effects of extending of co-planarity in a series of structurally relative polypyridyl palladium[II] complexes on DNA-binding and cytotoxicity properties

In depth interaction studies between calf thymus deoxyribonucleic acid [CT-DNA] and a series of four structurally relative palladium[II] complexes [Pd[en][HB]][NO[3]][2] [a-d], where en is ethylenediamine and heterocyclic base [HB] is 2, 2›-bipyridine [bpy, a]; 1, 10-phenanthroline [phen, b]; dipyridoquinoxaline [dpq, c] and dipyridophenazine [dppz, d] [Figure 1], were performed. These studies have been investigated by utilizing the electronic absorption spectroscopy, fluorescence spectra and ethidium bromide [EBr] displacement and gel filtration techniques. a-d complexes cooperatively bind and denature the DNA at low concentrations. Their concentration at midpoint of transition, L1/2, follows the order a >> b > c > d. Also the g, the number of binding sites per 1000 nucleotides, follows the order a >> b c > d. EBr and Scatchard experiments for a-d complexes suggest efficient intercalative binding affinity to CT-DNA giving the order: d > c > b > a. Several binding and thermodynamic parameters are also described. The biological activity of these cationic and water soluble palladium complexes were tested against chronic myelogenous leukemia cell line, K562. b, c and d complexes show cytotoxic concentration [Cc[50]] values much lower than cisplatin

Cytotoxicity of diimine palladium [II] complexes of alkyldithiocarbamate derivatives on human lung, ovary and liver cells

Three new Complexes of formula [pd[bpy][R-NH-CSS]] Cl [where bpy is 2/2'- bipyridine, and R-NH-CSS is butylamine, hexylamine- and octyamine-dithiocabamate anion] have been synthesized by University of Sistan and Blachostan. These complexes have been characterized by spectroscopic methods such as ultraviolet-visible, infrared and [1]H-NMR as well as conductivity measurements and chemical analysis. In these complexes, each of the dithiocarbamate ligands coordinates to Pd [II] center as bidentate with two sulfur atoms. We have found a 1:1 electrolyte in water conductivity test for the above mentioned compounds. To measure the biologic activity and potential anticancer efficacy of these compounds, they have been compared with cisplatin and its palladium analogue of [Pd [NH[3]][2] Cl[2]] on three different cell lines of human hepatocarcinoma HepG2, human ovarian carcinoma OV2008, and human lung adenocarcinoma A549. Clonogenic assay has shown LD[50]s in the range of 0.131 +/- 0.025 to 0.934 +/- 0.194 for these compounds on above cell lines. In comparison, cisplatin has shown LD[50]s of 0.838 +/- 0.074, 2.196 +/- 0.220, and 2.799 +/- 0.733 on OV2008, HepG2 and A549 cell lines, respectively. As a conclusion, above three new complexes have shown higher cytotoxicities compared to cisplatin on three different human cell lines. Based on biological tests, these compounds may potentially be considered as good anticancer candidates for further pharmacological studies