Two New Phenylpropanoid Glycosides from the Leaves and Flowers of Erica arborea

Two new phenylpropanoid glucosides, 1,2‐erythro‐1‐(3,4,5‐trimethoxyphenyl)‐2‐(β‐D ‐glucopyranosyloxy)propan‐1,3‐diol ( 1 ) and 7,8‐threo‐2′,8‐epoxysyringylglycerol‐7‐O‐α‐D ‐glucopyranoside (ericarboside; 2 ) have been isolated together with four known compounds 2′,7‐epoxysyringylglycerol‐8‐O‐β‐D ‐glucopyranoside (ficuscarpanoside B; 3 ), benzylrutinoside (hydrangeifolin; 4 ), phenethylrutinoside ( 5 ), and caffeic acid from the BuOH soluble part of the MeOH extract of the leaves and flowers of E. arborea L. Final purification of the compounds was achieved on a reversed‐phase HPLC. Their structures have been elucidated by extensive 1D‐ and 2D‐NMR, and mass spectroscopic techniques.     

Rheology, morphology and mechanical properties of polyethylene/ethylene vinyl acetate copolymer (PE/EVA) blends

Rheology, morphology and mechanical properties of binary PE and EVA blends together with their thermal behavior were studied. The results of rheological studies showed that, for given PE and EVA, the interfacial interaction in PE-rich blends is higher than EVA-rich blends, which in turn led to finer and well-distributed morphology in PE-rich blends. Using two different models, the phase inversion composition was predicted to be in 45 and 47 wt% of the PE phase. This was justified by morphological studies, where a clear co-continuous morphology for 50/50 blend was observed. The tensile strength for PE-rich blends showed positive deviation from mixing rule, whereas the 50/50 blend and EVA-rich blends displayed negative deviation. These results were in a good agreement with the results of viscoelastic behavior of the blends. The elongation at break was found to follow the same trend as tensile strength except for 90/10 PE/EVA blend. The latter was explained in terms of the effect of higher co-crystallization in 90/10 composition, which increased the tensile strength and decreased the elongation at break in this composition. The results of thermal behavior of the blends indicated that the melting temperatures of PE and EVA decrease and increase, respectively, due to the dilution effect of EVA on PE and nucleation effect of PE on EVA.     

Convenient,Easy and Highly Regioselective Preparation of Haloalcohols from the Reaction of Epoxides with Elemental Halogen Catalyzed by Hexamethylenetetramine (HMTA)

The highly regioselective cleavage of epoxides into corresponding vicinal haloalcohols with elemental halogen has been catalyzed by hexamethylenetetramine (HMTA). This method occurred under neutral and mild conditions with high yields and short reaction times in various aprotic solvents even when sensitive functional groups were present.     

Electro membrane extraction of sodium diclofenac as an acidic compound from wastewater,urine, bovine milk,and plasma samples and quantification by high-performance liquid chromatography

Electro membrane extraction (EME) as a new microextraction method was applied for extraction of sodium diclofenac (SDF) as an acidic compound from wastewater, urine, bovine milk and plasma samples. Under applied potential of 20 V during the extraction, SDF migrated from a 2.1 mL of sample solution (1 mM NaOH), through a supported liquid membrane (SLM), into a 30 μL acceptor solution (10 mM NaOH), exist inside the lumen of the hollow fiber. The negative electrode was placed in the donor solution, and the positive electrode was placed in the acceptor solution. 1-octanol was immobilized in the pores of a porous hollow fiber of polypropylene as SLM. Then the extract was analyzed by means of high-performance liquid chromatography (HPLC) with UV-detection for quantification of SDF. Best results were obtained using a phosphate running electrolyte (10 mM, pH 2.5). The ranges of quantitation for different samples were 8–500 ng mL⁻¹. Intra- and inter-day RSDs were less than 14.5%. Under the optimized conditions, the preconcentration factors were between 31 and 66 and also the limit of detections (LODs) ranged from 2.7 ng mL⁻¹ to 5 ng mL⁻¹ in different samples. This procedure was applied to determine SDF in wastewater, bovine milk, urine and plasma samples (spiked and real samples). Extraction recoveries for different samples were between 44–95% after 5 min of extraction.     

