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Lin L, Zhu S, Chen Y, He X, Zhou R, Zhang J. Synthesis and characterization of bagasse cellulose-based quaternary ammonium peroxyphosphotungstate and their catalytic properties for cyclohexene oxidation in the absence of any solvent. Int J Biol Macromol 2024; 274:133549. [PMID: 38971653 DOI: 10.1016/j.ijbiomac.2024.133549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 06/17/2024] [Accepted: 06/27/2024] [Indexed: 07/08/2024]
Abstract
Bagasse cellulose, an industrial waste byproduct of sugar production, was demonstrated to be a viable solid support for a solid-phase ionic oxidation catalyst enabling organic solvent-free aqueous reaction conditions and facile catalyst recovery. Bagasse cellulose-supported quaternary ammonium peroxyphosphotungstate was synthesized from bagasse cellulose-supported quaternary ammonium chloride, phosphotungstic acid, and hydrogen peroxide. The chemical structure of this material was characterized by SEM, XRD, FT-IR, XPS, and 13C NMR, revealing stability of the cellulose matrix to the catalyst loading conditions and effective dispersion of the acicular catalyst crystals throughout the matrix. High catalytic activity of this synthetic complex was demonstrated in the oxidation of cyclohexene to 1,2-cyclohexanediol with hydrogen peroxide in the absence of solvent. Optimized conditions providing trans-1,2-cyclohexanediol with 86.2 % selectivity were 12 wt% catalyst and 4 mL/g 30 % H2O2 (vs. cyclohexene) at 50 °C for 10 h.
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Affiliation(s)
- Lishan Lin
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China
| | - Shouji Zhu
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China.
| | - Yingyi Chen
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China
| | - Xinmei He
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China
| | - Ruoxin Zhou
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China
| | - Jiayi Zhang
- College of chemical and environmental Engineering, Hanshan Normal University, Guangdong Province, Chaozhou 521041, China; Key laboratory of Resources Environmental and Green Low Carbon Processes in East Guangdong, Guangdong Province, Chaozhou 521041, China
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2
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Kostova I. Therapeutic and Diagnostic Agents based on Bioactive Endogenous and Exogenous Coordination Compounds. Curr Med Chem 2024; 31:358-386. [PMID: 36944628 DOI: 10.2174/0929867330666230321110018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/25/2023] [Accepted: 02/10/2023] [Indexed: 03/23/2023]
Abstract
Metal-based coordination compounds have very special place in bioinorganic chemistry because of their different structural arrangements and significant application in medicine. Rapid progress in this field increasingly enables the targeted design and synthesis of metal-based pharmaceutical agents that fulfill valuable roles as diagnostic or therapeutic agents. Various coordination compounds have important biological functions, both those initially present in the body (endogenous) and those entering the organisms from the external environment (exogenous): vitamins, drugs, toxic substances, etc. In the therapeutic and diagnostic practice, both the essential for all living organisms and the trace metals are used in metal-containing coordination compounds. In the current review, the most important functional biologically active compounds were classified group by group according to the position of the elements in the periodic table.
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Affiliation(s)
- Irena Kostova
- Department of Chemistry, Faculty of Pharmacy, Medical University-Sofia, 2 Dunav St., Sofia 1000, Bulgaria
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3
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Stereoselective formation and spectroscopic studies of [Cr(edda or eddp)(N N)]-type complexes (edda = ethylenediamine-N,N′-diacetate; eddp = ethylenediamine-N,N′-dipropionate). Polyhedron 2019. [DOI: 10.1016/j.poly.2018.12.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Mangiameli MF, Bellú S, Pérez Mora B, Sala L, Mamana N. Quinic acid and hypervalent chromium: a spectroscopic and kinetic study. RSC Adv 2018; 8:29356-29367. [PMID: 35547999 PMCID: PMC9084479 DOI: 10.1039/c8ra03809k] [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: 05/03/2018] [Accepted: 07/09/2018] [Indexed: 11/30/2022] Open
Abstract
The redox reaction between an excess of quinic acid (QA) and CrVI involves the formation of intermediates, namely, CrIV and CrV species, which in turn react with the organic substrates. As observed with other substrates that have already been studied, CrIV does not accumulate during this reaction because of the rate of the reaction. Its rate of disappearance is several times higher than that of the reaction of CrVI or CrV with QA. Kinetic studies indicate that the redox reaction proceeds via a combined mechanism that involves the pathways CrVI → CrIV → CrII and CrVI → CrIV → CrIII, which is supported by the observation of superoxo-CrIII (CrO22+) ions, free radicals, and oxo-CrV species as intermediates and the detection of CrVI ester species. The present study reports the complete rate laws for the QA/chromium redox reaction. The redox reaction between an excess of quinic acid (QA) and CrVI involves the formation of intermediates, namely, CrIV and CrV species, which in turn react with the organic substrates.![]()
