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Borosky GL, Laali KK. A DFT Computational and Synthetic Study of New Curcuminoidpropargyl Adducts with Pseudo‐Cofacial Aryl Rings. ChemistrySelect 2022. [DOI: 10.1002/slct.202203127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Gabriela L. Borosky
- INFIQC CONICET and Departamento de Química Teórica y Computacional Facultad de Ciencias Químicas Universidad Nacional de Córdoba, Ciudad Universitaria Córdoba 5000 Argentina
| | - Kenneth K. Laali
- Department of Chemistry University of North Florida, 1 UNF Drive Jacksonville Florida 32224 USA
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2
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Anchi A, Sutar SM, Kalkhambkar RG, Borosky GL, Laali KK. Tropylium‐BF
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as Organocatalyst for Efficient Synthesis of Nitriles from Aldoximes; Synthetic Scope and Mechanistic Insights. ChemistrySelect 2022. [DOI: 10.1002/slct.202202791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Athmanand Anchi
- Department of Chemistry Karnatak University's Karnatak Science College Dharwad Karnatak 580001 India
| | - Suraj M. Sutar
- Department of Chemistry Karnatak University's Karnatak Science College Dharwad Karnatak 580001 India
| | - Rajesh G. Kalkhambkar
- Department of Chemistry Karnatak University's Karnatak Science College Dharwad Karnatak 580001 India
| | - Gabriela L. Borosky
- INFIQC CONICET and Departamento de Química Teórica y Computacional Facultad de Ciencias Químicas Universidad Nacional de Córdoba, Ciudad Universitaria Córdoba 5000 Argentina
| | - Kenneth K. Laali
- Department of Chemistry University of North Florida, 1 UNF Drive Jacksonville Florida 32224 USA
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Malunavar SS, Anchi A, Prabhala P, Kalkhambkar RG, Borosky GL, Laali KK. N-ethyltetramethylguanidinium ionic liquid [ETMG][EtSO3] as organocatalyst and solvent for facile amide synthesis by formyl-transfer with N-formyl-saccharin. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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4
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Insuasty D, García S, Abonia R, Insuasty B, Quiroga J, Nogueras M, Cobo J, Borosky GL, Laali KK. Design, synthesis, and molecular docking study of novel quinoline-based bis-chalcones as potential antitumor agents. Arch Pharm (Weinheim) 2021; 354:e2100094. [PMID: 34050547 DOI: 10.1002/ardp.202100094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 11/09/2022]
Abstract
A novel series of quinoline-based symmetrical and unsymmetrical bis-chalcones was synthesized via a Claisen-Schmidt condensation reaction between 3-formyl-quinoline/quinolone derivatives with acetone or arylidene acetones, respectively, by using KOH/MeOH/H2 O as a reaction medium. Twelve of the obtained compounds were evaluated for their in vitro cytotoxic activity against 60 different human cancer cell lines according to the National Cancer Institute protocol. Among the screened compounds, the symmetrical N-butyl bis-quinolinyl-chalcone 14g and the unsymmetrical quinolinyl-bis-chalcone 17o bearing a 7-chloro-substitution on the N-benzylquinoline moiety and 4-hydroxy-3-methoxy substituent on the phenyl ring, respectively, exhibited the highest overall cytotoxicity against the evaluated cell lines with a GI50 range of 0.16-5.45 µM, with HCT-116 (GI50 = 0.16) and HT29 (GI50 = 0.42 μM) (colon cancer) representing best-case scenarios. Notably, several GI50 values for these compounds were lower than those of the reference drugs doxorubicin and 5-FU. Docking studies performed on selected derivatives yielded very good binding energies in the active site of proteins that participate in key carcinogenic pathways.
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Affiliation(s)
- Daniel Insuasty
- Departamento de Química y Biología, División de Ciencias Básicas, Universidad del Norte, Barranquilla, Colombia.,Department of Chemistry, Research Group of Heterocyclic Compounds, Universidad del Valle, Cali, Colombia
| | - Stephanie García
- Department of Chemistry, Research Group of Heterocyclic Compounds, Universidad del Valle, Cali, Colombia
| | - Rodrigo Abonia
- Department of Chemistry, Research Group of Heterocyclic Compounds, Universidad del Valle, Cali, Colombia
| | - Braulio Insuasty
- Department of Chemistry, Research Group of Heterocyclic Compounds, Universidad del Valle, Cali, Colombia
| | - Jairo Quiroga
- Department of Chemistry, Research Group of Heterocyclic Compounds, Universidad del Valle, Cali, Colombia
| | - Manuel Nogueras
- Departamento de Química Inorgánica y Orgánica, Universidad de Jaén, Jaén, Spain
| | - Justo Cobo
- Departamento de Química Inorgánica y Orgánica, Universidad de Jaén, Jaén, Spain
| | - Gabriela L Borosky
- INFIQC, CONICET and Departamento de Química Teórica y Computacional, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Kenneth K Laali
- Department of Chemistry, University of North Florida, Jacksonville, Florida, USA
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Borosky GL, Laali KK. Recent Advances in the Development of "Curcumin Inspired" Compounds as New Therapeutic Agents. Mini Rev Med Chem 2021; 20:1543-1558. [PMID: 32384026 DOI: 10.2174/1389557520666200508083302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 03/13/2020] [Accepted: 03/31/2020] [Indexed: 12/18/2022]
Abstract
Despite a huge body of research in the past two decades investigating the antioxidant, antiinflammatory, anti-microbial, and anti-carcinogenic properties of curcumin (CUR), a CUR-based antitumor drug is yet to be developed. Lack of success in achieving this goal stems from CUR's unfavorable biophysicochemical features, particularly poor solubility, low bioavailability, and rapid metabolism, coupled with a complex biological profile making it difficult to determine its mechanism of action. A significant body of literature aimed at improving its physicochemical properties through synthesis or by designing delivery methods has been published, and the progress in these areas has been reviewed. The present review aims to summarize recent progress in the synthesis of structurally diverse "curcumin-inspired" compounds along with computational docking and bioassay studies, through which a number of promising analogs have been identified that warrant further study.
