Publications by authors named "Anil Boda"

10 Publications

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Characterization of Thorium-Pyrazinoic acid complexation and its decorporation efficacy in human cells and blood.

Chemosphere 2021 May 4;271:129547. Epub 2021 Jan 4.

Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, 400094, India.

Thorium (Th) exposure to the human beings is a radiochemical hazard and the chelation therapy by suitable drugs is the major prevention approach to deal with. The present studies aimed at usage of pyrazinoic acid (PCA), which is a prodrug to treat tuberculosis, for its usage as decorporating agent for thorium from human body. The present studies provide a comprehensive knowledge on the chemical interaction and biological efficacy of pyrazinoic acid (PCA) for decorporation of Thorium from the human body. The thermodynamic parameters for Th-PCA speciation are determined by both experiment and theory. The potentiometric data analysis and Electro-Spray Ionization Mass Spectrometry (ESI-MS) studies revealed the formation of ML (i = 1-4) species with the decrease in stepwise stability constants. All the species formations are endothermic reactions and are predominantly entropy-driven. Biological experiments using human erythrocytes, whole blood and normal human lung cells showed cytocompatibility and decorporation ability of PCA for Thorium. Density functional calculations have been carried out to get insights on interaction process at molecular level. The experimental results and theoretical predictions found to be in line with each other. Present findings on complexation of Th by PCA and its evaluation in human cells and blood would further motivate determination of its safety levels and decorporation efficacy in animal models.
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http://dx.doi.org/10.1016/j.chemosphere.2021.129547DOI Listing
May 2021

Aquatic interaction of uranium with two naturally ubiquitous pyrazine compounds: Speciation studies by experiment and theory.

Chemosphere 2020 Jun 6;249:126116. Epub 2020 Feb 6.

Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.

The present studies interpret the speciation of uranyl (UO) with the most ubiquitous class of natural species named pyrazines in terms of stability, speciation and its identification, thermodynamics, spectral properties determined by a range of experimental techniques and further evidenced by theoretical insights. UO forms ML and ML kind of species with a qualitative detection of ML species, while the ESI-MS identified the formation of all the complexes including ML. Both the ligands act as bidentate chelators with a difference in ring size and coordinating atoms in the complex formed. The ML complexes involve the third ligand participation as monodentate via carboxylate only due to the restricted coordination number and space around the UO ion to accommodate three ligand molecules in its primary coordination sphere. All the complexes are found to be endothermic and purely entropy driven formations. The complex formations showed redshift in the absorption spectra and the shift was further enhanced from ML to ML formation. The UO ion redox properties are used to explore the redox potential and heterogeneous electron-transfer kinetic parameters as a function of pH and concentration of UO in presence of pyrazine carboxylates. Interestingly, the cyclic voltammograms identified the ligands also as redox sensitive. The theoretical calculation gave inputs to understand the complex formation at the molecular level with major emphasis on geometry optimization, energetics, bonding parameters, molecular orbital diagrams and bond critical point analyses. The experimental observations in combination with theoretical addendum provided detailed knowledge on the interaction of UO with pyrazine-2-carboxylate and pyrazine-2,3-dicarboxylates.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126116DOI Listing
June 2020

Reduction in Coordination Number of Eu(III) on Complexation with Pyrazine Mono- and Di-Carboxylates in Aqueous Medium.

Inorg Chem 2019 Aug 31;58(16):11180-11194. Epub 2019 Jul 31.

Chemical Engineering Division , Bhabha Atomic Research Centre , Mumbai 400085 , India.

The denticity, flexibility, and steric hindrance of the ligand are key factors in deciding the mode and number of coordination around a metal ion on complex formation. The thermodynamic aspects of lanthanide complexation with various multidentate ligands provides a significant insight into understand the coordination chemistry of lanthanides in framing the relevant metal organic networks for the applications in biological, biochemical and medical aspects. The pyrazine carboxylic acids are known to form many structurally important complexes and further can form chelates with coordination number of eight for europium in which more water molecules can be knocked out from the primary coordination sphere than demanded by denticity of the ligand. The present studies aimed at ESI-MS characterization and determination of the thermodynamic parameters (log β, Δ, Δ, and Δ), luminescence properties of europium complexes with pyrazine-2-carboxylate and pyrazine-2,3-dicarboxylate in aqueous solutions by experiment as well as theory. Time resolved luminescence spectroscopy supported by DFT calculations are carried out to optimize the stable geometries of the complexes with various modes of binding and coordination. Furthermore, the thermodynamic parameters estimated theoretically have been used to trace the path of complex formation.
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http://dx.doi.org/10.1021/acs.inorgchem.9b01772DOI Listing
August 2019

Thorium decorporation efficacy of rationally-selected biocompatible compounds with relevance to human application.

J Hazard Mater 2019 03 13;365:952-961. Epub 2018 Nov 13.

Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India. Electronic address:

During civil, nuclear or defense activities, internal contamination of actinides in humans and mitigation of their toxic impacts are of serious concern. Considering the health hazards of thorium (Th) internalization, an attempt was made to examine the potential of ten rationally-selected compounds/formulations to decorporate Th ions from physiological systems. The Th-induced hemolysis assay with human erythrocytes revealed good potential of tiron, silibin (SLB), phytic acid (PA) and Liv.52 (L52) for Th decorporation, in comparison to diethylenetriaminepentaacetic acid, an FDA-approved decorporation drug. This was further validated by decorporation experiments with relevant human cell models (erythrocytes and liver cells) and biological fluid (blood) under pre-/post-treatment conditions, using inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM). Furthermore, density functional theory-based calculations and extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed the formation of Th complex by these agents. Amongst the chosen biocompatible agents, tiron, SLB, PA and L52 hold promise to enhance Th decorporation for human application.
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http://dx.doi.org/10.1016/j.jhazmat.2018.11.038DOI Listing
March 2019

Complexation of thorium with pyridine monocarboxylate-N-oxides: Thermodynamic and computational studies.

J Chem Thermodyn 2018 Jul 8;122:13-22. Epub 2018 Mar 8.

Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.

The feed wastes and waste water treatment plants are the major sources for the entry of N-oxides into the soils then to aquatic life. The complexation of actinides with potentially stable anthropogenic ligands facilitate the transportation and migration of the actinides from the source confinement. The present study describes the determination of thermodynamic parameters for the complexation of Th(IV) with the three isomeric pyridine monocarboxylates (PCNO) namely picolinic acid-N-oxide (PANO), nicotinic acid-N-oxide (NANO) and isonicotinic acid-N-oxide (IANO). The potentiometric and isothermal calorimetric titrations were carried out to determine the stability and enthalpy of the formations for all the Th(IV)-PCNO complexes. Th-PANO complexes are more stable than Th-NANO and Th-IANO complexes which can be attributed to chelate formation in the former complexes. Formation of all the Th-PCNO complexes are endothermic and are entropy driven. The geometries for all the predicted complexes are optimized the energies, bond distances and charges on individual atoms are obtained using TURBOMOLE software. The theoretical calculation corroborated the experimental determinations.
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http://dx.doi.org/10.1016/j.jct.2018.02.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094258PMC
July 2018

Structural, luminescence, thermodynamic and theoretical studies on mononuclear complexes of Eu(III) with pyridine monocarboxylate-N-oxides in aqueous solution.

Spectrochim Acta A Mol Biomol Spectrosc 2018 Feb 9;190:150-163. Epub 2017 Sep 9.

Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.

The mononuclear complexes formed by Eu(III) with three isomeric pyridine monocarboxylate-N-oxides namely picolinic acid-N-oxide (PANO), nicotinic acid-N-oxide (NANO) and isonicotinic acid-N-oxide (IANO) in aqueous solutions were studied by potentiometry, luminescence spectroscopy and isothermal titration calorimetry (ITC) to determine the speciation, coordination, luminescence properties and thermodynamic parameters of the complexes formed during the course of the reaction. More stable six membered chelate complexes with stoichiometry (ML, i=1-4) are formed by Eu(III) with PANO while non chelating ML and ML complexes are formed by NANO and IANO. The stability of Eu(III) complexes follow the order PANO>IANO>NANO. The ITC studies inferred an endothermic and innersphere complex formation of Eu(III)-PANO and Eu(III)-IANO whereas an exothermic and outer-sphere complex formation for Eu(III)-NANO. The luminescence life time data further supported the ITC results. Density functional theoretical calculations were carried out to optimize geometries of the complexes and to estimate the energies, structural parameters (bond distances, bond angles) and charges on individual atoms of the same. Theoretical approximations are found to be in good agreement with the experimental observations.
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http://dx.doi.org/10.1016/j.saa.2017.09.013DOI Listing
February 2018

Benzene-centered tripodal diglycolamides: synthesis, metal ion extraction, luminescence spectroscopy, and DFT studies.

Dalton Trans 2017 Jan;46(5):1431-1438

Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

Three benzene-centered tripodal diglycolamides (Bz-T-DGAs) were synthesized and evaluated for actinide, lanthanide, and fission product ion extraction. 1,3,5-Triethylbenzene-based tripodal DGA (LI) showed high distribution ratio (D) values for Am and Eu in a mixture of 95% n-dodecane and 5% iso-decanol at 3 M HNO. Eu/Am separation factors, in the range of 8-10, were obtained at 1 M HNO which decreased at higher acidities with the exception of LII which did not show much change. Benzene-1,3,5-triamide-based tripodal DGA (LII) exhibited a high D-value for Pu compared to the other ligands. Slope analysis showed the formation of 1 : 1 or 1 : 2 complexes is dependent on the ligand. The nature of the complexes was further studied with luminescence spectroscopy (Eu complexes) and DFT calculations (Am complexes).
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http://dx.doi.org/10.1039/c6dt04034aDOI Listing
January 2017

Density functional theoretical investigation of remarkably high selectivity of the Cs+ ion over the Na+ ion toward macrocyclic hybrid calix-bis-crown ether.

