1
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Murke S, Chen W, Pezzotti S, Havenith M. Tuning Acid-Base Chemistry at an Electrified Gold/Water Interface. J Am Chem Soc 2024; 146:12423-12430. [PMID: 38599583 PMCID: PMC11082902 DOI: 10.1021/jacs.3c13633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 04/12/2024]
Abstract
Acid-base reactions are ubiquitous in solution chemistry, as well as in electrochemistry. However, macroscopic concepts derived in solutions, such as pKa and pH, differ significantly at electrified metal-aqueous interfaces due to specific solvation and applied voltage. Here, we measure the pKa values of an amino acid, glycine, at a gold/water interface under a varying applied voltage by means of spectroscopic titration. With the help of simulations, we propose a general model to understand potential-dependent shifts in pKa values in terms of local hydrophobicity and electric fields. These parameters can be tuned by adjusting the metal surface and applied voltage, respectively, offering promising, but still unexplored, paths to regulate reactivity. Our results change the focus with respect to common interpretations based on, for example, apparent local pH effects and open interesting perspectives for electrochemical reaction steering.
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Affiliation(s)
| | | | | | - Martina Havenith
- Department of Physical Chemistry
II, Ruhr University Bochum, D-44801 Bochum, Germany
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2
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Mahato M, Maiti A, Ahamed S, Rajbanshi M, Lama S, Das SK. Acid-base equilibrium in non-aqueous medium: colorimetric visualization, estimation of acidity constants and construction of molecular logic gates. RSC Adv 2024; 14:3480-3488. [PMID: 38259994 PMCID: PMC10801445 DOI: 10.1039/d3ra04696f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
A reversible acid-base probe, (N1E, N4E)-N1, N4-bis((Z)-3-(4-(dimethylamino)phenyl)allylidene)benzene-1,4-diamine (MM1), is introduced for the colorimetric visualization of acid-base equilibria in non-aqueous media. MM1 displays reversible acidochromic behavior, showing exciting colorimetric change varying from weak to strong acid. Also, we have fabricated a colorimetric paper strip-based test kit to visualize acid-base equilibria. A dipstick experiment has been demonstrated to visualize the acid-base equilibria in the gaseous state. This acid-base probe has also been employed to estimate the pKa values of several acidic compounds in a non-aqueous medium using overlapping indicator methods. Based on reversible acidochromic UV-visible absorption spectral and colorimetric behavior, we have constructed a reconfigurable dual input and dual output combinational logic circuit and set-reset memorized device employing acid and base as chemically encoded inputs and corresponding optical outputs. The current report evokes a new protocol for developing various reversible acidochromic probes and its implication for constructing opto-chemical molecular logic gates and estimating the acid dissociation constants of various acidic compounds in non-aqueous media.
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Affiliation(s)
- Manas Mahato
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
| | - Arpita Maiti
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
| | - Sabbir Ahamed
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
| | - Madan Rajbanshi
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
| | - Shubham Lama
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
| | - Sudhir Kumar Das
- Department of Chemistry, University of North Bengal Darjeeling West Bengal 734013 India
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3
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Chowdhury SN, Biswas S, Das S, Biswas AN. Kinetic and mechanistic investigations of dioxygen reduction by a molecular Cu(II) catalyst bearing a pentadentate amidate ligand. Dalton Trans 2023; 52:11581-11590. [PMID: 37548356 DOI: 10.1039/d3dt02194g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
A pentadentate Cu(II) complex, [CuII(dpaq)](ClO4) (1), featuring a redox active ligand, H-dpaq (H-dpaq = 2-[bis(pyridine-2-ylmethyl)]amino-N-quinolin-8-yl-acetamidate), catalyses four-electron reduction of dioxygen by decamethylferrocene (Fc*) in the presence of trifluoroacetic acid (CF3COOH) in acetone at 298 K. No catalytic oxygen reduction was observed in the presence of stronger Brønsted acids than CF3COOH, such as perchloric acid (HClO4) or trifluoromethanesulphonic acid (HOTf). In contrast, facile catalytic reduction of O2 occurs by Fc* with 1 and HClO4 or HOTf in dimethylformamide (DMF). The use of CF3COOH as the proton source in DMF results in the suppression of O2 reduction under otherwise identical reaction conditions. While the O2 reduction reactions in DMF are linearly dependent on the pKa of Brønsted acids, the acid dependence on catalytic O2-reduction reactivity by 1 in acetone showed complete reversal. Cyclic voltammetry studies using p-chloranil as the probe substrates in the presence of acids in the solvents reveal that the strengths of the protonic acids increase significantly in acetone compared to that in DMF. The amidate-N in [CuII(dpaq)](ClO4) (1) undergoes protonation in the presence of HClO4 or HOTf in DMF to form [CuII(H-dpaq)]2+ (1-H+), but not in the presence of CF3COOH. Enhanced acid strength of CF3COOH in acetone, however, effectively protonates 1 and triggers O2 reduction. Protonation of 1 with HClO4 or HOTf in acetone results in the change of its coordination environment, and this protonated species does not trigger O2 reduction. Detailed kinetic studies indicate that 1-H+ undergoes reduction by two-electrons and the reduced species binds O2 to form a Cu(II)-superoxo intermediate. This is followed by a rate-determining proton-coupled electron-transfer (PCET) reduction to generate the Cu(II)-hydroperoxo intermediate. While catalytic O2 reduction in acetone occurs predominantly via a 4e-/4H+ pathway, product selectivity (H2O vs. H2O2) in DMF depends upon the concentration of the reductant (Fc*). While dioxygen reduction to H2O2 is favoured at low [Fc*], mechanistic studies suggest that O2 reduction with high [Fc*] proceeds via a [2e- + 2e-] mechanism, where the released H2O2 during catalysis is further reduced to water.
