Journal of Chemistry https://www.hindawi.com The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Theoretical Study about the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals Tue, 21 Feb 2017 11:40:33 +0000 http://www.hindawi.com/journals/jchem/2017/9254831/ The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui () and Parr () functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were evaluated by bond dissociation enthalpy (BDE) and spin density (SD) calculations. This study has potential implications for the design of chromone analogues as anticancer compounds. Maximiliano Martínez-Cifuentes, Boris Weiss-López, and Ramiro Araya-Maturana Copyright © 2017 Maximiliano Martínez-Cifuentes et al. All rights reserved. Effect of Constituent Units, Type of Interflavan Bond, and Conformation on the Antioxidant Properties of Procyanidin Dimers: A Computational Outlook Tue, 21 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/3535148/ Procyanidin (PC) dimers are powerful antioxidants, abundant in plant tissues, and also bioavailable. However, the role of the molecular structure of PCs on their antioxidant properties is still a controversial and not fully understood issue that needs to be addressed in a more specific way. The objective of this study was to analyze the effect of the constituent units, type of interflavan bond, and conformation on the antioxidant properties of PC dimers including PB3, PB4, PB5, PB6, PB7, and PB8, using the density functional theory (DFT) computational method. The analysis was performed in function of parameters that allow determining the ability of the molecules to transfer or to capture electrons, among which the chemical potential, bond dissociation enthalpy (BDE), gap energy, Fukui indices, and charge distribution of HOMO-LUMO orbitals. The factors that showed the most notable effects on the antioxidant properties of the PC dimers were the type of interflavan bond and the conformation. The antioxidant ability of the dimers PB3 and PB4 containing the interflavan bond C4–C8, in their Compact conformation, was very similar to each other but greater than those of dimers PB5, PB6, PB7, and PB8 containing the C4–C6 interflavan bond. PB8 showed the lowest antioxidant ability. Ana María Mendoza-Wilson and René Renato Balandrán-Quintana Copyright © 2017 Ana María Mendoza-Wilson and René Renato Balandrán-Quintana. All rights reserved. Detection and Analytical Capabilities for Trace Level of Carbon in High-Purity Metals by Laser-Induced Breakdown Spectroscopy with a Frequency Quintupled 213 nm Nd:YAG Laser Mon, 20 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/1095183/ The laser-induced breakdown spectroscopy (LIBS) with a frequency quintupled 213 nm Nd:YAG laser was examined to the analysis of trace level of carbon (C) in high-purity metals and its detection and analytical capabilities were evaluated. Though C signal in a wavelength of 247.9 nm, which showed the highest sensitivity of C, could be obtained from Cd, Ti, and Zn ca. 7000 mg kg−1 C in Fe could not be detected due to the interferences from a lot of Fe spectra. Alternative C signal in a wavelength of 193.1 nm could not be also detected from Fe due to the insufficient laser output energy of the frequency quintupled 213 nm Nd:YAG laser. The depth analysis of C by LIBS was also demonstrated and the C in Cd and Zn was found to be contaminated in only surface area whereas the C in Ti was distributed in bulk. From these results, the frequency quintupled 213 nm Nd:YAG laser, which was adopted widely as a commercial laser ablation (LA) system coupled with inductively coupled plasma mass spectrometry (ICPMS) for trace element analysis in solid materials, could be used for C analysis to achieve simultaneous measurements for both C and trace elements in metals by LIBS and LA-ICPMS, respectively. Masaki Ohata and Toshiki Nakae Copyright © 2017 Masaki Ohata and Toshiki Nakae. All rights reserved. A Novel Green Synthesis of Thalidomide and Analogs Mon, 20 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/6436185/ Thalidomide and its derivatives are currently under investigation for their antiangiogenic, immunomodulative, and anticancer properties. Current methods used to synthesize these compounds involve multiple steps and extensive workup procedures. Described herein is an efficient microwave irradiation green synthesis method that allows preparation of thalidomide and its analogs in a one-pot multicomponent synthesis system. The multicomponent synthesis system developed involves an array of cyclic anhydrides, glutamic acid, and ammonium chloride in the presence of catalytic amounts of 4-N,N-dimethylaminopyridine (DMAP) to produce thalidomide and structurally related compounds within minutes in good isolated yields. Ellis Benjamin and Yousef M. Hijji Copyright © 2017 Ellis Benjamin and Yousef M. Hijji. All rights reserved. Impact of Kishnica and Badovci Flotation Tailing Dams on Levels of Heavy Metals in Water of Graçanica River (Kosovo) Sun, 19 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/5172647/ The main objective of this study was to perform assessment