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Aranda EE, Matias TA, Araki K, Vieira AP, de Mattos EA, Colepicolo P, Luz CP, Marques FLN, da Costa Ferreira AM. Design, syntheses, characterization, and cytotoxicity studies of novel heterobinuclear oxindolimine copper(II)-platinum(II) complexes. J Inorg Biochem 2016; 165:108-118. [PMID: 27503192 DOI: 10.1016/j.jinorgbio.2016.08.001] [Citation(s) in RCA: 8] [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: 04/12/2016] [Revised: 07/28/2016] [Accepted: 08/01/2016] [Indexed: 12/14/2022]
Abstract
Herein, the design and syntheses of two new mononuclear oxindolimine-copper(II) (1 and 2) and corresponding heterobinuclear oxindolimine Cu(II)Pt(II) complexes (3 and 4), are described. All the isolated complexes were characterized by spectroscopic techniques (UV/Vis, IR, EPR), in addition to elemental analysis and mass spectrometry. Cyclic voltammetry (CV) measurements showed that in all cases, one-electron quasi-reversible waves were observed, and ascribed to the formation of corresponding copper(I) complexes. Additionally, waves related to oxindolimine ligand reduction was verified, and confirmed using analogous oxindolimine-Zn(II) complexes. The Pt(IV/II) reduction, and corresponding oxidation, for complexes 3 and 4 occurred at very close values to those observed for cisplatin. By complementary fluorescence studies, it was shown that glutathione (GSH) cannot reduce any of these complexes, under the experimental conditions (room temperature, phosphate buffer 50mM, pH7.4), using an excess of 20-fold [GSH]. All these complexes showed characteristic EPR spectral profile, with parameters values gǁ>g⊥ suggesting an axially distorted environment around the copper(II) center. Interactions with calf thymus-DNA, monitored by circular dichroism (CD), indicated different effects modulated by the ligands. Finally, the cytotoxicity of each complex was tested toward different tumor cells, in comparison to cisplatin, and low values of IC50 in the range 0.6 to 4.0μM were obtained, after 24 or 48h incubation at 37°C. The obtained results indicate that such complexes can be promising alternative antitumor agents.
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Affiliation(s)
- Esther Escribano Aranda
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Tiago Araújo Matias
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Koiti Araki
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adriana Pires Vieira
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Elaine Andrade de Mattos
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil; Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Pio Colepicolo
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil; Departamento de Radiologia e Oncologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Carolina Portela Luz
- Departamento de Radiologia e Oncologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fábio Luiz Navarro Marques
- Departamento de Radiologia e Oncologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Ana Maria da Costa Ferreira
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil.
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