Abstract  A panel of lipases was screened for the selective acetylation and alcoholysis of silychristin and silychristin peracetate, respectively. Acetylation at primary alcoholic group (C-22) of silychristin was accomplished by lipase PS (Pseudomonas cepacia) immobilized on diatomite using vinyl acetate as an acetyl donor, whereas selective deacetylation of 22-O-acetyl silychristin was accomplished by Novozym 435 in methyl tert-butyl ether/ n-butanol. Both of these reactions occurred without diastereomeric discrimination of silychristin A and B. Both of these enzymes were found to be capable to regioselective deacetylation of hexaacetyl silychristin to afford penta-, tetra- and tri-acetyl derivatives, which could be obtained as pure synthons for further selective modifications of the parent molecule.

Abstract  A strategy for the mild deprotection of alkyl-thiolated (6-mercaptohexanoic acid, MHA, and 3-mercaptopropanoic acid, MPA) gold nanoclusters (Au NCs) supported on hydroxyapatite (HAP) has been developed by employing a peroxide (tert-butyl hydroperoxide, TBHP, or hydrogen peroxide, H2O2) as an oxidant. The thiol ligands on the supported Au NCs were removed after oxidation, and the size and integrity of the supported clusters were well-preserved. The bare gold clusters on HAP after removal of the ligands were catalytically effective for the epoxidation of styrene and the aerobic oxidation of benzyl alcohol. These two reactions were also investigated on calcined Au NCs that were supported on HAP for comparison, and the resulting Au NCs that were prepared by using this new strategy showed superior catalytic activity.

Abstract  Cooperative catalysis between Cu(II) and redox-active organic cocatalysts is a key feature of important chemical and enzymatic aerobic oxidation reactions, such as alcohol oxidation mediated by Cu/TEMPO and galactose oxidase. Nearly 20 years ago, Markó and co-workers reported that azodicarboxylates, such as di-tert-butyl azodicarboxylate (DBAD), are effective redox-active cocatalysts in Cu-catalyzed aerobic alcohol oxidation reactions [Markó, I. E., et al. Science 1996, 274, 2044], but the nature of the cooperativity between Cu and azodicarboxylates is not well understood. Here, we report a mechanistic study of Cu/DBAD-catalyzed aerobic alcohol oxidation. In situ infrared spectroscopic studies reveal a burst of product formation prior to steady-state catalysis, and gas-uptake measurements show that no O2 is consumed during the burst. Kinetic studies reveal that the anaerobic burst and steady-state turnover have different rate laws. The steady-state rate does not depend on [O2] or [DBAD]. These results, together with other EPR and in situ IR spectroscopic and kinetic isotope effect studies, reveal that the steady-state mechanism consists of two interdependent catalytic cycles that operate in sequence: a fast Cu(II)/DBAD pathway, in which DBAD serves as the oxidant, and a slow Cu(II)-only pathway, in which Cu(II) is the oxidant. This study provides significant insight into the redox cooperativity, or lack thereof, between Cu and redox-active organic cocatalysts in aerobic oxidation reactions.

Abstract  BACKGROUND: Our previous study suggested that licorice has anti-inflammatory activity in lipopolysaccharide-stimulated microglial cells and anti-oxidative activity in tert-butyl hydroperoxide-induced oxidative liver damage. In this study, we evaluated the effect of licorice on chronic alcohol-induced fatty liver injury mediated by inflammation and oxidative stress.

METHODS: Raw licorice was extracted, and quantitative and qualitative analysis of its components was performed by using LC-MS/MS. Mice were fed a liquid alcohol diet with or without licorice for 4 weeks.

RESULTS: We have standardized 70% fermented ethanol extracted licorice and confirmed by LC-MS/MS as glycyrrhizic acid (GA), 15.77 ± 0.34 μg/mg; liquiritin (LQ), 14.55 ± 0.42 μg/mg; and liquiritigenin (LG), 1.34 ± 0.02 μg/mg, respectively. Alcohol consumption increased serum alanine aminotransferase and aspartate aminotransferase activities and the levels of triglycerides and tumor necrosis factor (TNF)-α. Lipid accumulation in the liver was also markedly induced, whereas the glutathione level was reduced. All these alcohol-induced changes were effectively inhibited by licorice treatment. In particular, the hepatic glutathione level was restored and alcohol-induced TNF-α production was significantly inhibited by licorice.