of water quality of Graçanica River (Kosovo), impacted by Kishnica and Badovci flotation tailing dams, using ICP-OES method. The obtained results show that the mean values of all heavy metals in studied river water samples were significantly high, with following maximal concentrations: As (0.033 mgL−1), Cd (0.002 mgL−1), Cr (0.225 mgL−1), Cu (0.015 mgL−1), Hg (0.004 mgL−1), Mn (15.66 mgL−1), Ni (0.255 mgL−1), Pb (0.013 mgL−1), and Zn (0.612 mgL−1), but only two samples from locations influenced by Kishnica and Badovci flotation tailing dams showed statistically anomalous values of Cr3+, Cu2+, Mn2+, Zn2+, and Hg2+. According to assessment based on Croatian standards, locations near both flotation tailing dams are significantly polluted with majority of studied metals, while downstream sampling stations are almost unpolluted or slightly polluted. Mercury is found to be the most significant contaminant. According to WHO recommended values for drinking water, on all locations values were within the limits for Al, Cd, Cu, and Zn, while for As, Cr, Hg, Mn, Ni, and Pb values exceed recommended values on some sampling stations. Further monitoring of water and possibly sediments of Graçanica River is advised, as well as performing of remediation of Kishnica and Badovci mine tailing dams. Fatbardh Gashi, Stanislav Frančišković-Bilinski, Halka Bilinski, Agron Shala, and Anilë Gashi Copyright © 2017 Fatbardh Gashi et al. All rights reserved. Epoxidation of Ethylene by Whole Cell Suspension of Methylosinus trichosporium IMV 3011 Thu, 16 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/9191382/ Methane monooxygenase (MMO) has been found in methanotrophic bacteria, which catalyzes the epoxidation of gaseous alkenes to their corresponding epoxides. The whole cell suspension of Methylosinus trichosporium IMV 3011 was used to produce epoxyethane from ethylene. The optimal reaction time and initial ethylene concentration for ethylene epoxidation have been described. The product epoxyethane is not further metabolized and accumulates extracellularly. Thus, exhaustion of reductant and the inhibition of toxic products make it difficult to accumulate epoxyethane continuously. In order to settle these problems, regeneration of cofactor NADH was performed in batch experiments with methane and methanol. The amount of epoxyethane formed before cosubstrate regeneration was between 0.8 and 1.0 nmol/50 mg cells in approximately 8 h. Combining data from 7 batch experiments, the total production of epoxyethane was 2.2 nmol. Production of epoxyethane was improved (4.6 nmol) in 10% gas phase methane since methane acts as an abundant reductant for epoxidation. It was found that the maximum production of epoxyethane (6.6 nmol) occurs with 3 mmol/L methanol. The passive effect of epoxyethane accumulation on epoxyethane production capacity of Methylosinus trichosporium IMV 3011 in batch experiments was studied. Removal of product was suggested to overcome the inhibition of epoxyethane production. Jia-Ying Xin, Ning Xu, Sheng-Fu Ji, Yan Wang, and Chun-Gu Xia Copyright © 2017 Jia-Ying Xin et al. All rights reserved. Synthesis and Characterization of Ag-Modified V2O5 Photocatalytic Materials Tue, 14 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/5849103/ V2O5 powders modified with different theoretical silver contents (1, 5, 10, 15, and 20 wt% as Ag2O) were obtained with acicular morphologies observed by scanning electron microscopy (SEM). Shcherbinaite crystalline phase is transformed into the Ag0.33V2O5 crystalline one with the incorporation and increase in silver content as was suggested by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. With further increase in silver contents the Ag2O phase appears. Catalysts were active in photocatalytic degradation of malachite green dye under simulated solar light, which is one of the most remarkable facts of this work. It was found that V2O5-20Ag was the most active catalytic formulation and its activity was attributed to the mixture of coupled semiconductors that promotes the slight decrease in the rate of the electron-hole pair recombination. Dora Alicia Solis-Casados, Luis Escobar-Alarcon, Antonia Infantes-Molina, Tatyana Klimova, Lizbeth Serrato-Garcia, Enrique Rodriguez-Castellon, Susana Hernandez-Lopez, and Alejandro Dorazco-Gonzalez Copyright © 2017 Dora Alicia Solis-Casados et al. All rights reserved. Influence of Gliricidia sepium Biochar on Attenuate Perchlorate-Induced Heavy Metal Release in Serpentine Soil Tue, 14 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/6180636/ Perchlorate () is a strong oxidizer, capable of accelerating heavy metal release into regolith/soil. Here, we assessed interactions between and serpentine soil to simulate and understand the fate of Ni and Mn and their immobilization with the presence of biochar (BC). A soil incubation study (6 months) was performed using serpentine soil in combination with different concentrations (0.25, 0.5, 0.75, and 1 wt.%) and three different amendment rates (1, 2.5, and 5 wt.