Synthesis and Characterization of Ru(II)–DMSO–Cl–Chalcone Complexes: DNA Binding, Nuclease, and Topoisomerase II Inhibitory Activity

Abstract

The complexes of type cis-[Ru(S-DMSO)(3)(R-CO-CH═CH-R')Cl] (R = 2-hydroxyphenyl for all, R' = phenyl 1, naphthyl 2, anthracenyl 3, thiophene 4, 3-methyl thiophene 5) are synthesized and characterized using spectroscopic (IR, (1)H and (13)C NMR, and UV-vis) and single crystal X-ray diffraction techniques. Their crystal structures show the formation of both intermolecular and intramolecular H-bonding. The molecular assembly of complex 5 using secondary interactions provides a butterfly structure. The binding of complexes with calf thymus DNA is monitored using UV-vis spectral titrations. The binding interaction of complexes 1, 2, and 3 with DNA increases with increasing conjugation of aromatic rings. However, complexes 4 and 5 interact with DNA strongly. The emission from ethidium bromide (EB) bound DNA recorded in phosphate buffer solution (pH = 7.2) decreases by incremental addition of solution of the complexes. The complexes 4 and 5 (100 μM) bind with the minor groove of DNA and cleave double-stranded pBR322 DNA significantly even in the absence of an activator. In the presence of H(2)O(2), they cleave supercoiled DNA via oxidative pathway even at lower concentration (20 μM). Both complexes 4 and 5 inhibit topoisomerase II activity with IC(50) values of 18 and 13. These values suggest that 4 and 5 are potential topoisomerase II inhibitors as compared to some of known inhibitors like novobiocin and etoposide.

Synthesis, structure and characterization of two new Zn(II) and Cd(II) complexes with the bidentate ligand 2-[(2-aminoethyl)amino]ethanaminium (AEEA)

“…The Zn(II) ion is tetracoordinated by two nitrogen atoms (N1 and N2) of the AEEA ligand and two chlorine atoms (Cl1 and Cl2). The detailed geometry of the ZnCl 2 N 2 tetrahedron ( Table 2) shows that the bond distances, Zn-N1 = 2.0216(10) Å, Zn-N2 = 2.0849 (9) Å, Zn-Cl1 = 2.2393(4) Å, and Zn-Cl2 = 2.2520(4) Å, are similar to those reported for other tetrahedral Zn(II) complexes with similar Schiff bases [26]. The bond angles around the Zn atom vary between 86.904(3) and 128.06(3)°, indicating that the ZnCl 2 N 2 species have a highly distorted tetrahedral geometry (Fig.…”

“…They are known to be a class of versatile ligands, capable of generating a variety of molecular architectures and coordination polyhedra [5][6][7]. The metal complexes of such Schiff bases have been extensively used as biological probes [8], DNA cleaving agents [9], catalysts [10,11], sensing materials [12,13] and corrosion inhibitors [14]. In recent years, the coordination chemistry of N coordinated ligands has also received a lot of attention because of their relevance to biological systems [15].…”

Synthesis and physico-chemical studies of a novel organo-metallic compound CdCl2(C6H4FNH2)2

“…They are known to be a class of versatile ligands, capable of generating a variety of molecular architectures and coordination polyhedral [16][17][18]. The metal complexes of such Schiff bases have been extensively used as biological probes [19], DNA cleaving agents [20], catalysts [21,22], sensing materials [23,24] and corrosion inhibitors [25]. In recent years, the coordination chemistry of N coordinated ligands has also received a lot of attention because of their relevance to biological systems [26].…”

Synthesis and electrochemical characterization of new ruthenium–terthiophene complexes

“…Bearing in mind the above, the growing interest that ruthenium complexes have aroused as therapeutic agents in recent years [27][28][29][30][31] and that polythiophene is one of the most widely studied polymers, in this paper we present the synthesis and characterization of two novel ruthenium complexes, in whose coordination sphere, there is a ligand derived from thiophene, more specifically terthiophene (TT), together with phosphine-like ligands, 1,3,5-triaza-7-phosphaadamantane (PTA) and derivatives. Subsequent to their synthesis and characterization, electropolymerization studies evidence the obtention of new polymers with quite interesting properties, that would make them not only good candidates as sensors and bio-sensors, but also for the development of batteries [32,33].…”