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Affiliation(s)
- Srijan Narayan Chowdhury
- Department of Chemistry, National Institute of Technology Sikkim, Ravangla, South Sikkim 737139, India.
| | - Sachidulal Biswas
- Department of Chemistry, National Institute of Technology Sikkim, Ravangla, South Sikkim 737139, India.
| | - Saikat Das
- Department of Chemistry, National Institute of Technology Sikkim, Ravangla, South Sikkim 737139, India.
| | - Achintesh N Biswas
- Department of Chemistry, National Institute of Technology Sikkim, Ravangla, South Sikkim 737139, India.
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4
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Han GE, Priefer R. A systematic review of various pK a determination techniques. Int J Pharm 2023; 635:122783. [PMID: 36858133 DOI: 10.1016/j.ijpharm.2023.122783] [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: 11/26/2022] [Revised: 02/19/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023]
Abstract
The pKa values of functional groups is crucial in determining the pharmacokinetic properties of a drug, affecting its absorption and thus bioavailability. This physicochemical property is also vital for the designing of drug excipients and vehicles. There are currently 13 known methods of determining a pKa value, namely: potentiometric titration, spectrometry, fluorometry, NMR, HPLC, conductometry, electrophoresis, voltammetry, solubility, partition coefficient, calorimetry, computational, and surface tension. Some of these techniques are more widely utilized and well-established compared to others, with each having their inherent advantages and disadvantages. This review discusses each of the aforementioned techniques with emphasis on their pros and cons.
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Affiliation(s)
- Gi Eun Han
- Massachusetts College of Pharmacy and Health Sciences, Boston, MA, United States
| | - Ronny Priefer
- Massachusetts College of Pharmacy and Health Sciences, Boston, MA, United States.
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5
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Onyido I, Obumselu OF, Egwuatu CI, Okoye NH. Solvent and solvation effects on reactivities and mechanisms of phospho group transfers from phosphate and phosphinate esters to nucleophiles. Front Chem 2023; 11:1176746. [PMID: 37179775 PMCID: PMC10172589 DOI: 10.3389/fchem.2023.1176746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/03/2023] [Indexed: 05/15/2023] Open
Abstract
Organophosphorus esters fulfil many industrial, agricultural, and household roles. Nature has deployed phosphates and their related anhydrides as energy carriers and reservoirs, as constituents of genetic materials in the form of DNA and RNA, and as intermediates in key biochemical conversions. The transfer of the phosphoryl (PO3) group is thus a ubiquitous biological process that is involved in a variety of transformations at the cellular level such as bioenergy and signals transductions. Significant attention has been paid in the last seven decades to understanding the mechanisms of uncatalyzed (solution) chemistry of the phospho group transfer because of the notion that enzymes convert the dissociative transition state structures in the uncatalyzed reactions into associative ones in the biological processes. In this regard, it has also been proposed that the rate enhancements enacted by enzymes result from the desolvation of the ground state in the hydrophobic active site environments, although theoretical calculations seem to disagree with this position. As a result, some attention has been paid to the study of the effects of solvent change, from water to less polar solvents, in uncatalyzed phospho transfer reactions. Such changes have consequences on the stabilities of the ground and the transition states of reactions which affect reactivities and, sometimes, the mechanisms of reactions. This review seeks to collate and evaluate what is known about solvent effects in this domain, especially their effects on rates of reactions of different classes of organophosphorus esters. The outcome of this exercise shows that a systematized study of solvent effects needs to be undertaken to fully understand the physical organic chemistry of the transfer of phosphates and related molecules from aqueous to substantially hydrophobic environments, since significant knowledge gaps exist.
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Nicomel NR, Li LY, Mohamed BA, Ramim SS. Adsorption of p-benzoquinone at low concentrations from aqueous media using biosolid-based activated carbon. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 316:115263. [PMID: 35584595 DOI: 10.1016/j.jenvman.2022.115263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/17/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
The toxic oxidation intermediate p-benzoquinone exists in aqueous environments at dilute concentrations above the fish-toxicity limit of 0.045 mg/L, affecting aquatic life. The reduction of this compound to the concentrations required to achieve safe discharge limits is challenging. In this study, the adsorptive removal of p-benzoquinone by a biosolid-based activated carbon (SBAC) was systematically investigated in batch experiments. The adsorption rate was rapid, and the bulk of p-benzoquinone adsorption occurred within 30 min. The maximum adsorption capacity of SBAC was estimated at 19.6 mg/g using the Langmuir isotherm model. Its adsorptivity was independent of temperature from 6 to 40 °C. The presence of 6 g/L of chloride and 500 mg/L of sulphate did not affect the removal of 1 mg/L p-benzoquinone, whereas 15 mg/L of humic acid media slightly decreased the p-benzoquinone removal from 87.0% to 83.2%. Diffusion, hydrophilic, and electrostatic interactions (i.e., dipole-dipole) govern the adsorption of p-benzoquinone and are influenced by the SBAC surface chemistry. Biosolid-based activated carbon can lower the residual p-benzoquinone to below the fish-toxicity limit of 0.045 mg/L within 1 h of sequential adsorption. Thus, biosolid-based activated carbon can effectively remove p-benzoquinone from aqueous environments; this is a waste-to-resource approach that addresses sustainability (waste disposal) and environmental protection (pollutant removal).
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Affiliation(s)
- Nina Ricci Nicomel
- Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada
| | - Loretta Y Li
- Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada.
