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Synthesis, characterization and computational investigation of the phosphatase activity of a dinuclear Zinc(II) complex containing a new heptadentate asymmetric ligand. J Inorg Biochem 2023; 239:112064. [PMID: 36410306 DOI: 10.1016/j.jinorgbio.2022.112064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/24/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
We report the synthesis of a new asymmetric heptadentate ligand based on the 1,3-diaminopropan-2-ol backbone. The ligand 3-[[3-(bis-pyridin-2-ylmethyl-amino)-2-hydroxy-propyl]-(2-carbamoyl-ethyl)-amino]-propionamide (HL1) contains two amide and two pyridine groups attached to the 1,3-diaminopropan-2-ol core. Reaction between HL1 and Zn(ClO4)2.6H2O resulted in the formation of the dinuclear [Zn2(L1)(μ-OAc)](ClO4)2 complex, characterized by single crystal X-ray diffraction, 1H, 13C and 15N NMR, ESI-(+)-MS, CHN elemental analysis as well as infrared spectroscopy. The phosphatase activity of the complex was studied in the pH range 6-11 employing pyridinium bis(2,4-dinitrophenyl)phosphate (py(BDNPP)) as substrate. The complex exhibited activity dependent on the pH, presenting an asymmetric bell shape profile with the highest activity at pH 9; at high pH ligand exchange is rate-limiting. The hydrolysis of BDNPP- at pH 9 displayed behavior characteristic of Michaelis-Menten kinetics, with kcat = 5.06 × 10-3 min-1 and Km = 5.7 ± 1.0 mM. DFT calculations map out plausible reaction pathways and identify a terminal, Zn(II)-bound hydroxide as likely nucleophile.
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2
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Preparation, cytotoxic activity and DNA interaction studies of new platinum(II) complexes with 1,10-phenanthroline and 5-alkyl-1,3,4-oxadiazol-2(3H)-thione derivatives. J Inorg Biochem 2022; 237:111993. [PMID: 36108344 DOI: 10.1016/j.jinorgbio.2022.111993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/05/2022] [Accepted: 09/05/2022] [Indexed: 01/18/2023]
Abstract
This work describes the synthesis, characterization and in vitro anticancer activity of two platinum(II) complexes of the type [Pt(L1)2(1,10-phen)] 1 and [Pt(L2)2(1,10-phen)] 2, where L1 = 5-heptyl-1,3,4-oxadiazole-2-(3H)-thione, L2 = 5-nonyl-1,3,4-oxadiazole-2-(3H)-thione and 1,10-phen = 1,10-phenanthroline. As to the structure of these complexes, the X-ray structural analysis of 1 indicates that the geometry around the platinum(II) ion is distorted square-planar, where two 5-alkyl-1,3,4-oxadiazol-2-thione derivatives coordinate a platinum(II) ion through the sulfur atom. A chelating bidentate phenanthroline molecule completes the coordination sphere. We tested these complexes in two breast cancer cell lines, namely, MCF-7 (a hormone responsive cancer cell) and MDA-MB-231 (triple negative breast cancer cell). In both cells, the most lipophilic platinum compound, complex 2, was more active than cisplatin, one of the most widely used anticancer drugs nowadays. DNA binding studies indicated that such complexes are able to bind to ct-DNA with Kb values of 104 M-1. According to data from dichroism circular and fluorescence spectroscopy, these complexes appear to bind to the DNA in a non-intercalative, probably via minor groove. Molecular docking followed by semiempirical simulations indicated that these complexes showed favorable interactions with the minor groove of the double helix of ct-DNA in an A-T rich region. Thereafter, flow cytometry analysis showed that complex 2 induced apoptosis and necrosis in MCF-7 cells.
