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Asiri AM, Sobahi TR, Al-Amari MM, Asad M, Zayed MEM, Khan SA. Physicochemical Investigation of HDDP Azomethine Dye as Turn-On Fluorescent Chemosensor for High Selectivity and Sensitivity of Al3+ Ions. J SOLUTION CHEM 2018. [DOI: 10.1007/s10953-018-0805-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Akbar R, Baral M, Kanungo BK. TAME5OX, abiotic siderophore analogue to enterobactin involving 8-hydroxyquinoline subunits: thermodynamic and photophysical studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 142:246-259. [PMID: 25703371 DOI: 10.1016/j.saa.2015.01.104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/12/2015] [Accepted: 01/30/2015] [Indexed: 06/04/2023]
Abstract
The synthesis, thermodynamic and photophysical properties of trivalent metal complexes of biomimetic nonadentate analogue, 5,5'-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1,3-diyl)bis(azanediyl)bis(methylene)diquinolin-8-ol (TAME5OX), have been described. Combination of absorption and emission spectrophotometry, potentiometry, electrospray mass spectrometry, IR, and theoretical investigation were used to fully characterize metal (Fe(+3), Al(+3) and Cr(+3)) chelates of TAME5OX. In solution, TAME5OX forms protonated complexes [M(H3L)](3+) below pH 3.4, which consecutively deprotonates through one to three-proton processes with rise of pH. The formation constants (Logβ11n) of neutral complexes formed at or above physiological pH, have been determined to be 30.18, 23.27 and 22.02 with pM values of 31.16, 18.07 and 18.12 for Fe(+3), Al(+3) and Cr(+3) ions, respectively, calculated at pH 7.4, indicating TAME5OX is a powerful among synthetic metal chelator. The results clearly demonstrate that the ligand in a tripodal orchestration firmly binds these ions over wide pH range and forms distorted octahedral complexes. The binding and the coordination event could be monitored from absorption and fluorescence spectroscopy. The high thermodynamic stability in water at physiological pH of ferric complex of TAME5OX indicates that these complexes are resistant to hydrolysis and therefore are well suited for the development of device for applications as probes. The ligand displays high sensitive fluorescence enhancement to Al(3+) at pH 7.4, in water. Moreover, TAME5OX can distinguish Al(3+) from Fe(3+) and Cr(3+) via two different sensing mechanisms: photoinduced electron transfer (PET) for Al(3+) and internal charge transfer (ICT) for Fe(3+) and Cr(3+). Density functional theory was employed for optimization and evaluation of vibrational modes, NBO analysis, excitation and emission properties of the different species of metal complexes observed by solution studies.
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Affiliation(s)
- Rifat Akbar
- Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal, Punjab 148106, India
| | - Minati Baral
- Department of Chemistry, National Institute of Technology Kurukshetra, Haryana 136119, India
| | - B K Kanungo
- Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal, Punjab 148106, India.
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Olsson U, Billberg A, Sjövall S, Al-Karadaghi S, Hansson M. In vivo and in vitro studies of Bacillus subtilis ferrochelatase mutants suggest substrate channeling in the heme biosynthesis pathway. J Bacteriol 2002; 184:4018-24. [PMID: 12081974 PMCID: PMC135158 DOI: 10.1128/jb.184.14.4018-4024.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2002] [Accepted: 04/26/2002] [Indexed: 11/20/2022] Open
Abstract
Ferrochelatase (EC 4.99.1.1) catalyzes the last reaction in the heme biosynthetic pathway. The enzyme was studied in the bacterium Bacillus subtilis, for which the ferrochelatase three-dimensional structure is known. Two conserved amino acid residues, S54 and Q63, were changed to alanine by site-directed mutagenesis in order to detect any function they might have. The effects of these changes were studied in vivo and in vitro. S54 and Q63 are both located at helix alpha3. The functional group of S54 points out from the enzyme, while Q63 is located in the interior of the structure. None of these residues interact with any other amino acid residues in the ferrochelatase and their function is not understood from the three-dimensional structure. The exchange S54A, but not Q63A, reduced the growth rate of B. subtilis and resulted in the accumulation of coproporphyrin III in the growth medium. This was in contrast to the in vitro activity measurements with the purified enzymes. The ferrochelatase with the exchange S54A was as active as wild-type ferrochelatase, whereas the exchange Q63A caused a 16-fold reduction in V(max). The function of Q63 remains unclear, but it is suggested that S54 is involved in substrate reception or delivery of the enzymatic product.
