Chromatography-Free Multicomponent Synthesis of Thioureas Enabled by Aqueous Solution of Elemental Sulfur

The development of a new three-component chromatography-free reaction of isocyanides, amines and elemental sulfur allowed us the straightforward synthesis of thioureas in water. Considering a large pool of organic and inorganic bases, we first optimized the preparation of aqueous polysulfide solution from elemental sulfur. Using polysulfide solution, we were able to omit the otherwise mandatory chromatography, and to isolate the crystalline products directly from the reaction mixture by a simple filtration, retaining the sulfur in the solution phase. A wide range of thioureas synthesized in this way confirmed the reasonable substrate and functional group tolerance of our protocol.     

Synthesis of vinca alkaloids and related compounds. 100. Stereoselective oxidation reactions of compounds with the aspidospermane and quebrachamine ring system. First synthesis of some alkaloids containing the epoxy ring

The first syntheses of the alkaloids (-)-mehranine (3), (+)-voaphylline/conoflorine (4), (+)-N(a)-methylvoaphylline/hecubine (5), and (-)-lochnericine (2) were achieved by stereoselective epoxidation starting from (-)-tabersonine (1), through intermediates with the aspidospermane and quebrachamine skeleton.     

Charge carrier mobility,photovoltaic, and electroluminescent properties of anthracene‐based conjugated polymers bearing randomly distributed side chains

This article reports on the synthesis, characterization, and properties of various anthracene‐containing poly (p‐phenylene‐ethynylene)‐alt‐poly(p‐phenylene‐vinylene) (PPE‐PPV) polymers (AnE‐PVs) bearing statistical distributions of various side chains. Primarily, the ratio of linear octyloxy and branched 2‐ethylhexyloxy side chains at the poly(p‐phenylene vinylene) (PPV) parts was varied, leading to the polymers stat, stat1, and stat2. Furthermore, polymers also containing asymmetric substituted PPV and poly(p‐phenylene ethynylene) units (bearing methoxy and 2‐ethylhexyloxy side chains) were prepared yielding stat3, stat4, and stat5. These materials exhibit a broad variation in their photovoltaic properties. It is once more shown that side chains and their distribution can crucially affect the photovoltaic device performance. The introduction of units with asymmetric substitution into these systems seems to be harmful for their utilization in photovoltaic applications. Organic field‐effect transistors were fabricated to investigate hole mobilities in these new materials. Large variance was observed, falling in the range of almost two orders of magnitude, indicating rather different π–π stacking behavior of the polymer backbones owing to side‐chain modifications. Moreover, a selection of the new polymeric systems was investigated regarding their potential for light‐emitting diode (LED) applications. Polymer LEDs using the polymers AnE‐PVstat, ‐stat3, ‐stat4, and ‐stat5, as the active layer showed turn‐on voltage of ～2 V and exhibited red light emission. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Pharmacological properties of dicyanidoaurate(I)-based complexes: characterization and single crystal X-ray analysis

The synthesis of three bimetallic cyanido complexes with edbea [2,2′-(ethylenedioxy)bis(ethylamine)] ligand is reported. [Ni^II(μ-edbea)₂{Au(μ-CN)₂}₂]_n (1), [{Cu^II(edbea)}₂{Au(μ-CN)₂}₄]_n (2) and [Cd^II(edbea)₂][Au(CN)₂]₂·H₂O (3) were fully characterized by elemental, infrared, XRD (3), ESI-MS and thermal analysis. The DNA/BSA binding properties of these complexes were evaluated by spectrophotometric titration, fluorometric ethidium bromide kinetics, and DNA electrophoresis studies and their partially minor groove binding mode between the base pairs of DNA and electrostatic interaction between the amino acid residues of BSA were explained. The complexes were tested for their pharmacological properties. These molecules had excellent in vitro antiproliferative activity and also exhibited a strong tumor inhibiting effect against HT29, HeLa, C6 and Vero cell lines. These complexes had metastatic features as they are able to reduce cell migration activity and suppress tumor growth in vitro. Analysis of the DNA topoisomerase I relaxing activity indicates that the complexes do not inhibit topoisomerase I which regulates the topological states of the DNA double helix during DNA processing reactions. The TUNEL and DNA laddering assay results indicated that these compounds may destroy cell maintenance by triggering apoptosis. Immunohistochemistry staining analysis demonstrated that these complexes significantly decreased the expression of Bcl-2 in HeLa and HT29 cells while increasing the expression of P53 levels. Overall, the potent antiproliferative activity, low cytotoxic effect, good solubility, and micro molar range dosage observed for these complexes emphasizes their potential as anticancer drug candidates.     