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Affiliation(s)
- María Florencia Mangiameli
- Área Química General e Inorgánica
- Departamento de Química-Física
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- S2002LRK Rosario
| | - Sebastián Bellú
- Área Química General e Inorgánica
- Departamento de Química-Física
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- S2002LRK Rosario
| | - Bárbara Pérez Mora
- Área Química General e Inorgánica
- Departamento de Química-Física
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- S2002LRK Rosario
| | - Luis Sala
- Área Química General e Inorgánica
- Departamento de Química-Física
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- S2002LRK Rosario
| | - Nadia Mamana
- Área Química General e Inorgánica
- Departamento de Química-Física
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- S2002LRK Rosario
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5
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Nieczyporowska E, Kita E, Katafias A, Bajek A, Kaźmierski Ł. Oxidation in vitro of chromium(III) dietary supplements mer-[Cr(pic)3] and trans(S,S)-[Cr(Cys)2]− by hydrogen peroxide. TRANSIT METAL CHEM 2017. [DOI: 10.1007/s11243-017-0168-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Spectroscopic characterization of genotoxic chromium(V) peptide complexes: Oxidation of Chromium(III) triglycine, tetraglycine and pentaglycine complexes. J Inorg Biochem 2016; 162:227-237. [DOI: 10.1016/j.jinorgbio.2016.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 06/07/2016] [Accepted: 06/14/2016] [Indexed: 11/23/2022]
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7
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Van Doorslaer S, Beirinckx Q, Nys K, Mangiameli MF, Cuypers B, Callens F, Vrielinck H, González JC. EPR and DFT analysis of biologically relevant chromium(V) complexes with d-glucitol and d-glucose. J Inorg Biochem 2016; 162:216-226. [PMID: 27460210 DOI: 10.1016/j.jinorgbio.2016.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 07/15/2016] [Accepted: 07/18/2016] [Indexed: 10/21/2022]
Abstract
1,2-diolato ligands, such as carbohydrates and glycoproteins, tend to stabilize chromium(V), thus forming important intermediates that have been implicated in the genotoxicity of Cr(VI). Since many years, room-temperature continuous-wave electron paramagnetic resonance (EPR) at X-band microwave frequencies has been used as a standard characterization tool to study chromium(V) intermediates formed during the reduction of Cr(VI) in the presence of biomolecules. In this work, the added value is tested of using a combination of pulsed and high-field EPR techniques with density functional theory computations to unravel the nature of Cr(V) complexes with biologically relevant chelators, such as carbohydrates. The study focuses on the oxidochromium(V) complexes formed during reduction of potassium dichromate with glutathione in the presence of the monosaccharide d-glucose or the polyalcohol d-glucitol. It is shown that although the presence of a multitude of Cr(V) intermediates may hamper a complete structural determination, the combined EPR and DFT approach reveals unambiguously the effect of freezing on the location of the counterions, the gradual replacement of water ligands by the diols, and the preference of Cr(V) to bind certain conformers.
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Affiliation(s)
- Sabine Van Doorslaer
- University of Antwerp, Department of Physics, Universiteitsplein 1, B-2610 Antwerp, Belgium.
| | - Quinten Beirinckx
- University of Antwerp, Department of Physics, Universiteitsplein 1, B-2610 Antwerp, Belgium.
| | - Kevin Nys
- University of Antwerp, Department of Physics, Universiteitsplein 1, B-2610 Antwerp, Belgium.
| | - María Florencia Mangiameli
- Universidad National de Rosario, Departamento de Químico Física - Área Química General, Facultad de Ciencias Bioquímicas y Farmacéuticas, IQUIR-CONICET, Suipacha 531, Rosario, Santa Fe, Argentina.
| | - Bert Cuypers
- University of Antwerp, Department of Physics, Universiteitsplein 1, B-2610 Antwerp, Belgium.
| | - Freddy Callens
- Ghent University, Dept. of Solid State Sciences, Krijgslaan 281-S1, B-9000 Ghent, Belgium.
| | - Henk Vrielinck
- Ghent University, Dept. of Solid State Sciences, Krijgslaan 281-S1, B-9000 Ghent, Belgium.
| | - Juan Carlos González
- University of Antwerp, Department of Physics, Universiteitsplein 1, B-2610 Antwerp, Belgium; Universidad National de Rosario, Departamento de Químico Física - Área Química General, Facultad de Ciencias Bioquímicas y Farmacéuticas, IQUIR-CONICET, Suipacha 531, Rosario, Santa Fe, Argentina.