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Affiliation(s)
- Gabriela L Borosky
- INFIQC, CONICET and Departamento de Quimica Teorica y Computacional, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, Cordoba 5000, Argentina
| | - Kenneth K Laali
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, Florida 32224, United States
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Borosky GL. Alkaline Phosphatases: in Silico Study on the Catalytic Effect of Conserved Active Site Residues Using Human Placental Alkaline Phosphatase (PLAP) As a Model Protein. J Chem Inf Model 2020; 60:6228-6241. [PMID: 33306371 DOI: 10.1021/acs.jcim.0c00860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The metalloenzymes from the alkaline phosphatase (AP) superfamily catalyze the hydrolysis and transphosphorylation of phosphate monoesters. The role of several amino acids highly conserved in the active site of this family of enzymes was examined, using human placental AP (PLAP) as a model protein. By employing an active-site model based on the X-ray crystal structure of PLAP, mutations of several key residues were modeled by quantum mechanical methods in order to determine their impact on the catalytic activity. Kinetic and thermodynamic estimations were achieved for each reaction step of the catalytic mechanism by characterization of the intermediates and transition states on the reaction pathway, and the effects of mutations on the activation barriers were analyzed. A good accordance was observed between the present computational results and experimental measurements reported in the literature.
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Affiliation(s)
- Gabriela L Borosky
- INFIQC, CONICET and Departamento de Química Teórica y Computacional, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
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7
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Laali KK, Zwarycz AT, Beck N, Borosky GL, Nukaya M, Kennedy GD. Curcumin Conjugates of Non-steroidal Anti-Inflammatory Drugs: Synthesis, Structures, Anti-proliferative Assays, Computational Docking, and Inflammatory Response. ChemistryOpen 2020; 9:822-834. [PMID: 32802728 PMCID: PMC7425154 DOI: 10.1002/open.202000173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/13/2020] [Indexed: 12/26/2022] Open
Abstract
In an effort to combine the anti-proliferative effect of CUR-BF2 and CUR compounds with anti-inflammatory benefits of non-steroidal anti-inflammatory drugs (NSAIDs), a library of the bis- and mono-NSAID/CUR-BF2 and NSAID/CUR conjugates were synthesized by coupling flufenamic acid, flurbiprofen, naproxen, indomethacin, and ibuprofen to diversely substituted hydroxy-benzaldehydes via an ester linkage, and by subsequent reaction with acetylacetone-BF2 to form the bis- and the mono-NSAID/CUR-BF2 adducts. Since conversion to NSAID/CUR by the previously developed decomplexation protocol showed limited success, a set of NSAID/CUR conjugates were independently prepared by directly coupling the NSAIDs with parent curcumin. The bis-NSAID/CUR-BF2 and bis-NSAID-CUR hybrids exhibited low cytotoxicity in NCI-60 assay, and in independent cell viability assay on colorectal cancer (CRC) cells (HCT116, HT29, DLD-1, RKO, SW837, CaCo2) and in normal CR cells (CCD841CoN). By contrast, the mono-naproxin and mono-flurbiprofen CUR-BF2 adducts exhibited remarkable anti-proliferative and apoptopic activity in NCI-60 assay most notably against HCT-116 (colon), OVCAR-3 (ovarian), and ACHN (renal) cells. Computational molecular docking calculations showed favorable binding energies to HER2, VEGFR2, BRAF, and Bcl-2 as well as to COX-1 and COX-2, which in several cases exceeded known inhibitors. The main interactions between the ligands and the proteins were hydrophobic, although several hydrogen bonds were also observed. A sub-set of six compounds that had exhibited little or no cytotoxicity were tested for their anti-inflammatory response with THP-1 human macrophages in comparison to parent NSAIDs or parent curcumin.
