Advances in Chemistry http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Chiral Recognition by Fluorescence: One Measurement for Two Parameters Wed, 23 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ac/2014/987640/ This outlook describes two strategies to simultaneously determine the enantiomeric composition and concentration of a chiral substrate by a single fluorescent measurement. One strategy utilizes a pseudoenantiomeric sensor pair that is composed of a 1,1′-bi-2-naphthol-based amino alcohol and a partially hydrogenated 1,1′-bi-2-naphthol-based amino alcohol. These two molecules have the opposite chiral configuration with fluorescent enhancement at two different emitting wavelengths when treated with the enantiomers of mandelic acid. Using the sum and difference of the fluorescent intensity at the two wavelengths allows simultaneous determination of both concentration and enantiomeric composition of the chiral acid. The other strategy employs a 1,1′-bi-2-naphthol-based trifluoromethyl ketone that exhibits fluorescent enhancement at two emission wavelengths upon interaction with a chiral diamine. One emission responds mostly to the concentration of the chiral diamine and the ratio of the two emissions depends on the chiral configuration of the enantiomer but independent of the concentration, allowing both the concentration and enantiomeric composition of the chiral diamine to be simultaneously determined. These strategies would significantly simplify the practical application of the enantioselective fluorescent sensors in high-throughput chiral assay. Shanshan Yu and Lin Pu Copyright © 2014 Shanshan Yu and Lin Pu. All rights reserved. Study of Swelling Properties and Thermal Behavior of Poly(N,N-Dimethylacrylamide-co-Maleic Acid) Based Hydrogels Tue, 22 Jul 2014 08:38:55 +0000 http://www.hindawi.com/journals/ac/2014/147398/ Hydrogels copolymers N,N-dimethylacrylamide (DMA) and maleic acid (MA) were prepared by free-radical polymerization at 56°C in aqueous solution, using N,N-methylenebisacrylamide (NMBA) as cross-linking agent and potassium persulfate (KPS) as initiator. The effects of comonomer composition, cross-linker content, and variation of pH solutions on the swelling behavior of polymers were investigated. The obtained results showed an increase of the swelling of poly(N,N-dimethylacrylamide-co-maleic acid) (P(DMA-MAx)) as the content of maleic acid increases in the polymeric matrix, while they indicate a great reduction of the degree of swelling as the cross-linking agent ratio increases. It was also shown that the swelling of copolymer hydrogels increased with the increase of pH and the maximum extent was reached at pH 8.7 in all compositions. Fourier transform infrared spectroscopy (FTIR) revealed the existence of hydrogen bonding interactions between the carboxylic groups of MA and the carbonyl groups of DMA. Differential scanning calorimetry analysis (DSC) showed an increase of the glass-transition temperature () as concentrations of MA and NMBA increased. Thermogravimetric analysis (TGA) of copolymers was performed to investigate the degradation mechanism. Sadjia Bennour and Fatma Louzri Copyright © 2014 Sadjia Bennour and Fatma Louzri. All rights reserved. Selenium (Se) Regulates Seedling Growth in Wheat under Drought Stress Tue, 22 Jul 2014 06:51:32 +0000 http://www.hindawi.com/journals/ac/2014/143567/ Selenium (Se) is an essential micronutrient with a range of physiological and antioxidative properties. Reports regarding effect of Se application on plants growth and development are not consistent. The identification of effective Se dose and application method is crucial for better understanding of Se translocation within crop plants under drought stress. The present study aimed at investigating the role of Se supplementation in improving the drought tolerance potential of wheat at early growth stages. Two wheat genotypes (Kohistan-97 and Pasban-90) were grown in plastic pots (8 × 12 cm) in green/wire-house experiments. Results demonstrated that the growth and biomass of seedlings increased