Journal of Chemistry The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Synthesis and Storage Stability of Diisopropylfluorophosphate Thu, 26 May 2016 14:06:31 +0000 Diisopropylfluorophosphate (DFP) is a potent acetylcholinesterase inhibitor commonly used in toxicological studies as an organophosphorus nerve agent surrogate. However, LD50 values for DFP in the same species can differ widely even within the same laboratory, possibly due to the use of degraded DFP. The objectives here were to identify an efficient synthesis route for high purity DFP and assess the storage stability of both the in-house synthesized and commercial source of DFP at the manufacturer-recommended storage temperature of 4°C, as well as −10°C and −80°C. After 393 days, the commercial DFP stored at 4°C experienced significant degradation, while only minor degradation was observed at −10°C and none was observed at −80°C. DFP prepared using the newly identified synthesis route was significantly more stable, exhibiting only minor degradation at 4°C and none at −10°C or −80°C. The major degradation product was the monoacid derivative diisopropylphosphate, formed via hydrolysis of DFP. It was also found that storing DFP in glass containers may accelerate the degradation process by generating water in situ as hydrolytically generated hydrofluoric acid attacks the silica in the glass. Based on the results here, it is recommended that DFP be stored at or below −10°C, preferably in air-tight, nonglass containers. Derik R. Heiss, Donald W. Zehnder II, David A. Jett, Gennady E. Platoff Jr., David T. Yeung, and Bobby N. Brewer Copyright © 2016 Derik R. Heiss et al. All rights reserved. Synthesis and Characterization of Chloridobis(dimethylglyoximato)4-(2-ferrocenylvinyl)pyridinecobalt(III): A New Heterobinuclear Cobaloxime Wed, 25 May 2016 10:34:23 +0000 The synthesis of a new heterobinuclear cobaloxime with 4-(2-ferrocenylvinyl)pyridine, fcvpy, is reported. The complex [CoCl(dmgH)2(fcvpy)], where dmgH2 is dimethylglyoxime and dmgH is dimethylglyoximato, has been characterized by 1H-NMR, UV-Vis, cyclic voltammetry, and elemental analysis. The cyclic voltammogram of this complex shows a fc/fc+ reversible wave at +0.58 V versus Ag/AgCl, one irreversible wave, = −0.54 V versus Ag/AgCl, assigned to the reduction of Co(III) to Co(II), and two quasireversible processes at −1.02 V and −1.10 V versus Ag/AgCl associated with the reduction of Co(II). The complex showed ferrocene-ligand charge transfer bands at 334 nm and 505 nm. TDDFT/B3LYP/6-31G(d) calculations support this assignation. Sebastián Pizarro, Guillermo Saá, Francisco Gajardo, and Alvaro Delgadillo Copyright © 2016 Sebastián Pizarro et al. All rights reserved. Surface Modification Chemistries of Materials Used in Diagnostic Platforms with Biomolecules Wed, 25 May 2016 08:36:31 +0000 Biomolecules including DNA, protein, and enzymes are of prime importance in biomedical field. There are several reports on the technologies for the detection of these biomolecules on various diagnostic platforms. It is important to note that the performance of the biosensor is highly dependent on the substrate material used and its meticulous modification for particular applications. Therefore, it is critical to understand the principles of a biosensor to identify the correct substrate material and its surface modification chemistry. The imperative surface modification for the attachment of biomolecules without losing their bioactivity is a key to sensitive detection. Therefore, finding of a modification method which gives minimum damage to the surface as well as biomolecule is highly inevitable. Different surface modification technologies are invented according to the type of a substrate used. Surface modification techniques of the materials used as platforms in the fabrication of biosensors are reviewed in this paper. Mukesh Digambar Sonawane and Satish Balasaheb Nimse Copyright © 2016 Mukesh Digambar Sonawane and Satish Balasaheb Nimse. All rights reserved. REE Geochemistry of Euphrates River, Turkey Mon, 23 May 2016 13:17:56 +0000 The study area is located on the Euphrates River at 38°41°32.48′′N–38°14′24.10′′N latitude and 39°56′4.59′′E–39°8°13.41′′E longitude. The Euphrates is the longest river in Western Asia. The lithological units observed from the bottom to the top are Permo-Triassic Keban Metamorphites, Late Cretaceous Kömürhan Ophiolites, Upper Cretaceous Elazığ Magmatic Complex, Middle Eocene Maden Complex and Kırkgeçit Formation, Upper Pliocene and Lower Eocene Seske Formation and Upper Miocene, Pliocene Karabakır and Çaybağı Formations, Palu Formation, and Holocene Euphrates River sediments. The geochemical studies show that 87Sr/86Sr and 143Nd/144Nd isotopic compositions in the Euphrates River bank sediments are 0.7053, 0.7048, and 0.7057 and 0.512654, 0.512836, and 0.512775, respectively. These values indicate mixing of both carbonate-rich shallow marine sediment