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Lee W, Choi S, Kim H, Lee W, Lee M, Son H, Lee C, Cho M, Lee Y. Efficiency of ozonation and O 3/H 2O 2 as enhanced wastewater treatment processes for micropollutant abatement and disinfection with minimized byproduct formation. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131436. [PMID: 37146328 DOI: 10.1016/j.jhazmat.2023.131436] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/21/2023] [Accepted: 04/15/2023] [Indexed: 05/07/2023]
Abstract
Ozonation, a viable option for improving wastewater effluent quality, requires process optimization to ensure the organic micropollutants (OMPs) elimination and disinfection under minimized byproduct formation. This study assessed and compared the efficiencies of ozonation (O3) and ozone with hydrogen peroxide (O3/H2O2) for 70 OMPs elimination, inactivation of three bacteria and three viruses, and formation of bromate and biodegradable organics during the bench-scale O3 and O3/H2O2 treatment of municipal wastewater effluent. 39 OMPs were fully eliminated, and 22 OMPs were considerably eliminated (54 ± 14%) at an ozone dosage of 0.5 gO3/gDOC for their high reactivity to ozone or •OH. The chemical kinetics approach accurately predicted the OMP elimination levels based on the rate constants and exposures of ozone and •OH, where the quantum chemical calculation and group contribution method successfully predicted the ozone and •OH rate constants, respectively. Microbial inactivation levels increased with increasing ozone dosage up to ∼3.1 (bacteria) and ∼2.6 (virus) log10 reductions at 0.7 gO3/gDOC. O3/H2O2 minimized bromate formation but significantly decreased bacteria/virus inactivation, whereas its impact on OMP elimination was insignificant. Ozonation produced biodegradable organics that were removed by a post-biodegradation treatment, achieving up to 24% DOM mineralization. These results can be useful for optimizing O3 and O3/H2O2 processes for enhanced wastewater treatment.
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Affiliation(s)
- Woongbae Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Sangki Choi
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Hyunjin Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Woorim Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea; Busan Water Quality Institute, Gimhae, Gyeongsangnam 621-813, Republic of Korea
| | - Minju Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Heejong Son
- Busan Water Quality Institute, Gimhae, Gyeongsangnam 621-813, Republic of Korea
| | - Changha Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Seoul 08826, Republic of Korea
| | - Min Cho
- SELS Center, Division of Biotechnology, College of Environmental & Bioresource Sciences, Chonbuk National University, Iksan 54596, Republic of Korea.
| | - Yunho Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
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Falamaş A, Petran A, Hada AM, Bende A. Dopamine Photochemical Behaviour under UV Irradiation. Int J Mol Sci 2022; 23:ijms23105483. [PMID: 35628293 PMCID: PMC9141693 DOI: 10.3390/ijms23105483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 12/10/2022] Open
Abstract
To understand the photochemical behaviour of the polydopamine polymer in detail, one would also need to know the behaviour of its building blocks. The electronic absorption, as well as the fluorescence emission and excitation spectra of the dopamine were experimentally and theoretically investigated considering time-resolved fluorescence spectroscopy and first-principles quantum theory methods. The shape of the experimental absorption spectra obtained for different dopamine species with standard, zwitterionic, protonated, and deprotonated geometries was interpreted by considering the advanced equation-of-motion coupled-cluster theory of DLPNO-STEOM. Dynamical properties such as fluorescence lifetimes or quantum yield were also experimentally investigated and compared with theoretically predicted transition rates based on Fermi's Golden Rule-like equation. The results show that the photochemical behaviour of dopamine is strongly dependent on the concentration of dopamine, whereas in the case of a high concentration, the zwitterionic form significantly affects the shape of the spectrum. On the other hand, the solvent pH is also a determining factor for the absorption, but especially for the fluorescence spectrum, where at lower pH (5.5), the protonated and, at higher pH (8.0), the deprotonated forms influence the shape of the spectra. Quantum yield measurements showed that, besides the radiative deactivation mechanism characterized by a relatively small QY value, non-radiative deactivation channels are very important in the relaxation process of the electronic excited states of different dopamine species.
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Affiliation(s)
- Alexandra Falamaş
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, Romania; (A.F.); (A.P.)
| | - Anca Petran
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, Romania; (A.F.); (A.P.)
| | - Alexandru-Milentie Hada
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, 42 T. Laurian Str., 400271 Cluj-Napoca, Romania;
- Faculty of Physics, Babes-Bolyai University, 1 M. Kogalniceanu Str., 400084 Cluj-Napoca, Romania
| | - Attila Bende
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, Romania; (A.F.); (A.P.)
