Herein we illustrate the formation and characterization of new paramagnetic ruthenium compounds, trans‐P‐RuCl(PPh3)2(pmt)Cl (1) (Hpmt=1‐((pyridin‐2‐yl)methylene)thiosemicarbazide), ...trans‐P‐RuCl(PPh3)2(tmc)Cl (2) (Htmc=1‐((thiophen‐2‐yl)methylene)thiosemicarbazide) and a diamagnetic ruthenium complex, cis‐Cl, trans‐P‐RuCl2(PPh3)2(btm) (3) (btm=2‐((5‐hydroxypentylimino)methyl)benzothiazole). Agarose gel electrophoresis experiments of the metal compounds illustrated dose‐dependent binding to gDNA by 1–3, while methylene blue competition assays suggested that 1 and 2 are also DNA intercalators. Assessment of the effects of the compounds on topoisomerase function indicated that 1–3 are capable of inhibiting topoisomerase I activity in terms of the ability to nick supercoiled plasmid DNA. The cytotoxic activities of the metal complexes were determined against a range of cancer cell lines versus a non‐tumorigenic control cell line, and the complexes were, in general, more cytotoxic towards the cancer cells, displaying IC50 values in the low micromolar range. Time‐dependent stability studies showed that in the presence of strong nucleophilic species (such as DMSO), the chloride co‐ligands of 1–3 are rapidly substituted by the former as proven by the suppression of the substitution reactions in the presence of an excess amount of chloride ions. The metal complexes are significantly stable in both DCM and an aqueous phosphate buffer containing 2 % DMSO.
Thiosemicarbazone or benzothiazole Schiff base ruthenium compounds were found to display higher anticancer activities against HeLa cervical, HCC70 triple‐negative breast, and MCF‐7 hormone‐responsive breast cancer cells than against MCF‐12 A benign cells. DNA interaction studies showed that these octahedral metal complexes are partial DNA intercalators. These metal complexes illustrated optimal BSA uptake with preferential binding to BSA site I.
Transformation of biomass into valuable nitrogen‐containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO2, ...which could catalyze the reductive amination of a variety of biomass‐derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two‐step approach for production of ethanolamine, a large‐market nitrogen‐containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO2‐containing multivalence Ru association species worked as a bifunctional catalyst, with RuO2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation.
Amines from biomass: Ru/ZrO2 works as a highly efficient, bifunctional catalyst for the reductive amination of a variety of biomass‐based aliphatic and aromatic aldehydes/ketones in aqueous ammonia for the production of primary amines under mild reaction conditions. A broad spectrum of renewable primary amines is produced in good to excellent yields.
A ruthenium(II)‐catalyzed asymmetric intramolecular hydroarylation assisted by a chiral transient directing group has been developed. A series of 2,3‐dihydrobenzofurans bearing chiral all‐carbon ...quaternary stereocenters have been prepared in remarkably high yields (up to 98 %) and enantioselectivities (up to >99 % ee). By this methodology, a novel asymmetric total synthesis of CB2 receptor agonist MDA7 has been successfully developed.
Assisted by a chiral transient directing group, a highly enantioselective ruthenium‐catalyzed intramolecular hydroarylation, by means of an inert C−H activation process, has been realized in up to 98 % yield and 99 % ee by using the readily available and inexpensive metal catalyst Ru(p‐cymene)Cl22 (5 mol %) and a chiral primary amine (20 mol %).
Five osmium(II) polypyridyl complexes of the general formula Os(4,7‐diphenyl‐1,10‐phenanthroline)2L2+ were synthesized as photosensitizers for photodynamic therapy by varying the nature of the ligand ...L. Thanks to the pronounced π‐extended structure of the ligands and the heavy atom effect provided by the osmium center, these complexes exhibit a high absorption in the near‐infrared (NIR) region (up to 740 nm), unlike related ruthenium complexes. This led to a promising phototoxicity in vitro against cancer cells cultured as 2D cell layers but also in multicellular tumor spheroids upon irradiation at 740 nm. The complex Os(4,7‐diphenyl‐1,10‐phenanthroline)2(2,2′‐bipyridine)2+ was found to be the most efficient against various cancer cell lines, with high phototoxicity indexes. Experiments on CT26 tumor‐bearing BALB/c mice also indicate that the OsII complexes could significantly reduce tumor growth following 740 nm laser irradiation. The high phototoxicity in the biological window of this structurally simple complex makes it a promising photosensitizer for cancer treatment.
Osmium‐based polypyridyl complexes have been developed as photosensitizers for one‐photon photodynamic therapy in the near infrared.