CONCLUSION: Taken together, our data suggests that protective effect of licorice against alcohol-induced liver injury may be attributed to its anti-inflammatory activity and enhancement of antioxidant defense.

Abstract  Reducing expression or inhibiting translocation of protein kinase C epsilon (PKCε) prolongs ethanol intoxication and decreases ethanol consumption in mice. However, we do not know if this phenotype is due to reduced PKCε kinase activity or to impairment of kinase-independent functions. In this study, we used a chemical-genetic strategy to determine whether a potent and highly selective inhibitor of PKCε catalytic activity reduces ethanol consumption. We generated ATP analog-specific PKCε (AS-PKCε) knock-in mice harboring a point mutation in the ATP binding site of PKCε that renders the mutant kinase highly sensitive to inhibition by 1-tert-butyl-3-naphthalen-1-ylpyrazolo[3,4-d]pyrimidin-4-amine (1-NA-PP1). Systemically administered 1-NA-PP1 readily crossed the blood brain barrier and inhibited PKCε-mediated phosphorylation. 1-NA-PP1 reversibly reduced ethanol consumption by AS-PKCε mice but not by wild type mice lacking the AS-PKCε mutation. These results support the development of inhibitors of PKCε catalytic activity as a strategy to reduce ethanol consumption, and they demonstrate that the AS- PKCε mouse is a useful tool to study the role of PKCε in behavior.

Abstract  Reactions of amine-bridged bis(phenolate) protio-ligands N,N-bis(3,5-di-tert-butyl-2-hydroxybenzyl)aminoacetic acid (L(1)-H3) and N,N-bis[3,5-bis(α,α'-dimethylbenzyl)-2-hydroxybenzyl]aminoacetic acid (L(2)-H3), with 1 equiv. M[N(SiMe3)2]3 (M = La, Nd, Sm, Gd, Y) in THF at room temperature yielded the neutral rare-earth complexes [M2(L)2(THF)4] (L = L(1), M = La (), Nd (), Sm (), Gd (), Y (); L = L(2), M = La (), Nd (), Sm (), Gd (), Y ()). All of these complexes were characterized by single-crystal X-ray diffraction, elemental analysis and in the case of yttrium and lanthanum complexes, (1)H NMR spectroscopy. The molecular structure of revealed dinuclear species in which the eight-coordinate lanthanum centers were bonded to two oxygen atoms of two THF molecules, to three oxygen atoms and one nitrogen atom of one L(1) ligand, and two oxygen atoms of the carboxyl group of another. Complexes were also dinuclear species containing seven-coordinate metal centers similar to , albeit with bonding to one rather than two carboxyl group oxygens of another ligand. Further treatment of with excess benzyl alcohol provided dinuclear complex [La2(L(1))2(BnOH)6] (), in which each lanthanum ion is eight-coordinate, bonded to three oxygen atoms and one nitrogen atom of one ligand, three oxygen atoms of three BnOH molecules, as well as one oxygen atom of bridging carboxyl group of the other ligand. In the presence of BnOH, complexes efficiently catalyzed the ring-opening polymerization of l-lactide in a controlled manner and gave polymers with relatively narrow molecular weight distributions. The kinetic and mechanistic studies associated with the ROP of l-lactide using /BnOH initiating system have been performed.

Abstract  BACKGROUND: Strongyloidiasis is a parasitic disease widely present in tropical and subtropical areas. Strongyloides stercoralis represents the main species that infects human beings. Ivermectin is the current drug of choice; however, issues related with treatment failure in patients with diabetes or infected with T-lymphotropic virus-1 make the identification of new molecules for alternative treatment a priority. In the present study, the activity of sphingosine-related aminoalcohol and diamine were evaluated against Strongyloides venezuelensis third-stage larva (L3) cultures and experimental infections in mice.

