Inclusion Complex of Sea Buckthorn Fruit Oil with β-Cyclodextrin: Preparation Characterization and Antioxidant Activity

This study aims to produce an inclusion complex between β-cyclodextrin (β-CD) and sea buckthorn fruit oil (SBFO) by using the saturated aqueous solution method and then to compare the resultant solution with the crude mixtures. In this study, the SBFO is extracted by Soxhlet extraction, which is optimized through the single-factor test. The main constituent of the SBFO is identified by gas chromatography-mass spectrometry (GC-MS), which confirms eight fatty acids. Fourier transform infrared spectroscopy, thermogravimetric analysis-differential scanning calorimetry, optical microscopy, scanning electron microscopy, and the result-characterized synthesized compounds confirm the formation of stable inclusion compounds by the SBFO with β-CD. The yield values of the inclusion complex and the SBFO loading content are 64.87 ± 2.26% and 9.2 ± 1.58%, respectively. Comparing the crude fruit oil, β-CD–SBFO, and saponified fruit oil reveals differences in their 2,2-diphenyl-1-pycrylhydrazyl and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) antioxidant activities. These findings suggest that the SBFO inclusion complex after β-cyclodextrin is stabilized and is a good antioxidant. This solution improves the inadequacy of the water solution and the instability of the SBFO. This study also implies that β-CD is a cost-effective and straightforward carrier for extending the applications of SBFO as a food or medicinal additive. Practical applications: In this experiment, the SBFO is converted from oil to powder to increase its efficacy as an additive to health and food products.     

Physicochemical and Bioactive Compounds of ‘Cantaloupe’ Melon: Effect of Ozone Processing on Pulp and Seeds

Melon seeds are an important source of bioactive compounds, which are considered to be health beneficial. Therefore, the objective of this work was to assess the impact of gaseous ozone treatments (30 and 60 min) on melon seeds paste (nonedible part) and compare with the effect on pulp (edible part). Ozone treatments were evaluated in terms of physicochemical (color, pH, and soluble solids content) and nutritional profiles (total phenolics, total carotenoids, and total antioxidant capacity) of processed material. Results indicate that ozone has a different impact on the two fruit matrices, being seeds less affected by this preservation treatment.     

Synthesis,Characterization, and Antibacterial Activity of Polyindole/Ag–Cuo Nanocomposites by Reflux Condensation Method

Polyindole-based silver and copper oxide (polyindole/Ag–CuO) nanocomposites were synthesized using reflux condensation method by varying the concentrations of polyindole and silver nitrate with copper oxide in N₂ atmosphere. They were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques. The SEM images revealed fascinating shapes of CuO nanoparticles. The FTIR and XRD confirmed the functional group transformation and crystalline natures of silver and CuO existed in the nanocomposites. The polyindole/Ag–CuO nanocomposites were examined for antibacterial activity and found to exhibit the antibacterial activity against pathogenic bacteria.     

Synthesis, Characterization and HDS Activity of Carbon-Containing Ni–Mo Sulfide Nano-Spheres

Ni-promoted tetramethylammonium tetrathiomolybdate precursor was prepared by the aqueous solution precipitation method using (NH₄)₂MoS₄, (CH₃)₄NBr and NiCl₂.6H₂O as raw materials. Carbon-containing Ni–Mo sulfide nanospheres, namely Ni/C₁–MoS₂, were obtained by ex situ thermal decomposition of the precursor under N₂ atmosphere. Energy dispersive X-ray spectroscopy (EDS), low temperature N₂ adsorption (BET method), X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques were employed to characterize these as–synthesized sulfide particles. The results showed that the average size of solid Ni–Mo sulfide nanospheres, with surface composition MoNi₀.₄₀S₀.₇₃C₁.₄₃, is 75 nm and the solid structure leads to low surface area of Ni/C₁–MoS₂. In addition, the introduction of methyl chain improved the dispersion of nickel phases and resulted in C/Mo ratio, 1.4. By comparison with catalytic performance of the Ni/MoS₂ catalyst counterpart, Ni/C₁–MoS₂ revealed lower HDS activity but higher direct desulfurization (DDS) selectivity. Lower stacking number of MoS₂ slabs (5 layers) and shorter slabs length of MoS₂ slabs (6 nm) explained higher DDS selectivity satisfactorily. The formation of carbon-containing Ni–Mo sulfide nanospheres was possibly due to surfactant effect of tetramethylammonium cations and the potential measure to increase their surface area was discussed as well in this work.     

Characterization and functionalization by sol–gel route of SiC foams

Ceramic foam materials are commonly used for various applications, including catalyst supports or solar receivers. SiC foams are good candidates for the latter application as solar receivers. Its efficiency is directly related to the geometry, which can be evidenced by X-ray microtomography, and optical properties of the receiver. A promising route to add functionalities with homogenous and adhering oxide coatings onto complex SiC foams in a single step process is proposed. This oxide synthetic process is derived from the Pechini method. Foams are fully impregnated by precursor sols with a controlled viscosity making a thin and totally covering coating.     