%) of Gliricidia sepium BC. Bioavailable fraction of Ni and Mn was analyzed using CaCl2 extraction method. An increase of concentrations enhanced bioavailability fraction of Ni and Mn. However, BC amendments reduced the bioavailability of Ni and Mn. In comparison, 5% BC amendment significantly immobilized the bioavailability of Ni (68–92%) and Mn (76–93%) compared to other BC amendment rates. Electrostatic attractions and surface diffusion could be postulated for Ni and Mn immobilization by BC. In addition, may have adsorbed to BC via hydrogen bonding which may reduce the influence of on Ni and Mn mobility. Overall, it is obvious that BC could be utilized as an effective amendment to immobilize Ni and Mn in heavy metal and contaminated soil. Prasanna Kumarathilaka and Meththika Vithanage Copyright © 2017 Prasanna Kumarathilaka and Meththika Vithanage. All rights reserved. Relevance of the Physicochemical Properties of Calcined Quail Eggshell (CaO) as a Catalyst for Biodiesel Production Mon, 13 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/5679512/ The CaO solid derived from natural quail eggshell was calcined and employed as catalyst to produce biodiesel via transesterification of sunflower oil. The natural quail eggshell was calcined at 900°C for 3 h, in order to modify the calcium carbonate present in its structure in CaO, the activity phase of the catalyst. Both precursor and catalyst were characterized using Hammett indicators method, X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), CO2 temperature-programmed desorption (CO2-TPD), X-ray photoelectronic spectroscopy (XPS), Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption-desorption at −196°C, and distribution particle size. The maximum biodiesel production was of 99.00 ± 0.02 wt.% obtained in the following transesterification reaction conditions: (sunflower oil/methanol molar ratio of 1 : 10.5 mol : mol), (catalyst loading of 2 wt.%), (reaction time of 2 h), stirring rate of 1000 rpm, and temperature of 60°C. Leandro Marques Correia, Juan Antonio Cecilia, Enrique Rodríguez-Castellón, Célio Loureiro Cavalcante Jr., and Rodrigo Silveira Vieira Copyright © 2017 Leandro Marques Correia et al. All rights reserved. Photodynamic Efficiency of Xanthene Dyes and Their Phototoxicity against a Carcinoma Cell Line: A Computational and Experimental Study Sun, 12 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/7365263/ The aim of this study is to assess the insights of molecular properties of the xanthene dyes [fluorescein (FL), Rose Bengal (RB), erythrosin B (EB), and eosin Y (EY)] to correlate systematically their photodynamic efficiency as well as their phototoxicity against a carcinoma cell line. The phototoxicity was evaluated by comparing the values of the medium inhibitory concentration (IC50) upon HEp-2 cells with the xanthene corresponding photodynamic activity using the uric acid as a chemical dosimeter and their octanol-water partition coefficient (). RB was the more cytotoxic dye against HEp-2 cell line and the most efficient photosensitizer in causing photoxidation of uric acid; nevertheless it was the only one characterized as being hydrophobic among the xanthenes studied here. On the other hand, it was observed that the halogen substituents increased the hydrophilicity and photodynamic activity, consistent with the cytotoxic experiments. Furthermore, the reactivity index parameters, electric dipole moment, molecular volume, and the frontier orbitals were also obtained by the Density Functional Theory (DFT). The lowest dipole moment and highest molecular volume of RB corroborate with its highest hydrophobicity due to heavy atom substituents like halogens, while the halogen substituents did not affect expressively the electronic features at all. Suelen T. G. Buck, Fernanda Bettanin, Ednilson Orestes, Paula Homem-de-Mello, Hidetake Imasato, Rommel B. Viana, Janice R. Perussi, and Albérico B. F. da Silva Copyright © 2017 Suelen T. G. Buck et al. All rights reserved. Optimization of the Extraction of the Volatile Fraction from Honey Samples by SPME-GC-MS, Experimental Design, and Multivariate Target Functions Thu, 09 Feb 2017 14:38:32 +0000 http://www.hindawi.com/journals/jchem/2017/6437857/ Head space (HS) solid phase microextraction (SPME) followed by gas chromatography with mass spectrometry detection (GC-MS) is the most widespread technique to study the volatile profile of honey samples. In this paper, the experimental SPME conditions were optimized by a multivariate strategy. Both sensitivity and repeatability were optimized by experimental design techniques considering three factors: extraction temperature (from 50°C to 70°C), time of exposition of the fiber (from 20 min to 60 min), and amount of salt added (from 0 to 27.50%). Each experiment was evaluated by Principal Component Analysis (PCA) that allows to take into consideration all the analytes at the same time, preserving the information about their different characteristics. Optimal extraction conditions were identified independently for signal intensity (extraction temperature: 70°C; extraction time: 60 min; salt percentage: 27.50% w/w) and repeatability (extraction temperature: 50°C; extraction time: 60 