Read by QxMD icon Read

Green chemistry

Jiandi Liu, Bangbang He, Qiang Chen, Junshuai Li, Qing Xiong, Guanghui Yue, Xianhui Zhang, Size Yang, Hai Liu, Qing Huo Liu
Hydrogen peroxide (H2O2) is usually considered to be an important reagent in green chemistry since water is the only by-product in H2O2 involved oxidation reactions. Early studies show that direct synthesis of H2O2 by plasma-water interactions is possible, while the factors affecting the H2O2 production in this method remain unclear. Herein, we present a study on the H2O2 synthesis by atmospheric pressure plasma-water interactions. The results indicate that the most important factors for the H2O2 production are the processes taking place at the plasma-water interface, including sputtering, electric field induced hydrated ion emission, and evaporation...
December 5, 2016: Scientific Reports
Borbála Molnár, Blanka Fodor, Antal Csámpai, Előd Hidvégi, Ibolya Molnár-Perl
A novel, structure-related derivatization principle has been developed in order to quantify cathinone-type synthetic drugs (CTSDs), focusing on the most common pentedrone (PENT), including also 4-fluoromethcathinone (4-FMC), methcathinone (MCTN), 4-methylethcathinone (4-MEC), 3,4-dimethylmethcathinone (3,4-DMMC), and 4-ethylmethcathinone (4-EMC). Firstly, oximated and, secondly, trimethylsilylated CTSD derivatives were characterized by mass fragmentation patterns using GC/MS that led to the development of a harmonized, quantitative, two-steps derivatization methodology...
November 22, 2016: Journal of Chromatography. A
Mathew C Halter, James A Zahn
White biotechnology has made a positive impact on the chemical industry by providing safer, more efficient chemical manufacturing processes that have reduced the use of toxic chemicals, harsh reaction conditions, and expensive metal catalysts, which has improved alignment with the principles of Green Chemistry. The genetically-modified (GM) biocatalysts that are utilized in these processes are typically separated from high-value products and then recycled, or eliminated. Elimination routes include disposal in sanitary landfills, incineration, use as a fuel, animal feed, or reuse as an agricultural soil amendment or other value-added products...
December 1, 2016: Journal of Industrial Microbiology & Biotechnology
Atanu Ghosh, Debasmita Ghosh, Esma Khatun, Papri Chakraborty, Thalappil Pradeep
We report the synthesis and unique reactivity of a new green dithiol protected cluster (DTPC), Ag51(BDT)19(TPP)3 (BDT and TPP are 1,3-benzenedithiol and triphenylphosphine, respectively). The cluster composition was confirmed by electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric studies as well as by other supporting data. Surprisingly, the chemical reactivity between this DTPC and Au25(SR)18 involves only metal ion exchange in Au25(SR)18 without any ligand exchange, while reactions between monothiol protected clusters (MTPCs) show both metal and ligand exchange, an example being the reaction between Ag25DMBT18 and Au25PET18 (where DMBT and PET are 2,4-dimethylbenzenethiol and phenylethanethiol, respectively)...
December 1, 2016: Nanoscale
Gregory Chatel, Emmanuel Naffrechoux, Micheline Draye
Based on our original knowledge and experience on both polychlorinated biphenyls (PCBs) identification in aquatic ecosystems, and use of ionic liquids (ILs) as solvents and/or co-catalysts in green chemistry, we drawn a dared comparison between these two families. Indeed, PCBs has been used during several decades for their new properties, but are now considered as prevalent and persistent pollutants; some toxic effects on environment or human are still revealed. ILs, often designated as "green solvents" are increasingly used in numerous applications, but few studies reported about their environmental impact are still controversial...
November 21, 2016: Journal of Hazardous Materials
E Beristain-Montiel, R Villalobos-Pietrini, G E Arias-Loaiza, S L Gómez-Arroyo, O Amador-Muñoz
New clean technologies are needed to determine concentration of organic pollutants without generating more pollution. A method to extract Persistent Organic Pollutants (POPs) from airborne particulate matter was developed using a novel technology recently patented called ultrasound assisted extraction micro-scale cell (UAE-MSC). This technology extracts, filters, collects the sample, and evaporates the solvent, on-line. No sample transfer is needed. The cell minimizes sample manipulation, solvent consumption, waste generation, time, and energy; fulfilling most of the analytical green chemistry protocol...