- Correspondence:
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Gigliuto A, Cigala RM, Irto A, Felice MR, Pettignano A, De Stefano C, Crea F. The Effect of Metal Cations on the Aqueous Behavior of Dopamine. Thermodynamic Investigation of the Binary and Ternary Interactions with Cd 2+, Cu 2+ and UO 22+ in NaCl at Different Ionic Strengths and Temperatures. Molecules 2021; 26:7679. [PMID: 34946761 PMCID: PMC8709034 DOI: 10.3390/molecules26247679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 12/06/2021] [Accepted: 12/16/2021] [Indexed: 12/07/2022] Open
Abstract
The interactions of dopamine [2-(3,4-Dihydroxyphenyl)ethylamine, (Dop-)] with cadmium(II), copper(II) and uranyl(VI) were studied in NaCl(aq) at different ionic strengths (0 ≤ I/mol dm-3 ≤ 1.0) and temperatures (288.15 ≤ T/K ≤ 318.15). From the elaboration of the experimental data, it was found that the speciation models are featured by species of different stoichiometry and stability. In particular for cadmium, the formation of only MLH, ML and ML2 (M = Cd2+; L = dopamine) species was obtained. For uranyl(VI) (UO22+), the speciation scheme is influenced by the use of UO2(acetate)2 salt as a chemical; in this case, the formation of ML2, MLOH and the ternary MLAc (Ac = acetate) species in a wide pH range was observed. The most complex speciation model was obtained for the interaction of Cu2+ with dopamine; in this case we observed the formation of the following species: ML2, M2L, M2L2, M2L2(OH)2, M2LOH and ML2OH. These speciation models were determined at each ionic strength and temperature investigated. As a further contribution to this kind of investigation, the ternary interactions of dopamine with UO22+/Cd2+ and UO22+/Cu2+ were investigated at I = 0.15 mol dm-3 and T = 298.15K. These systems have different speciation models, with the MM'L and M2M'L2OH [M = UO22+; M' = Cd2+ or Cu2+, L = dopamine] common species; the species of the mixed Cd2+ containing system have a higher stability with respect the Cu2+ containing one. The dependence on the ionic strength of complex formation constants was modelled by using both an extended Debye-Hückel equation that included the Van't Hoff term for the calculation of the formation enthalpy change values and the Specific Ion Interaction Theory (SIT). The results highlighted that, in general, the entropy is the driving force of the process. The quantification of the effective sequestering ability of dopamine towards the studied cations was evaluated by using a Boltzmann-type equation and the calculation of pL0.5 parameter. The sequestering ability was quantified at different ionic strengths, temperatures and pHs, and this resulted, in general, that the pL0.5 trend was always: UO22+ > Cu2+ > Cd2+.
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Affiliation(s)
- Antonio Gigliuto
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
| | - Rosalia Maria Cigala
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
| | - Anna Irto
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
| | - Maria Rosa Felice
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
| | - Alberto Pettignano
- Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, V.le delle Scienze, ed. 17, I-90128 Palermo, Italy;
| | - Concetta De Stefano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
| | - Francesco Crea
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (A.G.); (R.M.C.); (A.I.); (M.R.F.); (C.D.S.)
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Jodko-Piórecka K, Sikora B, Kluzek M, Przybylski P, Litwinienko G. Antiradical Activity of Dopamine, L-DOPA, Adrenaline, and Noradrenaline in Water/Methanol and in Liposomal Systems. J Org Chem 2021; 87:1791-1804. [PMID: 34871499 PMCID: PMC8822484 DOI: 10.1021/acs.joc.1c02308] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Catecholamines play
a crucial role in signal transduction and are
also expected to act as endogeneous antioxidants, but the mechanism
of their antioxidant action is not fully understood. Here, we describe
the impact of pH on the kinetics of reaction of four catecholamines
(L-DOPA, dopamine, adrenaline, and noradrenaline) with model 2,2-diphenyl-1-picrylhydrazyl
radical (dpph•) in methanol/water. The increase
in pH from 5.5 to 7.4 is followed by a 2 order of magnitude increase
in the rate constant, e.g., for dopamine (DA) kpH5.5 = 1,200 M–1 s–1 versus kpH7.4 = 170,000 M–1 s–1, and such rate acceleration is attributed to a fast
electron transfer from the DA anion to dpph•. We
also proved that at pH 7.0 DA breaks the peroxidation chain of methyl
linoleate in liposomes assembled from neutral and negatively charged
phospholipids. In contrast to no inhibitory effect during peroxidation
in non-ionic emulsions, in bilayers one molecule of DA traps approximately
four peroxyl radicals, with a rate constant kinh >103 M–1 s–1. Our results from a homogeneous system and bilayers prove that catecholamines
act as effective, radical trapping antioxidants with activity depending
on the ionization status of the catechol moiety, as well as microenvironment:
organization of the lipid system (emulsions vs bilayers) and interactions
of catecholamines with the biomembrane.