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3
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Synthesis and in vitro and in silico studies of 1H- and 2H-1,2,3-triazoles as antichagasic agents. Bioorg Chem 2021; 116:105250. [PMID: 34469833 DOI: 10.1016/j.bioorg.2021.105250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/13/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
1,2,3-triazole heterocycles stand out in medicinal chemistry for having great structural diversity and bioactivities. In this study, two series of triazoles were synthesized. One was obtained by the 1,3-dipolar cycloaddition reaction between ethyl cyanoacetate and several phenyl azides forming 1H-1,2,3-triazoles and the other by rearrangement of Dimroth forming and 2H-1,2,3-triazoles. Both series were shown to be active against the epimastigote form of Trypanosoma cruzi. The 1,2,3-triazoles 16d (S.I. between 100 and 200), 17d and 16f (S.I. > 200) were the most active compounds and capable of breaking the plasma membrane of trypomastigotes acting on CYP51 and inhibiting ergosterol synthesis. Candidate 16d exhibited the best and most favorable profile when interacting with CYP51.
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4
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Semisynthesis of Dolabellane Diterpenes: Oxygenated Analogues with Increased Activity against Zika and Chikungunya Viruses. JOURNAL OF NATURAL PRODUCTS 2021; 84:1373-1384. [PMID: 33822611 DOI: 10.1021/acs.jnatprod.1c00199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Brown algae and soft corals represent the main marine sources of dolabellane diterpenes. The antiviral activity of dolabellanes has been studied for those isolated from algae, whereas dolabellanes isolated from soft corals have been barely studied. In this work, a collection of dolabellane diterpenes consisting of five natural and 21 semisynthetic derivatives was constructed, and their antiviral activities against Zika (ZIKV) and Chikungunya (CHIKV) viruses were tested. Dolabellatrienone (1) and (1R,7R,8R,11S)-7,8-epoxy-13-keto-dolabella-3,12(18)-diene (2), isolated from Eunicea genus soft corals, were employed to obtain 21 dolabellane and dolastane diterpenes by reactions such as allylic oxidations, reductions, acid-catalyzed epoxide ring opening, and acetylations. All of the compounds were identified by a combination of one- and two-dimensional NMR, mass spectrometry, and X-ray diffraction experiments. The cytotoxicites against Vero cells and the antiviral activities against ZIKV and CHIKV was tested to calculate the half-maximal effective concentration (EC50) and selectivity indexes (SIs). In general, the addition of oxygen-containing functional groups improved the bioactivity of dolabellane and dolastane diterpenes against ZIKV and CHIKV replication. Compound 9 showed an EC50 = 0.92 ± 0.08 μM and SI = 820 against ZIKV.
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5
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Effect of the hydroxamate group in the antitumoral activity and toxicity toward normal cells of new copper(II) complexes. Biometals 2021; 34:229-244. [PMID: 33559811 DOI: 10.1007/s10534-020-00275-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/26/2020] [Indexed: 02/07/2023]
Abstract
The synthesis, physico-chemical characterization and cytotoxicity of four copper(II) coordination complexes, i.e. [Cu(HBPA)Cl2] (1), [Cu(BHA)2] (2), [Cu(HBPA)(BHA)Cl] CH3OH (3) and [Cu(HBPA)2]Cl2·4H2O (4), are reported. HBPA is the tridentate ligand N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)amine and HBHA is the benzohydroxamic acid. The reaction between the HBHA and CuCl2.2H2O has resulted in the new complex (2) and the reaction between complex (1) and HBHA has resulted in the new complex (3). X-ray diffraction studies for complex (3) indicated the effective coordination of HBHA as BHA-. Their cytotoxicity was evaluated against three human tumoral cell lines (Colo-205, NCI-H460 and U937) and PBMC (peripheral blood mononuclear cells), using the MTT cytotoxic assay. The results toward PBMC reveal that the new copper(II) complex (2) presents lower toxicity toward normal cells. Furthermore, complex (2) presents IC50 values lower than cisplatin toward NCI-H460 and the best selectivity index obtained towards NCI-H460 (SI = 2.2) and U937 cell lines (SI = 2.0), as a result of the presence of two molecules of HBHA in its structure. Complex (3) presents IC50 values lower than cisplatin toward NCI-H460, Colo-205 and comparable to cisplatin toward U937. The evaluation of the cell death type promoted by complexes (2) and (4) was investigated toward NCI-H460 revealing better results than the standard drug cisplatin, according to the Annexin V and propidium iodide (PI) labeling experiment. Based on the studies here performed, HBHA seems to be related to lower toxicity toward PBMC and HBPA is improving directly the cytotoxity.