METHODS: The efficacy of each compound against L3 was assessed using both XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay and microscopic observation with concentrations ranging from 1 to 350 μM. Cytotoxicity was evaluated using J774.2 macrophage cell line and XTT assay. Lethal concentration 50 (LC50), selectivity index (SI) and structure-activity relationships were established. The activity compounds 4 (2-(ethylamino) hexadecan-1-ol), 6 (2-(butylamino) hexadecan-1-ol), 17 (tert-butyl N-(1-aminododecan-2-yl) carbamate) and 18 (tert-butyl N-(1-aminohexadecan-2-yl) carbamate) were further assessed against experimental S. venezuelensis infections in CD1 mice measuring reductions in the numbers of parthenogenetic females and egg passed in faeces. Mice were infected with 3,000 L3 and treated with 20 mg/kg/day for five days.

RESULTS: In the screening study of 15 aminoalcohols [lauryl (n = 9); palmityl (n = 13); stearyl (n = 15) and alcohol derivatives], the presence of a palmitol chain was associated with the highest efficacy against L3 (LC50 31.9-39.1 μM). Alkylation of the 2-amino group with medium size fragments as ethyl or n-butyl showed the best larvicidal activity. The dialkylation did not improve efficacy. Aminoalcohols 4 and 6 showed the highest SI (1.5 and 1.6, respectively). With respect to diamine derivative compounds, a chain size of sixteen carbon atoms (palmitoyl chain, n = 13), and the alkylation of the 2-amino group with medium-sized fragments, were associated with the highest lethal activities. The presence of carbamoyl group in diamines 17 and 18 yielded high SI (1.7 and 1.4, respectively). Infected mice treated with aminoalcohol 6 showed reduction in parthenogenetic females (59 %) and eggs in faeces (51 %).

CONCLUSIONS: These results support the potentiality of aminoalcohol and diamine sphingosine-related compounds as suitable prototypes for developing new promising drugs against strongyloidiasis.

Abstract  This data article is related to the subject of a publication in Process Biochemistry, entitled "Chloroperoxidase-catalyzed amino alcohol oxidation: Substrate specificity and novel strategy for the synthesis of N-Cbz-3-aminopropanal" (Masdeu et al., 2016) [1]. Here, the products of the chemical reaction involving the amino aldehyde (N-Cbz-3-aminopropanal) and peroxides (tert-butyl hydroperoxide and H2O2) are characterized by NMR. (1)H and (13)C NMR full characterization of the products was obtained based on 2D NMR, 1D selective NOESY and diffusion spectroscopy (DOSY) experiments.

Abstract  Ion-pair interactions between a cationic ruthenium complex, [Ru(dtb)2(dea)][PF6]2, C1(2+) where dea is 4,4'-diethanolamide-2,2'-bipyridine and dtb is 4,4'-di-tert-butyl-2,2'-bipyridine, and chloride, bromide, and iodide are reported. A remarkable result is that a 1:1 iodide:excited-state ion-pair, [C1(2+), I(-)](+*), underwent diffusional electron-transfer oxidation of iodide that did not occur when ion-pairing was absent. The ion-pair equilibrium constants ranged 10(4)-10(6) M(-1) in CH3CN and decreased in the order Cl(-) > Br(-) > I(-). The ion-pairs had longer-lived excited states, were brighter emitters, and stored more free energy than did the non-ion-paired states. The (1)H NMR spectra revealed that the halides formed tight ion-pairs with the amide and alcohol groups of the dea ligand. Electron-transfer reactivity of the ion-paired excited state was not simply due to it being a stronger photooxidant than the non-ion-paired excited state. Instead, work term, ΔGw was the predominant contributor to the driving force for the reaction. Natural bond order calculations provided natural atomic charges that enabled quantification of ΔGw for all the atoms in C1(2+) and [C1(2+), I(-)](+*) presented herein as contour diagrams that show the most favorable electrostatic positions for halide interactions. The results were most consistent with a model wherein the non-ion-paired C1(2+*) excited state traps the halide and prevents its oxidation, but allows for dynamic oxidation of a second iodide ion.