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Affiliation(s)
| | - Bożena Sikora
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Monika Kluzek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Paweł Przybylski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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Thomas J, Anitha P, Thomas T, Thomas N. Electrocatalytic sensing of dopamine: How the Co content in porous LaNixCoxO3 perovskite influences sensitivity? Microchem J 2021. [DOI: 10.1016/j.microc.2021.106443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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6
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Cernat A, Ştefan G, Tertis M, Cristea C, Simon I. An overview of the detection of serotonin and dopamine with graphene-based sensors. Bioelectrochemistry 2020; 136:107620. [DOI: 10.1016/j.bioelechem.2020.107620] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/23/2020] [Accepted: 07/23/2020] [Indexed: 02/06/2023]
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Rossi‐Fernández AC, Meier LA, Domancich NF, Castellani NJ. Electric Field Effects on the Adsorption of Dopamine Species on Ag(111): DFT Investigation of Interaction Mechanism. ChemistrySelect 2020. [DOI: 10.1002/slct.202001078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Ana C. Rossi‐Fernández
- INQUISURUniversidad Nacional del Sur, CONICET, Av. L. N. Alem 1253 B8000CPB - Bahía Blanca Argentina
| | - Lorena A. Meier
- IFISURUniversidad Nacional del Sur, CONICET. Av. L. N. Alem 1253 B8000CPB - Bahía Blanca Argentina
| | - Nicolás F. Domancich
- IFISURUniversidad Nacional del Sur, CONICET. Av. L. N. Alem 1253 B8000CPB - Bahía Blanca Argentina
| | - Norberto J. Castellani
- Departamento de FísicaUniversidad Nacional del SurBahía BlancaArgentinaIFISURUniversidad Nacional del Sur, CONICET, Departamento de Física, Av. L. N. Alem 1253 B8000CPB - Bahía Blanca Argentina
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8
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Crea F, De Stefano C, Irto A, Lando G, Materazzi S, Milea D, Pettignano A, Sammartano S. Understanding the Solution Behavior of Epinephrine in the Presence of Toxic Cations: A Thermodynamic Investigation in Different Experimental Conditions. Molecules 2020; 25:E511. [PMID: 31991662 PMCID: PMC7037007 DOI: 10.3390/molecules25030511] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/16/2020] [Accepted: 01/21/2020] [Indexed: 11/16/2022] Open
Abstract
The interactions of epinephrine ((R)-(-)-3,4-dihydroxy-α-(methylaminomethyl)benzyl alcohol; Eph-) with different toxic cations (methylmercury(II): CH3Hg+; dimethyltin(IV): (CH3)2Sn2+; dioxouranium(VI): UO22+) were studied in NaClaq at different ionic strengths and at T = 298.15 K (T = 310.15 K for (CH3)2Sn2+). The enthalpy changes for the protonation of epinephrine and its complex formation with UO22+ were also determined using isoperibolic titration calorimetry: HHL = -39 ± 1 kJ mol-1, HH2L = -67 ± 1 kJ mol-1 (overall reaction), HML = -26 ± 4 kJ mol-1, and HM2L2(OH)2 = 39 ± 2 kJ mol-1. The results were that UO22+ complexation by Eph- was an entropy-driven process. The dependence on the ionic strength of protonation and the complex formation constants was modeled using the extended Debye-Hückel, specific ion interaction theory (SIT), and Pitzer approaches. The sequestering ability of adrenaline toward the investigated cations was evaluated using the calculation of pL0.5 parameters. The sequestering ability trend resulted in the following: UO22+ >> (CH3)2Sn2+ > CH3Hg+. For example, at I = 0.15 mol dm-3 and pH = 7.4 (pH = 9.5 for CH3Hg+), pL0.5 = 7.68, 5.64, and 2.40 for UO22+, (CH3)2Sn2+, and CH3Hg+, respectively. Here, the pH is with respect to ionic strength in terms of sequestration.
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Affiliation(s)
- Francesco Crea
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
| | - Concetta De Stefano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
| | - Anna Irto
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
| | - Gabriele Lando
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
| | - Stefano Materazzi
- Dipartimento di Chimica, Università “La Sapienza” di Roma, Piazzale A. Moro 5, I-00185 Rome, Italy;
| | - Demetrio Milea
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
| | - Alberto Pettignano
- Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, V.le delle Scienze, ed. 17, I-90128 Palermo, Italy;
| | - Silvio Sammartano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, V.le F. Stagno d’Alcontres, 31, I-98166 Messina, Italy; (C.D.S.); (A.I.); (G.L.); (D.M.); (S.S.)
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Dimić D, Milanović Ž, Jovanović G, Sretenović D, Milenković D, Marković Z, Dimitrić Marković J. Comparative antiradical activity and molecular Docking/Dynamics analysis of octopamine and norepinephrine: the role of OH groups. Comput Biol Chem 2019; 84:107170. [PMID: 31810852 DOI: 10.1016/j.compbiolchem.2019.107170] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 12/20/2022]
Abstract
Octopamine is a neurotransmitter in invertebrates and a phenol analog of norepinephrine. The crystallographic and spectral (UV-visUV, and NMR) characteristics of octopamine were investigated experimentally and theoretically by applying appropriate level of theory, B3LYP-D3BJ/6-311++G(d,p), which reproduced well the experimental bond lengths and angles. The intramolecular interactions governing the stability of conformers were described by NBO and QTAIM analyses. The antiradical potencies of octopamine and norepinephrine towards DPPH and ABTS+ were examined with special emphasis on the preferred mechanism and effect of catechol moiety. Several techniques were used to distinguish Hydrogen Atom Transfer (HAT) and Proton Coupled Electron Transfer (PCET) mechanisms for reaction with DPPH. The calculated rate constants of the reactions with both radicals showed that Sequential Proton Loss Electron Transfer (SPLET) mechanism was dominant both thermodynamically and kinetically, with values of thermodynamic functions and rate constants clearly proving the importance of the second hydroxyl group in structure. The Molecular Docking and afterward Molecular Dynamics calculations of formed complexes between octopamine/norepinephrine with β1- and β2- adrenergic receptors examined in details the interactions that lead to the formation of stable complexes. The number of strong interactions of amino acids with norepinephrine was higher, but the absence of hydroxyl group in octopamine did not lead to a significant change in the type of interactions and stability. The formed complexes showed higher flexibility of amino acids, similar compactness of structure as proteins and increased interatomic distances of the backbone when compared to pure proteins.