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6
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Chemistry and anti-herpes simplex virus type 1 evaluation of 4-substituted-1H-1,2,3-triazole-nitroxyl-linked hybrids. Mol Divers 2020; 25:2035-2043. [DOI: 10.1007/s11030-020-10094-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/23/2020] [Indexed: 12/18/2022]
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7
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Crystal structure of 1-anilino-5-methyl-1 H-1,2,3-triazole-4-carb-oxy-lic acid monohydrate. Acta Crystallogr E Crystallogr Commun 2019; 75:738-741. [PMID: 31391956 PMCID: PMC6658979 DOI: 10.1107/s2056989019005711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022]
Abstract
The water molecule connects the molecules in the crystal packing. The crystal structure exhibits N—H⋯O, O—H⋯O and O—H⋯N interactions, resulting in the formation of a three-dimensional framework. In the molecular structure of the title compound, C10H10N4O2·H2O, the angle between the triazole and arene rings is 87.39 (5)°. The water of crystallization connects the molecules in the crystal packing. The crystal structure exhibits N—H⋯O, O—H⋯O and O—H⋯N interactions, resulting in the formation of a three-dimensional framework. The intermolecular interactions were identified and quantified using Hirshfeld surface analysis.
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8
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A New Mixed-Valence Mn(II)Mn(III) Compound With Catalase and Superoxide Dismutase Activities. Front Chem 2018; 6:491. [PMID: 30456211 PMCID: PMC6231112 DOI: 10.3389/fchem.2018.00491] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/26/2018] [Indexed: 12/17/2022] Open
Abstract
The synthesis, X-ray molecular structure, physico-chemical characterization and dual antioxidant activity (catalase and superoxide dismutase) of a new polymeric mixed valence Mn(III)Mn(II) complex, containing the ligand H2BPClNOL (N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)[(3-chloro)(2-hydroxy)] propylamine) is described. The monomeric unit is composed of a dinuclear Mn(II)Mn(III) moiety, [Mn(III)(μ-HBPClNOL)(μ-BPClNOL)Mn(II)(Cl)](ClO4)·2H2O, 1, in which the Mn ions are connected by two different bridging groups provided by two molecules of the ligand H2BPClNOL, a phenoxide and an alkoxide group. In the solid state, this mixed valence dinuclear unit is connected to its neighbors through chloro bridges. Magnetic measurements indicated the presence of ferromagnetic [J = +0.076(13) cm−1] and antiferromagnetic [J = −5.224(13) cm−1] interactions. The compound promotes O2•- dismutation in aqueous solution (IC50 = 0.370 μmol dm−3, kcat = 3.6x106 M−1 s−1). EPR studies revealed that a high-valent Mn(III)-O-Mn(IV) species is involved in the superoxide dismutation catalytic cycle. Complex 1 shows catalase activity only in the presence of a base, e.g., piperazine or triethylamine. Kinetic studies were carried out in the presence of piperazine and employing two different methods, resulting in kcat values of 0.58 ± 0.03 s−1 (detection of O2 production employing a Clark electrode) and 2.59 ± 0.12 s−1 (H2O2 consuption recorded via UV-Vis). EPR and ESI-(+)-MS studies indicate that piperazine induces the oxidation of 1, resulting in the formation of the catalytically active Mn(III)-O-Mn(IV) species.
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9
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Synthesis and Evaluation of the Anticancer and Trypanocidal Activities of Boronic Tyrphostins. ChemMedChem 2018; 13:1395-1404. [PMID: 29856519 DOI: 10.1002/cmdc.201800206] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/14/2018] [Indexed: 12/13/2022]
Abstract
Molecules containing an (cyanovinyl)arene moiety are known as tyrphostins because of their ability to inhibit proteins from the tyrosine kinase family, an interesting target for the development of anticancer and trypanocidal drugs. In the present work, (E)-(cyanovinyl)benzeneboronic acids were synthesized by Knoevenagel condensations without the use of any catalysts in water through a simple protocol that completely avoided the use of organic solvents in the synthesis and workup process. The in vitro anticancer and trypanocidal activities of the synthesized boronic acids were also evaluated, and it was discovered that the introduction of the boronic acid functionality improved the activity of the boronic tyrphostins. In silico target fishing with the use of a chemogenomic approach suggested that tyrosine-phosphorylation-regulated kinase 1a (DYRK1A) was a potential target for some of the designed compounds.
