Chlorambucil conjugates of dinuclear p-cymene ruthenium trithiolato complexes: synthesis, characterization and cytotoxicity study in vitro and in vivo

Aminocarbyne-Alkyne Coupling in Diruthenium Complexes: Exploring the Anticancer Potential of the Resulting Vinyliminium Complexes and Comparison with Diiron Homologues

New diruthenium complexes based on the scaffold Ru2Cp2(CO)2 (Cp = η5-C5H5) and containing a bridging vinyliminium ligand, [2a-d]CF3SO3, were synthesized through regioselective coupling of alkynes with an aminocarbyne precursor (85-90% yields). The reaction involving phenylacetylene proceeded with the formation of a diruthenacyclobutene byproduct, [4]CF3SO3 (10% yield). Complexes [2a-d]+ undergo partial alkyne extrusion in contact with alumina or CDCl3. All products were characterized by elemental analysis, infrared and multinuclear NMR spectroscopy, and single crystal X-ray diffraction in two cases. Complexes [2a-d]+ revealed an outstanding stability in DMEM cell culture medium at 37 °C (<1% degradation over 72 h). These complexes exhibited cytotoxicity in human colon colorectal adenocarcinoma HT-29 cells in the low micromolar range, with lower IC50 values than those obtained with the homologous diiron complexes previously reported. Evaluation of ROS (reactive oxygen species) production and O2 consumption rate (OCR) highlighted the higher potential of Ru2 complexes, compared to the Fe2 counterparts, to impact mitochondrial activity, with the heterometallic Ru2-ferrocenyl complex [2d]+ showing the best performance.

Anticancer Potential of Diruthenium Complexes with Bridging Hydrocarbyl Ligands from Bioactive Alkynols

Diruthenacyclopentenone complexes of the general composition [Ru2Cp2(CO)2{μ-η1:η3-CH═C(C(OH)(R))C(═O)}] (2a-c; Cp = η5-C5H5) were synthesized in 94-96% yields from the reactions of [Ru2Cp2(CO)2{μ-η1:η3-C(Ph)═C(Ph)C(═O)}] (1) with 1-ethynylcyclopentanol, 17α-ethynylestradiol, and 17-ethynyltestosterone, respectively, in toluene at reflux. Protonation of 2a-c by HBF4 afforded the corresponding allenyl derivatives [Ru2Cp2(CO)3{μ-η1:η2-CH═C═R}]BF4 (3a-c) in 85-93% yields. All products were thoroughly characterized by elemental analysis, mass spectrometry, and IR, UV-vis, and nuclear magnetic resonance spectroscopy. Additionally, 2a and 3a were investigated by cyclic voltammetry, and the single-crystal diffraction method was employed to establish the X-ray structures of 2b and 3a. The cytotoxicity in vitro of 2b and 3a-c was evaluated against nine human cancer cell lines (A2780, A2780R, MCF-7, HOS, A549, PANC-1, Caco-2, PC-3, and HeLa), while the selectivity was assessed on normal human lung fibroblast (MRC-5). Overall, complexes exert stronger cytotoxicity than cisplatin, and 3b (comprising 17α-estradiol derived ligand) emerged as the best-performing complex. Inductively coupled plasma mass spectrometry cellular uptake studies in A2780 cells revealed a higher level of internalization for 3b and 3c compared to 2b, 3a, and the reference compound RAPTA-C. Experiments conducted on A2780 cells demonstrated a noteworthy impact of 3a and 3b on the cell cycle, leading to the majority of the cells being arrested in the G0/G1 phase. Moreover, 3a moderately induced apoptosis and oxidative stress, while 3b triggered autophagy and mitochondrial membrane potential depletion.

Adding Diversity to a Diruthenium Biscyclopentadienyl Scaffold via Alkyne Incorporation: Synthesis and Biological Studies