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Affiliation(s)
- Kenneth K. Laali
- Department of ChemistryUniversity of North Florida1 UNF DriveJacksonville, FL32224USA
| | - Angela T. Zwarycz
- Department of ChemistryUniversity of North Florida1 UNF DriveJacksonville, FL32224USA
| | - Nicholas Beck
- Department of ChemistryUniversity of North Florida1 UNF DriveJacksonville, FL32224USA
| | - Gabriela L. Borosky
- INFIQC, CONICET and Departamento de Química Teórica y ComputacionalFacultad de Ciencias QuímicasUniversidad Nacional de CórdobaCiudad UniversitariaCórdoba5000Argentina
| | - Manabu Nukaya
- Department of SurgeryUniversity of Alabama-Birmingham School of MedicineBirminghamAL 35294-0016USA
| | - Gregory D. Kennedy
- Department of SurgeryUniversity of Alabama-Birmingham School of MedicineBirminghamAL 35294-0016USA
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Laali KK, Zwarycz AT, Bunge SD, Borosky GL, Nukaya M, Kennedy GD. Deuterated Curcuminoids: Synthesis, Structures, Computational/Docking and Comparative Cell Viability Assays against Colorectal Cancer. ChemMedChem 2019; 14:1173-1184. [DOI: 10.1002/cmdc.201900179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Kenneth K. Laali
- Department of ChemistryUniversity of North Florida 1 UNF Drive Jacksonville FL 32224 USA
| | - Angela T. Zwarycz
- Department of ChemistryUniversity of North Florida 1 UNF Drive Jacksonville FL 32224 USA
| | - Scott D. Bunge
- Department of Chemistry and BiochemistryKent State University Kent OH 44242 USA
| | - Gabriela L. Borosky
- INFIQCCONICET and Departamento de Química Teórica y ComputacionalFacultad de Ciencias QuímicasUniversidad Nacional de Córdoba Ciudad Universitaria Córdoba 5000 Argentina
| | - Manabu Nukaya
- Department of SurgeryUniversity of Alabama–Birmingham School of Medicine Birmingham AL 35294-0016 USA
| | - Gregory D. Kennedy
- Department of SurgeryUniversity of Alabama–Birmingham School of Medicine Birmingham AL 35294-0016 USA
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9
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Abonia R, Gutiérrez LF, Insuasty B, Quiroga J, Laali KK, Zhao C, Borosky GL, Horwitz SM, Bunge SD. Catalyst-free assembly of giant tris(heteroaryl)methanes: synthesis of novel pharmacophoric triads and model sterically crowded tris(heteroaryl/aryl)methyl cation salts. Beilstein J Org Chem 2019; 15:642-654. [PMID: 30931006 PMCID: PMC6423583 DOI: 10.3762/bjoc.15.60] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/26/2019] [Indexed: 01/02/2023] Open
Abstract
A series of giant tris(heteroaryl)methanes are easily assembled by one-pot three-component synthesis by simple reflux in ethanol without catalyst or additives. Diversely substituted indoles (Ar1) react with quinoline aldehydes, quinolone aldehydes, chromone aldehydes, and fluorene aldehydes (Ar2CHO) and coumarins (Ar3) in 1:1:1 ratio to form the corresponding tris(heteroaryl)methanes (Ar1Ar2Ar3)CH along with (Ar1Ar1Ar2)CH triads. A series of new 2:1 triads were also synthesized by coupling substituted indoles with Ar2CHO. The coupling reactions could also be carried out in water (at circa 80 °C) but with chemoselectivity favoring (Ar1Ar1Ar2)CH over (Ar1Ar2Ar3)CH. The molecular structure of a representative (Ar1Ar2Ar3)CH triad was confirmed by X-ray analysis. Model tris(heteroaryl/aryl)methylium salts were generated by reaction with DDQ/HPF6 and studied by NMR and by DFT and GIAO-DFT.
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Affiliation(s)
- Rodrigo Abonia
- Research Group of Heterocyclic Compounds (GICH), Department of Chemistry, Universidad del Valle, A. A. 25360, Cali, Colombia
| | - Luisa F Gutiérrez
- Research Group of Heterocyclic Compounds (GICH), Department of Chemistry, Universidad del Valle, A. A. 25360, Cali, Colombia
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, USA
| | - Braulio Insuasty
- Research Group of Heterocyclic Compounds (GICH), Department of Chemistry, Universidad del Valle, A. A. 25360, Cali, Colombia
| | - Jairo Quiroga
- Research Group of Heterocyclic Compounds (GICH), Department of Chemistry, Universidad del Valle, A. A. 25360, Cali, Colombia
| | - Kenneth K Laali
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, USA
| | - Chunqing Zhao
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, USA
| | - Gabriela L Borosky
- INFIQC, CONICET and Departamento de Química Teórica y Computacional, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Samantha M Horwitz
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Scott D Bunge
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
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Abstract
To probe the limits of the internal charge compensation approach for the generation of 10π aromatic hemispheres derived from hetero-acepentalenide zwitterions, the phospha- and arsa-bridged cyclononatetraenides were studied computationally by DFT at the B3LYP/6-311++G(d,p) level, and compared with the known aza-analog.
