Half‐sandwich Ruthenium (II) complexes with triphenylamine modified dipyridine skeleton and application in biology/luminescence imaging

Ferrocene-modified half-sandwich iridium(III) and ruthenium(II) propionylhydrazone complexes and anticancer application

Ferrocene, ruthenium(II) and iridium(III) organometallic complexes, potential substitutes for platinum-based drugs, have shown good application prospects in the field of cancer therapy. Therefore, in this paper, six ferrocene-modified half-sandwich ruthenium(II) and iridium(III) propionylhydrazone complexes were prepared, and the anticancer potential was evaluated and compared with cisplatin. These complexes showed potential in-vitro anti-proliferative activity against A549 cancer cells, especially for Ir-based complexes, and showing favorable synergistic anticancer effect. Meanwhile, these complexes showed little cytotoxicity and effective anti-migration activity. Ir3, the most active complex (ferrocene-appended iridium(III) complex), could accumulate in the intracellular mitochondria, disturb the cell cycle (S-phase), induce the accumulation of reactive oxygen species, and eventually cause the apoptosis of A549 cells. Then, the design of these complexes provides a good structural basis for the multi-active non‑platinum organometallic anticancer complexes.

Effects induced by η6-p-cymene ruthenium(II) complexes on Langmuir monolayers mimicking cancer and healthy cell membranes do not correlate with their toxicity

The mechanism of chemotherapeutic action of Ru-based drugs involves plasma membrane disruption and valuable insights into this process may be gained using cell membrane models. The interactions of a series of cytotoxic η6-p-cymene ruthenium(II) complexes, [Ru(η6-p-cymene)P(3,5-C(CH3)3-C6H3)3Cl2] (1), [Ru(η6-p-cymene)P(3,5-CH3-C6H3)3Cl2] (2), [Ru(η6-p-cymene)P(4-CH3O-3,5-CH3-C6H2)3Cl2] (3), and [Ru(η6-p-cymene)P(4-CH3O-C6H4)3Cl2] (4), were examined using Langmuir monolayers as simplified healthy and cancerous outer leaflet plasma membrane models. The cancerous membrane (CM1 and CM2) models contained either 40 % 1,2- dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 30 % cholesterol (Chol), 20 % 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and 10 % 1,2-dipalmitoyl-sn-glycero-3-phospho-l-serine (DPPS). Meanwhile, the healthy membrane (HM1 and HM2) models were composed of 60 % DPPC or DOPC, 30 % Chol and 10 % DPPE. The complexes affected surface pressure isotherms and decreased compressional moduli of cancerous and healthy membrane models, interacting with the monolayers headgroup and tails according to data from polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS). However, the effects did not correlate with the toxicity of the complexes to cancerous and healthy cells. Multidimensional projection technique showed that the complex (1) induced significant changes in the CM1 and HM1 monolayers, though it had the lowest cytotoxicity against cancer cells and is not toxic to healthy cells. Moreover, the most toxic complexes (2) and (4) were those that least affected CM2 and HM2 monolayers. The findings here support that the ruthenium complexes interact with lipids and cholesterol in cell membrane models, and their cytotoxic activities involve a multifaceted mode of action beyond membrane disruption.

In vitro and in vivo antitumor activity of novel half-sandwich ruthenium complexes containing quinoline derivative ligands

A series of half-sandwich ruthenium complexes containing quinoline derivative ligands was synthesized, which had excellent antitumor toxicity toward a variety of cell lines and could localize lysosomes. The damage of lysosomes promotes the release of cathepsin B and initiates downstream apoptotic cascade signals. The increase in reactive oxygen species (ROS) caused by the decrease in mitochondrial membrane potential (ΔΨ_m) synergistically amplified the damage degree of lysosomes. In addition, the complex could inhibit cell transfer and clone formation. In vivo results showed that the complex had excellent biological effects in tested mouse samples as the body weight of mice did not change much during the treatment, and the mean tumor volume was significantly lower than the control group.

Imidazole and Benzimidazole Modified Half-Sandwich IridiumIII N-Heterocyclic Carbene Complexes: Synthesis, Anticancer Application, and Organelle Targeting

Herein, we report the synthesis, characterization and anticancer activity of a series of half-sandwich iridium^III imidazole and benzimidazole N-heterocyclic carbene (NHC) anticancer complexes, and the general formula of which can be expressed as [(η⁵-Cp^x)Ir(C^∧N)Cl]Cl (Cp^x: pentamethylcyclopentadienyl (Cp^*) or biphenyl derivatives (Cp^xbiph); C^∧N: imidazole and benzimidazole NHC chelating ligands). Compared with cis-platin, these complexes showed interesting antitumor activity against A549 cells. Complexes could bind to bovine serum albumin (BSA) by means of static quenching mode, catalyze the oxidation of nicotinamide adenine dinucleotide (NADH) and increase the levels of reactive oxygen species (ROS). Meanwhile, these complexes could arrest the cell cycles of A549 cells and influence the mitochondrial membrane potential significantly. Due to the inherent luminescence property, laser confocal test show that complexes could enter cells followed an energy-dependent mechanism and effectively accumulate in lysosome (the value of Pearson's co-localization coefficient is 0.70 after 1 h), further destroy lysosome integrity and induce apoptosis.

Triphenylamine/carbazole-modified ruthenium(ii) Schiff base compounds: synthesis, biological activity and organelle targeting

N-phenylcarbazole/triphenylamine modified Schiff base half-sandwich ruthenium(ii) compounds showed potential anticancer activity against A549 and HeLa cells.