We report the synthesis and the assessment of the anticancer potential of two series of diruthenium biscyclopentadienyl carbonyl complexes. Novel dimetallacyclopentenone compounds (2-4) were obtained (45-92% yields) from the thermal reaction (PhCCPh exchange) of [Ru2Cp2(CO)(μ-CO){μ-η1:η3-C(Ph)═C(Ph)C(═O)}], 1, with alkynes HCCR [R = C5H4FeCp (Fc), 3-C6H4(Asp), 2-naphthyl; Cp = η5-C5H5, Asp = OC(O)-2-C6H4C(O)Me]. Protonation of 1-3 by HBF4 afforded the corresponding μ-alkenyl derivatives 5-7, in 40-86% yields. All products were characterized by IR and NMR spectroscopy; moreover, cyclic voltammetry (1, 2, 5, 7) and single-crystal X-ray diffraction (5, 7) analyses were performed on representative compounds. Complexes 5-7 revealed a cytotoxic activity comparable to that of cisplatin in A549 (lung adenocarcinoma), SW480 (colon adenocarcinoma), and ovarian (A2780) cancer cell lines, and 2, 5, 6, and 7 overcame cisplatin resistance in A2780cis cells. Complexes 2, 5, and 7 (but not the aspirin derivative 6) induced an increase in intracellular ROS levels. Otherwise, 6 strongly stabilizes and elongates natural DNA (from calf thymus, CT-DNA), suggesting a possible intercalation binding mode, whereas 5 is less effective in binding CT-DNA, and 7 is ineffective. This trend is reversed concerning RNA, and in particular, 7 is able to bind poly(rA)poly(rU) showing selectivity for this nucleic acid. Complexes 5-7 can interact with the albumin protein with a thermodynamic signature dominated by hydrophobic interactions. Overall, we show that organometallic species based on the Ru2Cp2(CO)x scaffold (x = 2, 3) are active against cancer cells, with different incorporated fragments influencing the interactions with nucleic acids and the production of ROS.

Half-Sandwich Ruthenium Arene Complexes Bearing Clinically Approved Drugs as Ligands: The Importance of Metal-Drug Synergism in Metallodrug Design

A novel strategy in metallodrug discovery today is incorporating clinically approved drugs into metal complexes as coordinating ligands. Using this strategy, various drugs have been repurposed to prepare organometallic complexes to overcome the resistance of drugs and to design promising alternatives to currently available metal-based drugs. Notably, the combination of organoruthenium moiety and clinical drug in a single molecule has been shown, in some instances, to enhance pharmacological activity and reduce toxicity in comparison to the parent drug. Thus, for the past two decades, there has been increasing interest in exploiting metal-drug synergism to develop multifunctional organoruthenium drug candidates. Herein, we summarized the recent reports of rationally designed half-sandwich Ru(arene) complexes containing different FDA-approved drugs. This review also focuses on the mode of coordination of drugs, ligand-exchange kinetics, mechanism of action, and structure-activity relationship of organoruthenated complexes containing drugs. We hope this discussion may serve to shed light on future developments in ruthenium-based metallopharmaceuticals.

Synthesis and Antiparasitic Activity of New Trithiolato-Bridged Dinuclear Ruthenium(II)-arene-carbohydrate Conjugates

Eight novel carbohydrate-tethered trithiolato dinuclear ruthenium(II)-arene complexes were synthesized using CuAAC ‘click’ (Cu(I)-catalyzed azide-alkyne cycloaddition) reactions, and there in vitro activity against transgenic T. gondii tachyzoites constitutively expressing β-galactosidase (T. gondii β-gal) and in non-infected human foreskin fibroblasts, HFF, was determined at 0.1 and 1 µM. When evaluated at 1 µM, seven diruthenium-carbohydrate conjugates strongly impaired parasite proliferation by >90%, while HFF viability was retained at 50% or more, and they were further subjected to the half-maximal inhibitory concentration (IC50) measurement on T. gondii β-gal. Results revealed that the biological activity of the hybrids was influenced both by the nature of the carbohydrate (glucose vs. galactose) appended on ruthenium complex and the type/length of the linker between the two units. 23 and 26, two galactose-based diruthenium conjugates, exhibited low IC50 values and reduced effect on HFF viability when applied at 2.5 µM (23: IC50 = 0.032 µM/HFF viability 92% and 26: IC50 = 0.153 µM/HFF viability 97%). Remarkably, compounds 23 and 26 performed significantly better than the corresponding carbohydrate non-modified diruthenium complexes, showing that this type of conjugates are a promising approach for obtaining new antiparasitic compounds with reduced toxicity.