89Zr Labeled Fe3O4@TiO2 Nanoparticles: In Vitro Afffinities with Breast and Prostate Cancer Cells

In this study, Fe₃O₄@TiO₂ nanoparticles were synthesized as a new Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) hybrid imaging agent and radiolabeled with ⁸⁹Zr. In addition, Fe₃O₄ nanoparticles were synthesized and radiolabeled with ⁸⁹Zr. Df-Bz-NCS was used as bifunctional ligand. The nanoconjugates were characterized with transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Radiolabeling yields were 100%. Breast and prostate cancer cell affinities and cytotoxicity were determined using in vitro cell culture assays. The results demonstrated that Fe₃O₄@TiO₂ nanoparticles are promising for PET/MR imaging. Finally, unlike Fe₃O₄ nanoparticles, Fe₃O₄@TiO₂ nanoparticles showed a fluorescence spectrum at an excitation wavelength of 250 nm and an emission wavelength of 314 nm. Therefore, in addition to bearing the magnetic properties of Fe₃O₄ nanoparticles, Fe₃O₄@TiO₂ nanoparticles display fluorescence emission. This provides them with photodynamic therapy potential. Therefore multimodal treatment was performed with the combination of PDT and RT by using human prostate cancer cell line (PC3). The development of ⁸⁹Zr-Df-Bz-NCS-Fe₃O₄@TiO₂ nanoparticles as a new multifunctional PET/MRI agent with photodynamic therapy and hyperthermia therapeutic ability would be very useful.     

Synthesis,characterization and biodistribution of 99mTc-Bioquin-HMPAO (99mTc-BH) as a novel brain imaging agent

Recently, the development of novel brain imaging agents has aroused much interest thanks to limited number of brain cancer or diseases diagnosis agents. It is aimed to synthesize a novel brain imaging agent including a promise for further studies on AD diagnosis potential and investigate its bioaffinity with biodistribution studies on healthy Balb/c mice. A novel radiolabeled agent was synthesized and characterized. Quality control of ^99mTc-BH was performed utilizing solvent extraction and chromatographic (Radio TLC and Radio HPLC) methods. Bioaffinity of the ^99mTc-BH was investigated on male Balb/c mice at various time points (5, 30, 60, 120 min post-injection). Paper electrophoresis showed that ^99mTc-BH has a neutral structure. Radiochemical purity of ^99mTc-BH was over 95 % with appropriate stability for imaging period. Selected brain regions have uptakes over 4 % ID/g following intravenous injection. Hippocampus has uptake approximately 10 % ID/g. ^99mTc-BH has shown brain uptake, so it may prove to be valuable for brain imaging as a novel technetium-labeled agent. Further investigations with AD animal model are our on going effort to show that this agent has AD diagnosis potential.     

Preparation of a 99mTc-labeled graft polymer and its in vitro and in vivo evaluation

Journal of Radioanalytical and Nuclear Chemistry - The aim of this study is the synthesis of a novel 99mTc-labeld graft polymer and the biological evaluation of its in vitro and in vivo properties....     

High-throughput prediction of blood-brain partitioning: a thermodynamic approach

A high-throughput in silico screening tool for potentially CNS active compounds was developed on the basis of the correlation of solvation free energies and blood-brain partitioning (log(cbrain/cblood) = log BB) data available from experimental sources. Utilizing a thermodynamic approach, solvation free energies were calculated by the fast and efficient generalized Born/surface area continuum solvation model, which enabled us to evaluate more than 10 compounds/min. Our training set involved a structurally diverse set of 55 compounds and yielded a function of log BB = 0.035Gsolv + 0.2592 (r = 0.85, standard error 0.37). Calculation of solvation free energies for 8700 CNS active compounds (CIPSLINE database) revealed that Gsolv is higher than -50 kJ/mol for the 96% of these compounds which can be used as suitable criteria for the identification of compounds preferable for CNS penetration.     

A Comparison of the LVDP and ΛCDM Cosmological Models

We compare the cosmological kinematics obtained via our law of linearly varying deceleration parameter (LVDP) with the kinematics obtained in the ΛCDM model. We show that the LVDP model is almost indistinguishable from the ΛCDM model up to the near future of our universe as far as the current observations are concerned, though their predictions differ tremendously into the far future.