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8
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A Abdel-Rahman E, Mahmoud AM, Khalifa AM, Ali SS. Physiological and pathophysiological reactive oxygen species as probed by EPR spectroscopy: the underutilized research window on muscle ageing. J Physiol 2016; 594:4591-613. [PMID: 26801204 DOI: 10.1113/jp271471] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/04/2015] [Indexed: 12/18/2022] Open
Abstract
Reactive oxygen and nitrogen species (ROS and RNS) play crucial roles in triggering, mediating and regulating physiological and pathophysiological signal transduction pathways within the cell. Within the cell, ROS efflux is firmly controlled both spatially and temporally, making the study of ROS dynamics a challenging task. Different approaches have been developed for ROS assessment; however, many of these assays are not capable of direct identification or determination of subcellular localization of different ROS. Here we highlight electron paramagnetic resonance (EPR) spectroscopy as a powerful technique that is uniquely capable of addressing questions on ROS dynamics in different biological specimens and cellular compartments. Due to their critical importance in muscle functions and dysfunction, we discuss in some detail spin trapping of various ROS and focus on EPR detection of nitric oxide before highlighting how EPR can be utilized to probe biophysical characteristics of the environment surrounding a given stable radical. Despite the demonstrated ability of EPR spectroscopy to provide unique information on the identity, quantity, dynamics and environment of radical species, its applications in the field of muscle physiology, fatiguing and ageing are disproportionately infrequent. While reviewing the limited examples of successful EPR applications in muscle biology we conclude that the field would greatly benefit from more studies exploring ROS sources and kinetics by spin trapping, protein dynamics by site-directed spin labelling, and membrane dynamics and global redox changes by spin probing EPR approaches.
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Affiliation(s)
- Engy A Abdel-Rahman
- Center for Aging and Associated Diseases, Helmy Institute of Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Ali M Mahmoud
- Center for Aging and Associated Diseases, Helmy Institute of Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Abdulrahman M Khalifa
- Center for Aging and Associated Diseases, Helmy Institute of Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Sameh S Ali
- Center for Aging and Associated Diseases, Helmy Institute of Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
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9
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Pang ZB, Li HF, Wang LL. Synthesis of novel cyclohexanediol-derived chiral phosphite ligands and their application in the Cu-catalyzed conjugate addition of organozinc to cyclic enones. CHINESE CHEM LETT 2016. [DOI: 10.1016/j.cclet.2015.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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10
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Wu LE, Levina A, Harris HH, Cai Z, Lai B, Vogt S, James DE, Lay PA. Carcinogenic Chromium(VI) Compounds Formed by Intracellular Oxidation of Chromium(III) Dietary Supplements by Adipocytes. Angew Chem Int Ed Engl 2015; 55:1742-5. [PMID: 26696553 DOI: 10.1002/anie.201509065] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Indexed: 12/31/2022]
Abstract
Chromium(III) nutritional supplements are widely consumed for their purported antidiabetic activities. X-ray fluorescence microscopy (XFM) and X-ray absorption near-edge structure (XANES) studies have now shown that non-toxic doses of [Cr3 O(OCOEt)6 (OH2 )3 ](+) (A), a prospective antidiabetic drug that undergoes similar H2 O2 induced oxidation reactions in the blood as other Cr supplements, was also oxidized to carcinogenic Cr(VI) and Cr(V) in living cells. Single adipocytes treated with A had approximately 1 μm large Cr hotspots containing Cr(III) , Cr(V) , and Cr(VI) (primarily Cr(VI) thiolates) species. These results strongly support the hypothesis that the antidiabetic activity of Cr(III) and the carcinogenicity of Cr(VI) compounds arise from similar mechanisms involving highly reactive Cr(VI) and Cr(V) intermediates, and highlight concerns over the safety of Cr(III) nutritional supplements.
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Affiliation(s)
- Lindsay E Wu
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.,Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,School of Medical Sciences, UNSW Australia, NSW, 2052, Australia
| | - Aviva Levina
- School of Chemistry, The University of Sydney, NSW, 2006, Australia
| | - Hugh H Harris
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.,School of Chemistry and Physics, The University of Adelaide, SA, 5005, Australia
| | - Zhonghou Cai
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Barry Lai
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Stefan Vogt
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - David E James
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,Charles Perkins Centre, The University of Sydney, NSW, 2006, Australia
| | - Peter A Lay
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.
