Syntheses and structures of new dicopper(ii) complexes bridged by N-(2-hydroxyphenyl)-N′-(3-aminopropyl)oxamide: DNA-binding properties and cytotoxic activities

Abstract

0 -(3aminopropyl)oxamide; phen = 1,10-phenanthroline; bpy = 2,2 0 -bipyridine; Me 2 bpy = 4,4 0 -dimethyl-2,2 0 -bipyridine], have been synthesized and characterized by elemental analyses, molar conductance measurements, IR and electronic spectra studies and X-ray single-crystal diffraction. In the three dicopper(II) complexes, the coordination environments around the copper(II) atoms are different: Cu1 and Cu2 atoms have a square-planar and a square-pyramidal geometry, respectively. The CuÁ Á ÁCu distances through the cis-papo 3À -bridge in complexes 1, 2 and 3 are 5.1936 (7), 5.1967(7) and 5.1919(15) Å , respectively. In the crystals of the three dicopper(II) complexes, there are abundant hydrogen bonds contributing to the complicated supramolecular structure. The reactivity towards DNA, and cytotoxic studies show that all three dicopper(II) complexes can bind to herring sperm DNA (HS-DNA) in the mode of intercalation, and the cytotoxic activities are consistent with their DNA-binding abilities, following the order of 1 4 2 4 3. The influence of structural variation of the terminal ligands in the dinuclear complexes on the DNA-binding property and cytotoxic activity is preliminarily discussed.

Synthesis and crystal structure of new dicopper(II) complexes having asymmetric N,N′-bis(substituted)oxamides with DNA/protein binding ability: In vitro anticancer activity and molecular docking studies

“…(7) 121 Symmetry codes for complex 1: (i) Àx, Ày + 1, Àz; (ii) x À 1, y, z. Symmetry codes for complex 2: (i) Àx, Ày, Àz + 2; (ii) x, y, z À 1. presented significant hypochromism effect around 204 nm, and accompanied the slightly red-shifts in the absorbance maxima. These spectral characteristics reveal that the two complexes can interact with HS-DNA through the intercalation mode [24]. To quantitatively evaluate the binding affinity of the two complexes with HS-DNA, the intrinsic binding constant K b was determined by monitoring the changes in absorbance at about 240 nm using the following equation [51]: Fig.…”

“…Quite recently, we reported the synthesis, structure, DNA/protein-binding property and in vitro antitumor activity of two dicopper(II) with symmetric N,N 0 -bis(substituted)oxamides [27], and the results suggest that counterions may play an important role in changing the DNA/protein-binding abilities of dicopper(II) complexes. Considering the fact that complexes bridged by asymmetric N,N 0 -bis(substituted)oxamides have shown interesting magnetic properties and good anticancer activities [28][29][30], as well as copper(II) complexes containing perchlorate or picrate (pic) anions exhibited good cytotoxic activities [22][23][24][25][26][27]30], as a continuation of our ongoing program, we employed N-(5-chloro-2-hydroxyphenyl)-N 0 -[2-(dimethylamino)ethyl]oxami de (H 3 chdoxd) and N-hydroxypropyl-N 0 -(2-carboxylatophenyl)-oxamide (H 3 oxbpa) as asymmetric N,N 0 -bis(substituted)oxamide bridging ligands, 2,2 0 -bipyridine (bpy) as terminal ligand, and perchlorate and pic anions as counterions to synthesize and structurally characterize two new complexes with formulae of [Cu 2 (ClO 4 )(chdoxd)(CH 3 OH)(bpy)]-H 2 O (1) and [Cu 2 (pic)(oxbpa)-(CH 3 OH)(bpy)]Á0.5CH 3 OH (2). The comparative study of the interactions of these complexes with DNA and protein BSA, as well as the antitumor activities was explored both theoretically and experimentally to gain some new insight into the structure-activity relationship of the dicopper(II) complexes with asymmetric N,N 0 -bis(substituted)oxamide as bridging ligands.…”

“…Thus, a combination of suitable metal as well as design of ligand is considered an important prerequisite for the construction of a highly efficient DNA and BSA targeted drug. Along this line, lots of copper(II) complexes with different ligands have been widely studied [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], because copper, as a biologically relevant element, shows great effects on the endogenous oxidative DNA damage associated with aging and cancer and relates to many enzymatic activities which have been identified. Comparing the number of studies dealing with monocopper complexes [14][15][16][17][18][19][20][21][22], relatively few studies on dicopper(II) complexes have been reported to date.…”

“…Comparing the number of studies dealing with monocopper complexes [14][15][16][17][18][19][20][21][22], relatively few studies on dicopper(II) complexes have been reported to date. However, the enhancement of DNA-binding activity for dinuclear complexes prompts us to design and synthesize new dicopper(II) complexes in order to gain some insight into their DNA/protein binding property and antitumor activity of these kinds of complexes [23][24][25][26][27].…”

DNA/BSA‐binding property and in vitro anticancer activity of a new dicopper(II) complex with N‐(2‐hydroxy‐5‐nitrophenyl)‐N′‐[3‐(diethylamino)propyl]oxamide as bridging ligand: Synthesis and crystal structure

“…Consequently, combination of a suitable metal and a well‐designed ligand is considered an important prerequisite for the construction of a highly efficient DNA or protein targeted drug. Many copper(II) complexes with different ligands have been widely studied . More importantly, several families of individual copper complexes have been studied as potential antitumor agents.…”