at high Se foliar concentrations and decreased at low and high Se fertigation levels. The seedlings exhibited the highest values for plant height stress tolerance index (PHSI), root length stress tolerance index (RLSI), dry matter stress tolerance index (DMSI), and fresh matter stress tolerance indices (FMSI) at Se fertigation level of 7.35 μM, whereas Se foliar treatment of 7.06 μM resulted in maximum values for these indices. The seedlings foliarly sprayed with Se maintained higher DMSI and FMSI than those fertigated with Se which suggests that Se foliar spray is more effective than Se fertigation for improving drought tolerance. Fahim Nawaz, Muhammad Yasin Ashraf, Rashid Ahmad, Ejaz Ahmad Waraich, and Rana Nauman Shabbir Copyright © 2014 Fahim Nawaz et al. All rights reserved. Synthesis and Antimicrobial Activity of New Schiff Base Compounds Containing 2-Hydroxy-4-pentadecylbenzaldehyde Moiety Mon, 21 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ac/2014/921857/ Various novel Schiff base compounds have been synthesized by reaction of 2-hydroxy-4-pentadecylbenzaldehyde with substituted benzothiophene-2-carboxylic acid hydrazide and different substituted aromatic or heterocyclic amines in the presence of acetic acid in ethanol. The structures of all these compounds were confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral data and have been screened for antibacterial and antifungal activity. Gadada Naganagowda, Reinout Meijboom, and Amorn Petsom Copyright © 2014 Gadada Naganagowda et al. All rights reserved. Solar UV-Assisted Pretreatment of River Water Samples for the Voltammetric Monitoring of Nickel and Cobalt Ultratraces Mon, 21 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ac/2014/938419/ The application of solar UV radiation as sample digestion method is reported. The method is employed in adsorptive stripping voltammetric determination of nickel and cobalt in river water samples. The river water samples were collected from downstream of Warnow River (Germany) and acidified to pH of by addition of ultrapure 65% HNO3. Furthermore, 3.4 mgL−1 ultrapure hydrogen peroxide solution was added to the samples as photochemical reaction initiator. The samples were transferred to UV-A transparent polyethylene terephthalate bottles and put in the sunshine for UV irradiation for six and 12 hours at a UV-A intensity of 3.90 mW/m2. The comparison of the concentration values showed that, 6 hours of solar UV irradiation at 3.90 mW/m2 UV-A intensity is not sufficient to complete the digestion process though it yields much better results than the undigested original sample. However, 12 hours of solar UV-A irradiation under similar conditions is almost as effective as a 30 W artificial UV lamp (254 nm) and can be applied to the digestion of dissolved organic carbon in trace nickel (II) and cobalt (II) analysis in natural waters such as river water, lake waters, and well waters. Gelaneh Woldemichael and Gerd-Uwe Flechsig Copyright © 2014 Gelaneh Woldemichael and Gerd-Uwe Flechsig. All rights reserved. Heteroring Annulated Benzimidazolinone Condensed Azepinone Derivatives: A New Class of Highly Potent Antioxidants Sun, 20 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ac/2014/961076/ A new class of benzimidazolinone condensed azepinone derivatives annulated on its face “d” with pyrazole, isoxazole, pyrimidine, benzodiazepine, and benzothiazepine nucleus in 3–8, respectively, have been evaluated for their antioxidant activity by DPPH method. Results indicate these to belong to a novel class of highly potent antioxidant agents. Neha Garg, Priyanka Jain, and D. Kishore Copyright © 2014 Neha Garg et al. All rights reserved. Synthesis of Disperse Dyes from Pyridone and Resorcinol Coupled to Diazotized 2-Amino-4-chloro-5-formylthiazole and Application to Polyester Thu, 17 Jul 2014 10:31:05 +0000 http://www.hindawi.com/journals/ac/2014/864286/ The aim of this study was to synthesize disperse dyes in the derivative of 2-amino-4-chloro-5-formylthiazole by conventional diazotization and couplings with pyridone and resorcinol. The