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11
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Wu LE, Levina A, Harris HH, Cai Z, Lai B, Vogt S, James DE, Lay PA. Carcinogenic Chromium(VI) Compounds Formed by Intracellular Oxidation of Chromium(III) Dietary Supplements by Adipocytes. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lindsay E. Wu
- School of Chemistry; The University of Sydney; NSW 2006 Australia
- Garvan Institute of Medical Research; 384 Victoria St Darlinghurst NSW 2010 Australia
- School of Medical Sciences; UNSW Australia; NSW 2052 Australia
| | - Aviva Levina
- School of Chemistry; The University of Sydney; NSW 2006 Australia
| | - Hugh H. Harris
- School of Chemistry; The University of Sydney; NSW 2006 Australia
- School of Chemistry and Physics; The University of Adelaide; SA 5005 Australia
| | - Zhonghou Cai
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - Barry Lai
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - Stefan Vogt
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - David E. James
- Garvan Institute of Medical Research; 384 Victoria St Darlinghurst NSW 2010 Australia
- Charles Perkins Centre; The University of Sydney; NSW 2006 Australia
| | - Peter A. Lay
- School of Chemistry; The University of Sydney; NSW 2006 Australia
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12
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Mangiameli MF, González JC, Bellú S, Bertoni F, Sala LF. Redox and complexation chemistry of the CrVI/CrV-D-glucaric acid system. Dalton Trans 2015; 43:9242-54. [PMID: 24816781 DOI: 10.1039/c4dt00717d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
When an excess of uronic acid over Cr(VI) is used, the oxidation of D-glucaric acid (Glucar) by Cr(VI) yields D-arabinaric acid, CO2 and Cr(III)-Glucar complex as final redox products. The redox reaction involves the formation of intermediate Cr(IV) and Cr(V) species. The reaction rate increases with [H(+)] and [substrate]. The experimental results indicated that Cr(IV) and Cr(V) are very reactive intermediates since their disappearance rates are much faster than Cr(VI). Cr(IV) and Cr(V) intermediates are involved in fast steps and do not accumulate in the redox reaction of the mixture Cr(VI)-Glucar. Kinetic studies show that the redox reaction between Glucar and Cr(VI) proceeds through a mechanism combining one- and two-electron pathways: Cr(VI) → Cr(IV) → Cr(II) and Cr(VI) → Cr(IV) → Cr(III). After the redox reaction, results show a slow hydrolysis of the Cr(III)-Glucar complex into [Cr(OH2)6](3+). The proposed mechanism is supported by the observation of free radicals, CrO2(2+) (superoxo-Cr(III) ion) and oxo-Cr(V)-Glucar species as reaction intermediates. The continuous-wave electron paramagnetic resonance, CW-EPR, spectra show that five-coordinate oxo-Cr(V) bischelates are formed at pH ≤ 4 with the aldaric acid bound to oxo-Cr(V) through the carboxylate and the α-OH group. A different oxo-Cr(V) species with Glucar was detected at pH 6.0. The high g(iso) value for the last species suggests a mixed coordination species, a five-coordinated oxo-Cr(V) bischelate with one molecule of Glucar acting as a bi-dentate ligand, using the 2-hydroxycarboxylate group, and a second molecule of Glucar with any vic-diolate sites. At pH 7.5 only a very weak EPR signal was observed, which may point to instability of these complexes. This behaviour contrasts with oxo-Cr(V)-uronic species, and must thus be related to the Glucar acyclic structure. In vitro, our studies on the chemistry of oxo-Cr(V)-Glucar complexes can provide information on the nature of the species that are likely to be stabilized in vivo.
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Affiliation(s)
- María Florencia Mangiameli
- Área Química General, Departamento de Químico-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, UNR, Instituto de Química de Rosario-CONICET, Suipacha 531, S2002LRK, Rosario, Santa Fe, Argentina.
