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Crystal structure, Hirshfeld surface analysis and computational studies of (E)-2, 2-dimethyl-4-styryl-2, 3-dihydro-1H-benzo [b][1, 4] diazepine

  • Authors: Odame, Felix , Madanhire, T , Hosten, Eric C , Lobb, Kevin A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452677 , vital:75161 , xlink:href="https://doi.org/10.48317/IMIST.PRSM/morjchem-v11i3.40773"
  • Description: The crystal structure, Hirshfeld surface analysis, and computational studies of (E)-2,2-dimethyl-4-styryl-2,3-dihydro-1H-benzo[b][1,4]diazepine have been presented. The compound crystallized in the monoclinic space group P21/c with 8 molecules in it unit cell. A comparison of the experimental and computed bond lengths and bond angles showed good agreement among the results with varying deviations from each other. A discussion of the Hirshfeld surface analysis of the compound have been carried out to provide insight into the structural properties of the compound.
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  • Date Issued: 2023

Crystal Structure, Hirshfeld Surface Analysis and Computational Studies of Two Benzo [b][1, 4] Diazepine Derivatives

  • Authors: Odame, Felix , Madanhire, T , Hosten, Eric C , Lobb, Kevin A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452689 , vital:75162 , xlink:href="https://doi.org/10.1134/S0022476623120041"
  • Description: The DFT computational studies, crystal structures and Hirshfeld surface analysis of (E)-4-(2-chlorostyryl)-2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (1) and (E)-4-(2-(2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-4-yl)vinyl)phenol (2) have been presented. The compounds crystallized in the monoclinic space group P21/c with 4 molecules in their unit cells each. The experimental and computed bond lengths and bond angles deviated from each other to some extent but also showed good agreement with each other in some cases. Hirshfeld surface analysis of the compounds provided further information about the structural properties of the compounds.
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  • Date Issued: 2023

Solvent promoted tautomerism in thione-containing tetraazatricyclics: evidence from 1H NMR spectroscopy and transition state studies

  • Authors: Odame, Felix , Tshentu, Zenixole R , Lobb, Kevin A
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/453198 , vital:75230 , xlink:href="https://link.springer.com/article/10.1007/s00894-022-05204-w"
  • Description: Tautomerism in the nitro substituted thione-containing traazatricyclics has been investigated. Evidence from 1 H NMR indicating the existence of the tautomers has been augmented with computational studies providing evidence of the stability or otherwise of these tautomers. The role of water and DMSO in the formation of the tautomers has been explained. The role of the nitro group in assisting in the formation of the tautomers has been discussed.
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  • Date Issued: 2022

Synthesis, characterization, computational studies and DPPH scavenging activity of some triazatetracyclic derivatives

  • Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Krause, Jason , Frost, Carminita L , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/451186 , vital:75026 , xlink:href="https://doi.org/10.1007/s13738-021-02158-3"
  • Description: Some dihydrobenzo[4,5]imidazo[1,2-c]quinazolines have been synthesized from aldehydes and ketones, using the ketones as both reagents and solvents and tetrahydrofuran (THF) as the solvent for the aldehydes, to yield the triazatetracyclics. The compounds have been characterized with spectroscopy and microanalysis. The crystal structures of 9,9-dimethyl-8,10,17- triazatetracyclo[8.7.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaene (I), 9-butyl-9-methyl-8,10,17-triazatetracyclo[8.7.0.02 , 7 .011,16]heptadeca-(17),2,4,6,11(16),12,14-heptaene (III) and 9-phenyl-8,10,17-triazatetracyclo[8.7.0 02 7.011,16] heptadeca-1(17),2,4,6,11(16),12,14-heptaene (VIII) have been discussed. The computed NMR, IR, molecular electrostatic potential and frontier molecular orbitals of compounds I, III and VIII have been discussed. The M06 functional gave most of its values closest to the experimental values for the bond lengths and bond angles of compounds I and III. For compound VIII, none of the functionals gave values for bond lengths and bond angles that were consistent with the experimental values, but M06 gave values closest to experimental values. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of the triazatetracyclics showed that compound I exhibits signifcant DPPH scavenging activity with an IC50 of 56.18 µM compared to 2.37 µM for ascorbic acid.
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  • Date Issued: 2021

A novel gold (I)-mediated intramolecular transamidation of benzoyl thiourea derivatives to form benzamides via dethiocyanation