Synthesis, Photophysical Properties and Biological Evaluation of New Conjugates BODIPY: Dinuclear Trithiolato-Bridged Ruthenium(II)-Arene Complexes

The synthesis, photophysical properties and antiparasitic efficacy against Toxoplasma gondii β-gal (RH strain tachyzoites expressing β-galactosidase) grown in human foreskin fibroblast monolayers (HFF) of a series of 15 new conjugates BODIPY-trithiolato-bridged dinuclear ruthenium(II)-arene complexes are reported (BODIPY=4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, derivatives used as fluorescent markers). The influence of the bond type (amide vs. ester), as well as that of the length and nature (alkyl vs. aryl) of the spacer between the dye and the diruthenium(II) complex moiety, on fluorescence and biological activity were evaluated. The assessed photophysical properties revealed that despite an important fluorescence quenching effect observed after conjugating the BODIPY to the diruthenium unit, the hybrids could nevertheless be used as fluorescent tracers. Although the antiparasitic activity of this series of conjugates appears limited, the compounds demonstrate potential as fluorescent probes for investigating the intracellular trafficking of trithiolato-bridged dinuclear Ru(II)-arene complexes in vitro.

New Nucleic Base-Tethered Trithiolato-Bridged Dinuclear Ruthenium(II)-Arene Compounds: Synthesis and Antiparasitic Activity

Aiming toward compounds with improved anti-Toxoplasma activity by exploiting the parasite auxotrophies, a library of nucleobase-tethered trithiolato-bridged dinuclear ruthenium(II)-arene conjugates was synthesized and evaluated. Structural features such as the type of nucleobase and linking unit were progressively modified. For comparison, diruthenium hybrids with other type of molecules were also synthesized and assessed. A total of 37 compounds (diruthenium conjugates and intermediates) were evaluated in a primary screening for in vitro activity against transgenic Toxoplasma gondii tachyzoites constitutively expressing β-galactosidase (T. gondii β-gal) at 0.1 and 1 µM. In parallel, the cytotoxicity in non-infected host cells (human foreskin fibroblasts, HFF) was determined by alamarBlue assay. Twenty compounds strongly impairing parasite proliferation with little effect on HFF viability were subjected to T. gondii β-gal half maximal inhibitory concentration determination (IC₅₀) and their toxicity for HFF was assessed at 2.5 µM. Two promising compounds were identified: 14, ester conjugate with 9-(2-oxyethyl)adenine, and 36, a click conjugate bearing a 2-(4-(hydroxymethyl)-1H-1,2,3-triazol-1-yl)methyl substituent, with IC₅₀ values of 0.059 and 0.111 µM respectively, significantly lower compared to pyrimethamine standard (IC₅₀ = 0.326 µM). Both 14 and 36 exhibited low toxicity against HFF when applied at 2.5 µM and are candidates for potential treatment options in a suitable in vivo model.

Anticancer half-sandwich Ir(iii) complex and its interaction with various biomolecules and their mixtures – a case study with ascorbic acid

An anticancer azo bond-containing half-sandwich Ir(iii) complex oxidizes ascorbate to dehydroascorbate, and ascorbate recovers in the presence of reduced glutathione.

Water-soluble trithiolato-bridged dinuclear ruthenium(II) and osmium(II) arene complexes with bisphosphonate functionalized ligands as anticancer organometallics

Trithiolato-bridged dinuclear ruthenium(II) complexes [Ru₂(p-cym)₂(SR)₃]Cl (p-cym = p-cymene, R = benzyl derivatives) are regarded as the most cytotoxically potent metal(II) arene antineoplastics, but are oftentimes limited by their poor solubility in aqueous media. Thus, we designed bisphosphonate-functionalized ligands for use in a modular two-step complexation process to synthesize six trithiolato-bridged dinuclear ruthenium(II) and osmium(II) arene complexes bearing one to three bisphosphonate-benzylmercaptane derived ligands. In addition to improved aqueous solubility the high affinity of bisphosphonates towards apatite structures found in bone and bone metastases may grant selective targeting properties to functionalized organometallics. The complex stabilities and hydroxyapatite binding behavior were determined by UV/Vis spectroscopy. The bisphosphonate functionalization decreases antiproliferative activity in vitro, which was correlated to lower cellular accumulation, due to the different lipophilic profiles of the drug candidates.