and felsic-mafic rocks from Elazığ Magmatic Complex into the stream sediments. The positive values (0.35, 3.9, and 2.7) are higher downstream in the studied sediments due to weathering of the mafic volcanic rocks. The chondrite, NAS, and UCC normalized patterns show that the REE compositions of the Euphrates River sediments are higher than chondrite composition but close to NAS and UCC. The river sediments in the tectonic zone and the weathered granodioritic rocks of the Elazığ Magmatic complex affect upstream water compositions. Leyla Kalender and Gamze Aytimur Copyright © 2016 Leyla Kalender and Gamze Aytimur. All rights reserved. Physicochemical and Nutritional Characterization of Starch Isolated from Colocasia antiquorum Cultivated in Oaxaca, Mexico Mon, 23 May 2016 09:26:29 +0000 The physicochemical and nutritional characteristics of Colocasia antiquorum (taro coconut or Chinese taro) starch cultivated in Oaxaca, Mexico, were determined. The granules of Colocasia antiquorum presented a truncated ellipsoidal shape. The chemical composition analysis showed levels of moisture, ash, protein, fat, fiber, and NFE in a dry base of 10.29, 0.18, 2.0, 0.05, 0.01, and 97.76, respectively, as well as amylose and amylopectin contents of 13.05 and 86.95%, respectively. Gelatinization temperatures, onset (), peak (), and final (), were 72.86, 82.91, and 93.05°C, respectively. Solubility, swelling power (SP), and water absorption capacity (WAC) correlate directly with increments in temperature. Transmittance value (% T) for taro coconut was 0.3% and its apparent viscosity ranged from 100 to 150 cp. The nutritional characterization of Colocasia antiquorum’s starch amounted to 97.88% of total starch (TS), while available (AS) and resistant starch (RS) were 93.47 and 3.70%, respectively. Colocasia antiquorum, grown in Oaxaca, Mexico, is an unconventional source of starch with added value due to its potential use as an ingredient in the development of new products or as a substitute for conventional starch sources in industrial processes. Karina Ríos-Ríos, Edith González-Mondragón, Maira Segura-Campos, Mariela Ramírez-Jiménez, Jesús López-Luna, Irma López-Martínez, and David Betancur-Ancona Copyright © 2016 Karina Ríos-Ríos et al. All rights reserved. Hybrid Nanomaterials Based on Iron Oxide Nanoparticles and Mesoporous Silica Nanoparticles: Overcoming Challenges in Current Cancer Treatments Tue, 17 May 2016 14:19:02 +0000 The current approaches used for the treatment of cancer face some clinical limitations such as induction of severe side effects, multidrug resistance (MDR), and low specificity toward metastatic cancer cells. Hybrid nanomaterials hold a great potential to overcome all these challenges. Among hybrid nanoparticles, those based on mesoporous silica and iron oxide nanoparticles (MSNs and IONPs) have gained a privileged place in the biomedical field because of their outstanding properties. There are many studies demonstrating their effectiveness as drug delivery systems, nanoheaters, and imaging contrast agents. This review summarizes the advances related to the utilization of IONPs and MSNs for reducing side effects, overcoming MDR, and inhibiting metastasis. Furthermore, we give a future perspective of the clinical application of these technologies. Merlis P. Alvarez-Berríos, Naisha Sosa-Cintron, Mariel Rodriguez-Lugo, Ridhima Juneja, and Juan L. Vivero-Escoto Copyright © 2016 Merlis P. Alvarez-Berríos et al. All rights reserved. Sulfur Speciation in the Surface Sediments of Lakes from Different Regions, China: Characterization by S K-Edge XANES Spectroscopy Mon, 16 May 2016 06:23:24 +0000 X-ray absorption near edge structure (XANES) spectroscopy affords the opportunity to determine redox status for element S in the aquatic ecosystems. However, there have been relatively few studies of S XANES spectroscopy in the terrestrial aquatic ecosystems. In this study, XANES technology was used to examine changes in S speciation in the sediments collected from Taihu Lake, Qinghai Lake, Dianchi Lake, Caohai Lake, and Hongfeng Lake located in distinct geological background areas of China. The results showed that sedimentary S in Qinghai Lake has a high proportion of sulfate averaged 88.9% due to physical weathering of watershed rocks, while deposited S in Taihu Lake has a high fraction of intermediate S (36.5%), which may be the response of the agricultural nonpoint source pollution in drainage basin. The three lakes located in Southwest China have similar composition characteristics of S species, indicating similar S sources including chemical weathering of carbonate and atmospheric deposition. 