| | - Badr A Mohamed
- Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada; Department of Agricultural Engineering, Cairo University, Giza 12613, Egypt
| | - Samia Syeoti Ramim
- Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada
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7
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Rahman Z, Rajbanshi M, Mahato M, Ghanta S, Kumar Das S. A phthalimide scaffold smart molecule for visualization of acid-base equilibrium and determination of acid dissociation constants in the non-aqueous medium. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Yazan Z, Eskiköy Bayraktepe D, Dinç E. Square wave voltammetric pKa determination of aspirin using multi-way data analysis models. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-022-02250-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Teng J, Pang J, Sun Y, Wang J. A New Approach to the Determination of pKa and pKb of Brønsted–Lowry Weak Acid and Weak Base in Aprotic Solvent. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116172] [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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10
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Gamov G, Kiselev A, Murekhina A, Zavalishin M, Aleksandriiskii V, Kosterin D. Synthesis, protolytic equilibria, and antimicrobial action of nifuroxazide analogs. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Butsch K, Haseloer A, Schmitz S, Ott I, Schur J, Klein A. Fe III, Cu II and Zn II Complexes of the Rigid 9-Oxido-phenalenone Ligand-Spectroscopy, Electrochemistry, and Cytotoxic Properties. Int J Mol Sci 2021; 22:3976. [PMID: 33921452 PMCID: PMC8070161 DOI: 10.3390/ijms22083976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 01/10/2023] Open
Abstract
The three complexes [Fe(opo)3], [Cu(opo)2], and [Zn(opo)2] containing the non-innocent anionic ligand opo- (opo- = 9-oxido-phenalenone, Hopo = 9-hydroxyphenalonone) were synthesised from the corresponding acetylacetonates. [Zn(opo)2] was characterised using 1H nuclear magnetic resonance (NMR) spectroscopy, the paramagnetic [Fe(opo)3] and [Cu(opo)2] by electron paramagnetic resonance (EPR) spectroscopy. While the EPR spectra of [Cu(opo)2] and [Cu(acac)2] in dimethylformamide (DMF) solution are very similar, a rather narrow spectrum was observed for [Fe(opo)3] in tetrahydrofuran (THF) solution in contrast to the very broad spectrum of [Fe(acac)3] in THF (Hacac = acetylacetone, 2,4-pentanedione; acac- = acetylacetonate). The narrow, completely isotropic signal of [Fe(opo)3] disagrees with a metal-centred S = 5/2 spin system that is observed in the solid state. We assume spin-delocalisation to the opo ligand in the sense of an opo- to FeIII electron transfer. All compounds show several electrochemical opo-centred reduction waves in the range of -1 to -3 V vs. the ferrocene/ferrocenium couple. However, for CuII and FeIII the very first one-electron reductions are metal-centred. Electronic absorption in the UV to vis range are due to π-π* transitions in the opo core, giving Hopo and [Zn(opo)2] a yellow to orange colour. The structured bands ranging from 400 to 500 for all compounds are assigned to the lowest energy π-π* transitions. They show markedly higher intensities and slight shifts for the CuII (brown) and FeIII (red) complexes and we assume admixing metal contributions (MLCT for CuII, LMCT for FeIII). For both complexes long-wavelength absorptions assignable to d-d transitions were detected. Detailed spectroelectrochemical experiments confirm both the electrochemical and the optical assignments. Hopo and the complexes [Cu(opo)2], [Zn(opo)2], and [Fe(opo)3] show antiproliferative activities against HT-29 (colon cancer) and MCF-7 (breast cancer) cell lines in the range of a few µM, comparable to cisplatin under the same conditions.
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Affiliation(s)
- Katharina Butsch
- Department für Chemie, Institut für Anorganische Chemie, Universität zu Köln, Greinstraße 6, D-50939 Köln, Germany; (K.B.); (A.H.); (S.S.)
| | - Alexander Haseloer
- Department für Chemie, Institut für Anorganische Chemie, Universität zu Köln, Greinstraße 6, D-50939 Köln, Germany; (K.B.); (A.H.); (S.S.)
| | - Simon Schmitz
- Department für Chemie, Institut für Anorganische Chemie, Universität zu Köln, Greinstraße 6, D-50939 Köln, Germany; (K.B.); (A.H.); (S.S.)
| | - Ingo Ott
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstrasse 55, D-38106 Braunschweig, Germany; (I.O.); (J.S.)
| | - Julia Schur
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstrasse 55, D-38106 Braunschweig, Germany; (I.O.); (J.S.)
| | - Axel Klein
- Department für Chemie, Institut für Anorganische Chemie, Universität zu Köln, Greinstraße 6, D-50939 Köln, Germany; (K.B.); (A.H.); (S.S.)
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12
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Pramanik P, Sahoo R, Kumar Das S, Halder M. Fabrication of a GUMBOS-based acid-base indicator: smart probe for sensing acids and bases in any solvent. Phys Chem Chem Phys 2020; 22:28045-28054. [PMID: 33367395 DOI: 10.1039/d0cp03157g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This report outlines the synthesis of an ionic liquid-based pH-responsive indicator to sense acids or bases in non-polar as well as polar solvents. Herein, we have assembled a new ionic liquid (IL) comprised of a group of uniform materials based on organic salts (GUMBOS) by attaching a quaternary phosphonium ionic liquid with a very common acid-base indicator, methyl orange, via simple ion-exchange reaction. This integrated IL-based indicator is highly soluble in less polar solvents and exhibits good sensitivity toward the presence of acids/bases in those media. Furthermore, this indicator has been exploited in determining the dissociation constants of several acids in non-aqueous aprotic solvents by overlapping indicator method and hence this report provides essential information toward the understanding of many fundamental chemical reactions. This report has further scope for the synthesis of novel aqueous suspended nanomaterials, i.e., the nanoparticles derived from GUMBOS (nanoGUMBOS) by a simple flash nano-precipitation method. The nanomaterial has been well characterized by different spectroscopic and microscopic studies. The obtained nanoparticles also exhibit substantial pH-responsive behaviors in aqueous medium and show better susceptibility as compared to the free organic indicator. Thus, this report explores detailed studies on the IL-based indicator in sensing the acidity/basicity of various media.