Abstract  Xerogels based on resorcinol-formaldehyde (XRF) doped with different doses of Tris(2,2'-bipyridine) ruthenium(II) (RuBpy) were synthesized and characterized, and their photoactivity was determined in the presence of solar radiation. The addition of RuBpy did not modify the morphological and textural properties of the xerogels, which were all ultramicroporous, with a mean micropore surface of 240 m(2) g(-1); micropore volume of 0.10 cm(3) g(-1), and pore diameter of 0.64 nm. The addition of RuBpy reduced the band gap energy (E-g) values of the xerogels, which were 5.68 eV for XRF and 0.98 eV for XRF doped with 150 mg L-1 of RuBpy (X150RuB), due to the inclusion of RuBpy as charge center. The photocatalytic activity of the doped xerogels in pollutant degradation by solar radiation was analyzed in the photooxidation of chlortetracycline (CTC) as a model pollutant. The degradation percentages of CTC were 35.23% for XRF, 36.17% for X50RuB, 50.16% for X15ORuB, and 31.33% for direct photolysis. The effect of radical scavengers (NO3- and tert-butanol) on the degradation and XPS analysis demonstrated that the hydrated electron (e(aq)(-)) generated by irradiation in the charge centers of the material migrates through the material and interacts with its functional groups, promoting the generation of OH center dot radicals and the reduction and subsequent deactivation of the material. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  This study investigated the activation of periodate (IO4-) by granular activated carbon (GAC) for acid orange 7 (AO7) decolorization at ambient temperature. It was found that there existed a remarkable synergistic effect in the GAC/IO4- system. Some influential parameters, including periodate concentration, GAC dosage, initial solution pH and anions (CI- and CO32-) were examined and analyzed. The results from radical scavenging experiments (with ethanol and tert-butyl alcohol) and electron spin resonance (ESR) analysis revealed that hydroxyl radical ((OH)-O-center dot) made a minor contribution to AO7 decolorization. Furthermore, the increasing formation of iodate (IO3-) as the reaction proceeded in the presence of excessive ethanol indirectly suggested that iodyl radical (IO3 center dot) was likely to be the dominating reactive species that controlling the oxidation process. In the reuse experiments, the efficiencies of AO7 decolorization enhanced surprisingly and remained 100% when the dried-GAC (GAC collected from the former cycle experiment and dried at 105 degrees C for 24 h) was reused for over ten cycles, which indicated that the dried-GAC showed remarkable catalytic ability and sustainable reuse capability. Besides, a series of experiments were conducted to testify the main contributor to the strong enhancement of AO7 decolorization with the dried-GAC. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Abstract  The removal of bisphenol A (BPA) in aqueous solution by an oxidation process involving peroxymonosulfate (PMS) activated by CuFe2O4 magnetic nanoparticles (MNPs) is reported herein. The effects of PMS concentration, CuFe2O4 dosage, initial pH, initial BPA concentration, catalyst addition mode, and anions (Cl(-), F(-), ClO4(-) and H2PO4(-)) on BPA degradation were investigated. Results indicate that nearly complete removal of BPA (50 mg/L) within 60 min and 84.0% TOC removal in 120 min could be achieved at neutral pH by using 0.6 g/L CuFe2O4 MNPs and 0.3 g/L PMS. The generation of reactive radicals (mainly hydroxyl radicals) was confirmed using electron paramagnetic resonance (EPR). Possible mechanisms on the radical generation from CuFe2O4/PMS system are proposed based on the results of radical identification tests and XPS analysis. The lack of inhibition of the reaction by free radical scavengers such as methanol and tert-butyl alcohol suggests that these species may not be generated in the bulk solution, and methylene blue probe experiments confirm that this process does not involve free radical generation. Surface-bound, rather than free radicals generated by a surface catalyzed-redox cycle involving both Fe(III) and Cu(II), are postulated to be responsible for the mineralization of bisphenol A.

Abstract  This study aims to clarify the roles played by endogenous small molecular components in soymilk coagulation process and the properties of gels. Soymilk samples with decreasing levels of small molecules were prepared by ultrafiltration, to reduce the amount of phytate and salts. CaSO4-induced coagulation process was analyzed using rheological methods. Results showed that removal of free small molecules decreased the activation energy of protein coagulation, resulting in accelerated reaction and increased gel strength. However, too fast a reaction led to the drop in storage modulus (G'). Microscopic observation suggested that accelerated coagulation generated a coarse and non-uniform gel network with large pores. This network could not hold much water, leading to serious syneresis. Endogenous small molecules in soymilk were vital in the fine gel structure. Coagulation rate could be controlled by adjusting the amount of small molecules to obtain tofu products with the optimal texture.

