Arene Ruthenium Research Articles

Arene Ruthenium Complexes Specifically Inducing Apoptosis in Breast Cancer Cells

Monocationic arene ruthenium complexes (RuL1–RuL4) incorporating phenothiazinyl-hydrazinyl-thiazole ligands (L1–L4) have been synthesized, characterized and evaluated as anticancer agents. Their cytotoxicity, antiproliferative activity and alteration of apoptotic gene expression were studied on three cancer cell lines, a double positive breast cancer cell line MCF-7 and two triple negative breast cancer cell lines Hs578T and MDA-MB-231. All arene ruthenium complexes were able to reduce the viability of the breast cancer cell lines, with the highest cytotoxicities being recorded for the [(p-cymene)RuL3Cl]+ (RuL3) complex on the MCF-7 (IC50 = 0.019 µM) and Hs578T cell lines (IC50 = 0.095 µM). In the double positive MCF-7 breast cancer cells, the complexes [(p-cymene)RuL1Cl]+ (RuL1) and [(p-cymene)RuL2Cl]+ (RuL2) significantly upregulated pro-apoptotic genes including BAK, FAS, NAIP, CASP8, TNF, XIAP and BAD, while downregulating TNFSF10. In the triple negative breast cancer cell line Hs578T, RuL1 reduced TNFSF-10 and significantly upregulated BAK, CASP8, XIAP, FADD and BAD, while complex RuL2 also increased BAK and CASP8 expression, but had limited effects on other genes. The triple negative MDA-MB-231 cancer cells treated with RuL1 upregulated NOD1 and downregulated p53, while RuL2 significantly downregulated p53, XIAP and TNFSF10, with minor changes in other genes. The significant alterations in the expression of key apoptotic genes suggest that such complexes have the potential to target cancer cells.

Ruthenium Complexes of Phenylbenzothiazole‐Quinoline based Ligands for Selective α‐Olefination of Methylazaarenes

This report describes synthesis of a new ligand (E)‐N‐(4‐(benzo[d]thiazol‐2‐yl)phenyl)‐1‐(quinolin‐2‐yl)methanimine (L1) and its three ruthenium(II) arene complexes with [RuCl2(p‐cymene)]2 (C1), [RuCl2(benzene)]2 (C2), and [RuCl2(hmb)]2 [hmb = hexamethylbenzene] (C3). The new ligand and complexes were characterized with the help of standard spectroscopic and analytical techniques like 1H and 13C{1H} Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR), High‐resolution mass spectrometry (HRMS), UV‐Visible, cyclic voltammetry, and elemental analysis. The structure of ruthenium complex (C1) and its binding mode with ligand were authenticated with the help of single crystal X‐ray diffraction. The ruthenium arene complexes (C1‐C3) were used as a catalyst for the α‐olefination of Methylazaarenes. First, methylazaarenes were reacted with alcohols under optimized reaction conditions to produce α‐olefinated products (up to 66%) selectively. Among the three ruthenium complexes, C1 demonstrated the highest yield of olefinated products with 5 mol% catalyst loading. Finally, selected olefin derivatives were tested for their inhibitory potential towards the aggregation of amyloid‐b‐40 (Aβ40) peptide relevant to Alzheimer’s disease. Overall, these complexes are promising catalysts for organic transformations, and the synthesized α‐olefinated derivatives could have potential applications for the development of therapeutic agents for Alzheimer’s disease.

Developing an Arene Binuclear Ruthenium(II) Complex to Induce Ferroptosis and Activate the cGAS-STING Pathway: Targeted Inhibiting Growth and Metastasis of Triple Negative Breast Cancer.

