Synthesis, structural characterization, oxygen sensitivity, and antimicrobial activity of ruthenium(II) carbonyl complexes with thiosemicarbazones

Half-Sandwich Arene Ruthenium(II) Thiosemicarbazone Complexes: Evaluation of Anticancer Effect on Primary and Metastatic Ovarian Cancer Cell Lines

In this study, we describe the synthesis, characterization and antiproliferative activity of three organo-ruthenium(II) half-sandwich complexes [RuCl(η6-p-cym)(N,S-L)]Cl (I, II, and III). To form these complexes, three thiosemicarbazone ligands (TSCs) were synthesized; L = 5-nitro-2-carboxyaldehyde-thiophen-N-methyl-thiosemicarbazone, (L1); 2-acetyl-5-bromo-thiophen-N-methyl-thiosemicarbazone, (L2) and 2-acetyl-5-bromo-thiophen-N,N-dimethyl-thiosemicarbazone, (L3). The isolated compounds were analyzed using spectroscopic techniques such as elemental analysis, conductance measurements, FT-IR, 1H NMR spectroscopy, MALDI-TOF mass spectrometry, and single-crystal XRD. Our results demonstrated that the synthesized thiosemicarbazone ligands (TSCs) are bound to the metal ion as a bidentate ligand that coordinates through the thiocarbonyl sulfur and azomethine nitrogen atoms in all complexes (I, II, and III). The X-ray crystal structures of L1 and L2 revealed that both compounds are crystallized in the triclinic crystal system with space group P-1. The biological potency of newly synthesized TSC ligands (L1, L2, and L3) and their corresponding ruthenium complexes (I, II, and III) were investigated on human primary ovarian (A2780) and human metastatic ovarian (OVCAR-3) cell lines. To get detailed information respecting antitumor properties, cytotoxicity, DNA/BSA binding affinity, cellular uptake, DNA binding competition, and trans-epithelial resistance measurement assays were performed. Our results demonstrate that newly synthesized ruthenium(II) complexes possess potential biological activity. Moreover, we observe that the ruthenium complexes reported here show anticancer activity on primary (A2780) and metastatic (OVCAR-3) ovarian cancer cells.

Crystal structures, spectroscopic properties of new cobalt(II), nickel(II), zinc(II) and palladium(II) complexes derived from 2-acetyl-5-chloro thiophene thiosemicarbazone: Anticancer evaluation

The reactions of cobalt(II), nickel(II), zinc(II) chlorides and [Pd(DMSO)₂Cl₂] with 2-acetyl-5-chloro-thiophene thiosemicarbazone (HL) leads to the formation of a series of new complexes: [CoCl₂(S-HL)₂], 1; [Ni(N,S-L)₂], 2 [ZnCl₂(S-HL)₂], 3 and [PdCl₂(N,S-HL)], 4. All the complexes have been characterized by elemental analysis, IR, LC-MS. ¹H and ¹³C NMR spectroscopy have been performed for Zn(II) and Pd(II) complexes. The crystal structures of the complexes 1-3 have been determined by single-crystal X-ray diffraction methods. The compounds, (1) and (3), crystallized in the monoclinic crystal system with C2/c space group. In both complexes, the metal centers are four-coordinated in a distorted tetrahedral configuration by two sulfur atoms from two thiosemicarbazone ligands and two Cl anions. The crystal structure of (2) consists of monomeric entities where the nickel(II) ion exhibit distorted square planar geometry. The coordination geometry around nickel ion is four-coordinate with four atoms of the two chelating thiosemicarbazone ligands which are in cis position. The τ₄ value of 0.255 obtained from the τ₄ analysis of complex (2) shows that the four-coordinate geometry around the central nickel ion is close to square planar. Complex (4) is mononuclear, the central ion is coordinated through the sulfur and the azomethine nitrogen atom of neutral ligand. The cytotoxic effects of all complexes were analyzed for three cancer cell lines, Caco-2, DLD-1, and SW620 compared to normal colon epithelial cell line, CCD18Co. Complex (4) is more active against DLD-1, SW620 and Caco-2 than CCD18Co. The efficiency of complex (4) is more effective in aggressive cancer cell lines. Therefore, it can be used as a new chemotherapeutic, especially in the treatment of resistant cancer types caused by long-term use of platinum-based drugs.

Screening organometallic thiophene containing thiosemicarbazone ruthenium (II/III) complexes as potential anti-tumour agents

The new ruthenium (III) complex has been synthesized and characterized by elemental analysis, FT-IR, UV-Vis, EI-Mass, EPR spectroscopy, and magnetic susceptibility measurement. Cytotoxic effects of organoruthenium (II/III) complexes 1a, 1b, and 2a, and their ligands (TSC¹ and TSC²) in cultured human ovarian (A2780, SKOV-3, and OVCAR-3) and colon (DLD, CCD18Co, and Caco-2) cells have been investigated comparing reactivity of the Ru (II/III) complexes and their free TSC ligands. The complexes exhibit higher cytotoxicity in three cancer cell lines than in normal cells. The binding with CT-DNA and BSA of the all complexes were weak compared with their ligand in spite of the cellular uptake of these complexes into the cytoplasm and then nucleus while their cytotoxic effects were vice versa. All the results showed that Complex 1b has more efficient cytotoxicity on the colon cancer cells than ovarian cancer cells. However, Complex 2a is a better drug candidate especially for antitumor therapy of metastasized ovarian cancer.

Synthesis, characterization, computational and antimicrobial activities of a novel iridium thiourea complex

A novel octahedral iridium(iii)thiourea complex with potential medical applications.