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10
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Screening of acetylcholinesterase inhibitors in marine organisms from the Caribbean Sea. Nat Prod Res 2018; 33:3533-3540. [DOI: 10.1080/14786419.2018.1481837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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11
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A new system for cyclohexane functionalization employing iron(iii) catalysts and trichloroisocyanuric acid. NEW J CHEM 2017. [DOI: 10.1039/c7nj01164d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, dinuclear and mononuclear iron complexes were investigated as catalysts in the reaction of cyclohexane chlorination employing trichloroisocyanuric acid as oxidant.
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12
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Synthesis and antimicrobial evaluation of promising 7-arylamino-5,8-dioxo-5,8-dihydroisoquinoline-4-carboxylates and their halogenated amino compounds for treating Gram-negative bacterial infections. RSC Adv 2017. [DOI: 10.1039/c7ra00825b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this work we described the synthesis and antimicrobial evaluation of 7-arylamino-5,8-dioxo-5,8-dihydroisoquinoline-4-carboxylates derivatives that exhibited remarkable activity against two Gram-negative strains of clinical importance.
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13
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Near infrared organic light emitting devices based on a new erbium(iii) β-diketonate complex: synthesis and optoelectronic investigations. RSC Adv 2017. [DOI: 10.1039/c6ra27473k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This paper deals with the synthesis of a new near infra-red emitting Er(iii) β-diketonate complex of low coordinate structure, its characterisation and fabrication of organic light emitting diode using the complex as emitting layer.
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14
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Synthesis and evaluation of copper(II) complexes with isoniazid-derived hydrazones as anticancer and antitubercular agents. Biometals 2016; 29:953-963. [DOI: 10.1007/s10534-016-9968-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 08/28/2016] [Indexed: 02/06/2023]
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15
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Synthesis and antimalarial activity of quinones and structurally-related oxirane derivatives. Eur J Med Chem 2015; 108:134-140. [PMID: 26638044 DOI: 10.1016/j.ejmech.2015.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 12/01/2022]
Abstract
A series of eighteen quinones and structurally-related oxiranes were synthesized and evaluated for in vitro inhibitory activity against the chloroquine-sensitive 3D7 clone of the human malaria parasite Plasmodium falciparum. 2-amino and 2-allyloxynaphthoquinones exhibited important antiplasmodial activity (median inhibitory concentrations (IC50) < 10 μM). Oxiranes 6 and 25, prepared respectively by reaction of α-lapachone and tetrachloro-p-quinone with diazomethane in a mixture of ether and ethanol, exhibited the highest antiplasmodial activity and low cytotoxicity against human fibroblasts (MCR-5 cell line). The active compounds could represent a good prototype for an antimalarial lead molecule.
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16
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A new and efficient procedure for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones. Beilstein J Org Chem 2015; 11:1235-40. [PMID: 26425181 PMCID: PMC4578459 DOI: 10.3762/bjoc.11.137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 07/03/2015] [Indexed: 11/23/2022] Open
Abstract
A new and efficient method for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones in one step with high yields from the reaction of lawsone with 1,3,5-triazinanes was developed.
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17
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Combining Nuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations to Characterize Carvedilol Polymorphs. J Pharm Sci 2015; 105:2648-2655. [PMID: 26372719 DOI: 10.1002/jps.24641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/29/2015] [Accepted: 08/19/2015] [Indexed: 11/06/2022]
Abstract
The experiments of carvedilol form II, form III, and hydrate by (13)C and (15)N cross-polarization magic-angle spinning (CP MAS) are reported. The GIPAW (gauge-including projector-augmented wave) method from DFT (density functional theory) calculations was used to simulate (13)C and (15)N chemical shifts. A very good agreement was found for the comparison between the global results of experimental and calculated nuclear magnetic resonance (NMR) chemical shifts for carvedilol polymorphs. This work aims a comprehensive understanding of carvedilol crystalline forms employing solution and solid-state NMR as well as DFT calculations.
