Structure-dependent in vitro cytotoxicity of the isomeric complexes [Ru(L)2Cl2] (L=o-tolylazopyridine and 4-methyl-2-phenylazopyridine) in comparison to [Ru(azpy)2Cl2]

Abstract

The dichlorobis(2-phenylazopyridine)ruthenium(II) complexes, [Ru(azpy) 2 Cl 2 ], are under renewed investigation due to their potential anticancer activity. The three most common isomers a-, b-and c-[RuL 2 Cl 2 ] with L=o-tolylazopyridine (tazpy) and 4-methyl-2-phenylazopyridine (mazpy) (a indicating the coordinating Cl, N(pyridine) and Nazo atoms in mutual cis, trans, cis positions, b indicating the coordinating Cl, N(pyridine) and Nazo atoms in mutual cis, cis, cis positions, and c indicating the coordinating Cl, N(pyridine) and Nazo atoms in mutual trans, cis, cis positions) are synthesized and characterized by NMR spectroscopy.

Ruthenium polypyridyl complexes containing the bischelating ligand 2,2′-azobispyridine. Synthesis, characterization and crystal structures

“…The [Ru(apy)(tpy)L nÀ ](ClO 4 ) (2Àn) complexes show an improved solubility. Moreover the ligand apy is structurally related to azpy, which is present in recently reported cytotoxic ruthenium complexes [3,4]. Therefore it is of interest to find out how these compounds interact with DNA model bases and DNA, since the anticancer properties of a number of platinum and ruthenium complexes are generally accepted to be related to their binding to the DNA of cancerous cells [1].…”

“…Ru(tpy)Cl 3 shows a pronounced in vitro cytotoxicity and exhibits antitumor activity [2]. The compound a-[Ru(azpy) 2 Cl 2 ] has been reported to show a remarkably high cytotoxicity, even more pronounced than cisplatin in most of the tested cell lines [3,4]. The increased amount of possible binding modes of ruthenium polypyridyl complexes to DNA as compared to those of the first generations of platinum drugs, including intercalation of the ligands between two parallel base pairs, could be crucial in order to overcome resistance to cisplatin [5].…”

“…First described by Kirpal in 1927 [8], the availability of two possible coordination sites has made it attractive in the synthesis of multiple dinuclear complexes, most of which were symmetric, as reviewed by Kaim [9]. On the other hand apy is structurally related to 2-phenylazopyridine, azpy, a ligand present in the recently reported cytotoxic bis(2-phenylazo)pyridine ruthenium(II) compounds, such as the above-mentioned a-[Ru(azpy) 2 Cl 2 ] [3,4].…”

Synthesis, characterization, and biological studies of novel Ni(II) and Zn(II) complexes with 5-chloro-2-(phenylazo)pyridine

“…The applications of azoimine complexes are many and varied in industrial and pharmaceutical fields 4,5 . The versatility of [Ru(azpy) 2 Cl 2 ], a wellknown complex of ruthenium(II) with 2-(phenylazo)pyridine (azpy), has been extensively explored.…”

“…It is an effective catalyst in the epoxidation reaction of olefin 6 as well as an anticancer agent in various cancer cell lines [5][6][7] . Recently, other azpy derivatives and their ruthenium complexes have been synthesized: for example, [Ru(Hsazpy) 2 Cl 2 ] when Hsazpy = 2-phenylazo pyridine-5-sulphonic acid 8 , [Ru(4mazpy) 2 Cl 2 ] when 4mazpy = 4-methyl-2-phenylazopyridine 5 , and [Ru(Clazpy) 2 Cl 2 ] when Clazpy is 5-chloro-2-(phenylazo) pyridine 9 .…”