  • Authors: Odame, Felix , Woodcock, Guillaume , Hosten, Eric C , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/446988 , vital:74575 , xlink:href="https://doi.org/10.1016/j.jorganchem.2020.121359"
  • Description: A novel gold(I)-mediated intramolecular transamidation of thiourea derivatives to yield benzamides via dethiocyanation have been achieved by the reaction of 3-(1,3-benzothiazol-2-yl)-1-(benzoyl)thiourea derivatives in the presence of gold(I) precursors. The compounds have been characterized using IR, NMR, GC-MS and microanalysis. The single crystal XRD of 3-(1,3-benzothiazol-2-yl)-1-(3-bromobenzoyl)thiourea (5), 3-(1,3-benzothiazol-2-yl)-1-(3-methoxybenzoyl)thiourea (6), N-(benzothiazol-2-yl)benzamide (10), N-(benzothiazol-2-yl)-3-chlorobenzamide (11), N-(benzothiazol-2-yl)-4-nitrobenzamide (12), N-(benzothiazol-2-yl)-3-bromobenzamide (14) have been discussed. The novel transformation is thought to proceed by a gold(I)-mediated intramolecular transamidation reaction which releases thiocyanate to yield the benzamide. Density functional theory calculations have been used to support the proposed mechanism for this transformation.
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  • Date Issued: 2020

Synthesis, characterization and biological activity of some Dithiourea Derivatives:

Ultrasound promoted synthesis, characterization and computational studies of some thiourea derivatives

  • Authors: Odame, Felix , Hosten, Eric C , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/451199 , vital:75028 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128302"
  • Description: Synthesis of some thiourea derivatives have been achieved by using ultrasound, the compounds have been characterised using IR, NMR, GC-MS and elemental analysis. The single crystal X-ray structure of N-[(benzyloxy)methanethioyl]benzamide (IV), 1-benzoyl-3-(2-hydroxyethyl)thiourea (V) and 3-benzoyl-1-(1-benzylpiperidin-4-yl)thiourea (VI) has been presented and the bond lengths and bond angles contrasted with computed results. The HOMO and LUMO energy levels as well as the global chemical reactivity descriptors of the compounds have also been computed and discussed. Two comformers were obtained for compounds IV to VI in the molecular Electrostatic potential and the vibrational frequency computations and these have been discussed.
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  • Date Issued: 2020

Characterization and computational studies of 2-(benzamido) thiazol-5-yl benzoate

  • Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2019
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447003 , vital:74576 , xlink:href="https://doi.org/10.1134/S0022476619010190"
  • Description: Thiazoles have shown a broad range of biological activities and are found in many potent biologically active molecules such as Sulfathiazol (antimicrobial drug), Ritonavir (antiretroviral drug), Abafungin (antifungal drug), and Tiazofurin (antineoplastic drug) [1]. They have exhibited some degree of plant growth regulatory and antifungal activities [2], whilst some thiazoles have shown anti-infective [3] as well as antibacterial activities [4]. The regio-controlled synthesis of 2,5-disubstituted and 2,4,5-trisubstituted thiazoles from ethyl-2-bromo-5-chloro-4-thiazolecarboxylates using sequential palladium-catalyzed coupling reactions has been reported [5]. An efficient general method for the preparation of 2,4-di- and trisubsituted thiazoles is via P–TsOH. H2O-Catalyzed cyclization of trisubstituted propargylic alcohols with thioamides has been accomplished with moderate to excellent product yields under mild and standard conditions [6]. In the presence of triethylamine, (Z)-(2-acetoxyl-1-alkenyl) phenyl-λ3 iodanes reacts with thioureas or thioamides in methanol to afford 2,4- disubstituted thiazoles in good yields. The reaction is thought to proceed by the generation of highly reactive α-λ3 iodanyl ketones through ester exchange of the β-acetoxy group with liberation of methyl acetate, followed by nucleophilic substitutions with thioureas or thioamides [7].
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  • Date Issued: 2019

A New Synthetic Method for Tetraazatricyclic Derivatives and Evaluation of Their Biological Properties

  • Authors: Odame, Felix , Betz, Richard , Hosten, Eric C , Krause, Jason , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D , Sayed, Yasien , Frost, P Carminita , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/123189 , vital:35413 , https://doi.org/10.1002/slct.201802930
  • Description: Herein, we propose novel quinolones incorporating an INH moiety as potential drug templates against TB. The quinolone-based compounds bearing an INH moiety attached via a hydrazide–hydrazone bond were synthesised and evaluated against Mycobacterium tuberculosis H37Rv (MTB). The compounds were also evaluated for cytotoxicity against HeLa cell lines. These compounds showed significant activity (MIC90) against MTB in the range of 0.2–8 μM without any cytotoxic effects. Compounds 10 (MIC90; 0.9 μM), 11 (MIC90; 0.2 μM), 12 (MIC90; 0.8 μM) and compound 15 (MIC90; 0.8 μM), the most active compounds in this series, demonstrate activities on par with INH and superior to those reported for the fluoroquinolones. The SAR analysis suggests that the nature of substituents at positions −1 and −3 of the quinolone nucleus influences anti-MTB activity. Aqueous solubility evaluation and in vitro metabolic stability of compound 12 highlights favourable drug-like properties for this compound class.
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  • Date Issued: 2018