60–90% of S compounds in the surface sediments were in the form of sulfate and FeS. In deeper layers, the ratio of FeS2 and the intermediate S significantly increased, suggesting rapid processes of sulfate reduction and sulfide reoxidation with the increasing depths. Wang Jingfu, Chen Jingan, Dai Zhihui, Yang Haiquan, and Ma Chenyan Copyright © 2016 Wang Jingfu et al. All rights reserved. Synthesis of Some Polysubstituted Nicotinonitriles and Derived Pyrido[2,3-d]pyrimidines as In Vitro Cytotoxic and Antimicrobial Candidates Sun, 15 May 2016 08:01:11 +0000 The synthesis of polysubstituted pyridines, in addition to some derived pyrido[2,3-d]pyrimidine ring systems supported with chemotherapeutically active functionalities, is described. They were evaluated for their in vitro cytotoxic effects against three different human tumor cell lines (human colon carcinoma HT29, hepatocellular carcinoma Hep-G2, and Caucasian breast adenocarcinoma MCF7). Nine compounds displayed variable cytotoxic potential, among which alkylthio analogs 33, 34, and 37 emerged as the most active members, being almost twice as active as doxorubicin against the colon carcinoma HT29 cell line. In addition, the same three analogs showed a clear differential cytotoxic profile as they exhibited a marginal inhibitory effect on the growth of the normal nontransformed human foreskin fibroblast Hs27 cell line. Meanwhile, nineteen compounds were able to exhibit significant antibacterial activity against both Gram-positive and Gram-negative bacteria, together with moderate antifungal activities. The pyrido[2,3-d]pyrimidine-2(1H)-thione 30 together with its alkylthio derivatives 33 and 34 stemmed as the most active antimicrobial members being equipotent to ampicillin against S. aureus, E. coli, and P. aeruginosa, together with a noticeable antifungal activity against C. albicans. Compounds 33 and 34 could be considered as a promising template for possible dual antimicrobial-anticancer candidates. Hassan M. Faidallah, Sherif A. F. Rostom, and Khalid A. Khan Copyright © 2016 Hassan M. Faidallah et al. All rights reserved. Determination of Cefoperazone Sodium in Presence of Related Impurities by Improved Classical Least Squares Chemometric Methods: A Comparative Study Wed, 11 May 2016 14:29:56 +0000 A comparative study is established among 4 chemometric models depending on classical least squares (CLS) approach, namely, spectral residual augmented CLS (SRACLS), net analyte processing CLS (NAP-CLS), orthogonal signal correction CLS (OSC-CLS), and direct orthogonal signal correction CLS (DOSC-CLS). The comparison is expressed through analysis of a case study dataset of UV spectral data of Cefoperazone Sodium (CEF) and its two related impurities: in pure powder form and in pharmaceutical dosage form. Four-level three-factor experimental design was established for optimum analysis. The adopted experimental design gave rise to a training set consisting of 16 mixtures (containing different ratios of interfering species). To test the prediction power of the suggested models, an independent test set consisting of 9 mixtures was used. The presented results show the ability of the proposed models to quantify CEF in presence of two related impurities with high accuracy and selectivity (, , , and for SRACLS, NAP-CLS, OSC-CLS, and DOSC-CLS, resp.). Dosage form analysis results were compared statistically to a published HPLC methodology showing insignificant difference in terms of precision and accuracy, indicating the suggested models reliability and their suitability for quality control analysis of drug product. Compared to other models, OSC-CLS and DOSC-CLS models gave more accurate results with lower prediction error for test set samples. Ibrahim A. Naguib and Hany W. Darwish Copyright © 2016 Ibrahim A. Naguib and Hany W. Darwish. All rights reserved. Synthesis, X-Ray Crystal Structures, Biological Evaluation, and Molecular Docking Studies of a Series of Barbiturate Derivatives Wed, 11 May 2016 14:05:46 +0000 A series of barbiturates derivatives synthesized and screened for different set of bioassays are described. The molecular structures of compounds 5a, 5d, and 5f were solved by single-crystal X-ray diffraction techniques. The results of bioassay show that compounds 4a, 4b, 4c, 4d, 4e, 4f, and 4g are potent antioxidants in comparison to the tested standards, butylated hydroxytoluene (BHT), and -acetylcysteine. Compounds 4a–4e () and 4g () were more potent antioxidants than the standard (BHT, ). The enzyme inhibition potential of these compounds was also evaluated, in vitro, against thymidine phosphorylase, -glucosidase, and -glucuronidase enzymes. Compounds 4c, 4h, , 4p, 4q, 5f, and 5m were found to be potent -glucosidase inhibitors and showed more activity than the standard drug acarbose, whereas compounds 4v, and 5h were found to be potent thymidine phosphorylase inhibitors, more active than the standard drug, 7-deazaxanthine. All barbiturates derivatives (4a–4x, 4z, and 5a–5m) were found to be noncytotoxic against human prostate (PC-3), Henrietta Lacks cervical (HeLa) and Michigan Cancer Foundation-7 breast (MCF-7) cancer cell lines, and 3T3 normal fibroblast cell line, except 4y which was cytotoxic against