Abstract  Cesium exchanged tungstophosphoric acid (CsTPA) supported on tin oxide catalysts were prepared and their physio-chemical properties were derived from X-ray diffraction, FT-IR, laser Raman spectroscopy and temperature programmed desorption of NH3. The catalysts activity was evaluated for etherification of glycerol with tert-butanol. The characterization results of the catalysts revealed that the primary Keggin structure remained intact during the exchange of TPA protons with Cs+ ions. The activity results showed that etherification activity depended on the amount of the CsTPA over SnO2 and the catalyst with 20 wt% CsTPA supported on SnO2 showed high catalytic activity with 90% glycerol conversion with 44% selectivity toward higher ethers. The activity of the catalyst depends on amount of surface acidic sites and dispersion amount of CsTPA over SnO2. The etherification reaction was carried at different reaction parameters and optimum reaction conditions were established. The catalysts were recyclable and showed constant activity up on reuse. (C) 2015 Elsevier B.V. All rights reserved.

Abstract  In the present study, a new lipase SL-4 from Burkholderia ubonensis SL-4, was purified by 80% ammonium sulphate precipitation, Q Sepharose FF anion exchange and Superdex 75 gel filtration chromatography finally leading to 68.5-fold purification and 13.34% recovery. It had a molecular mass of ca. 33 kDa and the whole gene (1095-bp) was cloned by using degenerate primers. Amino acid sequence analysis revealed that lipase SL-4 is a new member of subfamily 1.2 lipases. Lipase SL-4 exhibited optimum activity toward p-NP myristate (C14) at pH 8.5 and 65 degrees C with a K-m of 0.72 mM, a k(cat) of 391.63 s(-1) and a k(cat)/K-m of 543.93 s(-1) mM(-1). It had good thermostability at 50 degrees C and pH 8.5, and could be activated strongly by Ca2+ and Mn2+, but inhibited by some transition metal ions and EDTA, PMSF, DTT and beta-ME. Additionally, lipase SL-4 possessed non-ionic detergent stability and organic solvent stability. When preliminarily employed to catalyze soybean oil for biodiesel production, the liquid lipase SL-4 could attain a conversion ratio of 92.24% in a solvent-free system. These results demonstrate that the new thermo-solvent-stable lipase possesses an attractive potential for biotechnological applications as biocatalyst, especially for biodiesel production. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  The vapor phase isopropylation of 2-naphthol (2-NP) with isopropyl alcohol (IPA) in the presence of recently developed mesoporous silicoaluminophosphate assembled from a microporous SAPO-37 precursor (MESO-SAPO-37) was investigated. The bond dissociation energy calculation revealed that the reaction proceeds by O-alkylation followed by rearrangment into C-alkylated products. The presence of a phenolic hydroxyl group facilitates o- and p-directing (1- and 6-positions of 2-NP) and favors 1- and 6-isopropyl-2-naphthols as the major products. The moderately acidic MESO-SAPO-37 showed a maximum 2-NP conversion of 60% achieved with a selectivity of 60% for 6-isopropyl-2-naphthol (6-IP-2-NP) under optimum reaction conditions (T = 250 degrees C, WHSV = 9.4 h(-1) and a 2-NP: IPA ratio of 1: 20).

Abstract  Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures--while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields.