November 23, 2016: Journal of Chromatography. A
Cristian Vidal, Joaquín García-Álvarez, Alberto Hernán-Gómez, Alan R Kennedy, Eva Hevia
Shattering the long-held dogma that organolithium chemistry needs to be performed under inert atmospheres in toxic organic solvents, chemoselective addition of organolithium reagents to non-activated imines and quinolines has been accomplished in green, biorenewable deep eutectic solvents (DESs) at room temperature and in the presence of air, establishing a novel and sustainable access to amines. Improving on existing methods, this approach proceeds in the absence of additives; occurs without competitive enolization, reduction or coupling processes; and reactions were completed in seconds...
November 28, 2016: Angewandte Chemie
Yang Song, Howard G Mayes, Matthew J Queensen, Eike B Bauer, Cynthia M Dupureur
The growing interest in green chemistry has fueled attention to the development and characterization of effective iron complex oxidation catalysts. A number of iron complexes are known to catalyze the oxidation of organic substrates utilizing peroxides as the oxidant. Their development is complicated by a lack of direct comparison of the reactivities of the iron complexes. To begin to correlate reactivity with structural elements, we compare the reactivities of a series of iron pyridyl complexes toward a single dye substrate, malachite green (MG), for which colorless oxidation products are established...
November 19, 2016: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
David W Green, Besim Ben-Nissan, Kyung Sik Yoon, Bruce Milthorpe, Han-Sung Jung
Coral skeletons can regenerate replacement human bone in nonload-bearing excavated skeletal locations. A combination of multiscale, interconnected pores and channels and highly bioactive surface chemistry has established corals as an important alternative to using healthy host bone replacements. Here, we highlight how coral skeletal systems are being remolded into new calcified structures or synthetic corals by biomimetic processes, as places for the organized permeation of bone tissue cells and blood vessels...
November 23, 2016: Trends in Biotechnology
David Hughes, Gus Koerbin, Julia M Potter, Nicholas Glasgow, Nic West, Walter P Abhayaratna, Juleen Cavanaugh, David Armbruster, Peter E Hickman
For more than a decade there has been a global effort to harmonise all phases of the testing process, with particular emphasis on the most frequently utilised measurands. In addition, it is recognised that calculated parameters derived from these measurands should also be a target for harmonisation. Using data from the Aussie Normals study we report reference intervals for three calculated parameters: serum osmolality, serum anion gap and albumin-adjusted serum calcium. The Aussie Normals study was an a priori study that analysed samples from 1856 healthy volunteers...
August 2016: Clinical Biochemist. Reviews
Sergi Ruiz-Barragan, Jordi Ribas Ariño, Motoyuki Shiga
The use of high-temperature liquid water (HTW) as a reaction medium is a very promising technology in the field of green chemistry. In order to fully exploit this technology, it is crucial to unravel the reaction mechanisms of the processes carried out in HTW. In this work, the reaction mechanism of 2,5-hexanediol dehydration in HTW has been studied by means of three different ab initio simulations: the string method, metadynamics and molecular dynamics in real time. It is found that the whole reaction involving protonation, bond exchange and deprotonation occurs in a single step without a stable intermediate...
November 30, 2016: Physical Chemistry Chemical Physics: PCCP
Lucy Currie, Julio Fernandez-Cestau, Luca Rocchigiani, Benoît Bertrand, Simon J Lancaster, David L Hughes, Helen Duckworth, Saul T E Jones, Dan Credgington, Thomas J Penfold, Manfred Bochmann
A new family of cyclometallated gold(III) thiolato complexes based on pyrazine-centred pincer ligands has been prepared, (C^N(pz) ^C)AuSR, where C^N(pz) ^C=2,6-bis(4-Bu(t) C6 H4 )pyrazine dianion and R=Ph (1), C6 H4 tBu-4 (2), 2-pyridyl (3), 1-naphthyl (1-Np, 4), 2-Np (5), quinolinyl (Quin, 6), 4-methylcoumarinyl (Coum, 7) and 1-adamantyl (8). The complexes were isolated as yellow to red solids in high yields using mild synthetic conditions. The single-crystal X-ray structures revealed that the colour of the deep-red solids is associated with the formation of a particular type of short (3...
