Browsing by Author "Silva, Thales E. M."

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    Antitumor activity of Pd(II) complexes with N,S or O,S coordination modes of acylthiourea ligands.
    (2020) Stevens, Ana María Plutín; Ramos Cairo, Raúl; Mocelo, Raúl; Alvarez Hernández, Anislay; Castellano, Eduardo Ernesto; Cominetti, Márcia Regina; Oliveira, Katia Mara de; Oliveira, Tamires Donizeth de; Silva, Thales E. M.; Oliveira, Rodrigo Corrêa de; Batista, Alzir Azevedo
    Seven new complexes (1–7) of Pd(II) with N-alkyl- and N,N-dialkyl-N0 -acylthioureas were prepared and characterized by elemental analysis and spectroscopic techniques. The crystal structures of the coordination compounds [PdCl(PPh3)(5-cloropiridyl-N0 -benzoylthioureato-k2 N,S)] (2), cis-[Pd(PPh3)2 (N-morpholyn-N0 -benzoylthioureato-k2 O,S)]PF6 (4) and cis-[Pd(PPh3)2(N,N-diphenyl-N0 -thiophenylth ioureato-k2 O,S)]PF6 (7) were determined by X-ray crystallography. The present study reports on an inter esting contribution on the chemistry of Pd(II)/acylthiourea complexes, where the use of monosubstituted acylthiourea conducts to formation of neutral complexes with general formula [Pd(Cl)(PPh3) (acylthiourea)], with a N,S-coordination mode. On the other hand, cationic complexes with formula [Pd (PPh3)2(acylthiourea)]+ , with O,S bidentately coordinated to the metal, are obtained by using a disubsti tuted acylthiourea derivative. The antitumor activity of the N-alkyl- and N,N-dialkyl-N0 -acylthiourea ligands and their palladium (II) complexes with synthesized triphenylphosphine were evaluated against the growth of the DU-145 tumor cells (prostate cancer cells), (MDA-MB-231 (breast cancer cells), L929 (healthy mouse cells). The ligands are not cytotoxic, but the complexes showed good cytotoxicity against the tumor cells tested in this work, and were even better, when compared to the IC50 reported for the cis platin. The complexes showed better activity results in MDA-MB-231 tumor cells, than for the DU-145 tumor cells. Complexes 1 and 6 showed high cytotoxic activity at low micromolar concentrations (IC50 = 1.93 ± 0.45, 0.62 ± 0.08 lM) against MDA-MB-231 (human breast cancer cells). This result indicated that the binding of the ligands to the metal center increases their antitumor activity.
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    New heteroleptic RuII/diphosphine complexes with cytotoxicity against human breast and murine ascitic sarcoma 180 tumor cells.
    (2020) Lima, Benedicto Augusto Vieira; Correa, Rodrigo de Souza; Graminha, Angelica Ellen; Varela Júnior, Jaldyr de Jesus Gomes; Silva, Albérico B. F. da; Ellena, Javier Alcides; Silva, Thales E. M.; Batista, Alzir Azevedo
    The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (dppf-4)], is here presented. The complexes 1-4, with general formula [Ru(pic)(P-P)(bipy)]PF6, were characterized by elemental analysis and by infrared (IR), UV-Vis, nuclear magnetic resonance (NMR 1 H and 13P{1 H}) spectroscopies, cyclic voltammetry and X-ray crystallography technique. Additionally, preliminary in vitro tests against human breast (MDA-MB-231) and murine ascitic sarcoma 180 (S180) tumor cell lines were carried out, and compared with cisplatin, a reference drug. The drug concentration at which 50% of the cells are viable relative to the control (IC50) values found for complexes 1, 2, 3 and 4 against MDA-MB-231 tumor cells were around 14.6, 7.6, 3.3 and 0.4 μM, respectively, while against S180 tumor cells these complexes showed IC50 values of 71.9, 31.3, 11.2 and 3.5 μM, respectively. Therefore, the complexes were more active against MDA-MB-231 than S180.