To effectively inhibit the growth and metastasis of triple-negative breast cancer (TNBC), we developed a high-efficiency and low-toxicity arene ruthenium (Ru) complex based on apoferritin (AFt). To achieve this, we optimized a series of Ru(II) 1,10-phenanthroline-2,9-diformaldehyde thiosemicarbazone complexes by studying their structure-activity relationships to obtain an arene binuclear Ru(II) complex (C5) with significant cytotoxicity and high accumulation in the mitochondria of tumor cells. Subsequently, a C5-AFt nanoparticle (NPs) delivery system was constructed. We found that the C5/C5-AFt NPs effectively inhibited TNBC growth and metastasis with few side effects. The C5-AFt NPs improved the anticancer and targeting abilities of C5 in vivo. Moreover, we confirmed the mechanism by which C5/C5-AFt NPs inhibit tumor growth and metastasis via mitochondrial damage-mediated ferroptosis and activation of the cGAS-STING pathway.

Discovery of Arene Ruthenium(II) Complexes as Potential VEGF Inhibitors for Glioblastoma Metastasis Suppression.

Developing drugs for treating glioblastoma has been a significant challenge. Herein, a series of arene ruthenium(II) complexes have been synthesized and investigated as potential candidates to suppress the proliferation and metastasis of glioblastoma. It is found that para-substituent-modified molecules, especially 6, exhibit higher antitumor activity than ortho-substituents. Further studies show that 6 can trigger tumor cell autophagy by regulating the PI3K/AKT/mTOR pathway. Moreover, it is also found that 6 can induce DNA damage in glioblastoma cells through binding and stabilizing VEGF G-quadruplex DNA. Furthermore, it is confirmed that 6 can inhibit the proliferation and metastasis of U87-MG glioblastoma cell in situ xenograft in the zebrafish model. Hence, arene ruthenium(II) complexes can be developed as promising therapeutic agents for glioblastoma treatment in the future.

Photodynamic Therapy against Colorectal Cancer Using Porphin-Loaded Arene Ruthenium Cages

Colorectal cancer (CRC) is the third most common cancer in the world, with an ongoing rising incidence. Despite secure advancements in CRC treatments, challenges such as side effects and therapy resistance remain to be addressed. Photodynamic therapy (PDT) emerges as a promising modality, clinically used in treating different diseases, including cancer. Among the main challenges with current photosensitizers (PS), hydrophobicity and low selective uptake by the tumor remain prominent. Thus, developing an optimal design for PS to improve their solubility and enhance their selective accumulation in cancer cells is crucial for enhancing the efficacy of PDT. Targeted photoactivation triggers the production of reactive oxygen species (ROS), which promote oxidative stress within cancer cells and ultimately lead to their death. Ruthenium (Ru)-based compounds, known for their selective toxicity towards cancer cells, hold potential as anticancer agents. In this study, we investigated the effect of two distinct arene-Ru assemblies, which lodge porphin PS in their inner cavity, and tested them as PDT agents on the HCT116 and HT-29 human CRC cell lines. The cellular internalization of the porphin-loaded assemblies was confirmed by fluorescence microscopy. Additionally, significant photocytotoxicity was observed in both cell lines after photoactivation of the porphin in the cage systems, inducing apoptosis through caspase activation and cell cycle progression disruptions. These findings suggest that arene-Ru assemblies lodging porphin PS are potent candidates for PDT of CRC.

N‐heterocyclic carbene complexes RuII(arene) and their application as ROMP catalysts, antioxidant and anticancer agents

N‐Heterocyclic carbenes (NHCs) play an important role in metal complex catalysis and stabilisation, providing stability under non‐inert conditions and a high σ‐donor capacity. They are crucial ligands for the synthesis of organometallic compounds like RuII‐complexes, which can operate as very active catalysts for a variety of chemical transformations and functionalizations. RA(Ruthenium‐arene)NHC complexes, known for their piano‐stool structure, stabilise Ru(II) oxidation by occupying three ruthenium coordination sites with a η6‐coordinated arene ligand. The development of dual‐acting RuII‐arene complexes has sparked increased interest in their catalytic and biological properties. Because of their broad spectrum, metal complexes can give distinct mechanisms of pharmacological action than organic drugs. This study aimed to explore the impact of ligand amphiphilicity and counterion on bioactivity, designing a family of compounds with the NHC ligand bearing an ester moiety and switching the wingtip substituent from methyl to benzyl units. All synthesized compounds were tested in norbornene ROMP, a benchmark reaction for RuII potential catalysts and as anticancer and antioxidant compounds.