dyes were characterized by visible absorption spectroscopy, IR spectral studies, and 1H and 13C NMR. The pyridone and resorcinol substituted dyes exhausted well with good depth on 100% polyester fabrics with a shade of brown and purple colours, respectively. The heteroatom and the intrinsic conjugation in the thiazole structure results in high bathochromic shifts and lead to brightness of shades. The dyed fabrics showed very good to excellent wash fastness and moderate to good light and perspiration fastness properties. Yusuf Y. Lams, P. O. Nkeonye, K. A. Bello, M. K. Yakubu, and A. O. Lawal Copyright © 2014 Yusuf Y. Lams et al. All rights reserved. The Biological Side of Water-Soluble Arene Ruthenium Assemblies Thu, 17 Jul 2014 07:55:44 +0000 http://www.hindawi.com/journals/ac/2014/589686/ This review article covers the synthetic strategies, structural aspects, and host-guest properties of ruthenium metalla-assemblies, with a special focus on their use as drug delivery vectors. The two-dimensional metalla-rectangles show interesting host-guest possibilities but seem less appropriate for being used as drug carriers. On the other hand, metalla-prisms allow encapsulation and possible targeted release of bioactive molecules and consequently show some potential as drug delivery vectors. The reactivity of these metalla-prisms can be fine-tuned to allow a fine control of the guest’s release. The larger metalla-cubes can be used to stabilize the formation of G-quadruplex DNA and can be used to encapsulate and release photoactive molecules such as porphins. These metalla-assemblies demonstrate great prospective in photodynamic therapy. Bruno Therrien and Julien Furrer Copyright © 2014 Bruno Therrien and Julien Furrer. All rights reserved. Cu(II) Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line Mon, 14 Jul 2014 10:26:29 +0000 http://www.hindawi.com/journals/ac/2014/630575/ A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II). The ligands are coordinated to Cu(II) ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic. Pulipaka Ramadevi, Rinky Singh, Akhilesh Prajapati, Sarita Gupta, and Debjani Chakraborty Copyright © 2014 Pulipaka Ramadevi et al. All rights reserved. Synthesis of New Imidazolidine and Tetrahydropyrimidine Derivatives Mon, 14 Jul 2014 08:10:59 +0000 http://www.hindawi.com/journals/ac/2014/834641/ Synthesis of new imidazolidine and tetrahydropyrimidine derivatives 3a, b and 4a–c as cyclic 1,3-diamines under two reaction conditions (A and B) is described. Under reaction conditions-A, a suspension of (E)-2-cyano-2-(oxazolidin-2-ylidene)ethanethioamide 1 (1 eq.) and diaminoalkanes 2a–e (2 eq.) in absolute ethanol is heated under reflux for 16–22 h to afford 3a, b and 4a–c. Alternatively, under reaction conditions-B, a solution of thioamide 1 (1 eq.) in diaminoalkanes 2a–e (3 eq.) is stirred under solvent-free conditions at room temperature for 3 days to give desired products. Reaction conditions-A for having higher yields, shorter reaction times, and required less diamines is more effective than reaction conditions-B. Oxazolidine ring opening is observed by reacting compound 1 with all of the diamines 2a–e, but the thioamide group only reacts with nonbulky diamines 2a, b. The chemical structures of novel compounds were confirmed by 1H NMR, 13C NMR, elemental analysis, and FT-IR spectrometry. Hamid Beyzaei, Reza Aryan, and Zahra Keshtegar Copyright © 2014 Hamid Beyzaei et al. All rights reserved. Appraisal on Textured Grain Growth and Photoconductivity of ZnO Thin Film SILAR Sun, 13 Jul 2014 11:49:21 +0000 http://www.hindawi.com/journals/ac/2014/549019/ ZnO thin films were prepared by successive ionic layer adsorption reaction (SILAR) method. The textured grain growth along c-axis in pure ZnO thin films and doped with Sn was studied. The structural analysis of the thin films was done by X-ray diffraction and surface morphology by scanning electron microscopy. Textured grain growth of the samples was measured by comparing the peak intensities. Textured grain growth and photo current in ZnO thin films were