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Green chemistry

Napaporn Youngvises, Kittigan Suwannasaroj, Jaroon Jakmunee, Awadh AlSuhaimi
Multi-reverse flow injection analysis (Mr-FIA) integrated with multi-optical sensor was developed and optimized for the simultaneous determination of multi ions; Mn(II), Fe(II), Cu(II) and Fe(III) in water samples. The sample/standard solutions were propelled making use of a four channels peristaltic pump whereas 4 colorimetric reagents specific for the metal ions were separately injected in sample streams using multi-syringe pump. The color zones that formed in the individual mixing coils were then streamed into multi-channels spectrometer, which comprised of four flows through cell and four pairs of light emitting diode and photodiode, whereby signals were measured concurrently...
May 1, 2017: Talanta
Hao Li, Feng Qin, Zhiping Yang, Ximin Cui, Jianfang Wang, Lizhi Zhang
Selective organic transformation under mild conditions constitutes a challenge in green chemistry, especially for alcohol oxidation, which typically requires environmentally unfriendly oxidants. Here, we report a new plasmonic catalyst of Au supported on BiOCl containing oxygen vacancies. It photocatalyzes selective benzyl alcohol oxidation with O2 under visible light through synergistic action of plasmonic hot electrons and holes. Oxygen vacancies on BiOCl facilitate the trapping and transfer of plasmonic hot electrons to adsorbed O2, producing •O2(‒) radicals, while plasmonic hot holes remaining on the Au surface mildly oxidize benzyl alcohol to corresponding carbon-centered radicals...
February 17, 2017: Journal of the American Chemical Society
Siomenan Coulibali, Elsa Deruer, Elizabeth Godin, Sylvain Canesi
A new stereoselective arylative cyclopropanation process involving treatment of halogenated dienone systems in the presence of a Michael donor containing a nitro-aryl-sulfone has been developed. This transformation enables production of an arylated cyclopropane under mild conditions and occurs via a Michael-Smiles ring closure cascade process, reflecting the concepts of green chemistry and atom economy.
February 16, 2017: Organic Letters
Sergi Vela, Martin Verot, Emmanuel Fromager, Vincent Robert
The present paper reports the application of a computational framework, based on the quantum master equation, the Fermi's golden Rule, and conventional wavefunction-based methods, to describe electron transport through a spin crossover molecular junction (Fe(bapbpy) (NCS)2, 1, bapbpy = N-(6-(6-(Pyridin-2-ylamino)pyridin-2-yl)pyridin-2-yl)-pyridin-2-amine). This scheme is an alternative to the standard approaches based on the relative position and nature of the frontier orbitals, as it evaluates the junction's Green's function by means of accurate state energies and wavefunctions...
February 14, 2017: Journal of Chemical Physics
Antoine Duval, Luc Averous
Various biobased polyphenols (lignins and condensed tannins) were derivatized with vinyl ethylene carbonate, a functional cyclic carbonate, to obtain multifunctional aromatic polymers carrying vinyl groups. The reaction was optimized on a condensed tannin and soda lignin. In both cases, a full conversion of the phenol groups is achieved in only 1 h at 150 °C, without solvent and with K2CO3 as cheap and safe catalyst. This reaction was later applied to other condensed tannins and technical lignins (Kraft and organosolv), showing only little dependence on the chemical structure of the polyphenols...
February 14, 2017: ChemSusChem
Li-Wen Xu, Jiang-Bo Huang, Xing-Feng Bai, Li Li, Zhan-Jiang Zheng, Zheng Xu, Yu-Ming Cui, Jiao Cao
Direct functionalization of terpyridines is an increasingly important topic in the field of dyes and catalysis as well as supramolecular chemistry, but its synthesis and transformation is usually challenging. In this manuscript, we reported a HOMO-raising strategy for the construction of a super-stable novel terpyridine chromphores, in which the selective oxidation of terpyridines at its 3-position was determined successfully to the synthesis of phenol-functionalization of terpyridines (TPyOHs) bearing a hydrogen bonding group...
February 8, 2017: Chemistry: a European Journal
Aml I Mekkawy, Mohamed A El-Mokhtar, Nivien A Nafady, Naeima Yousef, Mostafa A Hamad, Sohair M El-Shanawany, Ehsan H Ibrahim, Mahmoud Elsabahy
In the present study, silver nanoparticles (AgNPs) were synthesized via biological reduction of silver nitrate using extract of the fungus Fusarium verticillioides (green chemistry principle). The synthesized nanoparticles were spherical and homogenous in size. AgNPs were coated with polyethylene glycol (PEG) 6000, sodium dodecyl sulfate (SDS), and β-cyclodextrin (β-CD). The averaged diameters of AgNPs were 19.2±3.6, 13±4, 14±4.4, and 15.7±4.8 nm, for PEG-, SDS-, and β-CD-coated and uncoated AgNPs, respectively...