Antimetastatic activity of (arene)ruthenium(II) complex of 4-aryl-4H-naphthopyran

Metastatic cancer remains a formidable challenge in anticancer therapy. Despite efforts to develop effective antimetastasis drugs over the past half-century, currently approved treatments fall short of expectations. This report highlights the promising antiproliferative activity of a ruthenium-based therapeutic agent, namely dichlorido(p-cymene)[2-amino-4-(pyridin-3-yl)-4H-benzo[h]-chromene-3-carbonitrile]ruthenium(II) (complex 1) against metastatic cell lines. Complex 1 shows significant efficacy in metastatic LoVo and Du-145 cell lines at nanomolar concentrations, being markedly more active than clinically used anticancer cisplatin. Studies on the MDA-MB-231 cell line, which displays invasive characteristics, demonstrated that 1 significantly reduces cell invasion. This efficacy was confirmed by its impact on matrix metalloproteinase production in MDA-MB-231 cells. Given that cell migration drives cancer invasion and metastasis, complex 1's effect on MDA-MB-231 cell migration was evaluated via wound healing assay and vimentin network analysis. Results indicated a strong reduction in migration. A re-adhesion assay further demonstrated that 1 significantly lowers the re-adhesion ability of MDA-MB-231 cells compared to cisplatin. To better simulate the human body environment, a 3D spheroid invasion assay was used. This method showed that 1 effectively inhibits tumor spheroids from infiltrating the surrounding extracellular matrix. This study underscores the potential of (arene)ruthenium(II) complexes with naphthopyran ligands as potent antimetastatic agents for chemotherapy.

Host-Guest Interactions of Ruthenium(II) Arene Complexes with Cucurbit[7/8]uril.

Cucurbit[n]urils (CB[n]s) have been recognized for their chemical and thermal stability, and their ability to bind many neutral and cationic guest molecules makes them excellent hosts in a range of supramolecular applications. In drug delivery, CB[n]s can enhance drug solubility, improve chemical and physical drug stability, and allow for triggered and controlled release. This study aimed to investigate the ability of CB[7] and CB[8] as molecular hosts to bind ruthenium(II) arene complexes that are current anticancer lead structures in the area of metallodrugs. Both, experimental and computational methods, led to insights into the binding preferences and geometries of [RuII(cym)Cl2]2 (1; cym = η6-p-cymene), [RuII(cym)(dmb)Cl2]) (2; cym = η6-p-cymene; dmb = 1,3-dimethylbenzimidazol-2-ylidene), and [RuII(cym)(pta)Cl2] (3, RAPTA-C; cym = η6-p-cymene; pta = 1,3,5-triaza-7-phospha-adamantane) with CB[7] and CB[8]. Competition experiments by mass spectrometry revealed clear preferences of 2 for CB[8] and 3 for CB[7]. Based on a comparison of the associated interaction energies from quantum chemical calculations as well as experimental data, 3@CB[7] clearly prefers a binding mode, where the pta ligand is located inside the cavity of the host, and the metal ion interacts with two of the carbonyl groups on the rim of CB[7]. In contrast, complex 2 binds in two different orientations with interaction energies similar to those of both CB[n]s, with the cym ligand being either inside or outside of the cavity. These findings suggest that ruthenium(II) arene complexes are able to form stable host-guest interactions with CB[n]s, which can be exploited as drug delivery vehicles in further metallodrug development to improve their chemical stability.

