with a dihedral angle of 47.00 (6)° between the planes of the two aromatic rings. Intra-molecular hydrogen bonding is observed between the O-H group and the N atom, resulting in a phenol-imine tautomeric form.
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94
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Schutte M, Visser HG, Brink A. [N,N-Bis(diphenyl-phosphino)propyl-amine-κP,P]bromidotricarbonyl-rhenium(I). Acta Crystallogr Sect E Struct Rep Online 2009; 65:m1575-6. [PMID: 21578608 PMCID: PMC2971857 DOI: 10.1107/s1600536809047242] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 11/09/2009] [Indexed: 05/26/2023]
Abstract
In the title compound, [ReBr(C27H27NP2)(CO)3], the ReI atom is octahedrally surrounded by three carbonyl ligands in a facial arrangement, a bromide ligand and the P,P′-bidentate ligand Bis(diphenylphosphino)propylamine. The compound exhibits substitutional disorder of the bromide ligand and the axial carbonyl ligand, with almost 50% occupancy for both Br amd CO [0.538 (4) and 0.462 (4), respectively]. In addition, the propyl chain on the N atom of the bidentate ligand exhibits a 0.648 (9):0.352 (9) disorder. C—H⋯O and C—H⋯Br hydrogen bonding consolidates the crystal packing.
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95
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Perovic O, Brink A, Richards G, Feldman C. P282 The clinical outcome of infections due to extended spectrum p-lactamase producing (ESBL) Enterobacteriaceae. Int J Antimicrob Agents 2009. [DOI: 10.1016/s0924-8579(09)70501-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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96
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Stopper H, Treutlein AT, Bahner U, Schupp N, Schmid U, Brink A, Perna A, Heidland A. Reduction of the genomic damage level in haemodialysis patients by folic acid and vitamin B12 supplementation. Nephrol Dial Transplant 2008; 23:3272-9. [DOI: 10.1093/ndt/gfn254] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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97
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Fink K, Brink A, Vienken J, Heidland A, Stopper H. Homocysteine exerts genotoxic and antioxidative effects in vitro. Toxicol In Vitro 2007; 21:1402-8. [PMID: 17590309 DOI: 10.1016/j.tiv.2007.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/05/2007] [Accepted: 05/08/2007] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Patients with end-stage renal disease suffer from increased genomic damage and cancer incidence. One possible reason is the accumulation of uremic toxins such as homocysteine (Hcy). Elevated Hcy levels--usually indicative of cardiovascular events--correlated with the genomic damage in cross-sectional studies. Therefore we investigated the genotoxic effects of Hcy in vitro. METHODS To analyse the genomic damage, micronucleus tests and the comet-assay were performed in L5178Y and HL60 cells. Additionally, the influence of Hcy on cell cycle progression, DNA-cytosine-methylation, oxidative stress levels and on the cellular glutathione content were determined. RESULTS Low millimolar concentrations of Hcy-induced micronuclei in both cell lines but did not enhance the DNA damage observed with the comet-assay. Cell cycle progression was inhibited in S-phase, while DNA-cytosine-methylation remained unchanged. Furthermore, Hcy protected cells challenged with H(2)O(2) from oxidative stress. This was accompanied by an increased cellular glutathione level. CONCLUSION Since the genotoxic effect was limited to high Hcy concentrations, a contribution of Hcy to the enhanced genomic damage in end-stage renal disease patients would only be conceivable upon local Hcy accumulation. Whether the detected antioxidant capacity of Hcy is relevant for any situation in patients remains to be elucidated.
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Brink A, Schomaker L, Bulacu M. Towards Explainable Writer Verification and Identification Using Vantage Writers. ACTA ACUST UNITED AC 2007. [DOI: 10.1109/icdar.2007.4377030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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99
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Anderson R, Steel HC, Cockeran R, Smith AM, von Gottberg A, de Gouveia L, Brink A, Klugman KP, Mitchell TJ, Feldman C. Clarithromycin alone and in combination with ceftriaxone inhibits the production of pneumolysin by both macrolide-susceptible and macrolide-resistant strains of Streptococcus pneumoniae. J Antimicrob Chemother 2007; 59:224-9. [PMID: 17218449 DOI: 10.1093/jac/dkl479] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To investigate the effects of clarithromycin (0.01-0.5 mg/L) alone or in combination with ceftriaxone (0.1 and 0.25 mg/L) on pneumolysin production by both macrolide-susceptible and -resistant [2 erm(B) positive and 2 mef(A) positive] strains of Streptococcus pneumoniae. METHODS The bacteria were cultured for 6 h at 37 degrees C/5% CO(2) in tryptone soy broth, washed, enumerated and resuspended to 0.5-3 x 10(8) cfu/mL in tissue culture medium, RPMI 1640. After 16 h of incubation at 37 degrees C / 5% CO(2), pneumolysin was assayed in the bacteria-free supernatants, as well as in lysates, using a functional assay based on the influx of calcium into human neutrophils. RESULTS Exposure of not only macrolide-susceptible strains, but also the macrolide-resistant strains, of S. pneumoniae to sub-MICs of clarithromycin resulted in dose-related inhibition of the pneumolysin production, whereas production of the toxin was unaffected by ceftriaxone. CONCLUSIONS These observations demonstrate that even in the setting of macrolide resistance the production of pneumolysin, a key virulence factor of the pneumococcus, is attenuated by exposure of this microbial pathogen to clarithromycin.
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100
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Brink A, Richards G. A post-authorization survey to evaluate plasma concentrations of teicoplanin in adult hospitalized patients treated for sepsis in Gauteng, South Africa. Crit Care 2007. [PMCID: PMC4095157 DOI: 10.1186/cc5263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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