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18
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Cytotoxicity and Leishmanicidal Activity of Isoniazid-Derived Hydrazones and 2-Pyrazineformamide Thiosemicarbazones. J BRAZIL CHEM SOC 2015. [DOI: 10.5935/0103-5053.20150330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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19
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Synthesis of a new class of naphthoquinone glycoconjugates and evaluation of their potential as antitumoral agents. RSC Adv 2015. [DOI: 10.1039/c5ra19192k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A novel series of carbohydrate-based naphthoquinones was synthesized and evaluated for cytotoxicity against different human cancer cell lines (HCT-116, A-549 and MDA-MB 435). The compounds derived from juglone showed better cytotoxicity profiles.
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20
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Synthesis, Crystal Structures, and in Silico Toxicity Prediction of Thienopyridine Phosphoramidates. SYNTHETIC COMMUN 2013. [DOI: 10.1080/00397911.2013.786092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Tautomerism in quinoxalines derived from the 1,4-naphthoquinone nucleus: acid mediated synthesis, X-ray molecular structure of 5-chlorobenzo[f]quinoxalin-6-ol and density functional theory calculations. J BRAZIL CHEM SOC 2013. [DOI: 10.1590/s0103-50532013000200007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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22
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A 3-D coordination network constructed from an angular bis-oxamato tecton and calcium ions. CrystEngComm 2013. [DOI: 10.1039/c3ce41376d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Tautomerism in Quinoxalines Derived from the 1,4-Naphthoquinone Nucleus: Acid Mediated Synthesis, X-ray Molecular Structure of 5-Chlorobenzo[f]quinoxalin-6-ol and Density Functional Theory Calculations. J BRAZIL CHEM SOC 2013. [DOI: 10.5935/0103-5053.20130028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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24
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25
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tert-Butyl N-{3-[(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-yl)amino]propyl}carbamate. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o2361. [PMID: 22904827 PMCID: PMC3414294 DOI: 10.1107/s1600536812029674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 06/29/2012] [Indexed: 11/23/2022]
Abstract
In the title compound, C18H21ClN2O4, the molecular sytructure is stabilized by two intramolecular N—H⋯O hydrogen bonds. In the crystal, molecules are linked by pairs of C—H⋯O hydrogen bonds, forming inversion dimers with graph-set motif R22(10). N—H⋯O hydrogen bonds further link the dimers into C(10) chains along [010].
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26
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New oxirane derivatives of 1,4-naphthoquinones and their evaluation against T. cruzi epimastigote forms. Bioorg Med Chem 2012; 20:4995-5000. [PMID: 22795899 DOI: 10.1016/j.bmc.2012.06.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/06/2012] [Accepted: 06/14/2012] [Indexed: 12/25/2022]
Abstract
New oxirane derivatives were synthesized using six naphthoquinones as the starting materials. Our biological results showed that these oxiranes acted as trypanocidal agents against Trypanosoma cruzi with minimal cytotoxicity in the VERO cell line compared to naphthoquinones. In particular, oxirane derivative 14 showed low cytotoxicity in a mammalian cell line and exhibited better activity against epimastigote forms of T.cruzi than the current drug used to treat Chagas disease, benznidazole.
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27
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Synthesis and evaluation of D-gluconamides as green mineral scales. Carbohydr Res 2012; 353:6-12. [PMID: 22513134 DOI: 10.1016/j.carres.2012.01.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 01/25/2012] [Accepted: 01/31/2012] [Indexed: 11/26/2022]
Abstract
A series of 13 D-gluconamides were synthesized in moderate to good yields and evaluated as green scale inhibitors. The crystal structures of two compounds were determined by X-ray crystallography. The compounds 6c and 6d showed a reasonable inhibition of BaSO(4) precipitation from aqueous solution (47% and 51%, respectively) that indicated the potential for these derivatives of δ-gluconolactone.