2017: International Journal of Nanomedicine
Salman A Khan
2-amino-4-(4-bromophenyl)-8-methoxy-5,6-dihydrobenzo[h]quinoline-3-carbonitrile (ABDC) was synthesized by the reaction of (2E)-2-(4 bromobenzylidene) - 6 -methoxy-3,4-dihydronaphthalen-1(2H)-one (Chalcone) with malononitrile and ammonium acetate under microwave irradiation. Chalcone was synthesised by the reaction 4-bromobenzaldehyd, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one under the same condition. Structure of ABDC was conformed by (1)H and (13)C NMR, FT-IR, EI-MS spectral studies and elemental analysis...
February 8, 2017: Journal of Fluorescence
Zaman Khan, Abdul Rehman, Muhammad Atif Nisar, Saima Zafar, Inga Zerr
Bacteria develop a variety of adaptations at transcriptomic, metabolomic and proteomic levels in order to survive potentially damaging environmental perturbations. Present study is exploring the fluctuations in proteome of E. coli P4 to knob Cd(+2)-induced cytotoxicity. An attempt was also made to integrate all these approaches to gain comprehensive insight of Cd(+2) stress response in E. coli P4. This study is exposing the altered behavior of various proteins and their underlying metabolic pathways which have previously not been reported with reference to Cd(+2) stress such as sulfoquinovose biosynthesis and degradation pathway...
January 27, 2017: Chemosphere
Prasanta Kumar Mohapatra
Studies on the extraction of actinide ions from radioactive feeds have great relevance in nuclear fuel cycle activities, mainly in the back end processes focused on reprocessing and waste management. Room temperature ionic liquid (RTIL) based diluents are becoming increasingly popular due to factors such as more efficient extraction vis-à-vis molecular diluents, higher metal loading, higher radiation resistance, etc. The fascinating chemistry of the actinide ions in RTIL based solvent systems due to complex extraction mechanisms makes it a challenging area of research...
January 31, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
C Afonso-Olivares, T Čadková, Z Sosa-Ferrera, J J Santana-Rodríguez, L Nováková
To follow the twelve "green analytical chemistry" (GAC) principles, it is necessary to continuously develop analytical extraction and determination methodologies to assess the presence of micropollutants, such as pharmaceuticals, in environmental samples. A reduction in the analysis time and solvent quantity, which is one of the GAC principles, has been achieved through a simplified solid-phase extraction (SPE) procedure combined with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of twenty-three pharmaceuticals in liquid environmental samples using N-vinylpyrrolidone-divinylbenzene copolymer (OASIS HLB) cartridges...
January 23, 2017: Journal of Chromatography. A
Armin Presser, Andrea Feichtinger, Silke Buzzi
ABSTRACT: An efficient and economically viable approach for the large-scale conversion of artemisinin into the antimalarial frontline drug artesunate was developed. This advanced synthesis includes an NaBH4-induced reduction, followed by an esterification with succinic anhydride under basic conditions. The entire conversion follows the principles of green chemistry, i.e., application of reusable solvents. GRAPHICAL ABSTRACT: HASH(0x42c2588)
2017: Monatshefte Für Chemie
Kavitha Rani P R, Annette Fernandez, Shiny P Laila, Arunkumar B, Sreelakshmi C S, Vishnu V S
A phenaxazone compound [5H-Benzo[a]phenoxazin-5-one (BP)]along with an aminoquinone[2-[(o-hydroxyphenyl)amino]-1,4-naphthaquinone (HAN)] derivatives were synthesized from lawsone using ultrasound irradiation technique. The structure of the compounds were characterized by elemental analysis and various spectral studies. Optoelectronic properties were studied using Schrodinger material science suit (2015). The compounds exhibit fluorescence emission in longer wave length it may find applications in photodynamic therapy...