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Affiliation(s)
- Prabal Pramanik
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India
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13
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Ito M, Ikai T, Yamamoto S, Taura D, Ousaka N, Yashima E. Chiral Guest-induced Catalytic Deracemization of a Spiroborate-based Double-stranded Helicate Bearing a Bisporphyrin Unit with Acids. CHEM LETT 2020. [DOI: 10.1246/cl.200352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Masaki Ito
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Tomoyuki Ikai
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Shinya Yamamoto
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Daisuke Taura
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Naoki Ousaka
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Eiji Yashima
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
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14
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Voronova ED, Golub IE, Pavlov A, Belkova NV, Filippov OA, Epstein LM, Shubina ES. Dichotomous Si-H Bond Activation by Alkoxide and Alcohol in Base-Catalyzed Dehydrocoupling of Silanes. Inorg Chem 2020; 59:12240-12251. [PMID: 32805120 DOI: 10.1021/acs.inorgchem.0c01293] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activation of silanes in dehydrogenative coupling with alcohols under general base catalysis was studied experimentally (using multinuclear NMR, IR, and UV-visible spectroscopies) and computationally (at DFT M06/6-311++G(d,p) theory level) on the example of Ph4-nSiHn (n = 1-3) interaction with (CF3)2CHOH in the presence of Et3N. The effect of the phenyl groups' number and H- substitution by the electron-withdrawing (CF3)2CHO- group on Si-H bond hydricity (quantified as hydride-donating ability, HDA) and Lewis acidity of silicon atom (characterized by maxima of molecular electrostatic potential) was accessed. Our results show the coordination of Lewis base (Y = Me3N, ROH, OR-) leads to the increased hydricity of pentacoordinate hypervalent Ph4-nSi(Y)Hn complexes and a decrease of the reaction barrier for H2 release. The formation of tertiary complexes [Ph4-nSi(Y)Hn]···HOR is a critical prerequisite for the dehydrocoupling with alkoxides being ideal activators. The latter can be external or internal, generated by in situ HOR deprotonation. The mutual effect of tetrel interaction and dihydrogen bonding in tertiary complexes (RO-)Ph4-nSiHn···HOR leads to dichotomous activation of Si-H bond promoting the proton-hydride transfer and H2 release.
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Affiliation(s)
- Evgenia D Voronova
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
| | - Igor E Golub
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
| | - Alexander Pavlov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
| | - Natalia V Belkova
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
| | - Oleg A Filippov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., Moscow 117997, Russia
| | - Lina M Epstein
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
| | - Elena S Shubina
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 28 Vavilova St., 119991 Moscow, Russia
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15
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Bay MV, Nam PC, Quang DT, Mechler A, Hien NK, Hoa NT, Vo QV. Theoretical Study on the Antioxidant Activity of Natural Depsidones. ACS OMEGA 2020; 5:7895-7902. [PMID: 32309698 PMCID: PMC7160836 DOI: 10.1021/acsomega.9b04179] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/11/2020] [Indexed: 05/16/2023]
Abstract
Depsidones are secondary metabolites in lichens with a range of potential health benefits. Among others, these compounds are believed to exhibit high hydroxyl radical and superoxide scavenging abilities, warranting a detailed investigation of their antioxidant properties. In this study, the radical scavenging activity of natural depsidones from Ramalina lichenized fungi was investigated in silico. Calculations of the thermodynamic parameters suggested that the main radical scavenging pathway follows the formal hydrogen transfer (FHT) mechanism; however, unexpectedly low rate constants were found in the CH3OO• scavenging reaction. Establishing that the depsidones are mostly ionized in an aqueous environment suggested that the single-electron transfer (SET) mechanism should not be ruled out. Consistently, depsidones were revealed to be excellent HO• and O2 •- scavengers in aqueous solutions (k = 4.60 × 105 - 8.60 × 109 M-1 s-1 and k = 2.60 × 108 - 8.30 × 109 M-1 s-1, respectively) following the sequential proton loss electron transfer (SPLET) mechanism. These results suggest that natural fungal depsidones are potent hydroxyl and superoxide radical scavengers in aqueous solutions.
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Affiliation(s)
- Mai Van Bay
- Department
of Chemistry, The University of Da Nang,
University of Science and Education, Da Nang 550000, Vietnam
| | - Pham Cam Nam
- Department
of Chemical Engineering, The University
of Da Nang, University of Science and Technology, Da Nang 550000, Vietnam
| | - Duong Tuan Quang
- University
of Education, Hue University, Hue City 530000, Vietnam
| | - Adam Mechler
- Department
of Chemistry and Physics, La Trobe University, Victoria 3086, Australia
| | - Nguyen Khoa Hien
- Mientrung
Institute for Scientific Research, Academy
of Science and Technology, Hue
City 530000, Vietnam
| | - Nguyen Thi Hoa
- Academic
Affairs, The University of Danang - University
of Technology and Education, Da
Nang 550000, Vietnam
| | - Quan V. Vo
- Institute
of Research and Development, Duy Tan University, Danang 550000, Vietnam
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16
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Zonouzi F, Shayesteh A, Alizadeh T, Dezhampanah H, Ghalami‐Choobar B, Zonouzi A. Determination of
pK
a
values for (
E
)‐2‐hydroxy‐5‐(aryldiazenyl) benzaldehydes in dimethyl sulfoxide: Cyclic voltammetry and density functional theory calculations. J CHIN CHEM SOC-TAIP 2020. [DOI: 10.1002/jccs.201800472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Forouzan Zonouzi
- Department of ChemistryUniversity campus 2, University of Guilan Rasht Iran
| | - Alireza Shayesteh
- School of Chemistry, College of ScienceUniversity of Tehran Tehran Iran
| | - Taher Alizadeh
- School of Chemistry, College of ScienceUniversity of Tehran Tehran Iran
| | - Hamid Dezhampanah
- Department of ChemistryUniversity campus 2, University of Guilan Rasht Iran
- Department of Chemistry, Faculty of ScienceUniversity of Guilan Rasht Iran
| | - Bahram Ghalami‐Choobar
- Department of ChemistryUniversity campus 2, University of Guilan Rasht Iran
- Department of Chemistry, Faculty of ScienceUniversity of Guilan Rasht Iran
| | - Afsaneh Zonouzi
- School of Chemistry, College of ScienceUniversity of Tehran Tehran Iran
- Pharmaceutical and Cosmetic Research Center (PCRC)University of Tehran Tehran Iran
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17
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Pang J, Dou Z, Lin M, Xu W, Zhai S, Han Y, Wang J. Mechanism of voltammetric determination of pKa of Brønsted–Lowry acids in aprotic solvent by quinone reduction. Microchem J 2020. [DOI: 10.1016/j.microc.2019.104324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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18
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Voltammetric and spectroscopic determination of polyphenols and antioxidants in ginger ( Zingiber officinale Roscoe). Heliyon 2019; 5:e01717. [PMID: 31193231 PMCID: PMC6522777 DOI: 10.1016/j.heliyon.2019.e01717] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/30/2019] [Accepted: 05/09/2019] [Indexed: 11/23/2022] Open
Abstract
Ginger (Zingiber officinale) is widely consumed as an important spice or a common condiment in food and beverages. This study focuses on the determination of pungent and bioactive components in ginger and their antioxidant activity using voltammetric and spectroscopic methods. Gas chromatography-mass spectroscopy analysis revealed that the major components of the pungent compounds were zingerone, shogaols, gingerols, paradols, wikstromol, and carinol. Using spectroscopic methods, the antioxidant capacity of ginger aqueous extract was found to be 16.0 μmol gallic acid equivalent (GAE) per gram of ginger extract, and the total phenolic and flavonoid content was estimated to be 7.8 mg GAE/g ginger extract and 15.4 mg Quercetin equivalent (QE) per gram of ginger extract, respectively. Electroanalytical quantification estimated the antioxidant capacity of the ginger infusion to be 23.5 μmol GAE/g ginger extract, which is slightly higher than that estimated using chemical assay. The results may provide useful information for the development of ginger processing and utilization as a flavoring agent, and for our understanding of ginger as a source of natural antioxidants.