min; salt percentage: 27.50% w/w) and a final global compromise (extraction temperature: 70°C; extraction time: 60 min; salt percentage: 27.50% w/w) was also reached. Considerations about the choice of the best internal standards were also drawn. The whole optimized procedure was than applied to the analysis of a multiflower honey sample and more than 100 compounds were identified. Elisa Robotti, Federica Campo, Marta Riviello, Marco Bobba, Marcello Manfredi, Eleonora Mazzucco, Fabio Gosetti, Giorgio Calabrese, Emanuele Sangiorgi, and Emilio Marengo Copyright © 2017 Elisa Robotti et al. All rights reserved. Description of Weak Halogen Bonding Using Various Levels of Symmetry-Adapted Perturbation Theory Combined with Effective Core Potentials Thu, 09 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/9031494/ The present work starts with providing a description of the halogen bonding (XB) interaction between the halogen atom of MH3X (where M = C–Pb and X = I, At) and the N atom of HCN. This interaction leads to the formation of stable yet very weakly bound MH3X⋯NCH complexes for which the interaction energy () between MH3X and HCN is calculated using various symmetry-adapted perturbation theory (SAPT) methods combined with the def2-QZVPP basis set and midbond functions. This basis set assigns effective core potentials (ECPs) not only to the I or At atom directly participating in the XB interaction with HCN but also to the M atom when substituted with Sn or Pb. Twelve SAPT methods (or levels) are taken into consideration. According to the SAPT analysis of , the XB interaction in the complexes shows mixed electrostatic-dispersion nature. Next, the accuracy of SAPT is evaluated by comparing with CCSD(T) reference data. This comparison reveals that high-order SAPT2+ method and the much less computationally demanding SAPT(DFT) method perform very well in describing of the complexes. However, the accuracy of these methods decreases dramatically if they are combined with the so-called Hartree-Fock correction. Piotr Matczak Copyright © 2017 Piotr Matczak. All rights reserved. Synthesis of Ruthenium Complex Based on 2,6-Bis(1-(phenyl)-1H-benzo[d]imidazol-2-yl)pyridine and 2-(1-Phenyl-1H-benzo[d]imidazol-2-yl)benzoate and Catalytical Oxidation Property of 1-(1H-Benzo[d]imidazol-2-yl)ethanol to 1-(1H-Benzo[d]imidazol-2-yl)ethanone with H2O2 Thu, 09 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/8647419/ A new ruthenium complex, Ru(bpbp)(pbb)Cl, based on 2,6-bis(1-(phenyl)-1H-benzo[d]imidazol-2-yl)pyridine (bpbp) and 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)benzoate (pbb) was synthesized. The complex Ru(bpbp)(pbb)Cl could catalytically oxidize 1-(1H-benzo[d]imidazol-2-yl)ethanol to 1-(1H-benzo[d]imidazol-2-yl)ethanone with H2O2 as oxidant. Influence of temperature and catalyst amount on the oxidation reaction was evaluated. The reaction optimal conditions are as follows: molar ratio of catalyst to substrate to H2O2 is 1 : 1000 : 3000, the proper reaction temperature is 50°C and reaction time lasts 5 h, and the isolated yield of 1-(1H-benzo[d]imidazol-2-yl)ethanol to 1-(1H-benzo[d]imidazol-2-yl)ethanone under the optimal reaction conditions is 57%. Shenggui Liu, Rongkai Pan, Guobi Li, Wenyi Su, and Chunlin Ni Copyright © 2017 Shenggui Liu et al. All rights reserved. CryoProtect: A Web Server for Classifying Antifreeze Proteins from Nonantifreeze Proteins Thu, 09 Feb 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/9861752/ Antifreeze protein (AFP) is an ice-binding protein that protects organisms from freezing in extremely cold environments. AFPs are found across a diverse range of species and, therefore, significantly differ in their structures. As there are no consensus sequences available for determining the ice-binding domain of AFPs, thus the prediction and characterization of AFPs from their sequence is a challenging task. This study addresses this issue by predicting AFPs directly from sequence on a large set of 478 AFPs and 9,139 non-AFPs using machine learning (e.g., random forest) as a function of interpretable features (e.g., amino acid composition, dipeptide composition, and physicochemical properties). Furthermore, AFPs were characterized using propensity scores and important physicochemical properties via statistical and principal component analysis. The predictive model afforded high performance with an accuracy of 88.28% and results revealed that AFPs are likely to be composed of hydrophobic amino acids as well as amino acids with hydroxyl and sulfhydryl side chains. The predictive model is provided as a free publicly available web server called CryoProtect for classifying query protein sequence as being either AFP or non-AFP. The data set and source code are for reproducing the results which are provided on GitHub. Reny Pratiwi, Aijaz Ahmad Malik, Nalini Schaduangrat, Virapong Prachayasittikul, Jarl E. S. Wikberg, Chanin Nantasenamat, and Watshara Shoombuatong Copyright © 2017 Reny Pratiwi et al. All rights reserved. Molecular Descriptors of Nanotube, Oxide, Silicate, and Triangulene Networks Sun, 05 Feb 2017 10:10:24 +0000 