Voltammetric and amperometric determination of hydrogen peroxide using a carbon-ceramic electrode modified with a nanohybrid composite made from single-walled carbon nanotubes and silver nanoparticles

A nanohybrid composite material was prepared from single-walled carbon nanotubes and silver nanoparticles, and used to fabricate a modified carbon-ceramic electrode. The preparation of the composite is facile and efficient. The nanohybrid composite deposited on the carbon-ceramic electrode was characterized by X-ray diffraction and cyclic voltammetry. The new electrode displays favorable electrocatalytic ability towards hydrogen peroxide (H₂O₂) and can be used to electrocatalytically reduce this species. Under the optimum conditions, the current measured during hydrodynamic amperometry is linearly related to the concentration of H₂O₂ over the concentration range from 0.01 to 8 mM, with a detection limit of 2?×?10^?7 M at a signal-to-noise ratio of 3 and sensitivity of 3.23 μA/mM. The electrode exhibits good reproducibility, long-term stability and negligible interference by dopamine, uric acid, and other important biological compounds. The electrode was successfully applied to the determination of H₂O₂ in honey samples, and the recovery was 101.2%.

Targetry and specification of <Superscript>167</Superscript>Tm production parameters by different reactions

In recent years, there has been a rapid expansion in the use of radio nuclides for therapeutic purposes. Thulium–167 is an important radionuclide (T _1/2 = 9.25 d) due to it could be used for tumor and bone studies in nuclear medicine. ¹⁶⁷Tm complexed with hydroxy ethylene diamine tetra-acetic acid (HEDTA) could be used with the aim of bone imaging. ¹⁶⁷Tm emits a prominent γ ray of 208 keV energy and low energy electrons. This study describes calculations on the excitation functions of ¹⁶⁵Ho(α,2n)¹⁶⁷Tm, ¹⁶⁷Er(p,n)¹⁶⁷Tm, ^natEr(d,xn)¹⁶⁷Tm and ^natEr(p,xn)¹⁶⁷Tm reactions by ALICE/ASH (hybrid and GDH models) and TALYS-1.0 codes. In addition, calculated data by codes were compared to experimental data that earlier were published and TENDL-2010 database. Moreover, optimal thickness of the targets and physical yield were obtained by SRIM (stopping and range of ions in matter) code for each reaction. According to the results, the ¹⁶⁷Er(p,n)¹⁶⁷Tm and ¹⁶⁵Ho(α,2n)¹⁶⁷Tm reactions are suggested as the best method to produce ¹⁶⁷Tm owing to minimum impurities. The TALYS-1.0 code, predict the maximum cross-section of about 382 mb at 11 MeV and 849 mb at 26 MeV for ¹⁶⁷Er(p,n)¹⁶⁷Tm and ¹⁶⁵Ho(α,2n)¹⁶⁷Tm reactions, respectively. Finally, deposition of ^natEr₂O₃ on Cu substrate was carried out via the sedimentation method. The 516 mg of erbium(III)oxide with 103.2 mg of ethyl cellulose and 8 mL of acetone were used to prepare a ^natEr₂O₃ layer of 11.69 cm². ¹⁶⁷Tm was produced via the ^natEr(p,n)¹⁶⁷Tm nuclear process at 20 μA current and 15 → 7 MeV protons beam (1 h). Yield of about 3.2 MBq ¹⁶⁷Tm per μA h were experimentally obtained.     