found to be enhanced by doping with Sn. ZnO thin film having good crystallinity with preferential (002) orientation is a semiconductor with photonic properties of potential benefit to biophotonics. From energy dispersive X-ray analysis, it is inferred that oxygen vacancy creation is responsible for the enhanced textured grain growth in ZnO thin films. Deepu Thomas, Sunil C. Vattappalam, Sunny Mathew, and Simon Augustine Copyright © 2014 Deepu Thomas et al. All rights reserved. Synthesis and Characterization of Tolvaptan Impurities Thu, 10 Jul 2014 11:45:34 +0000 http://www.hindawi.com/journals/ac/2014/471950/ Twenty-six possible as well as observed impurities during the preparation of Tolvaptan have been identified, prepared, and characterized by HPLC (high performance liquid chromatography), NMR (nuclear magnetic resonance), and mass spectra. Control of these impurities, formed during various stages of Tolvaptan preparation, has been mentioned in this paper. Madhuresh Kumar Sethi, Vijendra Singh Rawat, Jayaprakash Thirunavukarasu, Rajakrishna Yerramalla, and Anish Kumar Copyright © 2014 Madhuresh Kumar Sethi et al. All rights reserved. Azadirachta indica Mediated Bioactive Lyocell Yarn: Chemical and Colour Characterization Tue, 01 Jul 2014 07:29:04 +0000 http://www.hindawi.com/journals/ac/2014/259171/ The study deals with preparing aesthetic textiles using methanolic extract of Azadirachta indica leaves. The extract with metallic and natural mordents was utilized to create various shades on lyocell yarn using exhaust technique of dyeing. Aesthetic values of dyed yarns were analyzed in terms of colourimetric parameters, that is, CIE and colour fastness. The attachment of Azadirachta indica compounds has been confirmed by using infrared spectroscopy (IR) analysis. The dyed samples exhibit moderate to good fastness properties. The study showed that lyocell yarn treated at 15% (owf) methanolic extract of Azadirachta indica leaves can be utilized as effective bioactive textiles. Azadirachta indica is an alternative to synthetic antimicrobial agents. This bioactive yarn can be used in fashion as well as in medicinal industry. B. H. Patel, K. U. Desai, and P. K. Jha Copyright © 2014 B. H. Patel et al. All rights reserved. Development and Validation of Stability Indicating LC-PDA Method for Mycophenolate Mofetil in Presence of Mycophenolic Acid and Its Application for Degradation Kinetics and pH Profile Study Mon, 30 Jun 2014 08:15:23 +0000 http://www.hindawi.com/journals/ac/2014/719385/ Factorial design tool applied for development of isocratic reversed-phase stability-indicating HPLC method for the analysis of mycophenolate mofetil (MMF) and its degradation products. MMF stress degradation products mycophenolate acid (MPA) and DP3 (USP impurity H) were isolated and used for quantitation. Separation achieved on a Symmetry C18 (250 mm × 4.6 mm, 5.0 μ) column using a methanol: acetate buffer (75 : 25 v/v), pH 6.0 (adjusted with acetic acid), at 0.5 mL flow rate, column maintained at 55°C, and data integrated at 251 nm. MMF is subjected to hydrolysis, oxidation, heat degradation, and so forth; under all these conditions degraded products are well separated. The method validation characteristics included accuracy, precision, linearity, range, specificity, and sensitivity. Robustness testing is conducted to evaluate the effect of minor changes to the chromatographic conditions and to establish appropriate system suitability parameters. The proposed method is used to investigate kinetics of acid, alkali hydrolysis and oxidation process. Major degradation products MPA and DP3 were isolated and quantitated. Characterization of MPA by NMR and LC-MS/MS and other degraded products by LC-MS/MS is attempted successfully. The method is used successfully for the quality assessment of three MMF drug commercial formations and its acid, alkali, and oxidative degradation kinetics study. Vishnu P. Choudhari and Anna Pratima G. Nikalje Copyright © 2014 Vishnu P. Choudhari and Anna Pratima G. Nikalje. All rights reserved. Metal-Enhanced Fluorescence and