http://www.hindawi.com/journals/jchem/2017/6540754/ A topological index is a real number associated with chemical constitution purporting for correlation of chemical structure with various physical properties, chemical reactivity, or biological activity. The concept of hyper Zagreb index, first multiple Zagreb index, second multiple Zagreb index, and Zagreb polynomials was established in chemical graph theory based on vertex degrees. It is reported that these indices are useful in the study of anti-inflammatory activities of certain chemical networks. In this paper, we study carbon nanotube networks which are motivated by molecular structure of regular hexagonal lattice and also studied interconnection networks which are motivated by molecular structure of a chemical compound . We determine hyper Zagreb index, first multiple Zagreb index, second multiple Zagreb index, and Zagreb polynomials for some important class of carbon nanotube networks, dominating oxide network, dominating silicate network, and regular triangulene oxide network. Wei Gao and Muhammad Kamran Siddiqui Copyright © 2017 Wei Gao and Muhammad Kamran Siddiqui. All rights reserved. Geometries and Electronic States of Divacancy Defect in Finite-Size Hexagonal Graphene Flakes Sun, 29 Jan 2017 07:59:11 +0000 http://www.hindawi.com/journals/jchem/2017/8491264/ The geometries and electronic properties of divacancies with two kinds of structures were investigated by the first-principles (U) B3LYP/STO-3G and self-consistent-charge density-functional tight-binding (SCC-DFTB) method. Different from the reported understanding of these properties of divacancy in graphene and carbon nanotubes, it was found that the ground state of the divacancy with 585 configurations is closed shell singlet state and much more stable than the 555777 configurations in the smaller graphene flakes, which is preferred to triplet state. But when the sizes of the graphene become larger, the 555777 defects will be more stable. In addition, the spin density properties of the both configurations are studied in this paper. Lili Liu and Shimou Chen Copyright © 2017 Lili Liu and Shimou Chen. All rights reserved. Pb(II) Removal Process in a Packed Column System with Xanthation-Modified Deoiled Allspice Husk Sun, 29 Jan 2017 07:38:47 +0000 http://www.hindawi.com/journals/jchem/2017/4296515/ The present research dealt with lead removal using modified Pimenta dioica L. Merrill as biosorbent in a batch and in continuous flow column systems, respectively. The allspice husk residues were modified first with a treatment through the xanthation reaction. For the adsorption tests, the atomic adsorption spectrophotometry method was used to determine the lead concentrations in the liquid samples. In the kinetic batch study (10 mg of sorbent in 10 mL of 25 mg L−1 lead solution), the removal efficiency was 99% (adsorption capacity of 25.8 mg g−1). The kinetic data followed the pseudo-second-order model. The adsorption isotherm was fitted to the Freundlich model, where constants were and (8.06 mg g−1 L and 0.52), corresponding to adsorption capacities of 8 and 62 mg g−1, at liquid equilibrium concentration of 1 and 50 mg L−1, respectively. In the continuous flow systems where lead solution of 50 mg L−1 was treated in 2 columns of 5 cm (4.45 g) and 10 cm (9.07 g) bed heights, the dynamic adsorption capacity obtained by fitting the Thomas model was 29.114 mg g−1 and 45.322 mg g−1, respectively. Efrain Palma-Anaya, Cheikh Fall, Teresa Torres-Blancas, Patricia Balderas-Hernández, Julian Cruz-Olivares, Carlos E. Barrera-Díaz, and Gabriela Roa-Morales Copyright © 2017 Efrain Palma-Anaya et al. All rights reserved. Sonocatalytic Degradation of Antibiotics Tetracycline by Mn-Modified Diatomite Mon, 23 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/2830138/ Mn-modified diatomite was prepared by wet impregnation and subsequent calcinations processes. It was used as catalyst for sonocatalytic degradation of antibiotics tetracycline. Characterizations by scanning electron microscopy and X-ray diffraction pattern showed that the morphology and crystal structure of the modified diatomite were similar to these of raw diatomite. Despite containing very limited amount of Mn oxides, the Mn-modified diatomite showed much higher sonocatalytic activity than the raw diatomite. The increases in both MnSO4 concentration of the wet impregnation solution and the catalyst dosage could enhance the degradation of antibiotics tetracycline significantly. values for ultrasonication, catalyst adsorption, and both processes combined (0.10 mol/L MnSO4-modified diatomite) were 1.22 × 10−4, 0.00193, and 0.00453 min−1, respectively, while the corresponding values of were 0.956, 0.986, and 0.953, respectively. These results demonstrated the significant synergetic effect by combining ultrasonication and catalyst adsorption processes. The presence of isopropanol, KBr, and NaN3 quenched a series of reactive oxygen species sharply, indicating the dominant role of reactive oxygen species in the sonocatalytic process. In contrast, the addition of Fe(II) enhanced the degradation due to the generation