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Affiliation(s)
- Gabriela L. Borosky
- INFIQC
- CONICET and Departamento de Química Teórica y Computacional
- Facultad de Ciencias Químicas
- Universidad Nacional de Córdoba
- Ciudad Universitaria
| | - Kenneth K. Laali
- Department of Chemistry
- University of North Florida
- Jacksonville
- USA
| | - Mark Mascal
- Department of Chemistry
- University of California Davis
- Davis
- USA
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Laali KK, Greves WJ, Zwarycz AT, Correa Smits SJ, Troendle FJ, Borosky GL, Akhtar S, Manna A, Paulus A, Chanan-Khan A, Nukaya M, Kennedy GD. Front Cover: Synthesis, Computational Docking Study, and Biological Evaluation of a Library of Heterocyclic Curcuminoids with Remarkable Antitumor Activity (ChemMedChem 18/2018). ChemMedChem 2018. [DOI: 10.1002/cmdc.201800584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kenneth K. Laali
- Department of Chemistry; University of North Florida; 1 UNF Drive Jacksonville FL 32224 USA
| | - William J. Greves
- Department of Chemistry; University of North Florida; 1 UNF Drive Jacksonville FL 32224 USA
| | - Angela T. Zwarycz
- Department of Chemistry; University of North Florida; 1 UNF Drive Jacksonville FL 32224 USA
| | | | - Frederick J. Troendle
- Department of Chemistry; University of North Florida; 1 UNF Drive Jacksonville FL 32224 USA
| | - Gabriela L. Borosky
- INFIQC, CONICET and Departamento de Química Teórica y Computacional; Facultad de Ciencias Químicas; Universidad Nacional de Córdoba; Ciudad Universitaria Córdoba 5000 Argentina
| | - Sharoon Akhtar
- Department of Cancer Biology; Mayo Clinic; Jacksonville FL USA
| | - Alak Manna
- Department of Cancer Biology; Mayo Clinic; Jacksonville FL USA
| | - Aneel Paulus
- Department of Cancer Biology; Mayo Clinic; Jacksonville FL USA
- Department of Hematology and Oncology; Mayo Clinic; Jacksonville FL USA
| | - Asher Chanan-Khan
- Department of Hematology and Oncology; Mayo Clinic; Jacksonville FL USA
| | - Manabu Nukaya
- Department of Surgery; University of Alabama-Birmingham School of Medicine; Birmingham AL 35294-0016 USA
| | - Gregory D. Kennedy
- Department of Surgery; University of Alabama-Birmingham School of Medicine; Birmingham AL 35294-0016 USA
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12
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Laali KK, Greves WJ, Zwarycz AT, Correa Smits SJ, Troendle FJ, Borosky GL, Akhtar S, Manna A, Paulus A, Chanan-Khan A, Nukaya M, Kennedy GD. Synthesis, Computational Docking Study, and Biological Evaluation of a Library of Heterocyclic Curcuminoids with Remarkable Antitumor Activity. ChemMedChem 2018; 13:1895-1908. [PMID: 30079563 DOI: 10.1002/cmdc.201800320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/27/2018] [Indexed: 12/16/2022]
Abstract
In a continuing search for curcuminoid (CUR) compounds with antitumor activity, a novel series of heterocyclic CUR-BF2 adducts and CUR compounds based on indole, benzothiophene, and benzofuran along with their aryl pyrazoles were synthesized. Computational docking studies were performed to compare binding efficiency to target proteins involved in specific cancers, namely HER2, proteasome, VEGFR, BRAF, and Bcl-2, versus known inhibitor drugs. The majority presented very good binding affinities, similar to, and even more favorable than those of known inhibitors. The indole-based CUR-BF2 and CUR compounds and their bis-thiocyanato derivatives exhibited high anti-proliferative and apoptotic activity by in vitro bioassays against a panel of 60 cancer cell lines, more specifically against multiple myeloma (MM) cell lines (KMS11, MM1.S, and RPMI-8226) with significantly lower IC50 values versus healthy PBMC cells; they also exhibited higher anti-proliferative activity in human colorectal cancer cells (HCT116, HT29, DLD-1, RKO, SW837, and Caco2) than the parent curcumin, while showing notably lower cytotoxicity in normal colon cells (CCD112CoN and CCD841CoN).
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Affiliation(s)
- Kenneth K Laali
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - William J Greves
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Angela T Zwarycz
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | | | - Frederick J Troendle
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Gabriela L Borosky
- INFIQC, CONICET and Departamento de Química Teórica y Computacional, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, 5000, Argentina
| | - Sharoon Akhtar
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Alak Manna
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Aneel Paulus
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA.,Department of Hematology and Oncology, Mayo Clinic, Jacksonville, FL, USA
| | - Asher Chanan-Khan
- Department of Hematology and Oncology, Mayo Clinic, Jacksonville, FL, USA
| | - Manabu Nukaya
- Department of Surgery, University of Alabama-Birmingham School of Medicine, Birmingham, AL, 35294-0016, USA
| | - Gregory D Kennedy
- Department of Surgery, University of Alabama-Birmingham School of Medicine, Birmingham, AL, 35294-0016, USA
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Laali KK, Greves WJ, Correa-Smits SJ, Zwarycz AT, Bunge SD, Borosky GL, Manna A, Paulus A, Chanan-Khan A. Novel fluorinated curcuminoids and their pyrazole and isoxazole derivatives: Synthesis, structural studies, Computational/Docking and in-vitro bioassay. J Fluor Chem 2018. [DOI: 10.1016/j.jfluchem.2017.11.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Affiliation(s)
- Gabriela L. Borosky
- INFIQC, CONICET and Departamento
de Química Teórica y Computacional, Facultad de Ciencias
Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
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Laali KK, Rathman BM, Bunge SD, Qi X, Borosky GL. Fluoro-curcuminoids and curcuminoid-BF2 adducts: Synthesis, X-ray structures, bioassay, and computational/docking study. J Fluor Chem 2016. [DOI: 10.1016/j.jfluchem.2016.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Borosky GL. Mutagenicity of heteroaromatic amines: Computational study on the influence of methyl substituents. J Mol Graph Model 2016; 69:92-102. [PMID: 27592197 DOI: 10.1016/j.jmgm.2016.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/18/2016] [Accepted: 08/27/2016] [Indexed: 10/21/2022]
Abstract
Quantum mechanical calculations were performed to elucidate the factors determining the variations in mutagenic activity within groups of isomeric heteroaromatic amines that differ in the position of methyl substituents. Formation energies for noncovalent complexes and covalent DNA adducts were evaluated by means of high level quantum chemical methods. According to the computational results in this work, covalent adduct stability is proposed to influence the relative mutagenicities of structurally related heterocyclic amines. The stability of covalent C8-dG DNA adducts was found to be mainly determined by π-stacking interactions between the fused ring system of the heteroaromatic amines and the flanking nucleobases. Relative mutagenicity of amines of very related structure is proposed to be regulated by both nitrenium ion and covalent adduct stabilities.