all the cell lines. Assem Barakat, Hazem A. Ghabbour, Abdullah Mohammed Al-Majid, Qurat-ul-ain, Rehan Imad, Kulsoom Javaid, Nimra Naveed Shaikh, Sammer Yousuf, M. Iqbal Choudhary, and Abdul Wadood Copyright © 2016 Assem Barakat et al. All rights reserved. Synthesis of Novel Derivatives of Carbazole-Thiophene, Their Electronic Properties, and Computational Studies Tue, 10 May 2016 16:37:04 +0000 A series of carbazole-thiophene dimers, P1–P9, were synthesized using Suzuki-Miyaura and Ullmann coupling reactions. In P1–P9, carbazole-thiophenes were linked at the N-9 position for different core groups via biphenyl, dimethylbiphenyl, and phenyl. Electronic properties were evaluated by UV-Vis, cyclic voltammogram, and theoretical calculations. Particularly, the effects of conjugation connectivity on photophysical and electrochemical properties, as well as the correlation between carbazole-thiophene and the core, were studied. Carbazole connecting with thiophenes at the 3,6-positions and the phenyl group as a core group leads to increased stabilization of HOMO and LUMO energy levels where the bandgap () is significantly reduced. E. F. Damit, N. Nordin, A. Ariffin, and K. Sulaiman Copyright © 2016 E. F. Damit et al. All rights reserved. Valorization of Wasted Black Tea as a Low-Cost Adsorbent for Nickel and Zinc Removal from Aqueous Solution Tue, 10 May 2016 13:39:49 +0000 Characteristics and efficiency of wasted black tea (WBT) were investigated as a low-cost sorbent in removal of Ni2+ and Zn2+ ions from aqueous solution. Initial findings showed WBT potential to be applied as an effective sorbent due to high concentrations of carbon and calcium and high porosity and availability of functional groups. Sorption dynamics were studied with varying pH, contact time, and adsorbent dose. Maximum percentages of metal ions removal were recorded at pH 5, contact time 250 min, and 20 g/L of adsorbent concentration. Binary metal sorption studies showed that Ni2+ and Zn2+ do not compete with each other for available sorption sites, so the adsorption trend in binary system appears similar to monocomponent metal adsorption. Evaluation of the isotherms confirmed that WBT has high value of adsorption capacity. Sorption data fitted well with both Freundlich and Langmuir models. In the optimum conditions, maximum capacity of WBT could reach up to 90.91 mg-Ni/g adsorbent and 166.67 mg-Zn/g adsorbent. This experiment demonstrated the ability of tea waste as an effective, sustainable, and low-cost adsorbent for removal of the heavy metal ions. Amirhossein Malakahmad, Sandee Tan, and Saba Yavari Copyright © 2016 Amirhossein Malakahmad et al. All rights reserved. Effect of Harvest Year and Altitude on Nutritional and Biometric Characteristics of Blueberry Cultivars Mon, 09 May 2016 16:43:34 +0000 In recent years the consumption of small fruits has increased continuously and knowledge about the more suitable production requirements is essential. This study aims to evaluate the influence of harvest year and altitude on chemical composition of four blueberry cultivars, in order to create rentable opportunities for producers and minimize eventual losses in quality fruits. Dry mass, protein, fat, energy, free sugars, organic acids, and vitamin C contents were determined using HPLC-UV-DAD and spectrophotometric methods. Differences () in the concentrations of free sugars, organic acids, and vitamin C were found among years, while the altitude had no () influence. Citric acid was the main organic acid and fructose the most abundant sugar in blueberries. Fruits of “Ozarkblue” had the highest mass and volume whilst the “Bluecrop” was the cultivar with highest crude protein and fat contents. “Goldtraube” showed the highest content of sucrose and organic acids and “Duke” had the highest content of fructose. Sofia Correia, Berta Gonçalves, Alfredo Aires, Ademar Silva, Luís Ferreira, Rosa Carvalho, Hortense Fernandes, Cândida Freitas, Valdemar Carnide, and Ana Paula Silva Copyright © 2016 Sofia Correia et al. All rights reserved. Ligand Synthesis Catalyst and Complex Metal Ion: Multicomponent Synthesis of 1,3-Bis(4-phenyl-[1,2,3]triazol-1-yl)-propan-2-ol Copper(I) Complex and Application in Copper-Catalyzed Alkyne-Azide Cycloaddition Thu, 05 May 2016 06:57:06 +0000 A new bistriazole copper complex was synthesized by direct treatment of an alkyne, an azide, and CuI as copper salt through in situ ligand formation under a multicomponent reaction process. This complex was analyzed by XPS, TGA, DSC, and SEM techniques and revealed a triangular-shaped morphology, high thermal stability, and catalytic power in CuAAC reactions, requiring only 2.5% mol catalyst to afford 1,2,3-triazoles in good yields which can be reused at least for 4 cycles. María Teresa Ramírez-Palma, Jesús Segura-Arzate, Gustavo López-Téllez, and Erick Cuevas-Yañez Copyright © 2016 María Teresa Ramírez-Palma et al. All rights reserved. Two New 