A rapid,highly efficient,and general protocol for the synthesis of functionalized triarylmethanes: a straightforward access for the synthesis of (−)-tatarinoid C

A rapid, efficient, and convenient synthesis of functionalized triarylmethane is described by the Friedel–Crafts alkylation of methoxybenzenes with a variety of aldehydes in the presence of BF₃·OEt₂. The generality of the method is demonstrated by screening a variety of di- or tri-substituted arenes as well as substituted aromatic, heteroaromatic, and aliphatic aldehydes. (−)-Tatarinoid C is synthesized in a single step following the same protocol.     

Trace element determination in high-purity aluminum clad samples by k 0-based internal monostandard instrumental neutron activation analysis

The k₀-based internal monostandard instrumental neutron activation analysis (IM-INAA) method was applied for quantification of trace impurities in seven high purity aluminum samples used as fuel cladding in a research reactor. Samples along with BCS CRM 182 (Si–Al alloy) were irradiated in high flux reactor neutrons for 10–15 h. In situ detection efficiency, needed in concentration calculation ratio by IM-INAA, was obtained using gamma rays of activation products produced in the samples. Elemental concentration ratios obtained with respect to Fe (used as internal monostandard) were converted to absolute concentrations by determining concentration of Fe by relative method of NAA. Concentrations of ten trace elements (Sc, Cr, Co, Zn, Ga, La, Ce, Sm, W and Hf) including major element Fe were determined in this work. The method used is non-destructive in nature and does not need multielement standards. Results of IM-INAA were compared with those obtained by relative method of INAA and inductively coupled plasma atomic emission spectrometry (ICP-AES). Details of methodologies and results obtained by all methods are discussed and compared in the paper.     

6,6′-Thiobis(methylene)-β-cyclodextrin dimer as a dimeric host and reusable promoter for synthesis of chromenones in water

Herein, two unit of β-cyclodextrin linked by thiomethylene bridge was synthesized and employed as a novel efficient supramolecular host for the synthesis of biologically active chromenones templates via three-component single-pot reaction. A possible reaction mechanism through molecular complexation is suggested based on 2D ROESY NMR spectroscopic analysis. Moreover, the catalyst could be easily recycled, while a 94% yield and 89% rate of catalyst recovery could be achieved after four cycles of catalyst recycling. Environmentally benign reaction conditions, excellent yields, and avoidance of organic solvent and conventional isolation as well as purification are the noteworthy credits of this developed protocol.     

Solution-processed electrochemical synthesis of ZnFe2O4 photoanode for photoelectrochemical water splitting

Journal of Solid State Electrochemistry - Herein, we report the synthesis of ZnO nanorod films onto FTO (fluorine-doped tin oxide) substrates using the solution-processed electrodeposition method....     

Feasibility of Polyvinyl Alcohol as a Transdermal Drug Delivery System for Terbutaline Sulphate

A series of terbutaline sulphate drug incorporated polyvinyl alcohol (PVA) matrix films were produced by the solvent evaporation method. The effect of xanthan gum and plasticizers (propylene glycol and dibutyl phthalate) on the rate and amount of drug diffusion from PVA membrane across the hydrated cellophane membrane has been evaluated, using an open glass diffusion‐tube. The obtained films were clear, smooth and flexible having sufficient mechanical strength. The mechanical performance of the dry PVA films with xanthan gum and plasticizers were also ascertained. Polyvinyl alcohol‐xanthan gum blends showed a high rate of drug release compared to that of polyvinyl alcohol film alone. Among the two plasticizers employed, propylene glycol showed better permeability. Among different formulations studied, the formulation PVA/xanthan gum/propylene glycol (F7) was found to be an optimized composition for efficient transdermal delivery of the model drug, terbutaline sulphate. The mechanism of drug diffusion has been evaluated using the Peppas model. Stability studies carried out on polymer‐drug formulations revealed that the drug is stable at 40°C and 75% RH for a period of 6 weeks.     

Design of selective TACE inhibitors using molecular docking studies: Synthesis and preliminary evaluation of anti-inflammatory and TACE inhibitory activity

Tumor necrosis factor-α (TNF-α) converting enzyme (TACE) has been considered one of the principal therapeutic targets for the treatment of TNF-dependent pathologies. Several TACE inhibitors have been reported, but none of them has been successfully passed to phase II clinical trials. In the present work, we attempted to design highly selective new non-hydroxamate sulfonamide TACE inhibitors. The docking study was performed on one of the crystal structures of TACE, selected based on its resolution and R value, to tackle the flexibility issue of the active site. The results allowed us to distinguish the analogues with a higher binding affinity toward the active site of TACE and to identify the substituent of analogues needed for binding with the surrounding site of the enzyme. Finally the analogues were docked on crystal structures of six different matrix metalloproteinases (MMPs) for a selectivity study of TACE over MMPs. Some of these analogues were synthesized and subjected to preliminary testing for in vivo anti-inflammatory activity and TACE inhibitory activity.     

Magnetic properties of electrochemically prepared crystalline films of Prussian blue-based molecular magnets K j CrII k [CrIII(CN)6] l · mH2O

Crystalline films (thickness ～1 μm) of Prussian blue-based molecular magnets, synthesized using electrochemical method at two different reduction potentials ?0.5 and ?0.9 V, result into K_0.1Cr^II _1.45[Cr^III(CN)₆]?·?mH₂O (film 1) and K_0.8Cr^II _1.1[Cr^III(CN)₆]?·?mH₂O (film 2), respectively. The structural and magnetic properties of such films are investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), infrared (IR) spectroscopy, and dc magnetization measurements. The film morphology, examined using AFM, shows uniformly distributed triangular crystallites over the substrate surface. The presence of Cr^III–C≡N–Cr^II sequence, in the range of 1,900 to 2,300 cm^?1 in IR spectra, confirms formation of Prussian blue analogues. The XRD results reveal information about the crystalline nature of the films and the relative intensities of the Bragg peaks change with the K⁺ ions. The exchange interaction between Cr ions through C≡N ligand confirms that the electron transfer from C≡N molecule to Cr ions is ferrimagnetic in nature. The high Curie temperatures (T _C) are found to be ～195 and ～215 K for film 1 and film 2, respectively. The higher value of T _C is attributed to the inclusion of more K⁺ ions for film 2, resulting decreases in the Cr^III(C≡N)₆ vacancies and increases in the number of nearest neighbors of Cr^II ions. The branching in the zero field-cooled and field-cooled magnetization data below Curie temperature is explained in terms of kinetic behavior of magnetic domains with different cooling conditions and the presence of water molecule vacancies in the lattice.