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Affiliation(s)
- Dušan Dimić
- Faculty of Physical Chemistry, University of Belgrade, 12-16 Studentski trg, 11000, Belgrade, Republic of Serbia
| | - Žiko Milanović
- Bioengineering Research and Development Center, Prvoslava Stojanovića 6, 34000, Kragujevac, Republic of Serbia
| | - Goran Jovanović
- Faculty of Physical Chemistry, University of Belgrade, 12-16 Studentski trg, 11000, Belgrade, Republic of Serbia
| | - Dragana Sretenović
- Faculty of Physical Chemistry, University of Belgrade, 12-16 Studentski trg, 11000, Belgrade, Republic of Serbia
| | - Dejan Milenković
- Bioengineering Research and Development Center, Prvoslava Stojanovića 6, 34000, Kragujevac, Republic of Serbia; Institute for Information Technologies, Department of Science, University of Kragujevac, Republic of Serbia
| | - Zoran Marković
- Institute for Information Technologies, Department of Science, University of Kragujevac, Republic of Serbia; Department of Chemical-Technological Sciences, State University of Novi Pazar, Vuka Karadžića bb, 36300, Novi Pazar, Republic of Serbia
| | - Jasmina Dimitrić Marković
- Faculty of Physical Chemistry, University of Belgrade, 12-16 Studentski trg, 11000, Belgrade, Republic of Serbia.
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10
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Highly selective electrochemical detection of serotonin on polypyrrole and gold nanoparticles-based 3D architecture. Electrochem commun 2017. [DOI: 10.1016/j.elecom.2016.12.015] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Mirzaei S, Taherpour AA, Mohamadi S. Mechanistic study of allopurinol oxidation using aldehyde oxidase, xanthine oxidase and cytochrome P450 enzymes. RSC Adv 2016. [DOI: 10.1039/c6ra19197e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The oxidation reaction of allopurinol to its active metabolite (oxypurinol) is investigated using the AO and P450 enzymes. To the contrary of AO (and XO), the P450 enzyme can metabolize the allopurinol with a not self-inhibitory mechanism.
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Affiliation(s)
- Saber Mirzaei
- Department of Organic Chemistry
- Faculty of Chemistry
- Razi University
- Kermanshah
- Iran
| | - Avat Arman Taherpour
- Department of Organic Chemistry
- Faculty of Chemistry
- Razi University
- Kermanshah
- Iran
| | - Shahryar Mohamadi
- Department of Organic Chemistry
- Faculty of Chemistry
- Razi University
- Kermanshah
- Iran
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12
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Bretti C, Cigala RM, Crea F, De Stefano C, Vianelli G. Solubility and modeling acid–base properties of adrenaline in NaCl aqueous solutions at different ionic strengths and temperatures. Eur J Pharm Sci 2015; 78:37-46. [DOI: 10.1016/j.ejps.2015.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/22/2015] [Accepted: 06/26/2015] [Indexed: 10/23/2022]
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13
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Giussi JM, Gastaca B, Lavecchia MJ, Schiavoni M, Susana Cortizo M, Allegretti PE. Solvent effect in keto–enol tautomerism for a polymerizable β-ketonitrile monomer. Spectroscopy and theoretical study. J Mol Struct 2015. [DOI: 10.1016/j.molstruc.2014.10.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Nagy PI. Competing intramolecular vs. intermolecular hydrogen bonds in solution. Int J Mol Sci 2014; 15:19562-633. [PMID: 25353178 PMCID: PMC4264129 DOI: 10.3390/ijms151119562] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/17/2014] [Accepted: 10/13/2014] [Indexed: 11/17/2022] Open
Abstract
A hydrogen bond for a local-minimum-energy structure can be identified according to the definition of the International Union of Pure and Applied Chemistry (IUPAC recommendation 2011) or by finding a special bond critical point on the density map of the structure in the framework of the atoms-in-molecules theory. Nonetheless, a given structural conformation may be simply favored by electrostatic interactions. The present review surveys the in-solution competition of the conformations with intramolecular vs. intermolecular hydrogen bonds for different types of small organic molecules. In their most stable gas-phase structure, an intramolecular hydrogen bond is possible. In a protic solution, the intramolecular hydrogen bond may disrupt in favor of two solute-solvent intermolecular hydrogen bonds. The balance of the increased internal energy and the stabilizing effect of the solute-solvent interactions regulates the new conformer composition in the liquid phase. The review additionally considers the solvent effects on the stability of simple dimeric systems as revealed from molecular dynamics simulations or on the basis of the calculated potential of mean force curves. Finally, studies of the solvent effects on the type of the intermolecular hydrogen bond (neutral or ionic) in acid-base complexes have been surveyed.
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Affiliation(s)
- Peter I Nagy
- Center for Drug Design and Development, the University of Toledo, Toledo, OH 43606-3390, USA.
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Cruickshank L, Kennedy AR, Shankland N. Tautomeric and ionisation forms of dopamine and tyramine in the solid state. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Giussi JM, Allegretti PE, Cortizo MS. New copolymers of a tautomerizable β-ketonitrile monomer: Synthesis, characterization and solution tautomerism. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/pola.26238] [Citation(s) in RCA: 7] [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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17
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Nagy PI. Theoretical studies of the solvent effect on the conformation of the HO-C-C-X (X = F, NH2, NO2) moiety with competing intra- and intermolecular hydrogen bonds. J Phys Chem A 2012; 116:7726-41. [PMID: 22731938 DOI: 10.1021/jp304164g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Theoretical calculations up to the ab initio IEF-PCM/CCSD(T)/CBS//IEF-PCM/B3LYP/6-311++G** and IEF-PCM/B97D/aug-cc-pvtz levels have been performed for 2X-ethanol and 2X-phenol systems with X = F, NH(2), NO(2) in chloroform and aqueous solution. The calculated relative free energies by means of the IEF-PCM continuum dielectric method do not differ very much at the DFT and ab initio levels. Application of explicit solvent models and the FEP/MC method for determining relative solvation free energies causes, however, large deviations in the predicted equilibrium compositions, although the predominant conformation for the solute is generally in agreement with that from the corresponding IEF-PCM calculations. Existence of an intramolecular hydrogen bond (HB structure) for species with the HO-C-C-X moiety is preferred compared with a conformation when the hydrogen bond is disrupted (NoHB) for the considered F- and NO(2)-substituted molecules both in chloroform and aqueous solution. For 2NH(2)-ethanol, the HB structure is predominant in chloroform, whereas the 93:7 ratio for the OCCN trans/gauche species was obtained in aqueous solution. 2NH(2)-phenol exhibits a subtle equilibrium of the HB and NoHB conformations in both solvents. Potential of mean force calculations predict about a 10% solute association for the trans 2NH(2)-ethanol solute even in the fairly dilute 0.22 molar solution, whereas direct MC simulations do not support the maintenance of a doubly hydrogen-bonded dimer. Aqueous solution characteristics, as coordination numbers and numbers of strongly bound water molecules to the solute at T = 298 K and p = 1 atm, correspond reasonably to the derived molecular structures.