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19
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Wagner C, Hübner O, Kaifer E, Himmel HJ. Probing the Proton-Coupled Electron-Transfer (PCET) Reactivity of a Cross-Conjugated Cruciform Chromophore by Redox-State-Dependent Fluorescence. Chemistry 2019; 25:3781-3785. [PMID: 30688382 DOI: 10.1002/chem.201900268] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 11/07/2022]
Abstract
Proton-coupled electron transfer (PCET) reactions are of great importance in synthetic chemistry and in biology, but the acquisition of kinetic information for these reactions is often difficult. Herein, we report the synthesis of a new PCET reagent, showing redox-state dependent fluorescence, by merging the concept of cross-conjugated cruciform chromophores with the strategy of imposing redox activity and Brønsted basicity to aromatic compounds by substitution with guanidino groups. The compound is isolated and characterized in all stable states-reduced, twofold and fourfold protonated and twofold oxidized-and then applied in PCET reactions by using its redox-state dependent fluorescence signal for kinetic measurements.
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Affiliation(s)
- Conrad Wagner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Olaf Hübner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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20
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Shi RRS, Tessensohn ME, Lauw SJL, Foo NABY, Webster RD. Tuning the reduction potential of quinones by controlling the effects of hydrogen bonding, protonation and proton-coupled electron transfer reactions. Chem Commun (Camb) 2019; 55:2277-2280. [PMID: 30720024 DOI: 10.1039/c8cc09188a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An all-organic cell comprising 2,3-dimethyl-1,4-napthoquinone and pyrano[3,2-f]chromene as electroactive elements exhibited a good combination of large cell voltage and stability of the reduced quinone upon the addition of diethyl malonate (a weak organic acid), as compared to the addition of trifluoroethanol (which led to a high cell potential but low stability via strong hydrogen bonding interactions) and the addition of trifluoroacetic acid (which led to a lower cell potential but high stability through proton transfer).
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Affiliation(s)
- Raymond R S Shi
- Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
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21
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Kuramochi Y, Yoshida T, Kodama K, Kiriyama M, Yoshioka S, Hirota S, Satake A. Efficient Photochemical Reduction of Quinone into Hydroquinone Promoted by Imidazolyl N-H Proton. CHEM LETT 2018. [DOI: 10.1246/cl.180635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yusuke Kuramochi
- Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Takeaki Yoshida
- Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Kazuhiro Kodama
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Masanari Kiriyama
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Seiko Yoshioka
- Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Shun Hirota
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Akiharu Satake
- Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
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22
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23
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Tessensohn ME, Lim S, Miechie, Koh YR, Hirao H, Webster RD. The Dual Roles of Phenylenediamines: Using their Voltammetric Behavior to Measure the Hydrogen Donor and Acceptor Abilities of Alcohols in Acetonitrile. Chemphyschem 2017; 18:3562-3569. [PMID: 28960814 DOI: 10.1002/cphc.201700976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Indexed: 11/09/2022]
Abstract
Cyclic voltammetry experiments on 2,3,5,6-tetramethyl-1,4-phenylenediamine (P) in acetonitrile in the presence of varying concentrations of alcohols indicate that the oxidized forms of the compound (P.+ and P2+ ) interact with the alcohols through a hydrogen-bonding mechanism where P.+ and P2+ act as the hydrogen donor and the alcohols act as acceptors. However, the neutral form (P) largely acts as a hydrogen acceptor but only for strong hydrogen donors that do not undergo proton-transfer reactions with the phenylenediamine. These results were ascertained based on measuring the difference in potential of the two one-electron transfer reactions (ΔEPox(1, 2) =|EPox(1) -EPox(2) |) in the oxidative electrochemistry of P, which thereby allows a simple measure of relative hydrogen bonding strengths.
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Affiliation(s)
- Malcolm E Tessensohn
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Sihao Lim
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Miechie
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Yu Rong Koh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Hajime Hirao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Richard D Webster
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
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24
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Application of capillary electrophoresis to the separation of rhenium complex of 1,2,3-trihydroxybenzene. MONATSHEFTE FUR CHEMIE 2017. [DOI: 10.1007/s00706-017-1982-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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25
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McCarthy BD, Dempsey JL. Decoding Proton-Coupled Electron Transfer with Potential-pK a Diagrams. Inorg Chem 2017; 56:1225-1231. [PMID: 28075117 DOI: 10.1021/acs.inorgchem.6b02325] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aqueous potential-pH diagrams, commonly called Pourbaix diagrams, were originally developed to study metal corrosion in the 1930s and 1940s. Pourbaix diagrams have since been widely adopted for use across chemistry disciplines, particularly for the study of aqueous proton-coupled electron transfer reactions. Despite this enormous versatility, a clear extension of analogous diagrams to nonaqueous solvents is lacking. The problem hinges on the difficulty of defining the nonaqueous solution pH. Here, we address this issue by reporting the development of diagrams based on nonaqueous pKa scales. We experimentally construct diagrams for two transition-metal complexes that undergo proton-coupled electron transfer reactivity by recording their reduction potentials in the presence of acids with varying pKa values. These experimental diagrams validate the potential-pKa theory and provide valuable thermochemical information for proton-coupled electron transfer reactions, including for fleetingly stable species.