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Affiliation(s)
- Gabriela L Borosky
- INFIQC, CONICET and Departamento de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina.
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Laali KK, Jamalian A, Borosky GL. Piperidine-appended imidazolium ionic liquids as task-specific catalysts: computational study, synthesis, and multinuclear NMR. J PHYS ORG CHEM 2016. [DOI: 10.1002/poc.3541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kenneth K. Laali
- Department of Chemistry; University of North Florida; 1, UNF Drive Jacksonville FL 32224 USA
| | - Arezu Jamalian
- Department of Chemistry; University of North Florida; 1, UNF Drive Jacksonville FL 32224 USA
| | - Gabriela L. Borosky
- INFIQC, CONICET and Departamento de Matemática y Física, Facultad de Ciencias Químicas; Universidad Nacional de Córdoba, Ciudad Universitaria; Córdoba 5000 Argentina
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19
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Borosky GL, Laali KK. In SilicoStudy on Chemical Properties and Reactivity of Enal Derivatives. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Affiliation(s)
- Gabriela L. Borosky
- INFIQC, CONICET and Departamento
de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
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Affiliation(s)
- Rudolf J. Wehmschulte
- Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, United States
| | - Kenneth K. Laali
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, Florida 32224, United States
| | - Gabriela L. Borosky
- Departamento de Matemática
y Fı́sica,
INFIQC, Facultad de Ciencias Quı́micas, Universidad Nacional de Córdoba , Ciudad Universitaria, Córdoba 5000, Argentina
| | - Douglas R. Powell
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
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Laali KK, Nandi GC, Borosky GL, Kumar GGKSN. Electrophilic Addition of Propargylic Cations to Allenes: Formation of Crowded Chloro- and Azido-Enynes by Trapping of the Resulting Allylic Cations with TMSX (X = Cl, N3): A Synthetic and Computational Study. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300553] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Laali KK, Borosky GL. α-Sulfur or α-fluorine—Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems. J Fluor Chem 2013. [DOI: 10.1016/j.jfluchem.2013.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Arylamines are well-known as widespread industrial and environmental mutagens and carcinogens. Their bioactivity stems from enzymatic metabolic activation to reactive and highly electrophilic intermediates. In this work, computational investigations related to the biological activity of these compounds have been reviewed, especially focusing on studies reporting results from quantum-mechanical calculations. Correlations between relative mutagenicities and structural and electronic features of the parent amines and of their derived nitrenium ion intermediates were examined, with the aim of achieving a clearer comprehension of the main factors determining the genotoxic potential of this type of compounds.
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Affiliation(s)
- Gabriela L Borosky
- Departamento de Matematica y Fisica, INFIQC, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, Cordoba 5000, Argentina.
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Affiliation(s)
- Gopalakrishnan Aridoss
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville,
Florida 32224, United States
| | - Chunqing Zhao
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville,
Florida 32224, United States
| | - Gabriela L. Borosky
- Departamento de Matemática
y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria,
Córdoba 5000, Argentina
| | - Kenneth K. Laali
- Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville,
Florida 32224, United States
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Affiliation(s)
- Gabriela L. Borosky
- Departamento de Matemática y Física, INFIQC, Facultad de Ciencias Químicas; Universidad Nacional de Córdoba; Ciudad Universitaria; Córdoba; 5000; Argentina
| | - Kenneth K. Laali
- Department of Chemistry; University of North Florida; 1, UNF Drive; Jacksonville; FL; 32224; USA
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Affiliation(s)
- Gabriela L. Borosky
- Departamento de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Susana Lin
- National Health Research Institutes, Division of Environmental Health and Occupational Medicine, No 35, Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan
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Muscia GC, Cazorla SI, Frank FM, Borosky GL, Buldain GY, Asís SE, Malchiodi EL. Synthesis, trypanocidal activity and molecular modeling studies of 2-alkylaminomethylquinoline derivatives. Eur J Med Chem 2011; 46:3696-703. [PMID: 21664012 DOI: 10.1016/j.ejmech.2011.05.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 04/19/2011] [Accepted: 05/13/2011] [Indexed: 01/15/2023]
Abstract
Research and development of new drugs effective in the treatment of Trypanosoma cruzi infections are a real need for the 16 million people infected in the Americas. In a previous work, a quinoline derivative substituted by a 2-piperidylmethyl moiety showed to be active against Chagas disease and was considered a lead compound for further optimization. A series of ten analogous derivatives were tested against epimastigotes as a first approach. In view of their promising results, six of them were evaluated against the blood and intracellular replicative forms of the parasite in humans. Among them, compound 12 which possesses a 6-acetamidohexylamino substituent showed remarkable improvement in activity against epimastigotes, trypomastigotes and amastigotes compared with the structure lead, as well as a good selectivity index for the two parasite stages present in humans. In addition, treatment of infected mice with compound 12 induced a significant reduction in parasitemia compared with non-treated mice. Molecular modeling studies were performed by computational methods in order to elucidate the factors determining these experimental bioactivities.