of more radicals in the concurrent Fenton reaction. All the results indicated that Mn-modified diatomite had the great potential for water treatment by sonocatalytic oxidation. Yiping Guo, Xiao Mi, Guoting Li, and Xi Chen Copyright © 2017 Yiping Guo et al. All rights reserved. Advances in the Preparation of Fluorinated Isoquinolines: A Decade of Progress Mon, 23 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/2860123/ Heterocyclic molecules incorporating fluorinated isoquinoline components are found in many medicinally and agriculturally important bioactive products as well as industrially impactful materials. Within the past decade, a variety of isoquinolinic ring assembly techniques has enabled the introduction of diverse fluorine-containing functionalities which can enhance potential bioactivity and industrial utility. This review examines recent noncatalyzed and transition metal catalyzed synthetic approaches to the assembly of isoquinoline derivatives that are ring-fluorinated and/or result in the incorporation of fluorine-containing functional groups. Specifically, efficient synthetic methods and regioselectivity in the incorporation of functional groups into isoquinoline ring systems are examined. Joseph C. Sloop Copyright © 2017 Joseph C. Sloop. All rights reserved. Surface Modification of SnO2 with Phosphonic Acids Sun, 22 Jan 2017 11:30:56 +0000 http://www.hindawi.com/journals/jchem/2017/2105938/ The aim of the present work was the study of phosphonic acids grafting on the surface of SnO2 at different molar ratios. In this paper we describe the functionalization of SnO2 surfaces with phosphonic acids RPO(OH)2. The surface modification process was achieved by using phenyl-phosphonic acid (PPA) and vinyl-phosphonic acid (VPA). The synthesized materials were investigated by using FT-IR, TGA (in air and in nitrogen), EDX, ESEM, and TEM methods. This synthetic approach has many advantages: films with optical quality and controlled thickness can be obtained using low temperatures and cheap raw materials, by using “green chemistry” synthetic routes. The hybrid materials have structures diversity and fascinating applications, attracting attention for a long time, due to their potential. Ramona Gheonea, Carmen Mak, Eleonora Cornelia Crasmareanu, Vasile Simulescu, Nicoleta Plesu, and Gheorghe Ilia Copyright © 2017 Ramona Gheonea et al. All rights reserved. Novel Synthetic Monothiourea Aspirin Derivatives Bearing Alkylated Amines as Potential Antimicrobial Agents Sun, 22 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/2378186/ A new series of aspirin bearing alkylated amines moieties 1–12 were synthesised by reacting isothiocyanate with a series of aniline derivatives in overall yield of 16–56%. The proposed structures of all the synthesised compounds were confirmed using elemental analysis, FTIR, and 1H and  13C NMR spectroscopy. All compounds were evaluated for antibacterial activities against E. coli and S. aureus via turbidimetric kinetic and Kirby Bauer disc diffusion method. Compound 5 bearing meta -CH3 substituent showed the highest relative inhibition zone diameter against tested bacteria compared to ortho and para substituent. Furthermore, aspirin derivatives bearing shorter chains exhibited better bacterial inhibition than longer alkyl chains. Norsyafikah Asyilla Nordin, Tchan Wei Chai, Bee Ling Tan, Ching Liang Choi, Ainaa Nadiah Abd Halim, Hasnain Hussain, and Zainab Ngaini Copyright © 2017 Norsyafikah Asyilla Nordin et al. All rights reserved. Synthesis and Characterization of La-Doped Luminescent Multilayer Films Sun, 22 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/8203581/ In this work, we have successfully designed ordered luminescent multilayer films based on La-doped nonmagnetic or magnetic inorganic nanostructure with electronic microenvironment (EM). The inorganic nanosheets with opposite charge can assemble EM between the interlayers. At the same time, their elements on nanosheets of layer double hydroxides (LDHs) are facile to be replaced so that we can introduce transition metal or lanthanide elements. Besides, ferromagnetic effect (FE) can be formed in this microenvironment due to introducing transition metal on LDHs nanosheets. As a result, we confirm that EM, FE, and doping La element in the LDHs can affect the vibration of backbone of chromophores and then prolong the luminescent lifetime, which suggests a new pathway for developing the novel light-emitting thin films. Tianlei Wang, Meitang Liu, Hongwen Ma, and Defu Cao Copyright © 2017 Tianlei Wang et al. All rights reserved. Application of Multivariate Statistical Analysis in Evaluation of Surface River Water Quality of a Tropical River Thu, 19 Jan 2017 14:21:06 +0000 http://www.hindawi.com/journals/jchem/2017/5737452/ The present study evaluated the spatial variations of surface water quality in a tropical river using multivariate statistical techniques, including cluster analysis (CA) and principal component analysis (PCA). Twenty physicochemical parameters were measured at 30 stations along the Batang Baram and its tributaries. The water quality of the