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Affiliation(s)
- Brian D McCarthy
- Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States
| | - Jillian L Dempsey
- Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States
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26
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Tessensohn ME, Ng SJ, Chan KK, Gan SL, Sims NF, Koh YR, Webster RD. Impurities in Nitrile Solvents Commonly Used for Electrochemistry, and their Effects on Voltammetric Data. ChemElectroChem 2016. [DOI: 10.1002/celc.201600266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Malcolm E. Tessensohn
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Shu Jun Ng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Kwok Kiong Chan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Sher Li Gan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Natalie F. Sims
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Yu Rong Koh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
| | - Richard D. Webster
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences; Nanyang Technological University; 21 Nanyang Link Singapore 637371 Singapore
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27
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Fudo S, Yamamoto N, Nukaga M, Odagiri T, Tashiro M, Hoshino T. Two Distinctive Binding Modes of Endonuclease Inhibitors to the N-Terminal Region of Influenza Virus Polymerase Acidic Subunit. Biochemistry 2016; 55:2646-60. [PMID: 27088785 DOI: 10.1021/acs.biochem.5b01087] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Influenza viruses are global threat to humans, and the development of new antiviral agents are still demanded to prepare for pandemics and to overcome the emerging resistance to the current drugs. Influenza polymerase acidic protein N-terminal domain (PAN) has endonuclease activity and is one of the appropriate targets for novel antiviral agents. First, we performed X-ray cocrystal analysis on the complex structures of PAN with two endonuclease inhibitors. The protein crystallization and the inhibitor soaking were done at pH 5.8. The binding modes of the two inhibitors were different from a common binding mode previously reported for the other influenza virus endonuclease inhibitors. We additionally clarified the complex structures of PAN with the same two endonuclease inhibitors at pH 7.0. In one of the crystal structures, an additional inhibitor molecule, which chelated to the two metal ions in the active site, was observed. On the basis of the crystal structures at pH 7.0, we carried out 100 ns molecular dynamics (MD) simulations for both of the complexes. The analysis of simulation results suggested that the binding mode of each inhibitor to PAN was stable in spite of the partial deviation of the simulation structure from the crystal one. Furthermore, crystal structure analysis and MD simulation were performed for PAN in complex with an inhibitor, which was already reported to have a high compound potency for comparison. The findings on the presence of multiple binding sites at around the PAN substrate-binding pocket will provide a hint for enhancing the binding affinity of inhibitors.
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Affiliation(s)
- Satoshi Fudo
- Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Norio Yamamoto
- Graduate School of Medicine, Juntendo University , 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.,Influenza Virus Research Center, National Institute of Infectious Diseases , 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Michiyoshi Nukaga
- Faculty of Pharmaceutical Sciences, Josai International University , 1 Gumyo, Togane-shi Chiba 283-8555, Japan
| | - Takato Odagiri
- Influenza Virus Research Center, National Institute of Infectious Diseases , 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Masato Tashiro
- Influenza Virus Research Center, National Institute of Infectious Diseases , 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
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28
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Martínez-Rodríguez L, Otalora Garmilla J, Kleij AW. Cavitand-Based Polyphenols as Highly Reactive Organocatalysts for the Coupling of Carbon Dioxide and Oxiranes. CHEMSUSCHEM 2016; 9:749-755. [PMID: 26914250 DOI: 10.1002/cssc.201501463] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/26/2015] [Indexed: 06/05/2023]
Abstract
A variety of cavitand-based polyphenols was prepared from cheap and accessible aldehyde and resorcinol/pyrogallol reagents to give the respective resorcin[4]- or pyrogallol[4]arenes. The preorganization of the phenolic units allows intra- and intermolecular hydrogen bond (HB) networks that affect both the reactivity and stability of these HB-donor catalysts. Unexpectedly, we found that the resorcin[4]arenes show cooperative catalysis behavior compared to the parent resorcinol in the catalytic coupling of epoxides and CO2 with a significantly higher turnover. At elevated reaction temperatures, the resorcin[4]arene-based catalyst 3 d displays the best catalytic performance with very high turnover numbers and frequencies, combining increased reactivity and stability compared to pyrogallol, and an ample substrate scope. This type of polyphenol structure thus illustrates the importance of a new, highly competitive organocatalyst design to devise sustainable CO2 conversion processes.
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Affiliation(s)
- Luis Martínez-Rodríguez
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
| | - Javier Otalora Garmilla
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
| | - Arjan W Kleij
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain.
- Catalan Institute of Research and Advanced Studies (ICREA), Pg. Lluís Companys 23, 08010, Barcelona, Spain.
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29
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30
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Galano A. Computational-aided design of melatonin analogues with outstanding multifunctional antioxidant capacity. RSC Adv 2016. [DOI: 10.1039/c6ra00549g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The IIcD melatonin-analogue was identified as the most promising multifunctional antioxidant from a set of 19, and better for that purpose than the parent molecule and Trolox.