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Affiliation(s)
- Ulf Olsson
- Department of Biochemistry, Lund University, Sweden
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Dutta DP, Jain VK, Knoedler A, Kaim W. Dithiocarbamates of gallium(III) and indium(III): syntheses, spectroscopy, and structures. Polyhedron 2002. [DOI: 10.1016/s0277-5387(01)00990-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Affiliation(s)
- H Sun
- Department of Chemistry, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, U.K., and Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
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Sanchiz J, Domínguez S, Mederos A, Brito F, Arrieta JM. Tetramethyl Carboxylic Acids Derived from o-Phenylenediamines as Sequestering Agents for Iron(III): Thermodynamic Studies. X-ray Crystal Structure of Sodium Aqua(4-chloro-1,2-phenylenediamine-N,N,N‘,N‘-tetraacetato)ferrate(III)−Water (1/1.5). Inorg Chem 1997. [DOI: 10.1021/ic9700617] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joaquín Sanchiz
- Department of Inorganic Chemistry, University of La Laguna, 38204 La Laguna, Tenerife, Canary Islands, Spain; Laboratory of Equilibria in Solution, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela; and Department of Inorganic Chemistry, University of the País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Sixto Domínguez
- Department of Inorganic Chemistry, University of La Laguna, 38204 La Laguna, Tenerife, Canary Islands, Spain; Laboratory of Equilibria in Solution, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela; and Department of Inorganic Chemistry, University of the País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Alfredo Mederos
- Department of Inorganic Chemistry, University of La Laguna, 38204 La Laguna, Tenerife, Canary Islands, Spain; Laboratory of Equilibria in Solution, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela; and Department of Inorganic Chemistry, University of the País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Felipe Brito
- Department of Inorganic Chemistry, University of La Laguna, 38204 La Laguna, Tenerife, Canary Islands, Spain; Laboratory of Equilibria in Solution, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela; and Department of Inorganic Chemistry, University of the País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Juan Manuel Arrieta
- Department of Inorganic Chemistry, University of La Laguna, 38204 La Laguna, Tenerife, Canary Islands, Spain; Laboratory of Equilibria in Solution, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela; and Department of Inorganic Chemistry, University of the País Vasco, Apartado 644, E-48080 Bilbao, Spain
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Aime S, Bergamasco B, Biglino D, Digilio G, Fasano M, Giamello E, Lopiano L. EPR investigations of the iron domain in neuromelanin. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1361:49-58. [PMID: 9247089 DOI: 10.1016/s0925-4439(97)00014-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The interactions between iron and neuromelanin (NM) have been studied by means of EPR spectroscopy. The variable temperature EPR spectral features of a specimen of NM extracted from normal human midbrains clearly indicate that iron is present as polynuclear oxy-hydroxy ferric aggregates as well as isolated Fe(III) centres. Ferric oxy-hydroxy phases are typical of the iron storage proteins ferritin and hemosiderin, but the comparison of the variable temperature EPR spectra of ferritin and NM highlights significant differences between the two iron(III)oxy-hydroxy domains. Moreover, further investigations on melanin models synthesised in the presence of either ferritin or a ferric salt as iron sources suggest that the same pathway of formation and inclusion of the polynuclear iron oxide is operating in NM and in the model systems, whatever is the source of iron.
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Affiliation(s)
- S Aime
- Department of Chemistry IFM, University of Turin, Italy.
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Heath SL, Jordan PA, Johnson ID, Moore GR, Powell AK, Helliwell M. Comparative X-ray and 27Al NMR spectroscopic studies of the speciation of aluminum in aqueous systems: Al(III) complexes of N(CH2CO2H)2(CH2CH2OH). J Inorg Biochem 1995. [DOI: 10.1016/0162-0134(94)00064-h] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Götz ME, Künig G, Riederer P, Youdim MB. Oxidative stress: free radical production in neural degeneration. Pharmacol Ther 1994; 63:37-122. [PMID: 7972344 DOI: 10.1016/0163-7258(94)90055-8] [Citation(s) in RCA: 349] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It is not yet established whether oxidative stress is a major cause of cell death or simply a consequence of an unknown pathogenetic factor. Concerning chronic diseases, as Parkinson's and Alzheimer's disease are assumed to be, it is possible that a gradual impairment of cellular defense mechanisms leads to cell damage because of toxic substances being increasingly formed during normal cellular metabolism. This point of view brings into consideration the possibility that, besides exogenous factors, the pathogenetic process of neurodegeration is triggered by endogenous mechanisms, either by an endogenous toxin or by inherited metabolic disorders, which become progressively more evident with aging. In the following review, we focus on the oxidative stress theory of neurodegeneration, on excitotoxin-induced cell damage and on impairment of mitochondrial function as three major noxae being the most likely causes of cell death either independently or in connection with each other. First, having discussed clinical, pathophysiological, pathological and biochemical features of movement and cognitive disorders, we discuss the common features of these biochemical theories of neurodegeneration separately. Second, we attempt to evaluate possible biochemical links between them and third, we discuss experimental findings that confirm or rule out the involvement of any of these theories in neurodegeneration. Finally, we report some therapeutic strategies evolved from each of these theories.
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Affiliation(s)
- M E Götz
- Department of Psychiatry, University of Würzburg, Germany
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