1,1,3,3-Tetramethylguanidinium Halochromates (C5H14N3CrO3X) (X: Cl, F): Efficient Reagents for Oxidation of Organic Substrates under Solvent-Free Conditions and Microwave Irradiation Tue, 03 May 2016 15:46:53 +0000 Two new mild oxidizing agents 1,1,3,3-tetramethylguanidinium fluorochromate (TMGFC) and 1,1,3,3-tetramethylguanidinium chlorochromate (TMGCC) were prepared in high yields by reacting tetramethylguanidine with CrO3 and related acid. These reagents are suitable to oxidize various primary and secondary alcohols and oximes to the corresponding carbonyl compounds under solvent-free conditions and microwave irradiation. Kıvılcım Şendıl, H. Beytiye Özgün, and Ebru Üstün Copyright © 2016 Kıvılcım Şendıl et al. All rights reserved. Ultrasmall, Ligand-Free Ag Nanoparticles with High Antibacterial Activity Prepared by Pulsed Laser Ablation in Liquid Tue, 03 May 2016 10:08:54 +0000 Since ancient times, silver and its compounds have been known to have a broad spectrum of antimicrobial activities for bacteria, fungi, and viruses. Due to the increasing bacterial resistance to classic antibiotics, the investigations of Ag NPs have increased. Herein, we present the preparation of ligand-free Ag NPs with 3 and 20 nm sizes by applying picosecond laser ablation in liquid at 355 and 1065 nm. Our laser processing system allows a high control on particle sizes. The produced nanoparticles were characterized by means of transmission electron microscopy, UV-Vis spectroscopy, and X-ray diffraction. The size effect on the antibacterial activity of Ag NPs was tested against E. coli and S. aureus. The growth curves of bacteria were monitored at 0–5 mg/L of Ag NPs by a multimode microplate reader. The size effects as well as the concentration of Ag NPs on their antibacterial activity are discussed. László Kőrösi, Marina Rodio, Dora Dömötör, Tamás Kovács, Szilvia Papp, Alberto Diaspro, Romuald Intartaglia, and Szabolcs Beke Copyright © 2016 László Kőrösi et al. All rights reserved. α-Amylase and α-Glucosidase Inhibitory Saponins from Polyscias fruticosa Leaves Sat, 30 Apr 2016 10:54:53 +0000 Three bisdesmosidic saponins 3-O-[β-D-glucopyranosyl-(14)-β-D-glucuronopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (1), polyscioside D (2), and 3-O--D-glucopyranosyl-(12)-[β-D-glucopyranosyl-(14)]-β-D- oleanolic acid 28-O-β-D-glucopyranosyl-(12)-β-D-galactopyranosyl ester (3) were isolated from a methanol extract of Polyscias fruticosa (L.) Harms leaves. Compound 1 was obtained as a main constituent and compound 3 was reported for the first time and named as polyscioside I. Saponin 1 inhibited porcine pancreas α-amylase and yeast α-glucosidase activities while 2 and 3 were inactive. Synergistic inhibitory effect on α-amylase was observed from the combination of low concentrations of 1 and acarbose. The findings suggest the use of P. fruticosa and its major saponin 1 for the prevention and treatment of diabetes and its complications. Tran Thi Hong Hanh, Nguyen Hai Dang, and Nguyen Tien Dat Copyright © 2016 Tran Thi Hong Hanh et al. All rights reserved. (+)-CSA Catalyzed Multicomponent Synthesis of 1-[(1,3-Thiazol-2-ylamino)methyl]-2-naphthols and Their Ring-Closure Reaction under Ultrasonic Irradiation Thu, 28 Apr 2016 16:18:59 +0000 New 1-[(1,3-thiazol-2-ylamino)methyl]-2-naphthols were obtained by condensation of 2-aminothiazole, aromatic aldehydes, and 2-naphthol in the presence of (+)-camphor-10-sulfonic acid ((+)-CSA) as an effective catalyst under ultrasound-promoted solvent-free conditions. The 1-[(1,3-thiazol-2-ylamino)methyl]-2-naphthol derivatives were converted in ring-closure reaction with formaldehyde to the corresponding naphthoxazine derivatives. Emel Pelit and Zuhal Turgut Copyright © 2016 Emel Pelit and Zuhal Turgut. All rights reserved. Antioxidant Composition of a Selection of Italian Red Wines and Their Corresponding Free-Radical Scavenging Ability Thu, 28 Apr 2016 11:08:15 +0000 This study correlates the antioxidant composition profiles and the overall antioxidant capacities of 36 Italian red wine samples. The samples were fully characterized by chromatographic and spectrophotometric techniques. The overall antioxidant capacity was determined by titrating a solution of the semistable free radical DPPH (1,1-diphenyl-2-picrylhydrazyl) with each wine sample followed by Electron Paramagnetic Resonance (EPR) spectroscopy and then measuring the resulting decrease in DPPH-signal. The antioxidant activities of the samples were expressed as (+)-catechin equivalents and related to their antioxidant composition profiles. Samples with a high polyphenol content showed a high DPPH scavenging ability as well. Seven well-defined groups, mainly constituted by wines coming from the same cultivar, were evidenced by PCA analysis. Alcohol content and pH did not influence the wine DPPH scavenging ability. The most important variables contributing to the wines’ antioxidant power are total flavonoid, total phenol, and