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Affiliation(s)
- Gisela C Muscia
- Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina
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Borosky GL, Okazaki T, Laali KK. A Computational (DFT, MP2) and GIAO NMR Study of Substituent Effects in Benzenediazonium Mono- and Dications. European J Org Chem 2011. [DOI: 10.1002/ejoc.201001655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Borosky GL, Laali KK. Oxidized metabolites from cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs). A DFT model study of their carbocations formed by epoxide ring opening. J PHYS ORG CHEM 2010. [DOI: 10.1002/poc.1666] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Borosky GL, Laali KK. A computational study (DFT, MP2, and GIAO-DFT) of substituent effects on protonation regioselectivity in β
,β
-disubstituted vinyldiazonium cations: formation of highly delocalized carbenium/diazonium dications. J PHYS ORG CHEM 2009. [DOI: 10.1002/poc.1588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Borosky GL, Laali KK. A DFT Model Study of the Carbocations Formed via the Fjord- and Bay-Region Diol Epoxide Metabolites of Isomeric Dibenzopyrenes and Naphthopyrene. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Laali KK, Borosky GL. Stable carbocations and onium ions from polycondensed aromatic and heteroaromatic compounds as models for biological electrophiles and DNA-transalkylating agents. Advances in Physical Organic Chemistry 2009. [DOI: 10.1016/s0065-3160(08)00004-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Borosky GL. Carcinogenic carbocyclic and heterocyclic aromatic amines: A DFT study concerning their mutagenic potency. J Mol Graph Model 2008; 27:459-65. [DOI: 10.1016/j.jmgm.2008.08.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 08/06/2008] [Accepted: 08/09/2008] [Indexed: 11/15/2022]
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Laali KK, Chun JH, Okazaki T, Kumar S, Borosky GL, Swartz C. Electrophilic chemistry of thia-PAHs: stable carbocations (NMR and DFT), S-alkylated onium salts, model electrophilic substitutions (nitration and bromination), and mutagenicity assay. J Org Chem 2007; 72:8383-93. [PMID: 17910504 PMCID: PMC2532494 DOI: 10.1021/jo701502y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
First examples of stable carbocations are reported from several classes of thia-PAHs with four fused rings, namely, benzo[b]naphtho[2,1-d]thiophene (1) and its 3-methoxy derivative (2), phenanthro[4,3-b]thiophene (3) and its 7-methoxy (4), 10-methoxy (5), and 9-methoxy (6) derivatives, phenanthro[3,4-b]thiophene (7) and its 7-methoxy (8) and 9-methoxy (9) derivatives, and 3-methoxybenzo[b]naphtha[1,2-d]thiophene (11). In several cases, the resulting carbocations were also studied by GIAO-DFT. Charge delocalization modes in the resulting carbocations were probed. A series of S-alkylated onium tetrafluoroborates, namely, 1Me+, 1Et+, 2Et+, and 7Me+ (from 1, 2, and 7), 10Me+ and 10Et+ (from benzo[b]naphtha[1,2-d]thiophene 10), 12Me+ and 12Et+ (from phenanthro[3,2-b][1]benzothiophene 12), 13Me+ (from 3-methoxyphenanthro[3,2-b]benzothiophene 13), 14Me+ (from phenanthro[4,3-b][1]benzothiophene 14), and 15Me+ (from 3-methoxyphenanthro[4,3-b][1]benzothiophene 15), were synthesized. PAH-sulfonium salts 1Me+, 1Et+, 10Me+, 10Et+, 12Me+, and 14Me+ proved to be efficient akylating agents toward model nitrogen nucleophile receptors (imidazole and azaindole). Facile transalkylation to model nucleophiles (including guanine) is also supported by favorable reaction energies computed by DFT. Ring opening energies in thia-PAH-epoxides from 1, 3, and 7 and charge delocalization modes in the resulting carbocations were also evaluated. The four-ring-fused thia-PAHs 1, 2, 3, 4, 5, 7, 8, and 11 are effectively nitrated under extremely mild conditions. Nitration regioselectivity corresponds closely to protonation under stable ion conditions. Bromination of 4 and 6 is also reported. Comparative mutagenicity assays (Ames test) were performed on 1 versus 1NO2, 5 versus 5NO2, and 11 versus 11NO2. Compound 5NO2 was found to be a potent direct acting mutagen.
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Affiliation(s)
- Kenneth K Laali
- Department of Chemistry, Kent State University, Kent, Ohio 44242, USA.