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Affiliation(s)
- Peter I Nagy
- Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390, USA.
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18
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Shiroma LY, Santhiago M, Gobbi AL, Kubota LT. Separation and electrochemical detection of paracetamol and 4-aminophenol in a paper-based microfluidic device. Anal Chim Acta 2012; 725:44-50. [DOI: 10.1016/j.aca.2012.03.011] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/05/2012] [Accepted: 03/07/2012] [Indexed: 10/28/2022]
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19
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Nagy PI. Combined ab Initio/DFT and Monte Carlo Calculation of Relative Standard Chemical Potentials in Solution. J Phys Chem B 2011; 115:9634-45. [DOI: 10.1021/jp204018s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter I. Nagy
- Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390, United States
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20
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Theoretical studies of the solvent effect on conformational equilibria and atomic charges for isolated and hydrogen-bonded dimethoxy thiadiazoles. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2011.02.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Nagy PI, Messer WS. Theoretical studies of the in-solution isomeric protonation of non-aromatic six-member rings with two nitrogens. J Phys Chem B 2011; 115:4758-67. [PMID: 21452810 DOI: 10.1021/jp202241m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
For exploring the preferred site for hydrogen bond formation, theoretical calculations have been performed for a number of six-member, nonaromatic rings allowing for alternative protonation on the ring nitrogens. Gas-phase protonation studies for test molecules indicate that the B3LYP/aug-cc-pvtz and QCISD(T)(CBS) calculations approach the experimental values within about 1 kcal/mol with considerable improvement for relative enthalpies and free energies. Relative free energies calculated at the IEF-PCM/B3LYP/aug-cc-pvtz level predict favorable protonation on the tertiary rather than on the secondary nitrogen both in aqueous solution and in a dichloromethane solvent for saturated rings. Protonation on a nitrogen atom next to a C═C bond is disfavored due to a large increase in internal energy. Monte Carlo simulations considering a counterion and Ewald summation for the long-range electrostatic effects for a 0.1 molar model system predict ΔG(solv)/MC values generally less negative than from the IEF-PCM calculations. These results make the protonation on the tertiary nitrogen even more favored. The solute-solvent pair-energy distribution depends sensitively on the applied model. In conclusion, the freely moving anion has been considered as the most relevant model with overall neutrality for the system and applying the least restrictions.
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Affiliation(s)
- Peter I Nagy
- Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390, United States.
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22
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Santos SM, Costa PJ, Lankshear MD, Beer PD, Félix V. Molecular dynamics study of a heteroditopic-calix[4]diquinone-assisted transfer of KCl and dopamine through a water-chloroform liquid-liquid interface. J Phys Chem B 2010; 114:11173-80. [PMID: 20690692 DOI: 10.1021/jp100724e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ability of two heteroditopic calix[4]diquinone receptors to transport a KCl ion-pair and a dopamine zwitterion through a water-chloroform interface was investigated via molecular dynamics (MD) simulations. Gas-phase conformational analysis has been carried on KCl and dopamine receptor binding associations and the lowest energy structures found in both cases show that the recognition of KCl and dopamine zwitterion occurs through multiple and cooperative N-H...anion and O...cation bonding interactions, with the receptor adopting equivalent folded conformations stabilized by pi-stacking interactions. The unconstrained MD simulations performed on KCl and dopamine complexes inserted in either the chloroform or water phase revealed that receptors are preferentially located at the interface with the hydrophobic tert-butyl groups of the calix[4]diquinone moiety immersed in the chloroform bulk while the polar anion binding cavity is directed toward the water phase. When the KCl complex is placed in chloroform, the release of the ion-pair occurs only after the first contact with the water interface, being a nonsimultaneous event, with the chloride anion leaving the receptor before the potassium cation. The dopamine, via the -NH(3)(+) binding entity, remains bound to the receptor during the entire time of the MD simulation (10 ns). In contrast, when both complexes were inserted in the water bulk, the full release of KCl and dopamine are fast events. The potentials of mean force (PMFs), associated with the migration of the complexes from chloroform to water through the interface, were calculated from steered molecular dynamics (SMD) simulations. The PMFs for the free KCl and zwitterionic dopamine migrations were also obtained for comparison purposes. The transport of KCl from water to chloroform (the reverse path) mediated by the receptor has a free energy barrier estimated in 6.50 kcal mol(-1), which is 3.0 kcal mol(-1) smaller than that found for the free KCl. The transport of dopamine complex along the reverse path is characterized by downhill energy profile, with a small free energy barrier of 6.56 kcal mol(-1).