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Affiliation(s)
- Annia Galano
- Departamento de Química
- Universidad Autónoma Metropolitana-Iztapalapa
- México D. F
- Mexico
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31
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Estimation of the pKa for various Brønsted acids in polar aprotic media using electrochemical measurements of chromium (III) with picolinic acid. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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32
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White TA, Witt SE, Li Z, Dunbar KR, Turro C. New Rh2(II,II) Architecture for the Catalytic Reduction of H+. Inorg Chem 2015; 54:10042-8. [DOI: 10.1021/acs.inorgchem.5b01823] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Travis A. White
- Department of Chemistry
and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Suzanne E. Witt
- Department of Chemistry
and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Zhanyong Li
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Kim R. Dunbar
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Claudia Turro
- Department of Chemistry
and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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33
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Yanai H. Chemistry of Fluorinated Carbon Acids: Synthesis, Physicochemical Properties, and Catalysis. Chem Pharm Bull (Tokyo) 2015; 63:649-62. [PMID: 26329858 DOI: 10.1248/cpb.c15-00487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The bis[(trifluoromethyl)sulfonyl]methyl (Tf2CH; Tf=SO2CF3) group is known to be one of the strongest carbon acid functionalities. The acidity of such carbon acids in the gas phase is stronger than that of sulfuric acid. Our recent investigations have demonstrated that this type of carbon acids work as novel acid catalysts. In this paper, recent achievements in carbon acid chemistry by our research group, including synthesis, physicochemical properties, and catalysis, are summarized.
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Affiliation(s)
- Hikaru Yanai
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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34
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Comparing a novel voltammetric method with a standardized method for quality control of biodiesel. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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35
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Karacan MS, Zharmukhamedov SK, Mamaş S, Kupriyanova EV, Shitov AV, Klimov VV, Özbek N, Özmen Ü, Gündüzalp A, Schmitt FJ, Karacan N, Friedrich T, Los DA, Carpentier R, Allakhverdiev SI. Screening of novel chemical compounds as possible inhibitors of carbonic anhydrase and photosynthetic activity of photosystem II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2014; 137:156-67. [PMID: 24418071 DOI: 10.1016/j.jphotobiol.2013.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 12/05/2013] [Indexed: 12/28/2022]
Abstract
Thirty novel chemical compounds were designed and synthesized expecting that they would be possible inhibitors. From this number eleven were organic bases, twenty-four were their organic derivatives and fourteen were metal complexes. Screening of these chemicals by their action on photosynthetic electron transfer (PET) and carbonic anhydrase (CA) activity (CAA) of photosystem II (PSII), α-CA, as well as β-CA was done. Several groups were revealed among them. Some of them are capable to suppress either one, two, three, or even all of the measured activities. As example, one of the Cu(II)-phenyl sulfonylhydrazone complexes (compound 25) suppresses CAA of α-CA by 88%, CAA of β-CA by 100% inhibition; CAA of PSII by 100% and the PSII photosynthetic activity by 66.2%. The Schiff base compounds (12, 15) and Cu(II)-phenyl sulfonylhydrazone complexes (25, 26) inhibited the CAA and PET of PSII significantly. The obtained data indicate that the PSII donor side is a target of the inhibitory action of these agents. Some physico- or electrochemical properties such as diffusion coefficient, number of transferred electrons, peak potential and heterogeneous standard rate constants of the compounds were determined in nonaqueous media. pKa values were also determined in nonaqueous and aqueous media. Availability in the studied group of novel chemical agents possessing different inhibitory activity allow in future to isolate the "active part" in the structure of the inhibitors responsible for different inhibitory mechanisms, as well as to determine the influence of side substituters on its inhibitory efficiency.
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Affiliation(s)
- Mehmet Sayım Karacan
- Gazi University, Science Faculty, Department of Chemistry, 06500 Ankara, Turkey.
| | - Sergei K Zharmukhamedov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia
| | - Serhat Mamaş
- Gazi University, Science Faculty, Department of Chemistry, 06500 Ankara, Turkey
| | - Elena V Kupriyanova
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Alexandr V Shitov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia
| | - Vyacheslav V Klimov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia
| | - Neslihan Özbek
- Ahi Evran University, Dept. of Primary Educ. Fac. Of Educ., 40100 Kırsehir, Turkey
| | - Ümmühan Özmen
- Gazi University, Science Faculty, Department of Chemistry, 06500 Ankara, Turkey
| | - Ayla Gündüzalp
- Gazi University, Science Faculty, Department of Chemistry, 06500 Ankara, Turkey
| | - Franz-Josef Schmitt
- Technical University of Berlin, Institute of Chemistry Sekr. PC 14, Max-Volmer-Laboratory of Biophysical Chemistry, Straβe des 17. Juni 135, D-10623 Berlin, Germany
| | - Nurcan Karacan
- Gazi University, Science Faculty, Department of Chemistry, 06500 Ankara, Turkey
| | - Thomas Friedrich
- Technical University of Berlin, Institute of Chemistry Sekr. PC 14, Max-Volmer-Laboratory of Biophysical Chemistry, Straβe des 17. Juni 135, D-10623 Berlin, Germany
| | - Dmitry A Los
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Robert Carpentier
- Department de Chimie, Biochimie et Physique, Université du Quebec à Trois Rivières, 3351 Boulevard des Forges, C.P. 500, Québec G9A 5H7, Canada
| | - Suleyman I Allakhverdiev
- Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia; Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
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36
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Ibis C, Ayla SS, Yavuz S. The Synthesis, Characterization, and Electrochemical Investigation of Novel Thio- and Alkoxy-Substituted Benzoquinone Derivatives. PHOSPHORUS SULFUR 2014. [DOI: 10.1080/10426507.2013.829833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Cemil Ibis
- a Department of Chemistry, Faculty of Engineering , Istanbul University , 34320 , Avcilar , Istanbul , Turkey
| | - Sibel Sahınler Ayla
- a Department of Chemistry, Faculty of Engineering , Istanbul University , 34320 , Avcilar , Istanbul , Turkey
| | - Senol Yavuz
- a Department of Chemistry, Faculty of Engineering , Istanbul University , 34320 , Avcilar , Istanbul , Turkey
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37
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Yanai H, Taguchi T. Synthesis and Catalysis of Strong Carbon Acids Containing Bis(triflyl)methyl Group. J SYN ORG CHEM JPN 2014. [DOI: 10.5059/yukigoseikyokaishi.72.158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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38
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Pérez-González A, Galano A, Alvarez-Idaboy JR. Dihydroxybenzoic acids as free radical scavengers: mechanisms, kinetics, and trends in activity. NEW J CHEM 2014. [DOI: 10.1039/c4nj00071d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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39
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Yanai H, Fujita M, Takahashi A, Zhang M, Mishima M, Kotani A, Matsumoto T, Taguchi T. Synthesis of δ-oxo-1,1-bis(triflyl)alkanes and their acidities. Molecules 2013; 18:15531-40. [PMID: 24352012 PMCID: PMC6269671 DOI: 10.3390/molecules181215531] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/03/2013] [Accepted: 12/11/2013] [Indexed: 11/22/2022] Open
Abstract
The reaction of 1,1-bis(triflyl)ethylene generated in situ with enolizable carbonyls yielded δ-oxo-1,1-bis(triflyl)alkane derivatives. Their acidities in both the gas and solution phases were determined.