FRET in Multilayer Core-Shell Nanoparticles Mon, 09 Jun 2014 08:53:43 +0000 http://www.hindawi.com/journals/ac/2014/812313/ In recent years, various methods for the synthesis of fluorescent core-shell nanostructures were developed, optimized, and studied thoroughly in our research group. Metallic cores exhibiting plasmonic properties in the UV and visible regions of the electromagnetic spectrum were used to increase substantially the brightness and stability of organic fluorophores encapsulated in silica shells. Furthermore, the efficiency and range of Förster resonant energy transfer (FRET) between donor and acceptor molecules located in the vicinity of the metallic core was shown to be enhanced. Such multilayer nanoparticle architectures offer, in addition to the aforementioned advantages, excellent chemical and physical stability, solubility in aqueous media, low toxicity, and high detectability. In view of these enviable characteristics, a plethora of applications have been envisioned in biology, analytical chemistry, and medical diagnostics. In this paper, advances in the development of multilayer core-shell luminescent nanoparticle structures and selected applications to bioanalytical chemistry will be described. Jérémie Asselin, Mathieu L. Viger, and Denis Boudreau Copyright © 2014 Jérémie Asselin et al. All rights reserved. Comparative Study on the Effects of Surfactants on the Electroless Copper Coated Solar Cell and Optimizing Its Process Parameters Thu, 05 Jun 2014 12:04:09 +0000 http://www.hindawi.com/journals/ac/2014/513715/ An experimental investigation on optimizing process parameters in the electroless copper coatings on solar photovoltaic cells under specific coating conditions has been carried out and reported. Coating parameters such as pH, temperature, and surfactants concentration were varied, and corresponding coating thickness and voltage were measured. To optimize the above parameters, design of experiment was conducted using full factorial method. The pH was varied at 4 different values such as 4-5, 5-6, 8-9, and 9-10 and temperature was varied at different values such as 75°C, 80°C, 85°C, and 90°C. The two different surfactants such as Sodium Do-decyl sulfate and Cetyl tri ammonium bromide were added and their concentration was varied from 0–1.5 g/L to 0–1.8 g/L, respectively. When pH was 8-9, the coating thickness was maximum of 12 μm and 11.63 μm and it was minimum of 3 μm and 2.6 μm, when pH was at 4-5 for Sodium Do-decyl sulfate and Cetyl tri ammonium bromide respectively. The coating thickness increases up to 12 μm when the temperature was 85°C and further increase in temperature destabilizes the electroless bath. The coating thickness was a maximum of 11.25 μm/hr and 10.53 μm/hr, when the Sodium Dodecyl sulfate and Cetyl tri ammonium bromide concentrations were 1.2 g/L and 1.5 g/L, respectively. The increased coating thickness of solar cells imparts increased open circuit voltage from 0.43 V to 0.65 V. The detailed experimental results and their analysis are presented in the main paper. M. Jeevarani and R. Elansezhian Copyright © 2014 M. Jeevarani and R. Elansezhian. All rights reserved. Synthesis and Characterization of Ferrocene Derivatives and Preliminarily Electrocatalytic Oxidation of L-Cysteine at Nafion-Ferrocene Derivatives Modified Glassy Carbon Electrode Sun, 25 May 2014 00:00:00 +0000 http://www.hindawi.com/journals/ac/2014/987481/ Five new structural ferrocene derivatives (2a~2e) were firstly synthesized and characterized by 1H NMR, 13C NMR, ESI-MS, and XRD. Subsequently, the preliminarily electrocatalytic oxidation of L-cysteine (L-Cys) at nafion-ferrocene derivatives modified glassy carbon electrode (GCE) has also been investigated by cyclic voltammetry. The results showed that 2e can dramatically electrocatalyze the oxidation of L-cysteine at its modified GCE in 0.1 mol L−1 NaNO3 aqueous solution with a quasireversible process with  mV. Jianping Yong, Xiaoyu Jiang, Xiaoyuan Wu, Shuijin Huang, Qikai Zhang, and Canzhong Lu Copyright © 2014 Jianping Yong et al. All rights reserved.