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Borosky GL. Ultimate Carcinogenic Metabolites from Aromatic and Heterocyclic Aromatic Amines: A Computational Study in Relation to Their Mutagenic Potency. Chem Res Toxicol 2007; 20:171-80. [PMID: 17261035 DOI: 10.1021/tx600278q] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The formation of nitrenium ions from their precursors was examined by density functional theory (DFT) calculations in order to analyze the role of these electrophilic intermediates on the mutagenic activity of the parent amines. The relative reactivities for N-O bond dissociation from the N-hydroxy, N-acetoxy and N-sulfate derivatives of aniline were evaluated. Furthermore, the N-acetoxy esters from a set of 17 aromatic and heteroaromatic amines of diverse structure were considered, and correlations were sought between the calculated properties and the reported mutagenic potencies. The mutagenic activity was found to increase when a more negative charge developed at the exocyclic nitrogen of the nitrenium ion (qN) and with nitrenium ion stability. Different functional correlations were observed for the amine derivatives grouped according to their classification as aromatic (Ar), imidazo-carbocyclic (Imi-C), and imidazo-heterocyclic (Imi-H). The formation of N-acetyl nitrenium ions from aromatic amides was also considered and found to be less favorable than nitrenium ion generation from the corresponding amines.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de MatemAtica y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina.
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Borosky GL, Laali KK. Oxidized metabolites from benzo[a]pyrene, benzo[e]pyrene, and aza-benzo[a]pyrenes. A computational study of their carbocations formed by epoxide ring opening reactions. Org Biomol Chem 2007; 5:2234-42. [PMID: 17609754 DOI: 10.1039/b704090c] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A DFT study aimed at understanding structure-reactivity relationships and fluorine substitution effects on carbocation stability in benzo[a]pyrene (BaP), benzo[e]pyrene (BeP), and aza-benzo[a]pyrene (aza-BaP) derivatives are reported. The relative energies of the resulting carbocations are examined and compared, taking into account the available biological activity data on these compounds. O-Protonation of the epoxides and diol epoxides leads to carbocation formation by barrierless processes. Charge delocalization modes in the resulting carbocations were deduced via NPA-derived changes in charges, and fluorine substitution effects were analyzed on the basis of charge density at different carbocation positions. Thus, fluorine substitution at sites bearing negative charge generated inductive destabilization of the carbocation, whereas a fluorine atom at a ring position which presented significant positive charge density produced a less pronounced destabilization due to fluorine p-pi back-bonding. Protonation reactions were also studied for the azaBaPs. In selected cases, the covalent adducts generated via bond formation with the exocyclic nitrogen of cytosine were computed and relative energies and geometries of the resulting adducts were examined.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, 5000, Argentina.
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Borosky GL, Laali KK. Carbocations from oxidized metabolites of benzo[a]anthracene: a computational study of their methylated and fluorinated derivatives and guanine adducts. Chem Res Toxicol 2006; 19:899-907. [PMID: 16841957 PMCID: PMC2538532 DOI: 10.1021/tx060067l] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structure-reactivity relationships and substituent effects on carbocation stability in benzo[a]anthracene (BA) derivatives have been studied computationally at the B3LYP/6-31G and MP2/6-31G levels. Bay-region carbocations are formed by O-protonation of the 1,2-epoxides in barrierless processes. This process is energetically more favored as compared to carbocation generation via zwitterion formation/O-protonation, via single electron oxidation to generate a radical cation, or via benzylic hydroxylation. Relative carbocation stabilities were determined in the gas phase and in water as solvent (PCM method). Charge delocalization mode in the BA carbocation framework was deduced from NPA-derived changes in charges, and substitution by methyl or fluorine was studied at different positions selected on basis of the carbocation charge density. A bay-region methyl group produces structural distortion with consequent deviation from planarity of the aromatic system, which destabilizes the epoxide, favoring ring opening. Whereas fluorine substitution at sites bearing significant positive charge leads to carbocation stabilization by fluorine p-pi back-bonding, a fluorine atom at a ring position which presented negative charge density leads to inductive destabilization. Methylated derivatives are less sensitive to substituent effects as compared to the fluorinated analogues. Although the solvent decreases the exothermicity of the epoxide ring-opening reactions due to greater stabilization of the reactants, it provokes no changes in relative reactivities. Relative energies in the resulting bay-region carbocations are examined taking into account the available biological activity data on these compounds. In selected cases, quenching of bay-region carbocations was investigated by analyzing relative energies (in the gas phase and in water) and geometries of their guanine adducts formed via covalent bond formation with the exocyclic amino group and with the N-7.
