Synthesis, characterization, andin vitroantioxidant and anticancer studies of ruthenium(III) complexes of symmetric and asymmetric tetradentate Schiff bases

Abstract

To cite this article: Ikechukwu P. Ejidike & Peter A. Ajibade (2015): Synthesis, characterization, and in vitro antioxidant and anticancer studies of ruthenium(III) complexes of symmetric and asymmetric tetradentate Schiff bases, Journal of Coordination Chemistry, Ruthenium(III) complexes of three tetradentate Schiff bases with N 2 O 2 donors formulated as [RuCl (LL 1 )(H 2 O)], [RuCl(LL 2 )(H 2 O)] and [RuCl(LL 3 )(H 2 O)] were synthesized and characterized by elemental analyses, molar conductance, FTIR, and electronic spectral measurements. The FTIR data showed that the tetradentate Schiff base ligands coordinate to Ru ions through the azomethine nitrogen and enolic oxygen. The antioxidant activities of the complexes were investigated through scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. The DPPH activity for [RuCl(LL 2 )(H 2 O)] with IC 50 = 0.031 mg mL −1 was higher than the values obtained for the other Ru(III) compounds. The study revealed that the synthesized Ru(III) complexes of the tetradentate Schiff base exhibited strong scavenging activities against DPPH and moderate against ABTS radicals. In addition, the antiproliferative studies of the complexes were also tested against human renal cancer cells (TK10), human melanoma cancer cells (UACC62), and human breast cancer cells (MCF7) using the SRB assay. The results indicated that the Ru(III) complexes showed low anticancer activities against the tested human cancer cell lines.

Synthesis, Characterization, Anticancer, and Antioxidant Studies of Ru(III) Complexes of Monobasic Tridentate Schiff Bases

“…These bands have been assigned to 2 T 2g → 2 A 2g transition and are in agreement with the assignment made for similar octahedral ruthenium(III) complexes [42, 43]. Absorption bands within the 452–525 nm regions were assigned to the charge transfer transitions [22, 44]. Overall, the absorption spectra of the Ru(III)-Schiff base complexes are typical of octahedral environment about the ruthenium(III) ions [22].…”

“…The values were found to be in the range of 30.1–38.8  μ Scm −1 suggesting the nonelectrolytic nature of the complexes in solution [22, 29]. …”

Anti‐hepatocellular carcinoma, antioxidant, anti‐inflammation and antimicrobial investigation of some novel first and second transition metal complexes

“…It gives a purple solution in methanol. The radical scavenging potentials of the complexes with DPPH radical were evaluated as described …”

In Vivo Enzymes Activities of Some Ru(II) Compounds with N-Alkylphenothiazines

“…New Ru(II)-DMSO and Ru(II)-p-cymene complexes with N-alkylphenothiazines were previously synthesized and characterized by elemental analysis and spectroscopic methods (FT-IR, UV-Vis, 1 H and 13 C NMR) [35,36]. These complexes showed effects on antioxidative enzymes, as well as malondyaldehyde and nitrite levels in rats blood.…”

“…The advantage of ruthenium complexes is their relatively low toxicity [6,11], lower than cisplatin, which can partly be explained by its reduced reactivity to DNA in intact cells. Many biological properties have been attributed to ruthenium complexes including antioxidant activity [12,13] and cytotoxicity [3,9,10]. Anticancer activities of Ru(II)-DMSO complexes are known for many years and some of them are in intensively clinical trials [14,15], while Ru(II)-arene complexes have been also widely studied as anticancerogenic compounds [3,16].…”