Arene ruthenium(II) complexes with 3-acetyl coumarin derivatives bearing a 3-hydroxy-2-naphthoic hydrazide moiety: Synthesis, DFT calculations and antioxidant studies

The reaction of [(arene)RuCl2]2 with coumarin hydrazone ligands in methanol yielded neutral chelating mononuclear N∩O metal complexes having the general formula [(arene)Ru(L)Cl] where arene = p-cymene, benzene; and L = 3‑hydroxy-N'-(1-(2-oxo-2H-chromen-3-yl)ethylidene)-2-naphthohydrazide (L1), 3‑hydroxy-N'-(1-(7‑methoxy-2-oxo-2H-chromen-3-yl)ethylidene)-2-naphthohydrazide (L2), (E)-N'-(1-(6‑bromo-2-oxo-2H-chromen-3-yl)ethylidene)-3‑hydroxy-2-naphthohydrazide (L3) and 3‑hydroxy-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)-2-naphthohydrazide (L4)}. All complexes (1–8) were fully characterized by spectroscopic techniques like IR, UV–Vis, NMR and ESI-MS spectral methods. The solid-state molecular structures of the three complexes were determined using a single-crystal X-ray diffraction study. The studies revealed that the ligands binding mode to the ruthenium metal centers is through the azomethine nitrogen and the imidolate oxygen forming a five-membered chelating ring. All the complexes and the ligands were screened for antibacterial and antioxidant activity studies. Some of the complexes exhibited antioxidant activity that is more prominent than their respective ligands.

Promoting the Anticancer Activity with Multidentate Furan-2-Carboxamide Functionalized Aroyl Thiourea Chelation in Binuclear Half-Sandwich Ruthenium(II) Complexes.

A new set of binuclear arene ruthenium complexes [Ru2(p-cymene)2(k4-N2OS)(L1-L3)Cl2] (Ru2L1-Ru2L3) encompassing furan-2-carboxamide-based aroylthiourea derivatives (H2L1-H2L3) was synthesized and characterized by various spectral and analytical techniques. Single-crystal XRD analysis unveils the N^O and N^S mixed monobasic bidentate coordination of the ligands constructing N, S, Cl/N, O, and Cl legged piano stool octahedral geometry. DFT analysis demonstrates the predilection for the formation of stable arene ruthenium complexes. In vitro antiproliferative activity of the complexes was examined against human cervical (HeLa), breast (MCF-7), and lung (A549) cancerous and noncancerous monkey kidney epithelial (Vero) cells. All the complexes are more efficacious against HeLa and MCF-7 cells with low inhibitory doses (3.86-11.02 μM). Specifically, Ru2L3 incorporating p-cymene and -OCH3 fragments exhibits high lipophilicity, significant cytotoxicity against cancer cells, and lower toxicity on noncancerous cells. Staining analysis indicates the apoptosis-associated cell morphological changes expressively in MCF-7 cells. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) analyses reveal that Ru2L3 can raise ROS levels, reduce MMP, and trigger mitochondrial dysfunction-mediated apoptosis. The catalytic oxidation of glutathione (GSH) to its disulfide form (GSSG) by the complexes may simultaneously increase the ROS levels, alluding to their observed cytotoxicity and apoptosis induction. Flow cytometry determined the quantitative classification of late apoptosis and S-phase arrest in MCF-7 and HeLa cells. Western blotting analysis confirmed that the complexes promote apoptosis by upregulating Caspase-3 and Caspase-9 and downregulating BCL-2. Molecular docking studies unfolded the strong binding affinities of the complexes with VEGFR2, an angiogenic signaling receptor, and BCL2, Cyclin D1, and HER2 proteins typically overexpressed on tumor cells.

Selective Targeting of Regulated Rhabdomyosarcoma Cells by Trinuclear Ruthenium(II)-Arene Complexes.