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Affiliation(s)
- Sérgio M Santos
- Departamento de Química-CICECO and Secção Autonóma de Ciências da Saúde, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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23
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Friant-Michel P, Ruiz-López MF. Glycine Dimers: Structure, Stability, and Medium Effects. Chemphyschem 2010; 11:3499-504. [DOI: 10.1002/cphc.201000354] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Tejwani RW, Stouch TR, Anderson BD. Substituent effects on the ionization and partitioning of p-(aminoethyl)phenols and structurally related compounds: Electrostatic effects dependent on conformation. J Pharm Sci 2009; 98:4534-44. [DOI: 10.1002/jps.21775] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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Mazák K, Dóczy V, Kökösi J, Noszál B. Proton speciation and microspeciation of serotonin and 5-hydroxytryptophan. Chem Biodivers 2009; 6:578-90. [PMID: 19353542 DOI: 10.1002/cbdv.200800087] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Protonation equilibria of the neurotransmitter serotonin and its precursor 5-hydroxytryptophan (5-HTP) are characterized at the macroscopic and microscopic levels. 1H-NMR-pH and UV-pH titrations were carried out to determine the macroconstants. Microconstants were obtained by appropriate combination of interactivity parameters and model compounds, allowing the calculation of all the twelve microconstants, the eight microspecies concentrations, and three site-interactivity parameters of 5-HTP, for which no microconstants have been reported earlier. NMR-pH Profiles, macro- and microscopic protonation schemes, and species-specific distribution diagrams are presented. The physicochemical data obtained can help to understand the steric and electronic features governing the selectivity of binding and to design new therapeutic agents.
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Affiliation(s)
- Károly Mazák
- Semmelweis University, Institute of Pharmaceutical Chemistry, Hogyes E. u. 9, H-1092 Budapest
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26
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Németh T, Jankovics P, Németh-Palotás J, Kőszegi-Szalai H. Determination of paracetamol and its main impurity 4-aminophenol in analgesic preparations by micellar electrokinetic chromatography. J Pharm Biomed Anal 2008; 47:746-9. [DOI: 10.1016/j.jpba.2008.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 02/26/2008] [Accepted: 03/06/2008] [Indexed: 10/22/2022]
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27
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Nucci NV, Scott JN, Vanderkooi JM. Coupling of complex aromatic ring vibrations to solvent through hydrogen bonds: effect of varied on-ring and off-ring hydrogen-bonding substitutions. J Phys Chem B 2008; 112:4022-35. [PMID: 18331017 DOI: 10.1021/jp0758770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we examine the coupling of a complex ring vibration to solvent through hydrogen-bonding interactions. We compare phenylalanine, tyrosine, l-dopa, dopamine, norepinephrine, epinephrine, and hydroxyl-dl-dopa, a group of physiologically important small molecules that vary by single differences in H-bonding substitution. By examination of the temperature dependence of infrared absorptions of these molecules, we show that complex, many-atom vibrations can be coupled to solvent through hydrogen bonds and that the extent of that coupling is dependent on the degree of both on- and off-ring H-bonding substitution. The coupling is seen as a temperature-dependent frequency shift in infrared spectra, but the determination of the physical origin of that shift is based on additional data from temperature-dependent optical experiments and ab initio calculations. The optical experiments show that these small molecules are most sensitive to their immediate H-bonding environment rather than to bulk solvent properties. Ab initio calculations demonstrate H-bond-mediated vibrational coupling for the system of interest and also show that the overall small molecule solvent dependence is determined by a complex interplay of specific interactions and bulk solvation characteristics. Our findings indicate that a full understanding of biomolecule vibrational properties must include consideration of explicit hydrogen-bonding interactions with the surrounding microenvironment.
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Affiliation(s)
- Nathaniel V Nucci
- Department of Biochemistry and Biophysics, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, Pennsylvania 19104, USA.
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28
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Tejwani RW, Anderson BD. Influence of Intravesicular pH Drift and Membrane Binding on the Liposomal Release of a Model Amine‐Containing Permeant. J Pharm Sci 2008; 97:381-99. [PMID: 17694543 DOI: 10.1002/jps.21108] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Accurate determination of intrinsic permeability coefficients is critical to the development of structure-permeability relationships and liposomal delivery systems. The apparent release rate of a drug from liposomes may reflect not only its intrinsic permeability coefficient and barrier properties but also a variety of underlying equilibria including drug ionization, membrane binding or complexation, and kinetic processes such as buffer exchange. Additionally, transport of ionizable drugs that are initially at high concentrations in liposomes can generate or dissipate pH gradients across the barrier causing deviations from classical pH-permeability profiles. In this study, the liposomal release of a model amine (tyramine) is determined as a function of drug loading, intravesicular pH, and buffer composition. Kinetic models are derived to study effects of such equilibria (e.g., ionization, membrane binding) and kinetic processes (e.g., pH drift and acid/base carriers). All equilibrium constants needed for the models were independently measured and used. The barrier properties of the lipid bilayers under the experimental conditions were assessed by monitoring the transport of mannitol and bretylium as a function of pH. A corrected intrinsic permeability coefficient of 0.04 cm/s was in close agreement with the value predicted from the barrier domain model for bilayer permeability, suggesting that all perturbing factors were properly addressed.