Synthesis and Characterization of Carbazole–Fluorene–Silole Copolymers as Efficient Green Light Emitting Diodes

A novel series of soluble polyfluorene–carbazole–silole-containing polymers (PF–Cz–S) were prepared through the Suzuki coupling reaction; and, the chemical structures were characterized by elemental analysis and NMR. Optoelectronic properties including UV absorption, electrochemistry, photoluminescence (PL), and electroluminescence (EL) of the copolymers were investigated. The copolymers exhibit main absorption peaks at 359?nm for solutions and 354?nm for films with combined contributions from the carbazole and fluorene units. Compared with the solution PL, complete PL excitation energy transfer from the wide band gap segment to a narrow band gap silole unit was achieved by film PL even at a lower silole content. The optical band gaps for PF–Cz–S are between 2.68 and 2.78?eV and the HOMO levels are ?5.65?eV, which are contributed by 3,6-carbazole and fluorene blocks. Light-emitting devices fabricated from these polymers display a maximum external quantum efficiency of 0.44?% with an indium–tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) (PEDOT)/PF–Cz–S/CsF/Al configuration whereas an ITO/PEDOT/PCz–F–S/1,3,5-tris(N-phenylbenzimidizol-2-yl)benzene (TPBI)/CsF/Al with TPBI hole-blocking layer device configuration boosts the efficiency to 2.43?%. The TPBI hole-blocking layer largely improved the efficiency of exciton formation from which the highly efficient green EL from the silole units could be displayed.     

Characterization of Aroma-Active Compounds in Iranian cv. Mari Olive Oil by Aroma Extract Dilution Analysis and GC–MS-Olfactometry

Aroma, aroma‐active compounds and fatty acid profiles of Iranian olive oil obtained from the cv. Mari were investigated for the first time in the current study. Aroma extracts were isolated from the oil by using a purge and trap extraction system and their compositions were analyzed by gas chromatography‐mass spectrometry‐olfactometry (GC–MS‐O). A total of 35 aroma compounds comprising alcohols, aldehydes, acids, esters, ketones, terpenes and volatile phenols were identified and quantified in the assayed samples. Aldehydes were present at the highest levels, followed by ketones and alcohols. (E)‐2‐Hexenal was quantitatively (1589 µg kg^?1) the main aroma compound in the analyzed oils, followed by hexanal and (E)‐2‐heptenal. The aroma‐active volatiles were elucidated in the aromatic extract by applying aroma extract dilution analysis (AEDA). The results of AEDA revealed 17 aroma‐active compounds. Under these condition it was possible to completely identify 16 of these compounds. Regarding to the flavor dilution (FD) factor, the most potent odorants with the highest FD factor were (E)‐2‐hexenal (512), followed by hexanal, 6‐methyl‐5‐hepten‐2‐one, (E)‐2‐decenal and one unknown compound (LRI = 1871). The fatty acid profile of the tested oils was composed of thirteen compounds. Oleic acid was the main fatty acid (76.01 %) followed by palmitic acid.     

Synthesis and Characterization of pH-Responsive Organic–Inorganic Hybrid Material with Excellent Catalytic Activity

Poly(N-isopropylmethacrylamide-co-methacrylic acid) [p(NipAam-Mac)] microgels were synthesized and used as microreactors to fabricate silver nanoparticles. Pure and hybrid microgels were characterized using Ultraviolet–Visible (UV/Vis) spectroscopy, Fourier transform infra-red (FTIR) spectroscopy and transmission electron microscopy (TEM). Catalytic activity of hybrid microgels and mechanism of catalysis by this system was explored using different reaction conditions. At the same temperature, apparent rate constant (k_app) was found to be varied from 0.0414 to 0.7852 min^?1 by increasing the concentration of NaBH₄ from 2.49 to 22.41 mM at constant concentration of substrate and catalyst. However upon extra increase in concentration of NaBH₄ from 22.41 to 37.35 mM reduced the value of k_app to 0.2178 min^?1. Likewise, the value of k_app was found to be increased from 0.1242 to 0.5495 min^?1 with increasing the concentration of 4-nitrophenol [Para-nitrophenol (p-Np)] from 0.063 to 0.079 mM keeping other parameters constant. Further increase in concentration of p-Np caused decline in the value of k_app. Kinetic data reveals that catalytic reduction of p-Np obeys Langmuir–Hinshelwood mechanism and p-Np is converted to p-Ap on the surface of the silver nanoparticles passing through various reaction intermediates.     