In this study, we have developed a series of new monofunctional Ru(II) complexes of the general formula mer-Ru(Cl-Ph-tpy)(N-N)ClCl in which Cl-Ph-tpy is 4′-(4-chlorophenyl)-2,2′:6′,2″-terpyridine, ...N-N is a bidentate chelating ligand (1,2-diaminoethane (en, 1), 1,2-diaminocyclohexane (dach, 2) or 2,2′-bipyridine (bpy, 3)). All complexes were fully characterized by elemental analysis and spectroscopic techniques (IR, UV–Vis, 1D and 2D NMR). Their chemical behavior in aqueous solution was studied by UV–Vis and NMR spectroscopy showing that all compounds are relatively labile leading to the formation of the corresponding aqua species 1aq–3aq. Their DNA binding ability was evaluated by UV–Vis spectroscopy, fluorescence quenching measurements and viscosity measurements. Competitive studies with ethidium bromide (EB) showed that the complexes can displace DNA-bound EB, suggesting strong competition with EB (Ksv=1.1–2.7×104M−1). These experiments show that the ruthenium complexes interact with DNA via intercalation. The complexes bind to serum protein albumin displaying relatively high binding constants (Ksv=104–105M−1). Compound 3 displayed from high to moderate cytotoxicity against two cancer cell lines HeLa and A549 (with IC50ca. 12.7μM and 53.8μM, respectively), while complexes 1 and 2 showed only moderate cytotoxicity (with IC50ca. 84.8μM and 96.3μM, respectively) against HeLa cells. The cell cycle analysis (by flow cytometry) of HeLa and A549 cells treated with complex 3 shows minor changes on the cell cycle phase distribution.
A series of new ruthenium(II)-chlorophenyl-terpyridine complexes were synthesized and fully characterized. The chlorido complexes proved to be labile in aqueous solution and capable of interacting with biomolecules. Furthermore, the complex with bidentate aromatic diamine proved to be superior to those with aliphatic diamines in terms of lipophilicity and biological activity. Display omitted
•Synthesis of new Ru(II) polypyridyl complexes with chlorophenyl-terpyridine ligand.•All complexes in aqueous solution release the Cl− ligand to form the aqua species.•Ruthenium complexes show good binding affinity to DNA and bovine serum albumin.•The complex with bidentate aromatic diamine displays the highest cytotoxicity.
In this study, we newly designed and synthesized a small library of ten structurally related C,N‐cyclometalated ruthenium(II) complexes containing various pyridine‐functionalized NHC ligand and ...chelating bipyridyl ligands (e.g., 2,2′‐bipyridine, 5,5′‐dimethyl‐2,2′‐bipyridine, and 1,10‐phenanthroline (phen)). The complexes were well characterized by NMR, electrospray ionization‐mass spectrometry, and single‐crystal X‐ray structure analyses. Among the new ruthenium(II) derivatives, we identified that the complex Ru8 bearing bulky moieties (i.e., phen and pentamethyl benzene) had the most potent cytotoxicity against all tested cancer cell lines, generating dose‐ and cell line‐dependent IC50 values at the range of 3.3–15.0 μm. More significantly, Ru8 not only efficiently inhibited the metastasis process against invasion and migration of tumor cells but also exhibited potent antivascular effects by suppressing HUVEC cells migration and tube formation in vitro and blocking vessel generation in vivo (chicken chorioallantoic membrane model). In a metastatic A2780 tumor xenograft‐bearing mouse model, administration of Ru8 outperformed antimetastatic agent NAMI‐A and clinically approved cisplatin in terms of antitumor efficacy and inhibition of metastases to other organs. Overall, these data provided compelling evidence that the new cyclometalated ruthenium complex Ru8 is an attractive agent because of synergistically suppressing bulky tumors and metastasized tumor nudes. Therefore, the complex Ru8 deserves further investigations.
The optimized C,N‐cyclometalated ruthenium(II) complex Ru8 not only showed potent cytotoxic activity but also effectively impeded tumor metastasis and angiogenesis, thereby synergistically enhancing the efficacy against metastatic cancer.
The fabrication of fully printable, flexible micro‐supercapacitors (MSCs) with high energy and power density remains a significant technological hurdle. To overcome this grand challenge, the 2D ...material MXene has garnered significant attention for its application, among others, as a printable electrode material for high performing electrochemical energy storage devices. Herein, a facile and in situ process is proposed to homogeneously anchor hydrous ruthenium oxide (RuO2) nanoparticles on Ti3C2Tx MXene nanosheets. The resulting RuO2@MXene nanosheets can associate with silver nanowires (AgNWs) to serve as a printable electrode with micrometer‐scale resolution for high performing, fully printed MSCs. In this printed nanocomposite electrode, the RuO2 nanoparticles contribute high pseudocapacitance while preventing the MXene nanosheets from restacking, ensuring an effective ion highway for electrolyte ions. The AgNWs coordinate with the RuO2@MXene to guarantee the rheological property of the electrode ink, and provide a highly conductive network architecture for rapid charge transport. As a result, MSCs printed from the nanocomposite inks demonstrate volumetric capacitances of 864.2 F cm−3 at 1 mV s−1, long‐term cycling performance (90% retention after 10 000 cycles), good rate capability (304.0 F cm−3 at 2000 mV s−1), outstanding flexibility, remarkable energy (13.5 mWh cm−3) and power density (48.5 W cm−3).
