A panel of iridium(iii) porphyrin complexes containing axial N-heterocyclic carbene (NHC) ligand(s) were synthesized and characterized. X-ray crystal structures of the bis-NHC complexes [Ir(ttp)(IMe)] (), [Ir(oep)(BIMe)] (), [Ir(oep)(I Pr)] () and [Ir(Ftpp)(IMe)] () display ruffled porphyrin rings with mesocarbon displacements of 0.483-0.
View Article and Find Full Text PDFDehydroeffusol (DHE) is a phenanthrene isolated from the Chinese medicinal plant Juncus effusus. Biological evaluation of DHE reveals in vitro and in vivo anticancer effects. We performed a shotgun proteomic analysis using liquid chromatography-tandem mass spectrometry to investigate the changes in the protein profiles in cancer cells upon DHE treatment.
View Article and Find Full Text PDFTwo classes of cationic palladium(II) acetylide complexes containing pincer-type ligands, 2,2':6',2''-terpyridine (terpy) and 2,6-bis(1-butylimidazol-2-ylidenyl)pyridine (C^N^C), were prepared and structurally characterized. Replacing terpy with the strongly σ-donating C^N^C ligand with two N-heterocyclic carbene (NHC) units results in the Pd acetylide complexes displaying phosphorescence at room temperature and stronger intermolecular interactions in the solid state. X-ray crystal structures of [Pd(terpy)(C≡CPh)]PF (1) and [Pd(C^N^C)(C≡CPh)]PF (7) reveal that the complex cations are arranged in a one-dimensional stacking structure with pair-like Pd ⋅⋅⋅Pd contacts of 3.
View Article and Find Full Text PDFA macrocyclic ruthenium(III) complex [Ru (N O )Cl ]Cl (Ru-1) is reported as an inhibitor of angiogenesis and an anti-tumor compound. The complex is relatively non-cytotoxic towards endothelial and cancer cell lines in vitro, but specifically inhibited the processes of angiogenic endothelial cell tube formation and cancer cell invasion. Moreover, compared with known anti-cancer ruthenium complexes, Ru-1 is distinct in that it suppressed the expression of vascular endothelial growth factor receptor-2 (VEGFR2), and the associated downstream signaling that is crucial to tumor angiogenesis.
View Article and Find Full Text PDFThe inhibition of amyloid β (Aβ) peptide production is a key approach in the development of therapeutics for the treatment of Alzheimer's disease (AD). We have identified that timosaponins consisting of sarsasapogenin (SSG) as the aglycone can effectively lower the production of Aβ peptides and stimulate neurite outgrowth in neuronal cell cultures. Structure-activity relationship studies revealed that the -fused AB ring, 3β-configuration, spiroketal F-ring and 25-configuration of SSG are the essential structural features responsible for the Aβ-lowering effects and neurite-stimulatory activity.
View Article and Find Full Text PDFIn recent years a blossoming interest in the synthesis, photophysics and application of phosphorescent Pt(ii) complexes, particularly on their uses in bioimaging, photocatalysis and phosphorescent organic light-emitting diodes (OLEDs), has been witnessed. The superior performance of phosphorescent Pt(ii) complexes in these applications is linked to their diverse spectroscopic and photophysical properties, which can be systematically modulated by appropriate choices of auxiliary ligands. Meanwhile, an important criterion for the practical application of phosphorescent metal complexes is their stability which is crucial for biological utilization and industrial OLED applications.
View Article and Find Full Text PDFLuminescent pincer-type Pt(II) complexes supported by C-deprotonated π-extended tridentate RC^N^NR' ligands and pentafluorophenylacetylide ligands show emission quantum yields up to almost unity. Femtosecond time-resolved fluorescence measurements and time-dependent DFT calculations together reveal the dependence of excited-state structural distortions of [Pt(RC^N^NR')(CC-C6 F5 )] on the positional isomers of the tridentate ligand. Pt complexes [Pt(R-C^N^NR')(CC-Ar)] are efficient photocatalysts for visible-light-induced reductive CC bond formation.
View Article and Find Full Text PDFTwo cytotoxic iron(II) complexes [Fe(L)(CH3 CN)n ](ClO4 )2 (L=qpy for Fe-1 a, Py5 -OH for Fe-2 a) were synthesized. Both complexes are stable against spontaneous demetalation and oxidation in buffer solutions. Cyclic voltammetry measurements revealed the higher stability of Fe-2 a (+0.
View Article and Find Full Text PDFConstruction of delivery systems for anticancer gold complexes to decrease their toxicity while maintaining efficacy is a key strategy to optimize and develop anticancer gold medicines. Herein, we describe cancer-targeted mesoporous silica nanoparticles (MSN) for delivery of a gold(III) porphyrin complex (Au-1 a@MSN(R)) to enhance its anticancer efficacy and selectivity between cancer and normal cells. Encapsulation of Au-1 a within mesoporous silica nanoparticles amplifies its inhibitory effects on thioredoxin reductase (TrxR), resulting in a loss of redox balance and overproduction of reactive oxygen species (ROS).
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