The use of benzimidazole-based trinuclear ruthenium(II)-arene complexes (1-3) to selectively target the rare cancer rhabdomyosarcoma is reported. Preliminary cytotoxic evaluations of the ruthenium complexes in an eight-cancer cell line panel revealed enhanced, selective cytotoxicity toward rhabdomyosarcoma cells (RMS). The trinuclear complex 1 was noted to show superior short- and long-term cytotoxicity in RMS cell lines and enhanced selectivity relative to cisplatin. Remarkably, 1 inhibits the migration of metastatic RMS cells and maintains superior activity in a 3D multicellular spheroid model in comparison to that of the clinically used cisplatin. Mechanistic insights reveal that 1 effectively induces genomic DNA damage, initiates autophagy, and prompts the intrinsic and extrinsic apoptotic pathways in RMS cells. To the best of our knowledge, 1 is the first trinuclear ruthenium(II) arene complex to selectively kill RMS cells in 2D and 3D cell cultures.

Effects of metalation on the PDT activity of arene ruthenium porphyrin-based photosensitizers on prostate cancer

SignificanceProstate cancer is a major health issue (second most common cancer in men worldwide). Despite therapeutic advances and early detection, many side effects are often observed during treatment. Photodynamic therapy (PDT) is a promising therapy to reduce side effects, many 2nd and 3rd generation of photosensitizer (PS) are poorly soluble in aqueous media, limiting their attractiveness. ApproachWe have developed and tested 3rd generation of PS vectorized by arene-ruthenium (Ru) complexes coordinated to tetrapyridylporphin (tpp-2H), Zn-tetrapyridylporphin (tpp-Zn) or Co-tetrapyridylporphin (tpp-Co). ResultsTwo of the three complexes show a good efficacy. The compounds localize into the cytoplasm. An analysis of the apoptotic process shows a cleavage of poly-ADP ribose polymerase (PARP) and a strong induction of DNA fragmentation following irradiation. ConclusionsArene-ruthenium tetrapyridylporphin complexes are excellent candidates for PDT application. The addition of the metal shows a decrease (tpp-Zn) or no effects (tpp-Co), compared to the metal free photosentizer (tpp-2H).

Cellular Uptake and Phototoxicity Optimization of Arene Ruthenium Porphyrin Derivatives

In this study, dinuclear and tetranuclear arene ruthenium porphyrins were synthesized and assessed for their potential as photosensitizers (PSs) in photodynamic therapy (PDT) using the Colo205 colon cancer cell line as a model system. Reactive oxygen species (ROS) production, cellular uptake, impact on cell viability, and mechanisms of cell death induced by the synthesized compounds were comprehensively investigated. Our results revealed that the number of arene ruthenium units, as well as zinc (Zn) metalation of the porphyrin core, significantly influenced ROS production and increased it two-folds compared to the Zn-free analogs. The uptake of tetra-substituted Zn-porphyrins by the cancer cells increased to 2.8 nmol/106 cells compared to 0.6 nmol/106 cells of the disubstituted Zn-free and Zn-chelating porphyrins. The anticancer photo-activity of the complexes, where the percentage of metabolic activity of disubstituted Zn-porphyrins decreased to 26% when Zn was inserted, was compared to disubstituted Zn-free analogs. A further decrease in metabolic activity was observed, when the number of arene ruthenium units increased in the tetra-substituted Zn-porphyrins and tetra-substituted Zn-free compounds, reaching 4% and 14% respectively. Moreover, the percentage of apoptotic cell deaths increased to 40% when Zn was inserted into disubstituted porphyrins, compared to disubstituted Zn-free analog, and 50% when the number of arene ruthenium units increased. Overall, the tetra-substituted Zn chelating porphyrins exhibited the highest PDT efficiency, followed by the di-substituted Zn-porphyrins. These findings underscore the importance of structural design in optimizing the efficacy of arene ruthenium porphyrins as PSs for PDT, offering valuable insights for the development of targeted cancer therapeutics.