J Phys Chem A 2012 Aug 14;116(33):8615-23. Epub 2012 Aug 14.

Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, India 400085.

Density functional theoretical analysis was performed to explore the enhanced selectivity of the Cs(+) ion over the Na(+) ion with hybrid calix[4]-bis-crown macrocyclic ligand compared to 18-crown-6 ether. The calculated selectivity data for Cs(+)/Na(+) with hybrid calix[4]-bis-crown ligand using the free energy of extraction employing thermodynamical cycle was found to be in excellent agreement with the reported solvent extraction results. The present study further establishes that the selectivity for a specific metal ion between two competitive ligands is primarily due to the complexation free energy of the ligand to the metal ions and is independent of the aqueous solvent effect but strongly depends on the dielectricity of the organic solvents and the presence of the coanion.
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http://dx.doi.org/10.1021/jp303817sDOI Listing
August 2012

Ab initio and density functional theoretical design and screening of model crown ether based ligand (host) for extraction of lithium metal ion (guest): effect of donor and electronic induction.

J Mol Model 2012 Aug 10;18(8):3507-22. Epub 2012 Feb 10.

Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India.

The structures, energetic and thermodynamic parameters of model crown ethers with different donor, cavity and electron donating/ withdrawing functional group have been determined with ab initio MP2 and density functional theory in gas and solvent phase. The calculated values of binding energy/ enthalpy for lithium ion complexation are marginally higher for hard donor based aza and oxa crown compared to soft donor based thia and phospha crown. The calculated values of binding enthalpy for lithium metal ion with 12C4 at MP2 level of theory is in good agreement with the available experimental result. The binding energy is altered due to the inductive effect imparted by the electron donating/ withdrawing group in crown ether, which is well correlated with the values of electron transfer. The role of entropy for extraction of hydrated lithium metal ion by different donor and functional group based ligand has been demonstrated. The HOMO-LUMO gap is decreased and dipole moment of the ligand is increased from gas phase to organic phase because of the dielectric constant of the solvent. The gas phase binding energy is reduced in solvent phase as the solvent molecules weaken the metal-ligand binding. The theoretical values of extraction energy for LiCl salt from aqueous solution in different organic solvent is validated by the experimental trend. The study presented here should contribute to the design of model host ligand and screening of solvent for metal ion recognition and thus can contribute in planning the experiments.
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http://dx.doi.org/10.1007/s00894-011-1348-1DOI Listing
August 2012

DFT modeling on the suitable crown ether architecture for complexation with Cs⁺ and Sr²⁺ metal ions.

J Mol Model 2011 May 30;17(5):1091-108. Epub 2010 Jul 30.

Chemical Engineering Group, Bhabha Atomic Research center, Mumbai 400085, India.

Crown ether architectures were explored for the inclusion of Cs(+) and Sr(2+) ions within nano-cavity of macrocyclic crown ethers using density functional theory (DFT) modeling. The modeling was undertaken to gain insight into the mechanism of the complexation of Cs(+) and Sr(2+) ion with this ligand experimentally. The selectivity of Cs(+) and Sr(2+) ions for a particular size of crown ether has been explained based on the fitting and binding interaction of the guest ions in the narrow cavity of crown ethers. Although, Di-Benzo-18-Crown-6 (DB18C6) and Di-Benzo-21-Crown-7 (DB21C7) provide suitable host architecture for Sr(2+) and Cs(+) ions respectively as the ion size match with the cavity of the host, but consideration of binding interaction along with the cavity matching both DB18C6 and DB21C7 prefers Sr(2+) ion. The calculated values of binding enthalpy of Cs metal ion with the crown ethers were found to be in good agreement with the experimental results. The gas phase binding enthalpy for Sr(2+) ion with crown ether was higher than Cs metal ion. The ion exchange reaction between Sr and Cs always favors the selection of Sr metal ion both in the gas and in micro-solvated systems. The gas phase selectivity remains unchanged in micro-solvated phase. We have demonstrated the effect of micro-solvation on the binding interaction between the metal ions (Cs(+) and Sr(2+)) and the macrocyclic crown ethers by considering micro-solvated metal ions up to eight water molecules directly attached to the metal ion and also by considering two water molecules attached to metal-ion-crown ether complexes. A metal ion exchange reaction involving the replacement of strontium ion in metal ion-crown ether complexes with cesium ion contained within a metal ion-water cluster serves as the basis for modeling binding preferences in solution. The calculated O-H stretching frequency of H(2)O molecule in micro-solvated metal ion-crown complexes is more red-shifted in comparison to hydrated metal ions. The calculated IR spectra can be compared with an experimental spectrum to determine the presence of micro-solvated metal ion-crown ether complexes in extractant phase.
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http://dx.doi.org/10.1007/s00894-010-0812-7DOI Listing
May 2011