A fully printed strategy is reported to assemble flexible micro‐supercapacitors by printing thixotropic nanocomposite inks for electrodes comprising RuO2·xH2O@Ti3C2Tx (MXene) nanosheets and silver nanowires. The resultant screen‐printed micro‐supercapacitors based on this RuO2·xH2O@MXene–AgNW nanocomposite ink exhibit a landmark volumetric capacitance of 864.2 F cm−3 at a scan rate of 1 mV s−1.
Breast cancer is the most frequent cause of cancer in women. In the current study, transition metal ruthenium was complexed with flavonoid chrysin to evaluate the chemotherapeutic potential of this ...compound in Michigan Cancer Foundation‐7 (MCF‐7) human mammary cancer cell line and 7,12‐dimethylbenz(α)anthracene‐induced mammary cancer in female Sprague–Dawley rats. The characterizations of the complex were accomplished through UV–visible, NMR, IR, Mass spectra, and XRD techniques and antioxidant activity was assessed by DPPH, FRAP, and ABTS methods. In vitro studies included cell viability, cell cycle analysis, DNA fragmentation, and marker analysis by western blot analysis and found that complex treatment suppressed cell growth‐induced cell cycle arrest and enhanced the induction of apoptosis in cancer cells. Moreover, complex treatment modulated signaling pathways including mTOR, VEGF, and p53 in the MCF‐7 cells. Acute and subacute toxicity was performed in rats to determine the therapeutic doses. Breast cancer in rats was initiated by the administration of 7,12‐dimethylbenz(α)anthracene (0.5 mg/100 g body weight) via single tail vein injection. The histopathological analysis after 24 weeks of carcinogenesis study depicted substantial repair of hyperplastic lesions. Immunohistochemical analysis revealed upregulation of Bax and p53 and downregulation of Bcl2 proteins and TUNEL assay showed an increase in apoptotic index in ruthenium–chrysin‐treated groups as compared to the carcinogen control. Our findings from the in vitro and in vivo study support the continued investigation of ruthenium–chrysin complex possesses a potential chemotherapeutic activity against breast cancer and was efficient in reducing hyperplastic lesions in the mammary tissues of rats by inducing apoptosis.
Our findings from the in vitro and in vivo study support the continued investigation of ruthenium–chrysin complex possesses a potential chemotherapeutic activity against breast cancer and was efficient in reducing hyperplastic lesions in the mammary tissues of rats by inducing apoptosis.
Guaranteeing satisfactory catalytic behavior while ensuring high metal utilization has become the problem that needs to be addressed when designing noble‐metal‐based catalysts for electrochemical ...reactions. Here, well‐dispersed ruthenium (Ru) based clusters with adjacent Ru single atoms (SAs) on layered sodium cobalt oxide (Ru/NC) are demonstrated as a superb electrocatalyst for alkaline HER. The Ru/NC catalyst demonstrates an activity increase by a factor of two relative to the commercial Pt/C. Operando characterizations in conjunction with density functional theory (DFT) simulations uncover the origin of the superior activity and establish a structure–performance relationship, that is, under HER condition, the real active species are Ru SAs and metallic Ru clusters supported on the NC substrate. The excellent alkaline HER activity of the Ru/NC catalyst can be understood by a spatially decoupled water dissociation and hydrogen desorption mechanism, where the NC substrate accelerates the water dissociation rate, and the generated H intermediates would then migrate to the Ru SAs or clusters and recombine to have H2 evolution. More importantly, comparing the two forms of Ru sites, it is the Ru cluster that dominates the HER activity.
Sodium cobalt oxide substrate provides active sites for the dissociation of water, and the generated H intermediates recombine to generate H2 on the Ru single atoms or clusters. Comparing the two kinds of Ru sites, Ru cluster dominates the alkaline HER activity due to the more fluent migration of H intermediates and its more favorable adsorption–desorption energetics toward H intermediates.
An efficient approach to the synthesis of olefin metathesis HG-type catalysts containing an N→Ru bond in a six-membered chelate ring was proposed. For the most part, these ruthenium chelates can be ...prepared easily and in high yields based on the interaction between 2-vinylbenzylamines and
(the common precursor for Ru-complex synthesis). It was demonstrated that the increase of the steric volume of substituents attached to the nitrogen atom and in the α-position of the benzylidene fragment leads to a dramatic decrease in the stability of the target ruthenium complexes. The bulkiest
Pr substituent bonded to the nitrogen atom or to the α-position does not allow the closing of the chelate cycle. N,N-Diethyl-1-(2-vinylphenyl)propan-1-amine is a limiting case; its interaction with
makes it possible to isolate the corresponding ruthenium chelate in a low yield (5%). Catalytic activity of the synthesized complexes was tested in RCM reactions and compared with α-unsubstituted catalysts obtained previously. The structural peculiarities of the final ruthenium complexes were thoroughly investigated using XRD and NMR analysis, which allowed making a reliable correlation between the structure of the complexes and their catalytic properties.
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