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Affiliation(s)
- Gabriela L. Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Kenneth K. Laali
- Department of Chemistry, Kent State University, Kent, Ohio 44242, USA
- * To whom correspondence should be addressed. Tel: 330-6722988. Fax: 330-6723816. E-mail:
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Borosky GL, Laali KK. A Computational Study of Carbocations from Oxidized Metabolites of Dibenzo[a,h]acridine and Their Fluorinated and Methylated Derivatives. Chem Res Toxicol 2005; 18:1876-86. [PMID: 16359178 DOI: 10.1021/tx0501841] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a model computational study aimed at understanding structure-reactivity relationships and substituent effects on carbocation stability in aza-polycyclic aromatic hydrocarbons, the epoxides, diol epoxides, and the dihydrodiols of dibenzo[a,h]acridine (DB[a,h]ACR) were studied by density functional theory at the B3LYP/6-31G level. Bay region carbocations were formed via the O-protonated epoxides in barrierless processes. Relative carbocation stabilities were determined in the gas phase and in water as solvent (polarized continuum model method). Charge delocalization modes in the resulting carbocations were deduced by gauge-independent atomic orbitals (GIAO) NMR (based on Delta delta13C values) and via the natural population analysis (NPA)-derived changes in charges. Although the solvent decreases the exothermicity of the epoxide ring-opening reactions due to greater stabilization of the reactants, relative reactivity trends remain the same. Whereas fluorine substitution at ring positions bearing significant positive charge leads to carbocation stabilization by fluorine p-pi back-bonding, fluorine substitution at a ring position that presented negative charge density in the unsubstituted compound leads to inductive destabilization. Methylated derivatives exhibit less sensitivity to substituent effects as compared to the fluorinated analogues. A bay region methyl group produces structural distortion, and this deviation from planarity destabilizes the epoxide, favoring ring opening. Relative energies, changes in NPA charges, and GIAO NMR data in the resulting "benzylic" carbocations are examined collectively and discussed, taking into account the available biological activity data on these compounds.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
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Borosky GL, Laali KK. Theoretical study of aza-polycyclic aromatic hydrocarbons (aza-PAHs), modelling carbocations from oxidized metabolites and their covalent adducts with representative nucleophiles. Org Biomol Chem 2005; 3:1180-8. [PMID: 15785805 DOI: 10.1039/b416429f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protonation of the epoxides, diol epoxides, and dihydrodiols of benzo[h]quinoline (BhQ), benzo[f]quinoline (BfQ), phenanthrene (Phe), benzo[c]phenanthridine (BcPhen), and chrysene (Chry) were studied by DFT at the B3LYP/6-31G* level, and selected cases were calculated with the 6-31+G* diffuse-function augmented basis set for comparison purposes. Bay-region carbocations were formed from O-protonated epoxides via a barrierless processes. Relative carbocation stabilities were determined in the gas phase and with water as solvent (PCM method). The presence of a heteroatom changes the regioselectivity of epoxide ring opening, in some cases favoring non-bay-region carbocations. The epoxide ring opening mode is also greatly influenced by N-protonation. The dications resulting from initial N-protonation followed by epoxide protonation were also studied by DFT. Charge delocalization modes in the resulting mono- and dications were derived by GIAO-NMR (based on Delta delta13C values) and via the NPA-derived changes in charges. Relative aromaticity in different rings in the arenium ions was gauged by NICS. In representative cases, the covalent adducts (syn and anti) formed by reaction of the benzylic carbocations derived from diol epoxides and dihydrodiols with methoxide and methanethiolate anions were studied. Relative energies (in the gas phase and with water as solvent) and geometries of the adducts formed by quenching of the carbocations derived from BhQ and Phe-epoxides with guanine via the exocyclic amino group and via the N-7 were also investigated computationally. Although aqueous phase calculations change the energy for the addition reactions because of greater stabilization of the reactants, relative reactivity trends remain the same. The data are discussed, taking into account the available experimental results concerning the biological activity of these compounds.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, 5000, Argentina
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Abstract
Fragmentation reactions upon electron attachment to 5-fluorouracil with CH2R substituents at N1 have been evaluated by means of density functional calculations. The present results show that electron attachment to R = F, HC=O or CN derivatives follows a stepwise pathway with radical anions as intermediates. For these compounds, the most stable species formed is the pi radical anion which bears an unpaired spin density at the C6=C5-C4=O pi-conjugated system of the uracil ring. Cleavage of the N1-CH2R or N1CH2-R bond of these intermediates proceeds through the mixing of the pi and sigma states by means of proper geometrical fluctuations along the reaction coordinate. No sigma radical anion could be characterised on any of these sigma basal potential surfaces. A noticeable decrease in the activation energy for the N1-CH2R bond dissociation was observed for R = H-C=O or CN. Therefore, such derivatives with unsaturated groups positioned vicinal to the N1-C1' bond are identified as targets for the development of novel radiation-activated antitumour drugs. On the other hand, the electron transfer to the compounds with R = Cl, Br is dissociative, i.e. it occurs without the mediation of radical anions. For compounds with R = halides or R = NO2, the fragmentation of the N1CH2-R bond is the preferred dissociation pathway.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
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Abstract
The opening reaction of N-protonated polycyclic aromatic hydrocarbon imines has been computed by means of ab initio, density functional, and semiempirical methods of calculation. Imines are predicted to be more stable than the corresponding O-protonated derivatives, epoxides and diol epoxides. On the other hand, the activated N-methanesulfonylbenzene imine presented more favorable DeltaE( not equal ) and DeltaE(r) for ring opening due to the effect of hydrogen-bond interactions. Anti and syn trans-diol benzene imines did not show a different behavior from the unsubstituted imine. According to these calculations, bay-region, fjord-region, and bay-region methyl-substituted compounds opened more easily among the imine derivatives, following the same reactivity pattern as the oxygen analogs. The exothermicity of the opening process correlated with the charge delocalization in the resulting carbocation.
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Affiliation(s)
- Gabriela L Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina.
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Borosky GL, Pierini AB, Rossi RA. Differences in reactivity of stabilized carbanions with haloarenes in the initiation and propagation steps of the SRN1 mechanism in DMSO. J Org Chem 2002. [DOI: 10.1021/jo00027a044] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Borosky GL, Pierini AB, Rossi RA. Photostimulated reaction of 1-iodoadamantane with carbanionic nucleophiles in DMSO by the SRN1 mechanism. J Org Chem 2002. [DOI: 10.1021/jo00299a001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- Gabriela L. Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
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Affiliation(s)
- Gabriela L. Borosky
- Unidad de Matemática y Física, INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Agencia Postal 4, Casilla 61, Córdoba 5000, Argentina
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