proanthocyanidin indices together with fertaric acid, trans-caftaric acid, trans-coutaric acid, and both quercetin glucoside and quercetin glucuronide. EPR is demonstrated to be faster than the other analytical methods (spectrophotometric and chromatographic analyses) to determine the wine overall antioxidant activity. Claudio Cassino, Valentina Gianotti, Federica Bonello, Christos Tsolakis, Maria Carla Cravero, and Domenico Osella Copyright © 2016 Claudio Cassino et al. All rights reserved. Activation of Sphalerite by Ammoniacal Copper Solution in Froth Flotation Wed, 27 Apr 2016 09:28:18 +0000 The activation of sphalerite particles by ammoniacal copper solution (ACS) was investigated in this study. This microflotation study was conducted on a single sphalerite mineral with the particles size of 38 μm to 75 μm. Results showed that ACS has somewhat better activation effect than copper sulphate (a traditional activator) with sodium isobutyl xanthate as the collector. Agglomeration observation, contact angle measurement, and X-ray photoelectron spectroscopy measurement results of sphalerite particles verified the superiority of this new activator. Therefore, the substitution of copper sulphate with ACS would increase the separation efficiency not only in marmatite flotation but also in sphalerite flotation. Xian Xie, Kai Hou, Bo Yang, and Xiong Tong Copyright © 2016 Xian Xie et al. All rights reserved. Highly Selective Synthesis of Chlorophenols under Microwave Irradiation Tue, 26 Apr 2016 13:09:14 +0000 Oxychlorination of various phenols is finished in 60 minutes with high efficiency and perfect selectivity under microwave irradiation. These reactions adopt copper(II) chloride (CuCl2) as the catalyst and hydrochloric acid as chlorine source instead of expensive and toxic ones. Oxychlorination of phenols substituted with electron donating groups (methyl, methoxyl, isopropyl, etc.) at ortho- and meta-positions is accomplished with higher conversion rates, lower reaction time, and excellent selectivity. A proposed reaction mechanism is deduced; one electron transfers from CuCl2 to phenol followed by the formation of tautomeric radical that can be rapidly captured by chlorine atom and converts into para-substituted product. Yawen Xiong, Hongdong Duan, Xia Meng, Zhaoyun Ding, and Weichun Feng Copyright © 2016 Yawen Xiong et al. All rights reserved. Synthesis and Characterization of Poly(urethane-ether azomethine) Fatty Amide Based Corrosion Resistant Coatings from Pongamia glabra Oil: An Eco-Friendly Approach Sun, 24 Apr 2016 12:16:16 +0000 A novel attempt has been made to incorporate azomethine group in the backbone of polyurethane ether Pongamia oil fatty amide. The overall reaction was carried out in different steps like preparation of N,N-bis(2-hydroxyethyl) Pongamia glabra oil fatty amide, poly(ether fatty amide), and poly(urethane-ether) fatty amide. The hydroxyl terminated Schiff base, ethane 1,2-di(azomethine) bisphenol, reacts with fatty amide diol and is further treated with toluylene 2,4-diisocynate (TDI) to form poly(urethane-ether azomethine) fatty amide (PUEAF). These synthesized resins were characterized by FT IR, 1H NMR, and 13C NMR spectroscopic techniques. Molecular weight of PUEAF resin was measured by gel permeation chromatography (GPC), coating was made on mild steel strips, and evaluating their physicochemical and physicomechanical analysis was carried out by standard methods. The PUEAF25 coating showed highest scratch hardness (2.5 kg), gloss (90) at 45°, pencil hardness (4H), and impact resistance (150 lb/inch). Atomic force microscopy (AFM) and differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA) were used to determine the topography and thermal behavior of PUEAF. Corrosion studies of PUEAF coated mild steel were used in different corrosive media (3.5 wt% HCl, 5 wt% NaCl, and tap water) at room temperature using potentiodynamic polarization technique. The results of this study showed that PUEAF coatings exhibit good physicomechanical, anticorrosive properties and get application up to 180°C. Manawwer Alam, Naser M. Alandis, Naushad Ahmad, and Mu Naushad Copyright © 2016 Manawwer Alam et al. All rights reserved. The Coffee Protective Effect on Catalase System in the Preneoplastic Induced Rat Liver Sun, 24 Apr 2016 11:47:15 +0000 This study aimed to evaluate the effect of organic/conventional coffee in liver tissues in the cancer process, taking into account the level and activities of catalase. The experiments were carried out with 8 groups of rats during 12 weeks. They received two injections of ethylenediaminetetraacetic acid solution 1.5% (v/v) prepared in 0.9% NaCl or 1,2-dimethylhydrazine (DMH) subcutaneous dose of 40 mg·kg−1·bw−1 for 2 weeks. The organic/conventional coffee infusions were at 5, 10, and 20% and were incorporated to feed (100 mL of infusion·kg−1 of diet). The catalase activity showed a decrease for livers which received DMH