The [Mo6Cl14]2− Cluster is Biologically Secure and Has Anti-Rotavirus Activity In Vitro

The molybdenum cluster [Mo6Cl14]2− is a fluorescent component with potential for use in cell labelling and pharmacology. Biological safety and antiviral properties of the cluster are as yet unknown. Here, we show the effect of acute exposition of human cells and red blood cells to the molybdenum cluster and its interaction with proteins and antiviral activity in vitro. We measured cell viability of HepG2 and EA.hy926 cell lines exposed to increasing concentrations of the cluster (0.1 to 250 µM), by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Hemolysis and morphological alterations of red blood cells, obtained from healthy donors, exposed to the cluster (10 to 200 µM) at 37 °C were analyzed. Furthermore, quenching of tryptophan residues of albumin was performed. Finally, plaque formation by rotavirus SA11 in MA104 cells treated with the cluster (100 to 300 µM) were analyzed. We found that all doses of the cluster showed similar cell viability, hemolysis, and morphology values, compared to control. Quenching of tryptophan residues of albumin suggests a protein-cluster complex formation. Finally, the cluster showed antiviral activity at 300 µM. These results indicate that the cluster [Mo6Cl14]2− could be intravenously administered in animals at therapeutic doses for further in vivo studies and might be studied as an antiviral agent

Graphene Oxide Quantum Dots as the Support for the Synthesis of Gold Nanoparticles and Their Applications as New Catalysts for the Decomposition of Composite Solid Propellants

Graphene oxide quantum dot (GOQD) and reduced GOOD (rGOQD) were synthetized using a simple and straight methodology based on an oxidative treatment and sonication. GOQD and rGOQD were used as supporting agents for the in situ generation of gold nanoparticles, avoiding the use of additional stabilizers. GOQD resulted as a better support than rGOQD because of the presence of higher functional groups that can interact with gold. Theoretical studies through density functional theory revealed the important role of the epoxy groups of GOQD on the stabilization of gold. GOQD and GOQD-Au were tested for the first time as catalysts for the decomposition of solid composite propellants. GOQD not only lowered the decomposition temperature of ammonium perchlorate (AP) but also enhanced the exothermic heat of AP, in comparison to graphene and GO. GOQD-Au increased the energy release; however, the effect on the decrease of the decomposition temperature of AP was not as significant as other previous reported catalysts

An Improved Synthesis of 3,6-Dihydro-as-indacene

This contribution describes an updated synthetic route to 3,6-dihydro-as-indacene along with full characterization of all inter­mediates. The title compound is prepared by Mannich condensation of 2-methylfuran with formaldehyde and dimethylamine hydrochloride, quaternization of the resulting amine with methyl iodide, and conversion into the ammonium hydroxide salt by treatment with silver oxide in water. Subsequent Hoffmann elimination and [6,6]-cycloaddition through pyrolysis produces a furanocyclophane, which after photooxidation, intramolecular cycloaddition, and dehydration with sodium carbonate affords 2,3,6,7-tetrahydro-1,8-dione-as-indacene. Reduction of this diketone gives a mixture of alcohols, which after dehydration under slightly basic or acidic conditions produces 3,6-dihydro-as-indacene. The structure is confirmed by X-ray diffraction, and all intermediates are characterized by means of 1H and 13C NMR spectroscopy.The authors are grateful for the financial support from Fondo Nacional de Desarrollo Cientifico y Tecnologico, Chile (FONDECYT) (Grants 1161297, EQM120021, EQM130032, EQM150102), the Pontificia Universidad Catolica de Chile (PUC) (Grant 3913-541-81), the Scheduled Tribes Welfare Department, Government of Karnataka, India for a student fellowship (Y.D.) to pursue a research stay at the Pontificia Uni-versidad Catolica de Chile. E.M. (ICMAB) acknowledges the Severo Ochoa Program, Ministerio de Economia y Competitividad (MINECO) (SEV-2015-0496).Peer reviewe

Novel and Convenient Synthesis of 2,7-Dialkyl-1,8-dihydro-as-indacenes­

A novel and convenient synthetic route towards dialkyl as-indacenes was achieved by alkylation of malonic esters with o-xylylene dibromide, to give the corresponding tetraester, and related diacid. The alkyl groups on the central benzene ring induce intramolecular, regiospecific cycloeliminations leading selectively to the diketones, the precursors of the corresponding 1,8-dihydro-as-indacenes. The structure of the 2,7-dimethyl-1,8-dihydro-as-indacene was determined by X-ray diffraction. The compound 2,7-diethyl-1,8-dihydro-as-indacene was characterized by means of 1H NMR, 13C NMR, FT-IR, UV/Vis measurements, electrochemistry, and elemental analysis. On the other hand, quantum chemical computations based on DFT methods were carried out to get insight into the molecular and electronic structures of the studied ligands. TDDFT approach was employed to calculate the vertical excitations and characterize the nature the UV/Vis absorption bands present in the experiments showing a very good agreement between experimental and calculated values. Finally, the reactivity of the compounds was assessed using the chemical potential (μ), chemical hardness (η), and electrophilicity (ω). Also, the electron-donating (ω–), electron-accepting (ω+), and the net electrophilicity powers (ω±) indexes were studied.The authors thank the financial support from the following grants: FONDECYT Grants 1161297 and 1141138.Peer reviewe

Heterobinuclear s-indacene rhodium complexes, synthesis and characterization

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