Synthesis and Antiparasitic Activity of New Conjugates—Organic Drugs Tethered to Trithiolato-Bridged Dinuclear Ruthenium(II)–Arene Complexes

Tethering known drugs to a metalorganic moiety is an efficient approach for modulating the anticancer, antibacterial, and antiparasitic activity of organometallic complexes. This study focused on the synthesis and evaluation of new dinuclear ruthenium(II)–arene compounds linked to several antimicrobial compounds such as dapsone, sulfamethoxazole, sulfadiazine, sulfadoxine, triclosan, metronidazole, ciprofloxacin, as well as menadione (a 1,4-naphtoquinone derivative). In a primary screen, 30 compounds (17 hybrid molecules, diruthenium intermediates, and antimicrobials) were assessed for in vitro activity against transgenic T. gondii tachyzoites constitutively expressing β-galactosidase (T. gondii β-gal) at 0.1 and 1 µM. In parallel, the cytotoxicity in noninfected host cells (human foreskin fibroblasts, HFF) was determined by an alamarBlue assay. When assessed at 1 µM, five compounds strongly impaired parasite proliferation by >90%, and HFF viability was retained at 50% or more, and they were further subjected to T. gondii β-gal dose-response studies. Two compounds, notably 11 and 13, amide and ester conjugates with sulfadoxine and metronidazole, exhibited low IC50 (half-maximal inhibitory concentration) values 0.063 and 0.152 µM, and low or intermediate impairment of HFF viability at 2.5 µM (83 and 64%). The nature of the anchored drug as well as that of the linking unit impacted the biological activity.

Conjugates Containing Two and Three Trithiolato-Bridged Dinuclear Ruthenium(II)-Arene Units as In Vitro Antiparasitic and Anticancer Agents

The synthesis, characterization, and in vitro antiparasitic and anticancer activity evaluation of new conjugates containing two and three dinuclear trithiolato-bridged ruthenium(II)-arene units are presented. Antiparasitic activity was evaluated using transgenic Toxoplasmagondii tachyzoites constitutively expressing β-galactosidase grown in human foreskin fibroblasts (HFF). The compounds inhibited T.gondii proliferation with IC50 values ranging from 90 to 539 nM, and seven derivatives displayed IC50 values lower than the reference compound pyrimethamine, which is currently used for treatment of toxoplasmosis. Overall, compound flexibility and size impacted on the anti-Toxoplasma activity. The anticancer activity of 14 compounds was assessed against cancer cell lines A2780, A2780cisR (human ovarian cisplatin sensitive and resistant), A24, (D-)A24cisPt8.0 (human lung adenocarcinoma cells wild type and cisPt resistant subline). The compounds displayed IC50 values ranging from 23 to 650 nM. In A2780cisR, A24 and (D-)A24cisPt8.0 cells, all compounds were considerably more cytotoxic than cisplatin, with IC50 values lower by two orders of magnitude. Irrespective of the nature of the connectors (alkyl/aryl) or the numbers of the di-ruthenium units (two/three), ester conjugates 6-10 and 20 exhibited similar antiproliferative profiles, and were more cytotoxic than amide analogues 11-14, 23, and 24. Polynuclear conjugates with multiple trithiolato-bridged di-ruthenium(II)-arene moieties deserve further investigation.

Interactions of Cationic Diruthenium Trithiolato Complexes with Phospholipid Membranes Studied by NMR Spectroscopy

To apprehend the possible mechanisms involved in the cellular uptake and the membrane interactions of cytotoxic dinuclear p-cymene trithiolato ruthenium(II) complexes, the interactions of the complexes [(η⁶-p-MeC₆H₄Prⁱ)₂Ru₂(R¹)₂(R²)]⁺ (R¹ = R² = SC₆H₄-m-Prⁱ:1; R¹ = SC₆H₄-p-OMe, R² = SC₆H₄-p-OH:2; R¹ = SCH₂C₆H₄-p-OMe, R² = SC₆H₄-p-OH:3) with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) vesicles and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) micelles were studied using nuclear magnetic resonance (NMR) spectroscopy. ¹H NMR, nuclear Overhauser effect (NOE), diffusion ordered spectroscopy (DOSY), and T₁ and T₂ relaxation data provided information on interactions between the complexes and the model membranes and on the submolecular localization of the complexes at the membrane interface. The results suggest that (a) the interaction takes place without new covalent adduct formation, (b) the cationic diruthenium complexes interact with DOPC head groups most likely involving electrostatic interactions while remaining structurally unchanged, (c) the changes indicating interactions are more pronounced for the most lipophilic complex 1, and (d) the diruthenium complexes remain at the exterior vesicle surface and are unlikely inserted between the phospholipid chains. The complexes also interact with micellar/free DHPC and seem to induce micellization or aggregation in solutions below critical micelle concentration (CMC). Our study suggests high affinity of the Ru complexes for the membrane surface that likely plays a key role in cellular uptake and possibly also in redistribution in mitochondria.