Structure–Activity Relationship of Inhibition of Fish Feeding by Sponge-derived and Synthetic Pyrrole–Imidazole Alkaloids

We investigated the relationship between the structures of pyrrole-containing alkaloids from marine sponges of the genus Agelas and their capacity to deter feeding by the omnivorous Caribbean reef fish, Thalassoma bifasciatum. Seven natural products were assayed at volumetric concentrations of 1, 5, and 10 mg/ml: dispacamide A, keramadine, oroidin, midpacamide, 4,5-dibromopyrrole-2-carboxylic acid, 4,5-dibromopyrrole-2carboxamide, and racemic longamide A. We also assayed 14 structural analogs obtained mostly by chemical synthesis. Of the seven natural products, only rac-longamide A was not significantly deterrent at any of the assay concentrations. The pyrrole moiety was required for feeding inhibition activity, while the addition of the imidazole group enhanced this activity. Variously functionalized imidazoles lacking the pyrrole moiety were not deterrent. Combinations of the natural products appeared to have an additive effect on feeding inhibition; there was no evidence of synergy. Given their high concentrations in sponge tissue, dispacamide A and oroidin most probably serve as the primary chemical defenses of many Agelas sp., while minor compounds such as keramadine are not present in high enough concentrations to contribute much to chemical defense.     

Agronomical Parameters,Sugar Profile and Antioxidant Compounds of “Catherine” Peach Cultivar Influenced by Different Plum Rootstocks

The influence of seven plum rootstocks (Adesoto, Monpol, Montizo, Puebla de Soto 67 AD, PM 105 AD, St. Julien GF 655/2 and Constantí 1) on individual and total sugars, as well as on antioxidant content in fruit flesh of “Catherine” peaches, was evaluated for three years. Agronomical and basic fruit quality parameters were also determined. At twelve years after budding, significant differences were found between rootstocks for the different agronomic and fruit quality traits evaluated. The Pollizo plum rootstocks Adesoto and PM 105 AD seem to induce higher sweetness to peach fruits, based on soluble solids content, individual (sucrose, fructose and sorbitol) and total sugars. A clear tendency was also observed with the rootstock Adesoto, inducing the highest content of phenolics, flavonoids, vitamin C and relative antioxidant capacity (RAC). Thus, the results of this study demonstrate the significant effect of rootstock on the sugar profile and phytochemical characteristics of peach fruits. In addition, this work shows the importance of the sugar profile, because specific sugars play an important role in peach flavour quality, as well as the studied phytochemical compounds when looking for high quality peaches with enhanced health properties.     

Synthesis and Digestibility Inhibition of Diarylheptanoids: Structure–Activity Relationship

(±)-5-Hydroxy-1,7-bis-(4-hydroxyphenyl)-3-heptanone (2a), (±)-5-hydroxyl-1-(4-hydroxyphenyl)-7-phenyl-3-heptanone (2b), (±)-5-hydroxy-7-(4-hydroxyphenyl)-1-phenyl-3-heptanone (2c), and (±)-5-hydroxy-1,7-bis-(phenyl)-3-heptanone (2d) have been synthesized to study the structure–activity relationship regarding digestibility inhibition in vitro in cow rumen fluid. The activities were compared with the activity of chiral (S)-2a and its glucoside platyphylloside (1), isolated from Betula pendula. Compound 2a was slightly less active, 2b and 2c were more active, and 2d was less active than (S)-2a and platyphylloside.     

Characterization and reactivity of VMgO catalysts prepared by wet impregnation and sol–gel methods

This paper reports the study of physicochemical, surface, and catalytic properties of two series of VMgO catalysts prepared by two different methods: wet impregnation and sol–gel. The characterizations of the elaborated materials were performed using N₂-sorption (Brunauer, Emmett and Teller (BET)), X-ray diffraction, Raman, transmission electron microscopy–energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analyses. The catalytic properties of the elaborated materials were investigated in the isopropanol decomposition reaction to determine their acid–base character and in the selective oxidation of n-butane to evaluate their dehydrogenation properties. The preparation method and vanadium content strongly affected the properties of our materials. The sol–gel method leads to smaller crystallite size, higher specific surface area, and uniform particle distribution compared to the impregnation one. Both impregnation and SG solids promote the formation of acetone, which is related to the presence of strong basic sites (O^2? species) on the catalytic exposed surface. The more pronounced basic character was obtained through the SG samples. The sol–gel samples exhibited the highest catalytic activity and C4-olefin selectivity in the partial oxidation of n-butane. Whatever the preparation procedure, the nature of surface oxygen species plays an important role in the orientation of catalytic performances.     