and DMH plus organic coffee at 5% and 10%. However, an increase was observed for those receiving organic 20% and conventional 10% coffee, slowing down and favoring the reversibility of the carcinogenic process. By SDS-PAGE, we observed an intensity decrease of 59 kDa bands, as the percentage of coffee was increased. The iron concentration (by ET-AAS) confirmed the electrophoretic results, suggesting that the DMH influenced the catalase expression conditions, reducing the activity by the loss of iron ions. Thus, the coffee may restore the catalase system in the liver, exerting its chemopreventive effects. Cristiana Schmidt de Magalhães, Jéssica Emi Takarada, Nathália Costa Carvalho, Dayene do C. Carvalho, Felipe Lopes de Andrade, Eric Batista Ferreira, Pedro Orival Luccas, and Luciana Azevedo Copyright © 2016 Cristiana Schmidt de Magalhães et al. All rights reserved. Impact of Roasting on Fatty Acids, Tocopherols, Phytosterols, and Phenolic Compounds Present in Plukenetia huayllabambana Seed Sun, 24 Apr 2016 08:02:20 +0000 The effect of roasting of Plukenetia huayllabambana seeds on the fatty acids, tocopherols, phytosterols, and phenolic compounds was evaluated. Additionally, the oxidative stability of the seed during roasting was evaluated through free fatty acids, peroxide, and p-anisidine values in the seed oil. Roasting conditions corresponded to 100, 120, 140, and 160°C for 10, 20, and 30 min, respectively. Results indicate that roasting temperatures higher than 120°C significantly affect the content of the studied components. The values of acidity, peroxide, and p-anisidine in the sacha inchi oil from roasted seeds increased during roasting. The treatment of 100°C for 10 min successfully maintained the evaluated bioactive compounds in the seed and quality of the oil, while guaranteeing a higher extraction yield. Our results indicate that P. huayllabambana seed should be roasted at temperatures not higher than 100°C for 10 min to obtain snacks with high levels of bioactive compounds and with high oxidative stability. Rosana Chirinos, Daniela Zorrilla, Ana Aguilar-Galvez, Romina Pedreschi, and David Campos Copyright © 2016 Rosana Chirinos et al. All rights reserved. Greenhouse Gases Emissions from Wastewater Treatment Plants: Minimization, Treatment, and Prevention Thu, 21 Apr 2016 14:13:47 +0000 The operation of wastewater treatment plants results in direct emissions, from the biological processes, of greenhouse gases (GHG) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as indirect emissions resulting from energy generation. In this study, three possible ways to reduce these emissions are discussed and analyzed: minimization through the change of operational conditions, treatment of the gaseous streams, and prevention by applying new configurations and processes to remove both organic matter and pollutants. In current WWTPs, to modify the operational conditions of existing units reveals itself as possibly the most economical way to decrease N2O and CO2 emissions without deterioration of effluent quality. Nowadays the treatment of the gaseous streams containing the GHG seems to be a not suitable option due to the high capital costs of systems involved to capture and clean them. The change of WWTP configuration by using microalgae or partial nitritation-Anammox processes to remove ammonia from wastewater, instead of conventional nitrification-denitrification processes, can significantly reduce the GHG emissions and the energy consumed. However, the area required in the case of microalgae systems and the current lack of information about stability of partial nitritation-Anammox processes operating in the main stream of the WWTP are factors to be considered. J. L. Campos, D. Valenzuela-Heredia, A. Pedrouso, A. Val del Río, M. Belmonte, and A. Mosquera-Corral Copyright © 2016 J. L. Campos et al. All rights reserved. Ecotoxicity and Preliminary Risk Assessment of Nonivamide as a Promising Marine Antifoulant Thu, 21 Apr 2016 14:04:30 +0000 The unclear environmental performance of nonivamide limits its application as a marine antifoulant. In this study, the natural degradation of nonivamide was studied in seawater and tap water. The half-life was 5.8 d, 8.8 d, 12.2 d, and 14.7 d in seawater and tap water in photolysis and biolysis, respectively. Furthermore, the ecotoxicity of nonivamide was assessed using marine microalgae, Chlorella vulgaris and Platymonas sp.; values on the growth of Chlorella vulgaris and Platymonas sp. were 16.9 mg L−1 and 19.21 mg L−1, respectively. The toxicity and environmental risk of nonivamide on microalgae were significantly decreased due to the natural degradation in seawater. Sujing Liu, Jun Zhou, Xuanxuan Ma, Ying Liu, Xing Ma, and Chuanhai Xia Copyright © 2016 Sujing Liu et al. All rights reserved. Identifying Antioxidant and Antimicrobial Activities of the Phenolic Extracts and Mineral Contents of Virgin Olive Oils (Olea europaea