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13
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Tziouris PA, Tsiafoulis CG, Vlasiou M, Miras HN, Sigalas MP, Keramidas AD, Kabanos TA. Interaction of chromium(III) with a N,N'-disubstituted hydroxylamine-(diamido) ligand: a combined experimental and theoretical study. Inorg Chem 2014; 53:11404-14. [PMID: 25329981 DOI: 10.1021/ic501778d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of hydroxylamine hydrochloride with prop-2-enamide in dichloromethane in the presence of triethylamine resulted in the isolation of the N,N'-disubstituted hydroxylamine-(diamido) ligand, 3,3'-(hydroxyazanediyl)dipropanamide (Hhydia). The ligand Hhydia was characterized by multinuclear NMR, high-resolution electrospray ionization mass spectrometry (ESI-MS), and X-ray structure analysis. Interaction of Hhydia with trans-[Cr(III)Cl2(H2O)4]Cl·2H2O in ethanol yields the ionization isomers [Cr(III)(Hhydia)2]Cl3·2H2O(1·2H2O) and cis/trans-[Cr(III)Cl2(Hhydia)2]Cl·2H2O (2·2H2O). The X-ray structure analysis of 1 revealed that the chromium atom in [Cr(III)(Hhydia)2](3+) is bonded to two neutral tridentate O,N,O-Hhydia ligands. The twist angle, θ, in [Cr(III)(Hhydia)2](3+) is 54.5(6)(0), that is, very close to an ideal octahedron. The intramolecular hydrogen bonds developed between the N-OH group of the first ligand and the amidic oxygen atom of the second ligand and vice versa contribute to the overall stability of the cation [Cr(III)(Hhydia)2](3+). The reaction rate constant of the formation of Cr(III) complexes 1·2H2O and 2·2H2O was found to be 8.7(±0.8) × 10(-5) M(-1) s(-1) at 25 °C in methyl alcohol and follows a first-order law kinetics based on the biologically relevant ligand Hhydia. The reaction rate constant is considerably faster in comparison with the corresponding water exchange rate constant for the hydrated chromium(III). The modification of the kinetics is of fundamental importance for the chromium(III) chemistry in biological systems. Ultraviolet-visible and electron paramagnetic resonance studies, both in solution and in the solid state, ESI-MS, and conductivity measurements support the fact that, irrespective of the solvent used in the interaction of Hhydia with trans-[Cr(III)Cl2(H2O)4]Cl·2H2O, the ionization isomers[Cr(III)(Hhydia)2]Cl3·2H2O (1·2H2O) and cis/trans-[Cr(III)Cl2(Hhydia)2]Cl·2H2O (2·2H2O) are produced.The reaction medium affects only the relevant percentage of the isomers in the solid state. The thermodynamic stability of the ionization isomers 1·2H2O and cis/trans-2·2H2O, their molecular structures as well as the vibrational spectra and the energetics of the Cr(III)- Hhydia/hydia(-) were studied by means of density functional theory calculations and found to be in excellent agreement with our experimental observations.
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Affiliation(s)
- Petros A Tziouris
- Section of Inorganic and Analytical Chemistry, Department of Chemistry and #NMR Center, University of Ioannina , Ioannina 45110, Greece
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14
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Pham THN, Aitken JB, Levina A, Lay PA. Solid-State Structural Studies of Chromium(III) Nicotinato Nutritional Supplements. Inorg Chem 2014; 53:10685-94. [DOI: 10.1021/ic501818w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T. H. Nguyen Pham
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jade B. Aitken
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
- Australian Synchrotron, Clayton, Victoria 3168, Australia
- Institute of Materials Structure Science, KEK, Tsukuba, Ibaraki 305-0801, Japan
| | - Aviva Levina
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Peter A. Lay
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
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15
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Abstract
Chromium is ubiquitous in the environment as Cr(III) and Cr(VI) oxidation states, which interconvert under environmentally and biologically relevant conditions (although Cr(III) usually predominates). While Cr(VI) is an established human carcinogen and a major occupational and environmental hazard, Cr(III) has long been regarded as an essential human micronutrient, although recent literature has cast serious doubts on the validity of this postulate. Despite five decades of research, no functional Cr-containing enzymes or cofactors have been characterized conclusively, and several hypotheses on their possible structures have been refuted. Gastrointestinal absorption pathways for both Cr(III) and Cr(VI) are apparent and whole-blood speciation can involve Cr(VI) uptake and reduction by red blood cells, as well as Cr(III) binding to both proteins and low-molecular-mass ligands in the plasma. DNA-damaging effects of Cr(VI) and anti-diabetic activities of Cr(III) are likely to arise from common mechanistic pathways that involve reactive Cr(VI/V/IV) intermediates and kinetically inert Cr(III)-protein and Cr(III)-DNA adducts. Both Cr(III) and Cr(VI) are toxic to plants and microorganisms, particularly Cr(VI) due to its higher bioavailability and redox chemistry. Some bacteria reduce Cr(VI) to Cr(III) without the formation of toxic Cr(V) intermediates and these bacteria are being considered for use in the bioremediation of Cr(VI)-polluted environments.
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Affiliation(s)
- Peter A. Lay
- School of Chemistry, The University of Sydney Sydney NSW 2006 Australia
| | - Aviva Levina
- School of Chemistry, The University of Sydney Sydney NSW 2006 Australia
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