Abstract  The anomalous behavior of aqueous solutions of amphiphiles in the water-rich region is analyzed via a phenomenological approach that utilizes the isobaric heat capacity C-p as an experimental probe. We report extensive data for solutions of 14 amphiphiles as a function of temperature at atmospheric pressure. Beyond that, C-p data but also isobaric thermal expansivities and isothermal compressibilities for three solutions of tert- butanol as a function of both temperature and pressure are presented. Results rule out the possibility that the observed phenomenology is associated with the anomalous thermodynamics of pure water. Indeed, our C-p data, quantitatively consistent with recent spectroscopic analyses, suggest that water-mediated interactions between the nonpolar parts of amphiphiles are at the origin of anomalies, with the effects of such ""hydrophobic aggregation"" being observed at mole fractions as small as 0.01. Physicochemical details like the size, the electronic charge distribution and the geometry of amphiphile molecules as well as third-order derivatives of the Gibbs energy and the associated Koga lines support the above claims while they further contribute to characterizing the role of hydrophobicity in these phenomena. Progress with a view to gain a deeper, more concrete understanding remains. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  A photocatalytic system involving visible light and BiVO4 (Vis/BiVO4) in the presence of peroxymonosulfate (PMS) has been developed to oxidize the target pollutant Rhodamine B (RhB) in aqueous solution. It was found that PMS could enhance the photocatalytic efficiency of BiVO4 and could be activated to promote the removal of RhB with sulfate radicals, hydroxyl radicals and superoxide radicals. Critical impacting factors in the Vis/BiVO4/PMS system were investigated concerning the influence of PMS concentration, solution pH, catalyst dosage, initial concentration of RhB and the presence of anions (Cl- and CO32-). In addition, by using isopropanol, tert-butanol, 1,4-benzoquinone and ethylenediamine tetraacetic acid disodium salt as probe compounds, the main active species were demonstrated including (SO4-)-S-center dot, (OH)-O-center dot and O-center dot(2)- in the system, and a detail photocatalytic mechanism for the Vis/BiVO4/PMS system was proposed. Finally, up to 10 intermediate products of RhB were identified by GC/MS, included benzenoid organic compounds, organic acids and three nitrogenous organic compounds. This study provides a feasible way to degrade organic pollutants in wastewater using BiVO4 with PMS under visible light. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  MCM-41 nanoporous silicas show a very high selectivity for monoalcohols over aprotic molecules during adsorption of a binary mixture in the gas phase. We present here an original use of gravimetric vapour sorption isotherms to characterize the role played by the alcohol hydrogen-bonding network in the adsorption process. Beyond simple selectivity, vapour sorption isotherms measured for various compositions help to completely unravel at the molecular level the step by step adsorption mechanism of the binary system in the nanoporous solid, from the first monolayers to the complete liquid condensation.

Abstract  Removal of Diethyl phthalate (DEP) from water has been accomplished through catalytic ozonation promoted by TiO2 and Al2O3. A laboratory setup was designed to evaluate and select the optimal oxidation process. The degradation rate is strongly dependant on the pH, initial concentrations of the phthalate, catalyst dosage, and O-3 dosage. The effect of these parameters has been studied. Results show that the addition of Al2O3 was effective to achieve almost 95% degradation of DEP in about 30min using 2g L-1 as compared to over 50min with TiO2. It was also found that radical reactions were the main mechanism by which DEP was degraded and adsorption has a small contribution to the removal of DEP by O-3/TiO2 and Al2O3 processes. Indeed, after 60min, adsorption alone achieved only about 12.5 and 15.5% removal, respectively, in the presence of TiO2 and Al2O3. Under same conditions, the kinetics of degradation was found to follow first-order reaction rules for both systems. After 1h treatment, the rate constant of DEP removal were 0.0093 and 0.053min(-1) using O-3/AlO3 and O-3/TiO2 processes, respectively. The O-3/Al2O3 system proved to be the most efficient and occurs at a much higher oxidation rate than O-3/TiO2 system and allows achieving 100% degradation of DEP (100 mg L-1) in 25min of reaction time. The notable decrease of DEP removal rate observed in the presence of radical scavenger tert-butanol indicates that the reaction between DEP and OH center dot proceeds mainly in the bulk of the aqueous phase. The results of the study showed that O- 3/TiO2 and O-3/Al2O3 systems were effective and economic treatment processes for DEP under neutral conditions by producing higher mineralization efficiency in a relatively short ozonation time compared to ozone alone process.