Uranyl sensor based on a N,N′-bis(salicylidene)-2-hydroxy-phenylmethanediamine and multiwall carbon nanotube electrode

The electrochemical determination of uranyl was investigated by using carbon paste electrode modified with a Schiff base namely N,N??-bis(salicylidene)-2-hydroxy-phenylmethanediamine (SHPMD/CPE) and also in the presence of carbon nanotube (SHPMD/CNT/CPE). The both modified electrodes displayed an irreversible peak at E _pa?=?0.798?V versus Ag/AgCl. The electrocatalytic reduction of uranyl has been studied on SHPMD/CNT/CPE, using cyclic and differential pulse voltammetry, chronocoulometry and linear sweep techniques. Electrochemical parameters including the diffusion coefficient (D), the electron transfer coefficient (??), the ionic exchange current (i) and the redox reaction rate constant (K) were determined for the reduction of uranyl on the surface of the modified electrodes. Linear range concentration is 0.002?C0.6???mol?L^?1 and the detection limit of uranyl is 0.206?nmol?L^?1. The proposed method was used to detect uranyl in natural waters and good recovery was achieved.     

Study of complexation process between N-phenylaza-15-crown-5 with yttrium cation in binary mixed solvents

The complexation reaction between Y³⁺ cation with N-phenylaza-15-crown-5(Ph-N15C5) was studied at different temperatures in acetonitrile–methanol (AN/MeOH), acetonitrile–propanol (AN/PrOH), acetonitrile–1,2 dichloroethane (AN/DCE) and acetonitrile–water (AN/H₂O) binary mixtures using the conductometric method. The results show that in all cases, the stoichiometry of the complex is 1:1 (ML). The values of formation constant of the complex which were determined using conductometric data, show that the stability of (Ph-N15C5.Y)³⁺ complex in pure solvents at 25?°C changes in the following order: PrOH?>?AN?>?MeOH and in the case of binary mixed solutions at 25?°C it follows the order: AN–DCE?>?AN–PrOH?>?AN–MeOH?>?AN–H₂O. The values of standard thermodynamic quantities (?H _c ^° and ?S _c ^° ) for formation of (Ph-N15C5.Y)³⁺ complex were obtained from temperature dependence of the formation constant using the van’t Hoff plots. The results show that in most cases, the complex is entropy and enthalpy stabilized and these parameters are influenced by the nature and composition of the mixed solvents. In most cases, a non-linear behavior was observed for variation of log K_f of the complex versus the composition of the binary mixed solvents. In all cases, an enthalpy–entropy compensation effect was observed for formation of (Ph-N15C5.Y)³⁺ complex in the binary mixed solvents.     

Gamma radiation effects on physico-chemical parameters of apple fruit during commercial post-harvest preservation

The physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Red Delicious apple subjected to γ radiation were evaluated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 300, 600, 900 and 1200 Gy and stored at 1 °C. Apples were evaluated at three month intervals. The results showed that there was a clear link between phenolic content and antioxidant activity, so that dose range of 900 Gy and higher significantly decreased phenolic content and antioxidant activity. The moisture percent of stored apples was more responsive to irradiation (at doses of 900–1200 Gy) than storage time and pathogen. Lesion diameter of pathogen-treated non-irradiated apples was significantly increased after three months. This means that storage at low temperature is not enough to avoid blue mold growth. As dose and storage time increased firmness decreased; also pathogen accelerated softening of stored apples. This study showed conclusively that low irradiation doses (300 and 600 Gy) combined with cold storage is a way to minimize apple quality losses during nine month storage period.     

Synthesis,structural characterization and antibacterial activity of diorganotin(Ⅳ) complexes with ONO tridentate Schiff bases containing pyridine ring

Five organotin（IV） complexes,were obtained by reaction of SnR₂Cl₂（R = Ph,Me,Bu） with ONO donor Schiff bases.The synthesized complexes have been investigated by elemental analysis and IR,¹H NMR,and ¹¹⁹Sn NMR spectroscopy.These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms.The Xray crystallography of complex 4 shows a dimeric structure for this molecule.The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive（Bacillus subtilis and Staphylococcus aureus） and Gram-negative （Escherichia coli and Pseudomonas aeruginosa） bacteria and compared with the standard antibacterial drugs.