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Affiliation(s)
- Ravindra W Tejwani
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40506, USA
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29
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Benbrahim N, Rahmouni A, Ruiz-López MF. A theoretical study of medium effects on the structure of the glycine analogue aminomethylphosphonic acid. Phys Chem Chem Phys 2008; 10:5624-32. [DOI: 10.1039/b804694h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Lu H, Chen X, Zhan CG. First-principles calculation of pKa for cocaine, nicotine, neurotransmitters, and anilines in aqueous solution. J Phys Chem B 2007; 111:10599-605. [PMID: 17691837 PMCID: PMC2882246 DOI: 10.1021/jp072917r] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The absolute pKa values of 24 representative amine compounds, including cocaine, nicotine, 10 neurotransmitters, and 12 anilines, in aqueous solution were calculated by performing first-principles electronic structure calculations that account for the solvent effects using four different solvation models, i.e., the surface and volume polarization for electrostatic interaction (SVPE) model, the standard polarizable continuum model (PCM), the integral equation formalism for the polarizable continuum model (IEFPCM), and the conductor-like screening solvation model (COSMO). Within the examined computational methods, the calculations using the SVPE model lead to the absolute pKa values with the smallest root-mean-square-deviation (rmsd) value (1.18). When the SVPE model was replaced by the PCM, IEFPCM, and COSMO, the rmsd value of the calculated absolute pKa values became 3.21, 2.72, and 3.08, respectively. All types of calculated pKa values linearly correlate with the experimental pKa values very well. With the empirical corrections using the linear correlation relationships, the theoretical pKa values are much closer to the corresponding experimental data and the rmsd values become 0.51-0.83. The smallest rmsd value (0.51) is also associated with the SVPE model. All of the results suggest that the first-principles electronic structure calculations using the SVPE model are a reliable approach to the pKa prediction for the amine compounds.
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Affiliation(s)
- Haiting Lu
- Key Laboratory of Pesticide & Chemical Biology of the Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, KY 40536
| | - Xi Chen
- Key Laboratory of Pesticide & Chemical Biology of the Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, KY 40536
| | - Chang-Guo Zhan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, KY 40536
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31
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Baker CM, Grant GH. The effect of solvation on biomolecular conformation: 2-amino-1-phenylethanol. J Phys Chem B 2007; 111:9940-54. [PMID: 17672488 DOI: 10.1021/jp071059w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small molecule neurotransmitters form one the most important classes of pharmaceutical molecules. While the behavior of these molecules in their neutral forms in the gas phase is well understood, their behavior in more biologically relevant scenarios (protonated and in aqueous solution) has received comparatively little attention. Here we address this problem by using molecular mechanics simulations to build up a detailed picture of the conformational behavior of 2-amino-1-phenylethanol, a noradrenaline analogue, in aqueous solution in both its neutral and protonated forms. For the sake of comparison, equivalent simulations are also performed on the gas-phase molecules and gas-phase hydrated clusters. These calculations reveal the important role that water has to play in determining the conformational preferences and dynamic behavior of the molecules. Water molecules are found to bridge between the various functional groups within the molecule, significantly affecting their relative stabilities in comparison to the gas-phase values. The reorganization of these solvation structures also provides a mechanism for conformational interconversion. The role of the solvent in mediating interactions between the various functional groups within the molecule suggests that in noradrenaline the catechol groups will be able to interact, albeit indirectly, with the other functional groups, thereby influencing the behavior of the molecule.
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Affiliation(s)
- Christopher M Baker
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3QZ
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32
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Structure of levofloxacin in hydrophilic and hydrophobic media: Relationship to its antibacterial properties. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.05.077] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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33
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Macleod NA, Simons JP. Infrared photodissociation spectroscopy of protonated neurotransmitters in the gas phase. Mol Phys 2007. [DOI: 10.1080/00268970701194285] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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34
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Macleod‡ NA, Simons JP. Infrared photodissociation spectroscopy of protonated neurotransmitters in the gas phase – ARTICLE WITHDRAWN. Mol Phys 2006. [DOI: 10.1080/00268970601110340] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Nagy PI, Tejada FR, Messer WS. Theoretical Studies of the Tautomeric Equilibria for Five-Member N-Heterocycles in the Gas Phase and in Solution. J Phys Chem B 2005; 109:22588-602. [PMID: 16853941 DOI: 10.1021/jp053076w] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tautomeric equilibria have been studied for five-member N-heterocycles and their methyl derivatives in the gas phase and in different solvents with dielectric constants of epsilon = 4.7-78.4. The free energy changes differently for tautomers upon solvation as compared to the gas phase, resulting in a shift of the equilibrium constant in solution. Solvents with increasing dielectric constant produce more negative solute-solvent interaction energies and increasing internal energies. The methyl-substituted imidazole and pyrrazole form delicate equilibria between two tautomeric forms. Depending on the solvent, the methyl-substituted triazoles and tetrazole have one or two major tautomers in solution. When estimating the relative solvation free energies by means of an explicit solvent model and using the FEP/MC method, one observes that the preferred tautomers differ in several cases from those predicted by the continuum solvent model. The 1,2-prototropic shift, as an intramolecular tautomerization path, requires about 50 kcal/mol activation energy for imidazole in the gas phase, and this route is also disfavored in a solution. The calculated activation free energy along the intramolecular path is 48-50 kcal/mol in chloroform and water as compared to a literature value of 13.6 kcal/mol for pyrrazole in DMSO. A molecular dynamics computer experiment favors the formation of an imidazole chain in chloroform, making the 1,3-tautomerization feasible along an intermolecular path in nonprotic solvents. In aqueous solution, one strong N-H...Ow hydrogen bond is formed for each species, whereas all other nitrogens in the ring form weaker, N...HwOw type hydrogen bonds. The tetrahydrofuran solvent acts as a hydrogen bond acceptor and forms N-H... Oether bonds. Molecules of the dichloromethane solvent are in favorable dipole-dipole interactions with the solute. The results obtained are useful in the design of N-heterocyclic ligands forming specified hydrogen bonds with protein side chains.