Using Machine Learning to Predict the Antibacterial Activity of Ruthenium Complexes.

Rising antimicrobial resistance (AMR) and lack of innovation in the antibiotic pipeline necessitate novel approaches to discovering new drugs. Metal complexes have proven to be promising antimicrobial compounds, but the number of studied compounds is still low compared to the millions of organic molecules investigated so far. Lately, machine learning (ML) has emerged as a valuable tool for guiding the design of small organic molecules, potentially even in low-data scenarios. For the first time, we extend the application of ML to the discovery of metal-based medicines. Utilising 288 modularly synthesized ruthenium arene Schiff-base complexes and their antibacterial properties, a series of ML models were trained. The models perform well and are used to predict the activity of 54 new compounds. These displayed a 5.7x higher hit-rate (53.7 %) against methicillin-resistant Staphylococcus aureus (MRSA) compared to the original library (9.4 %), demonstrating that ML can be applied to improve the success-rates in the search of new metalloantibiotics. This work paves the way for more ambitious applications of ML in the field of metal-based drug discovery.

Maschinelles Lernen zur Vorhersage antibakterieller Aktivität von Ruthenium‐Komplexen**

AbstractDie steigende antimikrobielle Resistenz (AMR) und der Mangel an Innovation in der Antibiotikaforschung erfordern neue Ansätze zur Entwicklung von Medikamenten. Metallkomplexe haben sich als vielversprechende antimikrobielle Verbindungen erwiesen. Allerdings ist die Anzahl der untersuchten Verbindungen noch klein, besonders im Vergleich zu den Millionen organischer Moleküle die bereits getestet wurden. In den letzten Jahren hat sich maschinelles Lernen (ML) als wertvolle Ressource für die Entwicklung organischer Moleküle herauskristallisiert, selbst wenn nur wenige Daten vorliegen. Erstmals erweitern wir die Anwendung von ML auf die Entdeckung von metallbasierten antimikrobiellen Verbindungen. Mithilfe von 288 modular synthetisierten Ruthenium‐Aren‐Schiff‐Basen‐Komplexen und deren antibakteriellen Eigenschaften haben wir eine Reihe von ML–Modellen trainiert. Die Modelle zeigen gute Leistungen und werden verwendet, um die Aktivität von 54 neuen Verbindungen vorherzusagen. Diese Verbindungen weisen eine 5.7‐fach höhere Trefferquote (53.7 %) gegen Methicillin‐resistente Staphylococcus aureus (MRSA) im Vergleich zur ursprünglichen Bibliothek (9.4 %) auf. Dadurch zeigen wir, dass ML zu höheren Erfolgsraten bei der Suche nach neuen Metalloantibiotika führen kann. Folglich ebnet diese Arbeit den Weg für fortschrittlichere Anwendungen von ML im Bereich der metallbasierten Wirkstoffentwicklung.

Analysis of antiproliferative activity of new half-sandwich arene Ru(II) thiophene based aroylhydrazone complexes.