January 22, 2017: Photodiagnosis and Photodynamic Therapy
Sara Mattiello, Myles Rooney, Alessandro Sanzone, Paolo Brazzo, Mauro Sassi, Luca Beverina
Recently, oxygen-equilibrated water solutions of Kolliphor EL, a well-known surfactant, have been seen to form nanomicelles with oxygen-free cores. This has prompted the successful testing of the core environment as a green medium for palladium-catalyzed Suzuki-Miyaura cross couplings. The versatility of these conditions is endorsed by several examples, including the synthesis of relevant molecular semiconductors. The reaction medium can also be recycled, opening the way for an extremely easy and green chemistry compliant methodology...
January 25, 2017: Organic Letters
Nitesh Dhiman, Markandeya, Amrita Singh, Neeraj K Verma, Nidhi Ajaria, Satyakam Patnaik
ZnO NPs were synthesized by a prudent green chemistry approach in presence of polyacrylamide grafted guar gum polymer (pAAm-g-GG) to ensure uniform morphology, and functionality and appraised for their ability to degrade photocatalytically Acridine Orange (AO) dye. These ZnO@pAAm-g-GG NPs were thoroughly characterized by various spectroscopic, XRD and electron microscopic techniques. The relative quantity of ZnO NPs in polymeric matrix has been estimated by spectro-analytical procedure; AAS and TGA analysis...
January 13, 2017: Journal of Colloid and Interface Science
Dipak Dilip Gadade, Sanjay Sudhakar Pekamwar
Cocrystal is a concept of the supramolecular chemistry which is gaining the extensive interest of researchers from pharmaceutical and chemical sciences and of drug regulatory agencies. The prominent reason of which is its ability to modify physicochemical properties of active pharmaceutical ingredients. During the development of the pharmaceutical product, formulators have to optimize the physicochemical properties of active pharmaceutical ingredients. Pharmaceutical cocrystals can be employed to improve vital physicochemical characteristics of a drug, including solubility, dissolution, bioavailability and stability of pharmaceutical compounds while maintaining its therapeutic activity...
December 2016: Advanced Pharmaceutical Bulletin
Martina Cugovčan, Jasna Jablan, Jasmina Lovrić, Dominik Cinčić, Nives Galić, Mario Jug
Mechanochemical activation using several different co-grinding additives was applied as a green chemistry approach to improve physiochemical and biopharmaceutical properties of praziquantel (PZQ). Liquid assisted grinding with an equimolar amount of citric acid (CA), malic acid (MA), salicylic acid (SA) and tartaric acid (TA) gained in cocrystal formation, which all showed pH-dependent solubility and dissolution rate. However, the most soluble cocrystal of PZQ with MA was chemically unstable, as seen during the stability testing...
January 10, 2017: Journal of Pharmaceutical and Biomedical Analysis
Timothy H Yosca, Aaron P Ledray, Joanna Ngo, Michael T Green
Protonated ferryl (or iron(IV)hydroxide) intermediates have been characterized in several thiolate-ligated heme proteins that are known to catalyze C-H bond activation. The basicity of the ferryl intermediates in these species has been proposed to play a critical role in facilitating this chemistry, allowing hydrogen abstraction at reduction potentials below those that would otherwise lead to oxidative degradation of the enzyme. In this contribution, we discuss the events that led to the assignment and characterization of the unusual iron(IV)hydroxide species, highlighting experiments that provided a quantitative measure of the ferryl basicity, the iron(IV)hydroxide pKa...
January 16, 2017: Journal of Biological Inorganic Chemistry: JBIC
Pik-Ling Lam, Wai-Yeung Wong, Zhaoxiang Bian, Chung-Hin Chui, Roberto Gambari
Nanotechnology manipulates therapeutic agents at the nanoscale for the development of nanomedicines. However, there are current concerns over nanomedicines, mainly related to the possible toxicity of nanomaterials used for health medications. Due to their small size, they can enter the human body more readily than larger sized particles. Green chemistry encompasses the green synthesis of drug-loaded nanoparticles by reducing the use of hazardous materials in the synthesis process, thus reducing the adverse health impacts of pharmaceutics...
January 12, 2017: Nanomedicine
Eric S Manas, Darren V S Green
The acronym "CADD" is often used interchangeably to refer to "Computer Aided Drug Discovery" and "Computer Aided Drug Design". While the former definition implies the use of a computer to impact one or more aspects of discovering a drug, in this paper we contend that computational chemists are most effective when they enable teams to apply true design principles as they strive to create medicines to treat human disease. We argue that teams must bring to bear multiple sub-disciplines of computational chemistry in an integrated manner in order to utilize these principles to address the multi-objective nature of the drug discovery problem...
January 9, 2017: Journal of Computer-aided Molecular Design
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