Characterization and computational studies of a co-crystal of 2-aminobenzimidazole and 2-[(benzoylcarbamothioyl) amino] propanoic acid

  • Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447030 , vital:74578 , xlink:href="https://doi.org/10.1134/S0022476618050268"
  • Description: A novel co-crystal of 2-aminobenzimidazole and 2-[(benzoylcarbamothioyl)amino] propanoic acid is synthesized and characterized by spectroscopy, elemental analysis, GC-MS, and single crystal XRD. A computation of the structures involved in the formation of the co-crystal are carried out and their contribution to reactivity is explained.
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  • Date Issued: 2018

Synthesis, characterization and DPPH scavenging activity of some benzimidazole derivatives

  • Authors: Odame, Felix , Krause, Jason , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R , Frost, Carminita L
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447209 , vital:74592 , xlink:href="https://dx.doi.org/10.4314/bcse.v32i2.8 "
  • Description: A base-catalyzed conversion of aldehydes to benzimidazoles has been achieved. The compounds have been characterized by IR, NMR, micoranalysis, and GC-MS. The reaction for the formation of benzimidazoles has been monitored with 1 H NMR and IR. The crystal structures of two derivatives, 2-(2- chlorophenyl)-1H-benzimidazole and 2-(1H-benzimidazol-2-yl)-4-nitrophenol, are presented. A study of the DPPH scavenging activity of these compounds showed that 2-(1H-benzimidazol-2-yl)phenol (2), 2-p-tolyl-1Hbenzimidazole (3) and 2-(4-methoxyphenyl)-1H-benzimidazole (7) gave IC50 values 1974, 773 and 800 µM.
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  • Date Issued: 2018

Benzoyl isothiocyanates derived ligands as potential HIV-1 protease inhibitors and their reactions with gold ions

  • Authors: Odame, Felix
  • Date: 2016
  • Subjects: HIV (Viruses) -- Enzymes Enzyme inhibitors -- Research , Pharmaceutical chemistry Biochemistry
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/33228 , vital:32585
  • Description: The synthesis and evaluation of benzoyl isothiocyanate derivatives as potential HIV-1 protease inhibitors is presented. The ligands were first designed to fit the protease active site using Autodock 4.2. The design was based on the deNOVO method of drug design in which the active site coordinates from the crystal structure of protease bound to ritonavir was used. An attempt to access the scaffolds designed initially led to the formation of 2,2,4-trimethyl 2,3-dihydro-1H-1,5-benzodiazepin-5-ium isophthalate and 2-2-(3-methylphenyl-1Hbenzimidazole which could not be converted to the desired intermediate. A further attempt led to formation of amino acid and amino acid ester derivatives of benzoyl isothiocyanates which have been fully characterized and the reasons why the desired intermediates were not readily accessible explained. Scaffolds based on the benzoyl isothiocyanate derivatives of structurally diverse diamines were then screened. Sixty compounds have been synthesized and fully characterized using elemental analysis, spectroscopy, GC-MS and twenty-six crystal structures have been discussed. The DFT transition state studies of 11-phenyl- 1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), N-(1Hbenzimidazol-2-yl)benzamide (21), 3-(1,3-benzothiazol-2-yl)-1-(benzoyl)thiourea (23), and N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (39), have been carried out and their detailed density functional theory reaction mechanism have be computed. The Bernly algorithm was used in the determination of saddle points (transtions states), and the intrinsic reaction coordinates leading to the determination of intermediates were traced and optimized to a global minimum or in some cases a local minimum was obtained. The cell viability tests of diamine derivatives which was done by exposing white blood cells to the compounds (inhibitors) at 37 °C and a pH of 7.4 showed that 1-(4-bromobenzoyl)-3-[2- ({[(4-bromophenyl)formamido]methanethioyl}amino)phenyl]thiourea (46), 1-(3-chloro benzoyl)-3-[2-({[(3-chlorophenyl)formamido]methanethioyl}amino)phenyl]thiourea (48), 1- (3-bromobenzoyl)-3-[2-({[(3-bromophenyl)formamido]methanethioyl}amino)phenyl] thiourea (49) and 3-benzoyl-1-(4-{[(phenylformamido)methanethioyl]amino}butyl)thiourea (54), in that group of compounds were cytotoxic with EC50 values of 17.04 ± 9.75 μM, 69.20± 38.16 μM, 35.90 ± 20.55 μM and 68.37 ± 26.45 μM, respectively. 4-Bromo-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (32), 4-methoxy-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene]benzamide (33) and 3-chloro-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (37) were also cytotoxic giving EC50 values of 45.47 ± 21.92, 45.09 ±13.79 and 74.94 ± 13.17 μM, respectively. 3-(1,3-Benzothiazol-2-yl)-1-(3-bromobenzoyl)thiourea (31) and 3-(1,3-benzothiazoyl-2-yl)-1-(4-nitrobenzoyl)thiourea (30) derivatives were also found to be cytotoxic with EC50 values of 1.207 ± 0.58 and 24.08 ±13.14 nM, respectively. 11-(4-Chlorophenyl-1,8,10, 12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (12), 11-(4-methoxyphenyl)-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,9,1-pentaene-13-thione (14), and 11-phenyl-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), were found to be cytotoxic giving EC50 values of 0.152 ± 0.051, 37.96 ± 21.87 and 5.28 ± 2.95 μM, respectively. In the enzyme inhibition studies compound 49 gave a percentage inhibition of 97.03 ± 10.61% at 100 μM, but the fact that it is cytoxic might make it less useful, whilst compounds 19 and 16 had a percentage inhibition of 59.57 ± 13.59% (4-nitro derivative) and 79.97 ± 11.97% (3-nitro derivative) respectively at 100 μM of inhibitor and 20 μM of enzyme (HIV-1 protease). The results suggests that the presence of the nitro group at position 3 (16) and 4 (19) leads to an increase in activity against HIV-1 protease.
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  • Date Issued: 2016