Abstract  The corn oil extracted from distillers dried grains with solubles (DDGS), which has a high acid value of 41.6 mg KOH/g and a high water content of 4.5%, is used to produce biodiesel in this article. The transesterification of dimethyl carbonate (DMC) and DDGS-extracted corn oil was studied at the catalysis of Novozym 435. Meanwhile, several water removal agents, which include acrylic super absorbent resin (SAP), 4A-molecular sieve, blue silica-gel and tert-butanol, were added to absorb the water during the reaction. The yield of fatty acid methyl esters (FAMEs) was analyzed by GC with internal standard method. The effect of different reaction conditions (type of water absorbent, molar ratio of DMC to oil, reaction time and temperature, lipase and SAP amount) on the yield of FAMEs were also discussed. Then the highest yield of FAMEs could reach 91.0% at 60 degrees C for 18 h with molar ratio of DMC to oil 15:1, Novozym 435 amount of 20 wt% and SAP amount of 10 wt% (based on the oil mass). Finally, Novozym 435/SAP showed excellent operational stability without losing any catalytic activity after 8 cycles of repeated use, and the water absorbed by Novozym 435/SAP can be dried at mild temperature (60 degrees C). Because it is easy to be recycled, the Novozym 435/SAP has a great potential to be used in the continuous biodiesel apparatus such as the fixed bed reactor. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract  Thermodynamically stable nanophases have been confirmed as an important technical means of nano-synthesis. In this work, CdS nanosheets with a thickness of 10 nm were confirmed as a new thermodynamically stable phase under hydrothermal conditions in a 4 M KOH-tert-butanol solution at 180 degrees C. The thermodynamically stable phase of CdS varied with the KOH concentration in the system, but the morphology of the nanosheets was independent of the size of the CdS precursor (3 nm, 9 nm, or bulk). The thermodynamically stable nanosheets were consistent with the negative effective interfacial free energy of the CdS (001) face of the wurtzite structure. Further research showed the microprocess of transformation into nanosheets from bulk CdS. The new thermodynamically stable nanostructures open up possibilities for industrial mass production of nanomaterials and green synthesis.

Abstract  We describe the fabrication of crystalline electrically conducting antimony-doped tin oxide (ATO) nanoparticles highly dispersible in polar solvents such as water and ethanol without any stabilizing agents. Nonagglomerated monodisperse ATO nanoparticles with different doping levels are obtained by a facile solvothermal reaction in tert-butanol, leading to the formation of monodisperse nanocrystals with a size of about 3 nm directly after synthesis. Electrical conductivity of ATO nanoparticles strongly increases due to the substitutional doping with antimony, reaching 6.8 x 10(-2) S cm(-1) for the as-synthesized nanoparticles prepared with 35 mol % Sb. This increase stems from transition from hopping in the undoped samples to band-like conduction in the doped samples as revealed by terahertz (THz) spectroscopy measurements describing transport on nanometer distances. The dc conductivity of the doped nanoparticles increases by about 3 orders of magnitude up to 62 S cm(-1) after annealing in air at 500 degrees C. The electrical conductivity, crystallinity, small size, and high dispersibility in polar solvents make the obtained ATO nanoparticles promising building blocks for the direct assembly of more complex conducting architectures using polymer templates that could be damaged in organic solvents. We illustrate the benefits of the water-dispersible ATO nanoparticles by their assembly to periodic macroporous electrodes using poly(methyl methacrylate) (PMMA) beads as the porosity templates. Aqueous dispersion of ATO nanoparticles can be directly combined with PMMA beads that are easily removed by calcination, enabling a facile deposition of 3D-macroporous ATO electrodes featuring optical transparency and a large periodically ordered conducting interface.

Abstract  Three technical lignins (Asian lignin (AL), Organosolv lignin (OL), and Inbicon lignin (IL)) were selectively degraded to alkylated phenols (AP) over Pt/C, Pd/C, Ru/C, and Ni/C in supercritical t-BuOH. AP and other phenolics present in the lignin depolymerized oil fraction (lignin oil) were subjected to several chemical analyses. GC/MS analysis showed AL yielded a maximum of 1.40 wt% of 4-ethylphenol and 4-ethylguaiacol, while OL produced 1.89, 1.11, and 1.43 wt% of syringol, 4-methylsyringol and 4-propylsyringol, respectively under Pt/C condition. Relatively small amounts of AP were obtained from IL because it contained not only lignin moiety but also carbohydrate, ash, and other components. Meanwhile, the average molecular weights (M-w) of the lignin-oils were significantly lower than those of the lignins, clear evidence of lignin depolymerization. Moreover, elemental analysis indicated hydrodeoxygenation mainly occurred during lignin depolymerization. With increasing catalyst amount (Pt/C), total monomeric phenol yields decreased due to side reaction, but some kind of AP such as 4-ethylphenol and 4-ethylguaiacol showed increase trend with increasing catalyst amount. (C) 2014 Elsevier B.V. All rights reserved.