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Affiliation(s)
- Hikaru Yanai
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
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Ibis C, Ayla SS, Asar H. Synthesis and Spectral and Electrochemical Characterization of Novel Substituted 1,4-Naphthoquinone Derivatives. SYNTHETIC COMMUN 2013. [DOI: 10.1080/00397911.2013.793774] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Cemil Ibis
- a Department of Chemistry , Istanbul University, Faculty of Engineering , Istanbul , Turkey
| | - Sibel Sahinler Ayla
- a Department of Chemistry , Istanbul University, Faculty of Engineering , Istanbul , Turkey
| | - Hatice Asar
- a Department of Chemistry , Istanbul University, Faculty of Engineering , Istanbul , Turkey
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41
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Nucleophilic substitution reactions of 1,4-naphthoquinone and biologic properties of novel S-, S,S-, N-, and N,S-substituted 1,4-naphthoquinone derivatives. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0806-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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42
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Reijenga J, van Hoof A, van Loon A, Teunissen B. Development of Methods for the Determination of pKa Values. ANALYTICAL CHEMISTRY INSIGHTS 2013; 8:53-71. [PMID: 23997574 PMCID: PMC3747999 DOI: 10.4137/aci.s12304] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The acid dissociation constant (pKa) is among the most frequently used physicochemical parameters, and its determination is of interest to a wide range of research fields. We present a brief introduction on the conceptual development of pKa as a physical parameter and its relationship to the concept of the pH of a solution. This is followed by a general summary of the historical development and current state of the techniques of pKa determination and an attempt to develop insight into future developments. Fourteen methods of determining the acid dissociation constant are placed in context and are critically evaluated to make a fair comparison and to determine their applications in modern chemistry. Additionally, we have studied these techniques in light of present trends in science and technology and attempt to determine how these trends might affect future developments in the field.
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Affiliation(s)
- Jetse Reijenga
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Arno van Hoof
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Antonie van Loon
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Bram Teunissen
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands
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43
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da Silva Figueiredo E, de Castro Vieira E, de Siqueira Cavalcanti EH, D'Elia E. Validation of a New Analytical Method for the Measurement of Free Fatty Acids in Biodiesel. ELECTROANAL 2013. [DOI: 10.1002/elan.201200513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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44
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Peters AJ, Rainka MP, Krishnan L, Laramie S, Dodd M, Reimer JA. Electrochemical characterization of hydrogen-bonding complexation between indoline and nitrogen containing bases. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2012.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Yanai H, Yoshino T, Fujita M, Fukaya H, Kotani A, Kusu F, Taguchi T. Synthesis, Characterization, and Applications of Zwitterions Containing a Carbanion Moiety. Angew Chem Int Ed Engl 2012; 52:1560-3. [DOI: 10.1002/anie.201208809] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Indexed: 11/11/2022]
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46
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Yanai H, Yoshino T, Fujita M, Fukaya H, Kotani A, Kusu F, Taguchi T. Synthesis, Characterization, and Applications of Zwitterions Containing a Carbanion Moiety. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201208809] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Yanai H, Ogura H, Fukaya H, Kotani A, Kusu F, Taguchi T. An Effective Method to Introduce Carbon Acid Functionality: 2,2-Bis(trifluoromethanesulfonyl)ethylation Reaction of Arenes. Chemistry 2011; 17:11747-51. [DOI: 10.1002/chem.201102023] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Indexed: 11/11/2022]
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48
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Mihichuk LM, Driver GW, Johnson KE. Brønsted Acidity and the Medium: Fundamentals with a Focus on Ionic Liquids. Chemphyschem 2011; 12:1622-32. [DOI: 10.1002/cphc.201100087] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 04/08/2011] [Indexed: 11/10/2022]
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49
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Spulber M, Schlick S. Using Cyclodextrins to Encapsulate Oxygen-Centered and Carbon-Centered Radical Adducts: The Case of DMPO, PBN, and MNP Spin Traps. J Phys Chem A 2010; 114:6217-25. [PMID: 20462228 DOI: 10.1021/jp100777u] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Mariana Spulber
- Department of Chemistry and Biochemistry, University of Detroit Mercy, 4001 West McNichols Road, Detroit, Michigan 48221
| | - Shulamith Schlick
- Department of Chemistry and Biochemistry, University of Detroit Mercy, 4001 West McNichols Road, Detroit, Michigan 48221
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50
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Abstract
Ribosomal incorporations of N-alkyl amino acids including proline are slower than incorporations of non-N-alkyl l-amino acids. The chemical reactivity hypothesis proposes that these results and the exclusion of nonproline N-alkyl amino acids from the genetic code are explained by intrinsic chemical reactivities of the amino acid nucleophiles. However, there is little data on the reactivities relevant to physiological conditions. Here, we use nonenzymatic, aqueous-based, buffered reactions with formylmethionine-N-hydroxysuccinimide ester to model 11 amino acid nucleophiles in dipeptide formation. The relative rates in the nonenzymatic and translation systems correlate well, supporting the chemical reactivity hypothesis and arguing that peptide bond formation, not accommodation, is rate limiting for natural Pro-tRNA(Pro) isoacceptors. The effects of N-substitution sterics, side chain sterics, induction, and pK(a) were evaluated in the chemical model. The dominant factor affecting relative rates was found to be N-substitution sterics.
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Affiliation(s)
- R Edward Watts
- Department of Pharmacology and Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, 2222 Pierce Avenue, Nashville, Tennessee 37232, USA
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