Coordination behavior of ligand based on NNS and NNO donors with ruthenium(III) complexes and their catalytic and DNA interaction studies

Thiosemicarbazone Complexes of Transition Metals as Catalysts for Cross-Coupling Reactions

Catalysis of cross-coupling reactions under phosphane-free conditions represents an important ongoing challenge. Although transition metal complexes based on the thiosemicarbazone unit have been known for a very long time, their use in homogeneous catalysis has been studied only relatively recently. In particular, reports of cross-coupling catalytic reactions with such complexes have appeared only in the last 15 years. This review provides a survey of the research in this area and a discussion of the prospects for future developments.

Bioactive Salen-type Schiff Base Transition Metal Complexes as Possible Anticancer Agents

Although metal-based anticancer drugs have been recognized as the most effective agents over the organic compounds, non-selectivity and high toxic effects have limited their applications in a way that only three Pt-analogues have progressed into clinical use. These problems have spurred chemists to develop different strategies based on alternative targets. This work focuses on predicting potency and mode of interactions of a series of salen type Schiff base transition metal complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine, over some proteins (HDAC7, HDAC2, CatB, B-RAF kinase, TopII, RNR, TS, and rHA) using computational docking method, to be later considered as possible anticancer agents. The obtained results showed that all complexes exhibited higher affinity for HDAC7 than the other targets. Moreover, the bromo-derivatives of the copper compounds were more active on HDAC7 than the other derivatives. Such bromo compounds showed considerable interactions with Kinase, RNR, TS, and CatB. Contrary to Histone deacetylase (HAD)C7; HDAC2 was predicted to be relatively poor target. As expected, formation of the hydrophobic interactions between the metal complexes and the protein targets were essential for activity of the metal compounds. This study provides some more information for further optimizations and development of new metallodrugs as enzyme inhibitors for potential therapeutic agents.

Investigation of in vitro anticancer and DNA strap interactions in live cells using carboplatin type Cu(II) and Zn(II) metalloinsertors

A series of carboplatin type Cu(II) and Zn(II) metalloinsertors (1-8) having β-diketone analogues and biologically significant cyclobutane-1,1-dicarboxylic acid have been synthesized and characterized by spectral and analytical methods. The binding and cleavage propensity of these metalloinsertors on DNA and their cytotoxic effects in live cells have been explored. From the gel electrophoresis study, it is observed that the complexes 1-8 cleave pBR322 DNA via a hydrolytic mechanism induced by hydroxyl radical scavengers, DMSO and EtOH as the reactive oxygen species (ROS). In vivo antitumor efficacy has been studied on EAC tumor bearing mice which is assessed by mean survival time, effect on hematological parameters and solid tumor volume. The results strongly support that complex 1 shows potent antitumor effect against EAC and higher than the standard drug carboplatin. Moreover, the cytotoxicity of the complexes, screened on a panel of human cancerous cell lines viz., human cervical cancer cells (HeLa), human breast adenocarcinoma cells (MCF-7), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines, reveals that complex 1 exhibits a better anticancer activity than other complexes and standards.

Ruthenium(II) carbonyl complexes bearing quinoline-based NNO tridentate ligands as catalyst for one-pot conversion of aldehydes to amides and o-allylation of phenols

Six new octahedral ruthenium(II) carbonyl complexes having the general molecular formula [RuCl(CO)(B)L(1-2)] (B = PPh3, AsPh3 or py; L(1-2) = quinoline based NNO ligand) were synthesized. The quinoline based ligands behave as monoanionic tridentate donor and coordinated to ruthenium via ketoenolate oxygen, azomethine nitrogen and quinoline nitrogen. The composition of the complexes has been established by elemental analysis and spectral methods (FT-IR, electronic, (1)H NMR, (13)C NMR, (31)P NMR and ESI-Mass). The complexes were used as efficient catalysts for one-pot conversion of various aldehydes to their corresponding primary amides in presence of NH2OH · HCl and NaHCO3. The effect of catalyst loading and reaction temperature on catalytic activity of the ruthenium(II) carbonyl complexes were also investigated. The synthesized complexes also possess good catalytic activity for the o-allylation of phenols in the presence of K2CO3 under mild conditions. The complexes afforded branched allyl aryl ethers according to a regioselective reaction.