Batang Baram was categorized as “slightly polluted” where the chemical oxygen demand and total suspended solids were the most deteriorated parameters. The CA grouped the 30 stations into four clusters which shared similar characteristics within the same cluster, representing the upstream, middle, and downstream regions of the main river and the tributaries from the middle to downstream regions of the river. The PCA has determined a reduced number of six principal components that explained 83.6% of the data set variance. The first PC indicated that the total suspended solids, turbidity, and hydrogen sulphide were the dominant polluting factors which is attributed to the logging activities, followed by the five-day biochemical oxygen demand, total phosphorus, organic nitrogen, and nitrate-nitrogen in the second PC which are related to the discharges from domestic wastewater. The components also imply that logging activities are the major anthropogenic activities responsible for water quality variations in the Batang Baram when compared to the domestic wastewater discharge. Teck-Yee Ling, Chen-Lin Soo, Jing-Jing Liew, Lee Nyanti, Siong-Fong Sim, and Jongkar Grinang Copyright © 2017 Teck-Yee Ling et al. All rights reserved. A Novel Synthesis of 1,2,3-Benzotriazinones from 2-(o-Aminophenyl)oxazolines Thu, 19 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/2384780/ 1,2,3-Benzotriazinones were synthesized in excellent yields by the reaction of 2-(o-aminophenyl)oxazolines and isoamyl nitrite in methanol. The crystal structure of the acetyl derivative of one of the 1,2,3-benzotriazinones provided additional support for the spectroscopic structural characterization of the title compounds. Fernando Rocha-Alonzo, Daniel Chávez, Adrián Ochoa-Terán, David Morales-Morales, Enrique F. Velázquez-Contreras, and Miguel Parra-Hake Copyright © 2017 Fernando Rocha-Alonzo et al. All rights reserved. A Method for Determination of Metals in Hybrid Metal Oxide/Metal-Carbon Nanotubes Catalysts Wed, 18 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/4954080/ Carbon nanotubes (CNTs), due to their special structure and unique properties, are still one of the most interesting materials for scientists. Recently, carbon nanotubes were proposed as a new type of carbon support for catalysts. Fe, Pt, Ni, Co, and other metals anchored to CNTs are used in various reactions. Due to the fact that production processes are usually unpredictable and the total amount of metal/metal oxide deposited on the CNTs may only be estimated, the methods for examining the chemical composition are necessary. In this study, fast and simple inductively coupled plasma atomic emission spectrometry (ICP-AES) with slurry nebulization was proposed for metal content determination in hybrid CeZrO2/CNT, Ni-CeZrO2/CNT, and Ni/CNT materials. Slurries were prepared by 30 min ultrasonication of appropriate amount of investigated material in 1% Triton X-100 solution. Optimal range of slurry concentration and optimal RF plasma power were established (40–400 mg L−1, 1.2 kW, resp.). Obtained results proved that this method may be applied for determination of Ce, Zr, and Ni in hybrid CNT-based materials. Joanna Bok-Badura, Agata Jakóbik-Kolon, Agata Łamacz, and Krzysztof Karoń Copyright © 2017 Joanna Bok-Badura et al. All rights reserved. Synthesis and Growth Stimulant Properties of 2-Acetyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidin-5-one Derivatives Wed, 18 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/8180913/ A convenient, accessible, and high yield method for preparing of 6-methyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (1) by treatment of acetoacetic acid ethyl ester with thiourea in sodium methylate was developed. The alkylation of the latter with 3-chloro-pentane-2,4-dione and further regioselective cyclization of intermediate compound (2) in high yield afforded 2-acetyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidin-5-one (3). The halogenation and some transformations of synthesized thiazolo[3,2-a]pyrimidine (3) due to its ketone group were carried out to obtain the corresponding carboxamide, carbothioamide, sulfonohydrazide, and oxime and its alkylated derivatives (5). At preliminary biological studies the synthesized compounds have shown growth stimulant properties. The activity of four of them was higher than 70%, compared with heteroauxin. Vergush A. Pivazyan, Emma A. Ghazaryan, Roza S. Shainova, Rafael A. Tamazyan, Armen G. Ayvazyan, and Aleksandr P. Yengoyan Copyright © 2017 Vergush A. Pivazyan et al. All rights reserved. Study of Fatty Acids Profile in Kernel Oil of Heynea trijuga Roxb. Ex Sims. (syn. Trichilia connaroides (Wight & Arn.) Bentv.) Tue, 17 Jan 2017 09:12:52 +0000 http://www.hindawi.com/journals/jchem/2017/5858720/ Seed oils have been used for centuries by communities as food, medicine, cosmetic applications, and fuel. Recently, there has been a renewed interest in these nontimber forest products specifically for use in cosmetic formulations. The fatty acid compositions of kernel oil of Heynea trijuga was analyzed by GC-FID. The results showed that the