Ternary copper(II) complexes with hippurate derivatives and 1,10-phenanthroline: Synthesis and biological activity

Iridium(III) coordination of N(6) modified adenine derivatives with aminoacid chains

In this manuscript we report the preparation of three N⁶-aminoacid-adenine-derivatives: N-(7H-purin-6-yl)glycine·0.5H₂O (N⁶-GlyAde), N-(7H-purin-6-yl)-β-alanine·1.5H₂O (N⁶-β-AlaAde) and N-(7H-purin-6-yl)-γ-aminobutyric·2H₂O (N⁶-GabaAde) and the synthesis and X-ray characterization of three Ir(III) NAMI-A derivatives (NAMI-A is [imidazoleH][trans-Ru^IIICl₄(DMSO-κS)(imidazole)]) [trans-Ir^IIICl₄(DMSO-κS)(N³-H)-(7H-purin-6-yl)glycine-κN⁹] (1), [trans-Ir^IIICl₄(DMSO-κS)(N³-H)-(7H-purin-6-yl)-β-alanine-κN⁹] hydrate (2) and [trans-Ir^IIICl₄(DMSO-κS)(N³-H)-(7H-purin-6-yl)-γ-aminobutyryl-κN⁹] (3). In all complexes the metal center shows octahedral geometry with coordination to four chlorido ligands and one S coordinated dimethylsulfoxide (DMSO-κS). The coordination sphere of the metal is completed by the modified adenine molecule which is bound via N(9) and protonated at N(3). In two complexes the importance of lone pair (lp)-π interactions involving the adenine ring have been studied using density functional theory (DFT) calculations and the Bader's theory of atoms in molecules. Furthermore, the ability of complexes (1-3) to affect the cell viability was evaluated against three different cancer cell lines: human lung carcinoma cells (A549), human cervical carcinoma cells (HeLa) and human breast cancer cells (MCF7). We have also analyzed their ability to cleave the DNA experimentally and their affinity for two models of DNA has been studied using molecular docking simulations.

Transition-metal norharmane compounds as possible cytotoxic agents: New insights based on a coordination chemistry perspective

New first-row transition-metal compounds with the ligand norharmane (9H-Pyrido[3,4-b]indole; Hnor) are reported. The compounds have the general formula [M(LL)(Hnor)(NO₃)₂](MeOH)_0-1 (M=Co, Ni, Cu, Zn; LL=2,2'-bipyridyl (bpy), 1,10-phenanthroline (phen)) and have been characterized by physical and analytical methods. X-ray structural analysis revealed that the compound of formula [Cu(phen)(Hnor)(NO₃)₂], (1) has a distorted 6-coordinated octahedrally-based geometry, with a planar-based [CuN₃O] core, where Cu-L varies between 1.99 and 2.04Å and two weak axial CuO contacts (2.209 and 2.644Å) from two different nitrates. Based on spectroscopic similarities, the other compounds appear to have the same or very similar coordination geometries. The compounds showed clear cell growth inhibitory effects in two different cancer cell lines in vitro, with the copper and zinc complexes being the most toxic and in fact almost comparable to cisplatin. Flow-cytometry analysis confirmed induction of apoptosis in cancer cells treated with the compounds. Interestingly, co-incubation of the cells with metal complexes and CuCl₂ induced an increase in the cytotoxic effects, most likely due to the conversion of the metal compounds in the corresponding, and most active, copper analogues.

Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties

Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells.

Biological activity and structure dependent properties of cuprous iodide complexes with phenanthrolines and water soluble tris (aminomethyl) phosphanes

This paper presents the biological activity of copper(I) iodide complexes with 1,10-phenanthroline (phen) or 2,9-dimethyl-1,10-phenanthroline (dmp) and three tris (aminomethyl) phosphanes: P(CH2N(CH2CH2)2NCH3)3 (1), P(CH2N(CH2CH2)2O)3 (2) and P (CH2N(CH3)CH2CH2OH)3 (3). Crystallographic and DFT data indicate a significantly stronger binding ability of 3 in the complexes [CuI (phen) P (CH2N (CH3)CH2CH2OH)3] (3P) and [CuI(dmp)P(CH2N(CH3)CH2CH2OH)3] (3N) in comparison to the 1 or 2 ligands. Most probably, this is caused by the relatively small steric requirements of 3. The complexes with dmp exhibit a very high in vitro activity against the Staphylococcus aureus strain (MIC - minimal inhibitory concentration: 2.5-5 μg/mL) and Candida albicans diploid fungus (MIC: 1.25-2.5 μg/mL). All the tested complexes also show a strong in vitro antitumor activity against human ovarian carcinoma cell lines: MDAH 2774 (IC50: 7-2 μM) and cisplatin-resistant SCOV3 (IC50: 3-2 μM). Interestingly, the complexes with dmp of higher biological activity more weakly interact with bovine serum albumin (BSA) and less efficiently cleave the pBluescriptSK+ plasmid.