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Affiliation(s)
- Peter I Nagy
- Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390, USA.
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36
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Nagy * PI, Völgyi G, Takács-Novák § K. Tautomeric and conformational equilibria of tyramine and dopamine in aqueous solution. Mol Phys 2005. [DOI: 10.1080/00268970500075370] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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37
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Nagy PI, Erhardt PW. Monte Carlo Simulations of the Solution Structure of Simple Alcohols in Water−Acetonitrile Mixtures. J Phys Chem B 2005; 109:5855-72. [PMID: 16851638 DOI: 10.1021/jp045570q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monte Carlo simulations have been performed to explore the solution structure of ethyl, isopropyl, isobutyl, and tertiary butyl alcohols in pure water, pure acetonitrile, and different mixtures of the two solvents. The explicit solvent studies in NpT ensembles at T = 298 K illustrate that the solute "discriminates" the solvent's components and that the composition of the first solvation shell differs from that of the bulk solution. Since the polarizable continuum dielectric method (PCM) does not presently model the solvation of molecules with both polar and apolar sites in mixed protic solvents, we suggest a direction for further program development wherein a continuum dielectric method would accept more than one solvent and the solute sites would be solvated by user-defined solvent components. The prevailing solvation model will be determined upon the lowest free energy calculated for a particular solvation pattern of the solute having a specific conformational/tautomeric state. Characterization of equilibrium hydrogen-bond formation becomes a complicated problem that depends on the chemical properties of the solute and its conformation, as well as upon the varying nature of the first solvation shell. For example, while the number of hydrogen bonds to secondary and tertiary alcohol solutes are nearly constant in pure water and in water-acetonitrile mixtures with at least 50% water content, the number of hydrogen bonds to primary alcohols gradually decreases for most of their conformations when acetonitrile content is increased. Nonetheless, the calculations indicate that O-H...O(water) hydrogen bonds are still possible in a small fraction of the arrangements for the solution models with water content of 30% or less. The isopentene solute does not form any observable hydrogen bonds, despite having an electron-rich, double-bond site.
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Affiliation(s)
- Peter I Nagy
- Center for Drug Design and Development, College of Pharmacy, The University of Toledo, Toledo, OH 43606-3390, USA.
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38
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Volz TJ, Schenk JO. A comprehensive atlas of the topography of functional groups of the dopamine transporter. Synapse 2005; 58:72-94. [PMID: 16088952 DOI: 10.1002/syn.20183] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The neuronal dopamine transporter (DAT) is a transmembrane transporter that clears DA from the synaptic cleft. Knowledge of DAT functional group topography is a prerequisite for understanding the molecular basis of transporter function, the actions of psychostimulant drugs, and mechanisms of dopaminergic neurodegeneration. Information concerning the molecular interactions of drugs of abuse (such as cocaine, amphetamine, and methamphetamine) with the DAT at the functional group level may also aid in the development of compounds useful as therapeutic agents for the treatment of drug abuse. This review will provide a cumulative and comprehensive focus on the amino acid functional group topography of the rat and human DATs, as revealed by protein chemical modification and the techniques of site-directed mutagenesis. The results from these studies, represented mostly by site-directed mutagenesis, can be classified into several main categories: modifications without substantial affects on substrate transport, DAT membrane expression, or cocaine analog binding; those modifications which alter both substrate transport and cocaine analog binding; and those that affect DAT membrane expression. Finally, some modifications can selectively affect either substrate transport or cocaine analog binding. Taken together, these literature results show that domains for substrates and cocaine analogs are formed by interactions with multiple and sometimes distinct DAT functional groups.
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Affiliation(s)
- Trent J Volz
- Department of Chemistry, Washington State University, Pullman, WA 99164, USA
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39
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Nagy PI, Tejada FR, Sarver JG, Messer WS. Conformational Analysis and Derivation of Molecular Mechanics Parameters for Esters and Thioesters. J Phys Chem A 2004. [DOI: 10.1021/jp0490251] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter I. Nagy
- Department of Medicinal and Biological Chemistry, The University of Toledo, Toledo, Ohio 43606-3390, Department of Pharmacology, The University of Toledo, Toledo, Ohio 43606-3390, and Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390
| | - Frederick R. Tejada
- Department of Medicinal and Biological Chemistry, The University of Toledo, Toledo, Ohio 43606-3390, Department of Pharmacology, The University of Toledo, Toledo, Ohio 43606-3390, and Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390
| | - Jeffrey G. Sarver
- Department of Medicinal and Biological Chemistry, The University of Toledo, Toledo, Ohio 43606-3390, Department of Pharmacology, The University of Toledo, Toledo, Ohio 43606-3390, and Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390
| | - William S. Messer
- Department of Medicinal and Biological Chemistry, The University of Toledo, Toledo, Ohio 43606-3390, Department of Pharmacology, The University of Toledo, Toledo, Ohio 43606-3390, and Center for Drug Design and Development, The University of Toledo, Toledo, Ohio 43606-3390
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40
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Nagy PI. Effects of the Solute Model and Concentration on the Calculated Free Energy of Hydration in Explicit Solvent Solution. J Phys Chem B 2004. [DOI: 10.1021/jp049249j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P. I. Nagy
- Department of Medicinal and Biological Chemistry, The University of Toledo, Toledo, Ohio 43606-3390
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