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28
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Aqua-(4,4'-bipyridine-κN)bis-(1,4-dioxo-1,4-dihydronaphthalen-2-olato-κO,O)zinc 4,4'-bipyridine mono-solvate dihydrate. Acta Crystallogr Sect E Struct Rep Online 2012; 67:m1489-90. [PMID: 22219743 PMCID: PMC3246923 DOI: 10.1107/s1600536811038682] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 09/20/2011] [Indexed: 11/10/2022]
Abstract
The reaction of 2-hydroxy-1,4-naphthoquinone and 4,4′-bipyridine with zinc acetate produced the title compound, [Zn(C10H5O3)2(C10H8N2)(H2O)]·C10H8N2·2H2O. The bond lengths and angles around the metal atom indicate a deviation from octahedral geometry. The two naphthoquinone ligands coordinate in a cis fashion, with the 4,4′-bipyridine ligand and the water molecules completing the coordination sphere of the metal atom. The asymmetric unit contains also one free 4,4′-bipyridine molecule and two uncoordinated water molecules. These molecules make contacts with the complex through O—H⋯N and O—H⋯O hydrogen bonds, creating a layer two-dimensional network parallel to (121).
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29
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Synthesis of carbohydrate-based naphthoquinones and their substituted phenylhydrazono derivatives as anticancer agents. RSC Adv 2012. [DOI: 10.1039/c2ra21514d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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30
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Determination of the relevant magnetic interactions in low-dimensional molecular materials: the fundamental role of single crystal high frequency EPR. Dalton Trans 2011; 40:10843-50. [PMID: 21860868 DOI: 10.1039/c1dt10780a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new one-dimensional copper(II) complex with formula [Cu(hfac)(2)(N(3)TEMPO)](n) (hfac = hexafluoroacetylacetonate and N(3)TEMPO = 4-azido-2,2,6,6-tetramethylpiperidine-1-oxyl) has been synthesized and investigated by X-ray crystallography, magnetometry and multifrequency single crystal EPR. The system crystallizes in the P1 space group with two non equivalent copper(II) ions in the unit cell, the two nitroxide radicals being coordinated to Cu(1) in axial positions. The copper(II) ions are bridged by N(3)TEMPO radicals resulting in a zig-zag chain structure. The magnetic susceptibility data were at first satisfactorily modeled assuming an alternating spin chain along the monodimensional covalent skeleton, with a ferromagnetic interaction between Cu(1) and the nitroxide moieties and a weaker antiferromagnetic interaction between these and Cu(2) (J(1) = -13.8 cm(-1), J(2) = +2.4 cm(-1)). However, single crystal EPR studies performed at the X- and W-band clearly demonstrate that the observed magnetic monodimensional character of the complex is actually due to the intermolecular contacts involving N(3)TEMPO ligands. This prompted us to fit the magnetic data using a consistent model, pointing out the fundamental role of single crystal EPR data in defining a correct model to describe the magnetic properties of molecular low dimensional systems.
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Synthesis, characterization and catalytic activity of two novel cis-dioxovanadium(v) complexes: [VO2(L)] and [VO2(Hlox)]. J BRAZIL CHEM SOC 2011. [DOI: 10.1590/s0103-50532011000400008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Synthesis of new 9-hydroxy-α- and 7-hydroxy-β-pyran naphthoquinones and cytotoxicity against cancer cell lines. Org Biomol Chem 2011; 9:4315-22. [DOI: 10.1039/c1ob05209h] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Synthesis of new 2-aminocarbohydrate-1,4-naphthoquinone derivatives promoted by ultrasonic irradiation. J BRAZIL CHEM SOC 2011. [DOI: 10.1590/s0103-50532011000100026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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1,2-Dihydr-oxy-2-(3-methyl-but-2-en-yl)-3-oxo-2,3-dihydro-1H-indene-1-carboxylic acid monohydrate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o341. [PMID: 21579770 PMCID: PMC2979928 DOI: 10.1107/s1600536810000516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 01/05/2010] [Indexed: 11/30/2022]
Abstract
The title compound, C15H16O5·H2O, is an intermediate of the Hooker oxidation reaction, used for the synthesis of 2-hydroxy-3-(2-methylprop-1-enyl)naphthalene-1,4-dione (nor-lapachol). The packing in the crystal structure is arranged by an O—H⋯O hydrogen-bonded network along the [100] and [010] directions. Each organic molecule is linked to four other molecules via the hydroxy groups. The water solvent molecule is connected to carboxylic acid groups by three hydrogen bonds.
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