Recent Advances Involving Palladium (II) Complexes for the Cancer Therapy

Abstract

This review deals with the most important results published on the structures, reactivity and biomedical applications of palladium(II) complexes in the cancer therapy in the last five years. Biological mechanisms of palladium(II) complexes, especially of palladacycle compounds were boarded. Among the most recent advances in the studies involving correlations between chemical structures of palladacycle compounds and biological activities we mention i) the synthesis of metallic isomer complexes containing ligands derivatives of pyridine and imines in trans position having high antitumoral activities, ii) the development of cationic complexes with biological activity, iii) the discovery of preferential nucleotides for the intercalation of metallic complexes in the double helix of DNA of cancerous cells, configuring irreparable lesions in the macromolecule and iv) the interaction of metallic complexes with other biological molecules, like proteins and peptides, through terminal amine groups, carboxylate groups, imidazolic group of histidine and mostly with the thiol group of methionine. Some of these interactions are related to drug nefrotoxicity effect, which understanding is of fundamental importance. v) Novel ortho-cyclopalladated compounds synthesized from p-isopropylbenzaldehyde thiosemicarbazone have been described with specific cytotoxic properties in tumor cells sensitive to cis-diamminedichloroplatinum(II). The lysosomal cysteine proteinases cathepsins B and L have been implicated in a variety of pathological conditions, especially in diseases involving tissue-remodeling states, such as tumor metastasis. Our research group is studying inhibition of Cathepsin B by new palladacycle compounds derived from N, N-dimethyl-1-phenethylamine and having biphosphine ligands. New palladacycle compounds derived from N,N-dimethyl-1-phenethylamine and the ligand bis(diphenylphosphine)ferrocene were presented as effective antitumoral agents.

Innovative Use of Palladium Compounds To Selectively Detect Live Enterobacteriaceae in Milk by PCR

“…Similarly, considering Fig. 4 and previous reports (17,18,30,(31)(32)(33)(34)(35)(36), it is conceivable that the components to which the Pd compound molecules (negatively charged in neutral pH) could be chelated and/or adsorbed are CW_TMP, positively charged DBP in neutral pH, and DNA bases in E. coli cells. In contrast, as shown in Fig.…”

“…These proteins help to mitigate exposure to heavy metals through chelation (28,29). Additionally, palladium reportedly interacts with proteins, enzymes, and peptides through terminal amine groups, carboxylate groups, histidine imidazole groups, methionine and cysteine thiol groups, arginine, and lysine (13,14,30,(31)(32)(33)(34)(35)(36). Furthermore, the Pd metal that chelated with the 2Cl groups in the original agent (complex form) is reported to be negatively charged.…”

Bis(ferrocenylimine)palladium(II) and platinum(II) complexes: Synthesis, molecular structures and evaluation as antitumor agents

“…The furan or thiophene groups on the complexes did not show any significant influence on the cytotoxic properties of the complexes. The observed activities exhibited by the complexes confirmed the potential of trans-isomers to exert cytotoxicity on cancer cell lines [45]. However, the complexes exhibited very low activities against A2780 cell lines (IC 50 >100 µM) to claim any remarkable achievement [19,46].…”

In Vitro and In Vivo Trypanocidal Effects of the Cyclopalladated Compound 7a, a Drug Candidate for Treatment of Chagas' Disease

“…The most probable explanation for this effect is that cyclopalladated compounds may directly inhibit cysteine proteases by direct oxidation of the catalytic domain (4). One of these enzymes is T. cruzi cruzain, which is important for parasite invasion (13).…”