Synthesis and Characterization of Catalytically Activity Fe3o4–3-Aminopropyl-triethoxysilane/Pd Nanocomposite

Herein we report the fabrication and characterization of Pd decorated Fe₃O₄ nanoparticles as highly effective catalysts for hydrogenation of 4-nitroaniline and 1,3-dinitrobenzene in liquid phase. The fabricated Fe₃O₄ nanoparticles exhibit an average size of 12 nm and super paramagnetic character with a high saturation magnetization (80 emu/g). The surface –NH₂ groups effectively binds the in situ formed Pd nanoparticles. Thus formed Fe₃O₄–APTES–Pd(0) catalyst showed a very high catalytic activity in reduction reactions of 4-nitroaniline and 1,3-dinitrobenzene in liquid phase. Electron donor –NH₂ groups supported Pd may be responsible for the increased catalytic activity. The superparamagnetic character of this system allows easy recovery and multiple uses without significant loss of its catalytic activity.     

Gas-Wall Partitioning of Oxygenated Organic Compounds: Measurements,Structure–Activity Relationships,and Correlation with Gas Chromatographic Retention Factor

Gas-wall partitioning of 50 oxygenated organic compounds was investigated by using gas chromatography to monitor time-dependent gas-phase concentrations of authentic standards added to a large Teflon environmental chamber. Compounds included C₈–C₁₄ monofunctional ketones and alcohols, C₅–C₉ monoacids, and C₄–C₁₀ diols with linear and cyclic structures. Measured time constants for reaching gas-wall partitioning equilibrium ranged from ～10 to 100 min with an average value of ～30 min and exhibited no obvious trend with compound structure, whereas the extent of equilibrium partitioning to the walls ranged from ～0 to 100% and increased with increasing carbon number and with functional group composition in the order ketones < alcohols < monoacids < diols. When results were modeled using an approach analogous to one commonly used to describe absorptive gas-particle partitioning in terms of compound vapor pressure and aerosol mass loading it was determined that the absorptive properties of the Teflon film walls were equivalent to 2–36 mg m^?3 of liquid organic aerosol particles. These results, when combined with those obtained in previous studies, indicate that most multifunctional products formed from the oxidation of atmospherically important hydrocarbons including isoprene, monoterpenes, aromatics, and alkanes have the potential to undergo significant partitioning to the walls of Teflon chambers and thus be lost from further chemical reaction and secondary organic aerosol formation as well as from gas and particle analyses. Two approaches for estimating equilibrium gas-wall partitioning in such studies are presented: one is a structure–activity relationship based on the absorptive gas-wall partitioning model and the other involves the use of observed correlations between gas-wall partitioning and compound retention on a gas chromatographic column.

Copyright 2015 American Association for Aerosol Research     

Alkanol-Induced Micelles of a Very Hydrophilic EO–PO–EO Block Copolymer: Characterization by Spectral and Scattering Methods

The aqueous solution behavior of a PEO–PPO–PEO block copolymer (EO₁₀₃PO₃₉EO₁₀₃), was investigated in the presence of aliphatic alkanols (C₂, C₄, C₆ and C₈). The non-associated polymer chains remain extremely hydrated in water, but aggregation in the form of spherical micelles was evidenced, triggered by the interaction of polymer chains with hydrophobic alkanol. We assume that the hydrophobic interaction between the PPO block of the copolymer and alkanol promotes micellization, which increases further with the introduction of higher chain length species. The critical micellization temperature (CMT), as measured by UV–visible spectroscopy, indicates an interaction of polymer chains with the alkanol bearing a higher chain length, which triggers aggregation. The micelles were characterized by small angle neutron scattering to elucidate the size and related micellar parameters. The gradual increase in the alkanol content increases the aggregation number, though the micelles were spherical in shape. We conclude that ethanol, due to its preferential solubility in the aqueous phase, does not affect the aggregation. The alkanols with chain lengths of C₄–C₈ chain, interact with the PPO block through hydrophobic interaction and shifts the CMTs to lower values. The combined effect of inorganic salt (NaCl) and alkanols show enhanced micellar properties.     

Characterization of fracture energy and toughness of air plasma PDMS–PDMS bonding by T-peel testing

The fracture energy, toughness and failure modes of air plasma oxidized polydimethylsiloxane (PDMS) bonding are evaluated in this paper. Each PDMS–PDMS bonded specimen was subjected to T-peel testing at a constant-displacement rate. The load–extension curve from each test was analyzed by the principle of energy balance in linearly elastic fracture mechanics, to calculate the fracture energy (critical strain energy), which is the maximal strain energy a bonded specimen can withstand without losing its assembly integrity, and toughness (surface energy), which is the bonding energy at the interface. A distribution of calculated values against the air plasma treatment parameters shows the predominant range of 0.1 to 0.4 N/mm for fracture energy and 0.1 to 0.2 N/mm for toughness. Together with an analysis of three failure modes (cohesive, adhesive, and mixed), the results suggest 0.1 N/mm as the threshold of the fracture energy for weak bonding, below which a specimen will be likely to fail through debonding. A set of treatment parameters are recommended for using air plasma to achieve strong bonding.