L. cv. Edincik Su) from Different Regions in Turkey Thu, 21 Apr 2016 07:47:15 +0000 The objective of this study was to identify the antioxidant and antimicrobial activities of the phenolic extracts and mineral contents of virgin olive oils (Olea europaea L. cv. Edincik Su) obtained from three different locations, Edincik, Gomec, and Izmir, in Turkey. Antioxidant activity was analysed spectrometrically, antimicrobial effect was evaluated by disc diffusion method, and mineral contents were determined by using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Total phenolic contents and free radical scavenging activities of Edincik Su olive cultivar were found between 159.99 and 189.64 mg gallic acid equivalent/kg and 21.76 and 31.79% inhibition of DPPH• radical values, respectively. Phenolic composition was also varied according to location and hydroxytyrosol and tyrosol were determined as major phenolic compounds. Fourteen pathogenic bacteria and two fungal strains were used to determine the antimicrobial activity. Phenolic extracts showed antimicrobial effect against a wide range of microorganisms and the descending rank of the antimicrobial activities was Gomec, Izmir, and Edincik samples. The highest antimicrobial activities were determined against Clostridium perfringens ATCC 13124 and Campylobacter jejuni ATCC  33291 in all samples. Sixteen elements were used as standards (eleven of them were heavy metals) to identify mineral contents. Fe, Mg, Sn, K, and Ca were determined in Gomec samples and Mg and K were detected in Edincik samples while no mineral content was detected in Izmir sample. Ayhan Dağdelen Copyright © 2016 Ayhan Dağdelen. All rights reserved. Recent Advances in the Total Synthesis of Tetramic Acid-Containing Natural Products Wed, 20 Apr 2016 07:06:08 +0000 With incredible bioactivities and fascinating structural complexities, tetramic acid- (TA-) containing natural products have attracted favorable attention among the organic chemistry community. Although the construction of the TA core is usually straightforward, the intricate C3-side chain sometimes asks for some deliberative strategy so as to fulfill an elegant total synthesis. This review mainly covers some exceptional synthetic examples for each type of natural product in recent years, showcasing the great achievements as well as unsettled obstacles in this area, in the hope of accelerating the synthetic and biological investigations for this unique type of natural product. Wen-Ju Bai, Chen Lu, and Xiqing Wang Copyright © 2016 Wen-Ju Bai et al. All rights reserved. Fenton Process Coupled to Ultrasound and UV Light Irradiation for the Oxidation of a Model Pollutant Tue, 19 Apr 2016 11:39:30 +0000 The Fenton process coupled to photosonolysis (UV light and Us), using Fe2O3 catalyst supported on Al2O3, was used to oxidize a model pollutant like acid green 50 textile dye (AG50). Dye degradation was followed by AG50 concentration decay analyses. It was observed that parameters like iron content on a fixed amount of catalyst supporting material, catalyst annealing temperature, initial dye concentration, and the solution pH influence the overall treatment efficiency. High removal efficiencies of the model pollutant are achieved. The stability and reusability tests of the Fe2O3 catalyst show that the catalyst can be used up to three cycles achieving high discoloration. Thus, this catalyst is highly efficient for the degradation of AG50 in the Fenton process. Karen E. Barrera-Salgado, Gabriela Ramírez-Robledo, Alberto Álvarez-Gallegos, Carlos A. Pineda-Arellano, Fernando Z. Sierra-Espinosa, J. Alfredo Hernández-Pérez, and Susana Silva-Martínez Copyright © 2016 Karen E. Barrera-Salgado et al. All rights reserved. A New Phase of GaN Thu, 14 Apr 2016 16:16:24 +0000 The structural, mechanical, and electronic properties of the orthorhombic GaN (Pnma-GaN) are investigated at ambient pressure by using first-principles calculations method with the ultrasoft pseudopotential scheme. The elastic constants and phonon calculations reveal Pnma-GaN is mechanically and dynamically stable at ambient pressure. The calculated Young modulus of Pnma-GaN is 170 GPa, which is the three-fifths of wurtzite-GaN. Electronic structure study shows that Pnma-GaN is a direct semiconductor with band gap of 1.847 eV. The anisotropic calculation shows that wurtzite-GaN has a smaller elastic anisotropy than that of Pnma-GaN in Young’s modulus. In addition, when the composition of aluminum increases from 0 to 0.063 in the alloy, the band gap decreases initially and increases afterward for Pnma-Ga1−xAlxN, while, for wurtzite-Ga1−xAlxN, the band gap increases with the increasing composition x. Due to the structural porous feature, Pnma-GaN can also be expected to be a good hydrogen storage material. Qingyang Fan, Changchun Chai, Qun Wei, Jionghao Yang, Peikun Zhou, Dongyun Zhang, and Yintang Yang Copyright © 2016 Qingyang Fan et al. All rights reserved.