Coumarin-Tagged Dinuclear Trithiolato-Bridged Ruthenium(II)⋅Arene Complexes: Photophysical Properties and Antiparasitic Activity

The synthesis, characterization, photophysical and biological properties of 13 new conjugate coumarin-diruthenium(II)⋅arene complexes against Toxoplasma gondii are presented. For all conjugate organometallic unit/coumarins, an almost complete loss of fluorescence efficacy was observed. However, the nature of the fluorophore, the type of bonding, the presence and length of a linker between the coumarin dye and the ruthenium(II) moiety, and the number of dye units influenced their biological properties. The in vitro activity against a transgenic T. gondii strain grown in human foreskin fibroblasts (HFF) leads to IC50 values for T. gondii β-gal from 105 to 735 nM. Of note is that nine compounds displayed lower IC50 than the standard drug pyrimethamine. One compound applied at its IC50 did not affect B-cell proliferation but had an impact on T-cell proliferation in murine splenocyte cultures. Transmission electron microscopy of T. gondii β-gal-infected HFF showed that treatment predominantly affected the parasites' mitochondrion.

Targeting of the mitochondrion by dinuclear thiolato-bridged arene ruthenium complexes in cancer cells and in the apicomplexan parasite Neospora caninum

A library of 18 dinuclear-thiolato bridged arene ruthenium complexes, some of which with demonstrated activity against cancer cells, was screened for activity against a transgenic Neospora caninum strain that constitutively expresses beta-galactosidase. Initial assessments were done at concentrations of 2500, 250, 25 and 2.5 nM, and 5 compounds were further evaluated with regard to their half maximal proliferation-inhibiting concentration (IC50). Among those, [(η6-p-MeC6H4Pri)2Ru2(μ2-SC6H4-p-CH3)3]Cl (1), [(η6-p-MeC6H4Pri)2Ru2(μ2-SC6H4-p-But)3]Cl (2) and [(η6-p-MeC6H4Pri)2Ru2(μ2-SCH2C6H4-p-But)2(μ2-SC6H4-p-OH)]BF4 (9) inhibited N. caninum proliferation with low C50 values of 15, 5 and 1 nM, respectively, while [(η6-p-MeC6H4Pri)2Ru2(μ2-SC6H4-p-OH)3]Cl (3) and [(η6-p-MeC6H4Pri)2Ru2(μ2-SC6H4-p-mco)3]Cl (5, mco = 4-methylcoumarinyl) were less active (IC50 = 280 and 108 nM, respectively). These compounds did not affect human foreskin fibroblast (HFF) host cells at dosages of 5 μM and above, but impaired proliferation of the human ovarian carcinoma cell line A2780 (IC50 values of 130 nM (1), 30 nM (2), 530 nM (3), 7730 nM (5), 130 nM (9)). A2780 cancer cells were treated with complexes 1, 2, and 5, and biodistribution analysis using inductively coupled plasma mass spectrometry (ICP-MS) showed that most of the drugs accumulated in the mitochondrial fractions. Transmission electron microscopy showed that the parasite mitochondrion is the primary target also in N. caninum tachyzoites, but these compounds, when applied at 200 nM for 15 days in vitro, did not act parasiticidal. Complexes 1, 2 and 9 applied orally at 2 and 10 mg kg-1 day-1 during 5 days in a neosporosis mouse model did not reduce parasite load and did not limit parasite dissemination to the central nervous system. In accordance with these results, ICP-MS carried out on different organs of mice orally administrated with complexes 1 and 9, demonstrated that the drugs were readily absorbed, and after 3 and 48 h, were mainly detected in liver and kidney, but were largely absent from the brain. Thus, dinuclear thiolato-bridged arene ruthenium complexes exhibit interesting activities against N. caninum in vitro, but further modifications of these promising molecules are required to improve their bioavailability and pharmacokinetic properties in order to exert a pronounced and selective effect against N. caninum in vivo.