Benzimidazole or Diamide From a Reaction of Diamines and Carboxylic Acids or Acid Chlorides: Crystal Structures and Theoretical Studies

  • Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2015
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447938 , vital:74685 , xlink:href="https://pdfs.semanticscholar.org/bf5a/ce94c9436f40059793eb988e08da8ef09886.pdf"
  • Description: A reaction of an acid chloride with a diamine yielded a diamide. m-Toluic acid was chlorinated to m-toluoyl chloride and subsequently reacted with 4-methyl-o-phenylenediamine in pyridine to obtain 3-methyl-N-[2-(3-methylbenzamido)phenylbenzamide (I). 2-(3-Methylphenyl)-1H-benzimidazole (II) has been obtained upon reacting o-phenylenediamine with m-toluic acid in polyphosphoric acid and toluene. The compounds have been characterized by IR, NMR, microanalyses and GC-MS. The crystal structures of the compounds have been discussed. DFT calculations of the frontier orbitals of the precursor compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity in the formation of the diamides and benzimidazoles. The synthesis of the amide from a diamine was seen to be favoured in the presence of a good leaving group attached to the carbonyl as in the case of acid chloride. However, the synthesis of benzimidazoles was found to be favoured in the presence of an excess of a protonating agent and high temperature.
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  • Date Issued: 2015

Characterization of some amino acid derivatives of benzoyl isothiocyanate: Crystal structures and theoretical prediction of their reactivity

  • Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2015
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447952 , vital:74686 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.05.053"
  • Description: The reaction of benzoyl isothiocyanate with L-serine, L-proline, D-methionine and L-alanine gave 2-[(benzoylcarbamothioyl)amino]-3-hydroxypropanoic acid (I), 1-(benzoylcarbamothioyl)pyrrolidine-2-carboxylic acid (II), 2-[(benzoylcarbamothioyl)amino]-4-(methylsulfanyl)butanoic acid (III) and 2-[(benzoylcarbamothioyl)amino]propanoic acid (IV), respectively. The compounds have been characterized by IR, NMR, microanalyses and mass spectrometry. The crystal structures of all the compounds have also been discussed. Compound II showed rotamers in solution. DFT calculations of the frontier orbitals of the compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity of these compounds. The calculations indicated that the carboxylic acid group in these compounds is unreactive hence making the conversion to benzimidazoles via cyclization on the carboxylic acids impractical. This has been further confirmed by the reaction of compounds I–IV, respectively, with o-phenylene diamine which was unsuccessful but gave compound V.
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  • Date Issued: 2015

The Formation of 2, 2, 4-Trimethyl-2, 3-dihydro-1 H-1, 5-Benzodiazepine from 1, 2-Diaminobenzene in the Presence of Acetone

  • Authors: Odame, Felix , Kleyi, Phumelele , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
  • Date: 2013
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448952 , vital:74773 , xlink:href="https://doi.org/10.3390/molecules181114293"
  • Description: In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of two moles of acetone with the amine groups resulted in the formation of the benzodiazepine which crystallized as an iminium cation forming a salt with the isophthalate anion. The formation of benzodiazepine was also confirmed by performing the reaction of o-phenylenediamine with excess acetone in ethanol under conventional heating conditions. The compounds were characterized by NMR, FTIR, HRMS and microanalysis as well as X-ray crystallography. The reaction mechanism leading to the formation of benzodiazepine is also discussed.
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  • Date Issued: 2013
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