oil content was 37.61 percent (w/w) in seed. Seed oil was rich in unsaturated fatty acids. Important fatty acids present were palmitic acid (22.12%), stearic acid (7.51%), oleic acid (25.20%), and linoleic acid (11.65%). Ashutosh K. Mittal and Shishir Tandon Copyright © 2017 Ashutosh K. Mittal and Shishir Tandon. All rights reserved. Synthesis of Ibuprofen Conjugated Molecular Transporter Capable of Enhanced Brain Penetration Mon, 16 Jan 2017 09:45:57 +0000 http://www.hindawi.com/journals/jchem/2017/4746158/ Based on the strong evidences between inflammation and neurodegeneration, nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are considered as effective agents to reduce the risk of Alzheimer’s and Parkinson’s disease. However, the clinical use of NSAIDs in these diseases is limited by low brain distribution. In this study, we had synthesized ibuprofen conjugate which has good brain penetration. S-(+)-Ibuprofen was covalently attached to a molecular transporter having FITC and eight terminal guanidine groups. This conjugate showed good cellular uptake property in live cells. It was also injected into a mouse and the distribution of the compound was examined in each organ. The conjugate was well delivered to mouse brain indicating the conjugate is able to cross the blood-brain barrier. Our novel synthetic ibuprofen conjugate will hopefully deliver other NSAIDs into brain and is therefore applicable to the neurodegenerative diseases treatment or prevention. Goutam Biswas, Wanil Kim, Kyong-Tai Kim, Junhwi Cho, Dongjun Jeong, Keon-Hyoung Song, and Jungkyun Im Copyright © 2017 Goutam Biswas et al. All rights reserved. The Adhesion Mechanism of Marine Mussel Foot Protein: Adsorption of L-Dopa on - and -Cristobalite Silica Using Density Functional Theory Sun, 15 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jchem/2017/8756519/ Marine mussels strongly adhere to various surfaces and endure their attachment under a variety of conditions. In order to understand the basic mechanism involved, we study the adsorption of L-dopa molecule on hydrophilic geminal and terminal isolated silanols of silica (001) surface. High content of modified amino acid L-dopa is found in the glue-like material secreted by the mussels through which it sticks to various surfaces under water. To understand the adsorption behavior, we have made use of periodic Density Functional Theory (DFT) study. The L-dopa molecule adheres to silica surfaces terminated with geminal and terminal silanols via its catechol part. In both cases, the adhesion is achieved through the formation of 4 H-bonds. A binding energy of 29.48 and 31.67 kcal/mol has been estimated, after the inclusion of dispersion energy, for geminal and terminal silanols of silica, respectively. These results suggest a relatively stronger adhesion of dopa molecule for surface with terminal isolated silanols. Shabeer Ahmad Mian and Younas Khan Copyright © 2017 Shabeer Ahmad Mian and Younas Khan. All rights reserved. Response Surface Optimization of Rotenone Using Natural Alcohol-Based Deep Eutectic Solvent as Additive in the Extraction Medium Cocktail Wed, 11 Jan 2017 07:21:01 +0000 http://www.hindawi.com/journals/jchem/2017/9434168/ Rotenone is a biopesticide with an amazing effect on aquatic life and insect pests. In Asia, it can be isolated from Derris species roots (Derris elliptica and Derris malaccensis). The previous study revealed the comparable efficiency of alcohol-based deep eutectic solvent (DES) in extracting a high yield of rotenone (isoflavonoid) to binary ionic liquid solvent system ([BMIM]OTf) and organic solvent (acetone). Therefore, this study intends to analyze the optimum parameters (solvent ratio, extraction time, and agitation rate) in extracting the highest yield of rotenone extract at a much lower cost and in a more environmental friendly method by using response surface methodology (RSM) based on central composite rotatable design (CCRD). By using RSM, linear polynomial equations were obtained for predicting the concentration and yield of rotenone extracted. The verification experiment confirmed the validity of both of the predicted models. The results revealed that the optimum conditions for solvent ratio, extraction time, and agitation rate were 2 : 8 (DES : acetonitrile), 19.34 hours, and 199.32 rpm, respectively. At the optimum condition of the rotenone extraction process using DES binary solvent system, this resulted in a 3.5-fold increase in a rotenone concentration of 0.49 ± 0.07 mg/ml and yield of 0.35 ± 0.06 (%, w/w) as compared to the control extract (acetonitrile only). In fact, the rotenone concentration and yield were significantly influenced by binary solvent ratio and extraction time () but not by means of agitation rate. For that reason, the optimal extraction condition using alcohol-based deep eutectic solvent (DES) as a green additive in the extraction medium cocktail has increased the potential of enhancing the rotenone concentration and yield extracted. Zetty Shafiqa Othman, Nur Hasyareeda Hassan, and Saiful Irwan Zubairi Copyright © 2017 Zetty Shafiqa Othman et al. All rights reserved.