Dinuclear thiolato-bridged arene ruthenium complexes: from reaction conditions and mechanism to synthesis of new complexes

Several dinuclear thiophenolato-bridged arene ruthenium complexes [(η⁶-p-MeC₆H₄Prⁱ)₂Ru₂(μ₂-SC₆H₄-R)₃]⁺ (R = H, NO₂, F) could so far only be obtained in fair yields using the synthetic route established in the early 2000s. With much less reactive aliphatic thiols or with bulky thiols, the reactions become even less efficient and the desired complexes are obtained with low yields or not at all. We employed density functional theory (DFT) calculations to gain a fundamental understanding of the reaction mechanisms leading to the formation of dithiolato and trithiolato complexes starting from the dichloro(p-cymene)ruthenium(ii) dimer [(η⁶-p-MeC₆H₄Prⁱ)Ru(μ₂-Cl)Cl]₂. The results of the DFT study enabled us to rationalise the experimental results and allowed us, via a modified synthetic route, to synthesise previously unreported and hitherto considered as unrealistic complexes. Our study opens up possibilities for the synthesis of so far inaccessible thiolato-bridged dinuclear arene ruthenium(ii) complexes but more generally, also the synthesis of other thiolato-bridged dinuclear group 8 and 9 metal complexes could be reexamined.

We used DFT calculations to understand the reaction mechanisms leading to the formation of dinuclear thiophenolato-bridged arene ruthenium complexes. DFT prompted us to modify the usual synthetic route, which enabled the synthesis of new complexes.

Modulation of the reactivity of nitrogen mustards by metal complexation: approaches to modify their therapeutic properties

Metal complexation of nitrogen mustards shows promise with an ability to control the mustards’ reactivity, perform selective hypoxia activation, overcome resistance, and control GSH deactivation.

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.

Characterization of the Activities of Dinuclear Thiolato-Bridged Arene Ruthenium Complexes against Toxoplasma gondii

The in vitro effects of 18 dinuclear thiolato-bridged arene ruthenium complexes (1 monohiolato compound, 4 dithiolato compounds, and 13 trithiolato compounds), originally designed as anticancer agents, on the apicomplexan parasite Toxoplasma gondii grown in human foreskin fibroblast (HFF) host cells were studied. Some trithiolato compounds exhibited antiparasitic efficacy at concentrations of 250 nM and below. Among those, complex 1 and complex 2 inhibited T. gondii proliferation with 50% inhibitory concentrations (IC₅₀s) of 34 and 62 nM, respectively, and they did not affect HFFs at dosages of 200 μM or above, resulting in selectivity indices of >23,000. The IC₅₀s of complex 9 were 1.2 nM for T. gondii and above 5 μM for HFFs. Transmission electron microscopy detected ultrastructural alterations in the matrix of the parasite mitochondria at the early stages of treatment, followed by a more pronounced destruction of tachyzoites. However, none of the three compounds applied at 250 nM for 15 days was parasiticidal. By affinity chromatography using complex 9 coupled to epoxy-activated Sepharose followed by mass spectrometry, T. gondii translation elongation factor 1α and two ribosomal proteins, RPS18 and RPL27, were identified to be potential binding proteins. In conclusion, organometallic ruthenium complexes exhibit promising activities against Toxoplasma, and the potential mechanisms of action of these compounds as well as their prospective applications for the treatment of toxoplasmosis are discussed.

A general strategy to add diversity to ruthenium arene complexes with bioactive organic compounds via a coordinated (4-hydroxyphenyl)diphenylphosphine ligand

Esterification of (4-hydroxyphenyl)diphenylphosphine, coordinated to the [Ru(η⁶-p-cymene)Cl₂] fragment, allows a series of bioactive carboxylic acids to be introduced directly into the organometallic molecule. Evaluation of the compounds on human ovarian cancer cells reveals synergistic enhancements in their antiproliferative activity relative to their bioactive organic and organometallic precursors.

Synthesis, photophysical properties and in vitro evaluation of a chlorambucil conjugated ruthenium(ii) complex for combined chemo-photodynamic therapy against HeLa cells

We designed a new heteroleptic Ru(ii) complex CHL-RuL as an imaging-guided chemotherapy/PDT agent, which shows a moderate antiproliferative effect in dark and strong photodynamic inhibitory effect against HeLa cells.