Efforts in researching the efficient anti-tumor properties of three novel arene ruthenium(II) complexes incorporating thiophene-based aroylhydrazone ligands have been undertaken. The complexes' elemental composition was [(η6-p-cymene)Ru(L)Cl]. They were comprehensively characterized through elemental and spectroscopic analyses (FT-IR, UV-vis, NMR, and HR-MS). Single crystal X-ray diffraction studies revealed a pseudo-octahedral geometry with bidentate coordination of the ligands in a representative complex. The in vitro assessment of the complexes' cancer cell growth inhibition was conducted using the MTT assay against A549 (human lung carcinoma), HeLa (human cervical carcinoma), HuH-7 (hepatocellular carcinoma), and NIH-3T3 (mouse fibroblast non-cancerous cell line). Results indicated significant cytotoxicity across all cancer cell lines, with IC50 concentrations of complex 2 being 6.8 μM for A549, 11.6 μM for HeLa, and 9.4 μM for HuH-7, compared to cisplatin with IC50 values of 18.9 μM, 17.68 μM, and 24 μM respectively. Notably, complex 2 demonstrated particularly promising cytotoxicity against all tested cancerous cell lines. Fluorescent staining analysis such as acridine orange/ethidium bromide (AO-EB) and HOECHST 33342 revealed cell death mechanisms involving membrane disintegration and nuclear condensation following treatment with complex 2. Further studies were conducted to measure reactive oxygen species (ROS) levels using the dichlorodihydrofluorescein diacetate (DCFH-DA) assay, and mitochondrial membrane potential (MMP) was assessed using the JC-1 dye assay. These studies demonstrated that complex 2 increased ROS levels, decreased membrane potential, and promoted mitochondrial dysfunction-mediated cell death pathways. Additionally, flow cytometry analysis, utilizing dual staining of Annexin V-FITC and propidium iodide (PI), was employed to quantitatively study apoptosis induction.

A bis-quinoline ruthenium(II) arene complex with submicromolar cytotoxicity in castration-resistant prostate cancer cells.

A new Ru(II) arene chlorido organometallic complex [(η6-p-cymene)(L)RuCl]PF6 (named as pCYRuL) using 2-bis(quinolin-2-ylmethylene) hydrazine (L) was developed that exhibits potent anticancer activity against castration-resistant prostate cancer (CRPC) (IC50 = 0.71 μM), and it is 45 times more effective than the standard drug cisplatin (IC50 = 31.3 μM) in a castration-resistant human prostatic adenocarcinoma cell line (PC-3) but non-toxic in normal human kidney cells (HK2) as well as normal breast cells (MCF10A) and found that pCYRuL exerted anticancer activity via apoptosis induction and cell cycle arrest in the G2/M phase of PC-3 cells.

Planar-chiral arene ruthenium complexes: synthesis, separation of enantiomers, and application for catalytic C-H activation.

Heating tert-butyl-tetraline with [(p-cymene)RuCl2]2 produces the racemic complex [(arene)RuCl2]2, which can be separated into enantiomers by chromatography of its diastereomeric adducts with chiral phosphine ligand. The resolved chiral complex catalyzes C-H activation of N-methoxy-benzamides and their annulation with N-vinyl-pivaloyl amide giving dihydroisoquinolones in 50-80% yields and with 40-80% enantiomeric excess.

Ferrocene- and ruthenium arene-containing glycomimetics as selective inhibitors of human galectin-1 and -3

This work presents a novel series of galectin inhibitors with ferrocene and ruthenium arene motifs. Diferrocene thiodigalactoside exhibited high binding affinity and selectivity for human galectin-1 over human galectin-3.

Andrographolide coordinated ruthenium(II) arene complexes: Synthesis, spectral characterization, antioxidant assays, in vitro cytotoxicity, and apoptosis investigation

Two new ruthenium(II)-complexes, [Ru(Ang)((benzene)Cl2] (RuB-Ang) and [Ru(Ang)((p-cymene)Cl2] (RuC-Ang), were synthesized using andrographolide (Ang) as a ligand with [RuCl2(arene)]2 (arene = benzene or p-cymene) and characterized by various spectroscopic techniques. These techniques ascertained the formation of the complexes. An assessment of the antioxidant activity of the compounds indicated better scavenging activity against ABTS•+, DPPH•, O2−, NO• and OH− radicals. The cytotoxic activities of RuB-Ang and RuC-Ang have been evaluated against A549 (human lung) and HeLa (human cervical) cancer cell lines. The complexes exhibited superior anticancer activity to cisplatin and was non-toxic towards human umbilical vein endothelial (HUVEC) cells. The morphological changes of the HeLa and A549 cells with the complexes have been studied by AO-EB and DAPI staining methods. The cytotoxic nature of the compounds was RuC-Ang > RuB-Ang > cisplatin > ligand.