November 9, 2016: Chemistry: a European Journal
Thomas D Canale, Dipankar Sen
The widespread use of organic solvents in industrial processes has focused in recent years on the utility of "green" solvents - those with less harmful environmental, health, and safety properties - such as methanol and formamide. However, protein enzymes, regarded as green catalysts, are often incompatible with organic solvents. Herein, we have explored the oxidative properties of a Fe(III)-heme, or hemin, utilizing catalytic DNA (heme·DNAzyme) in different green solvent-water mixtures. We find that the peroxidase and peroxygenase activities of the heme·DNAzyme are strongly enhanced in 20-30% v/v methanol or formamide, relative to water alone...
November 14, 2016: Biochimica et Biophysica Acta
Viviane P de Souza, Cristiane K Oliveira, Thiago M de Souza, Paulo H Menezes, Severino Alves, Ricardo L Longo, Ivani Malvestiti
Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative...
November 16, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Pınar Acar Bozkurt
Recently, the popularity for green chemistry and chemical process have increased. The approach must comprehensively be considered for these principles in the design of a synthesis method, chemical analysis, or chemical process. Utilization of nontoxic chemicals, environment friendly solvents, and renewable materials are some of the important issues in green synthesis methods. The importance of green synthesis arises in the production of Ag/graphene nanocomposites, due to their future potential applications in nanomedicine and materials engineering...
March 2017: Ultrasonics Sonochemistry
Srinivasan Senthilkumari, Rajendran Sharmila, Gowripriya Chidambaranathan, Ayyasamy Vanniarajan
PURPOSE: Aldose reductase (ALR), the first and rate-limiting enzyme involved in polyol pathway plays a central role in diabetes and its related complications, including diabetic retinopathy (DR). Inhibition of ALR may also be an ideal target for reducing the deleterious effects of DR. Therefore, the purpose of the present study was to investigate the protective effect of epalrestat (EPL), ALR inhibitor on glucose-induced toxicity in ARPE-19 cells. METHODS: ARPE-19 cells were challenged with normal glucose (NG, 5 mM) and high glucose (HG1, 25 mM and HG2, 50 mM) in the presence or absence of EPL...
November 11, 2016: Journal of Ocular Pharmacology and Therapeutics
Abdulrahman M Elbagory, Christopher N Cupido, Mervin Meyer, Ahmed A Hussein
The preparation of gold nanoparticles (AuNPs) involves a variety of chemical and physical methods. These methods use toxic and environmentally harmful chemicals. Consequently, the synthesis of AuNPs using green chemistry has been under investigation to develop eco-friendly nanoparticles. One approach to achieve this is the use of plant-derived phytochemicals that are capable of reducing gold ions to produce AuNPs. The aim of this study was to implement a facile microtitre-plate method to screen a large number of aqueous plant extracts to determine the optimum concentration (OC) for the bio-synthesis of the AuNPs...
November 8, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Katia Martina, Silvia Tagliapietra, Alessandro Barge, Giancarlo Cravotto
The combination of microwave heating and ultrasound irradiation has been successfully exploited in applied chemistry. Besides saving energy, these green techniques promote faster and more selective transformations. The aim of this review is to provide a practical overview of the complimentary and synergistic effects generated by the combination of microwaves and either ultrasound or hydrodynamic cavitation. This will begin with a brief history, as we outline pioneering achievements, and will also update the reader on recent developments...
December 2016: Topics in Current Chemistry (Journal)
Samuel Cheung, Catherine Greene, Robin M Yates
The biochemical processes within the phagosomes of macrophages and dendritic cells are essential to immunity and homeostasis. Measurable properties of the phagosomal lumen include: assessment of various hydrolytic activities, reduction and oxidation events, pH, ion concentrations, and electrochemical gradients. These often-interdependent phagosomal features are commonly evaluated individually, hindering the analysis of the biochemical relationship between these factors within the same phagosome. In addition, the ability of phagosomes within the same cell to behave autonomously is becoming more evident, thus highlighting the need for a technique capable of multiplex analyses of phagosomal lumenal chemistries at the single phagosome level...
2017: Methods in Molecular Biology
Zhen-Yu Wang, Shu-Rong Ban, Meng-Chen Yang, Qing-Shan Li
Organocatalysis and aqueous reactions are identified as the focus of the greening of chemistry. Combining these two strategies effectively remains an interesting challenge in organic synthesis. Herein, we used pyrrolidine-based benzoylthiourea 1c to catalyze the asymmetric Michael addition of cyclohexanone to various nitroolefins in water to afford the corresponding compounds in moderate to good yields, and with excellent diastereoselectivities (up to >99:1 dr) and enantioselectivities (up to 99% ee).
November 2016: Chirality
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"