The Experts below are selected from a list of 81699 Experts worldwide ranked by ideXlab platform
Denis Chusov - One of the best experts on this subject based on the ideXlab platform.
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Indenyl rhodium complexes. Synthesis and catalytic activity in reductive amination using carbon monoxide as a Reducing Agent
Journal of Organometallic Chemistry, 2018Co-Authors: Sofiya A. Runikhina, Mikhail A. Arsenov, Vladimir B. Kharitonov, Elizaveta R. Sovdagarova, Olga Chusova, Yulia V. Nelyubina, Gleb L. Denisov, Dmitry L. Usanov, Denis Chusov, Dmitry A. LoginovAbstract:Abstract Indenyl-ligated rhodium(III) catalyst [(η5-indenyl)RhX2]n (1) is reported for the synthesis of alkylated amines via catalytic reductive amination using carbon monoxide as a Reducing Agent. Water as a solvent was found to be the best media for the reaction. Complex 1 was synthesized via a high-yielding procedure based on the reaction of bis(ethylene) derivative (η5-indenyl)Rh(C2H4)2 with iodine.
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hydrogen free reductive amination using iron pentacarbonyl as a Reducing Agent
Organic and Biomolecular Chemistry, 2017Co-Authors: Oleg I Afanasyev, Dmitry L. Usanov, Denis ChusovAbstract:We developed solvent-free reductive amination without an external hydrogen source using iron pentacarbonyl as a Reducing Agent. Neither a catalyst nor any other additives were employed. Various types of substrates are suitable for the reaction, including those with low reactivity, e.g. benzophenone. Among others, the protocol tolerates bromo-, cyano-, benzyloxy-, pyrimidyl and styryl moieties.
Harry Gruppen - One of the best experts on this subject based on the ideXlab platform.
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Lytic polysaccharide monooxygenases from Myceliophthora thermophila C1 differ in substrate preference and Reducing Agent specificity.
Biotechnology for biofuels, 2016Co-Authors: Matthias Frommhagen, Jaap Visser, Martijn J. Koetsier, Sandra W.a. Hinz, Adrie H. Westphal, Jean-paul Vincken, Willem J. H. Van Berkel, Mirjam A. Kabel, Harry GruppenAbstract:Lytic polysaccharide monooxgygenases (LPMOs) are known to boost the hydrolytic breakdown of lignocellulosic biomass, especially cellulose, due to their oxidative mechanism. For their activity, LPMOs require an electron donor for Reducing the divalent copper cofactor. LPMO activities are mainly investigated with ascorbic acid as a Reducing Agent, but little is known about the effect of plant-derived Reducing Agents on LPMOs activity. Here, we show that three LPMOs from the fungus Myceliophthora thermophila C1, MtLPMO9A, MtLPMO9B and MtLPMO9C, differ in their substrate preference, C1-/C4-regioselectivity and Reducing Agent specificity. MtLPMO9A generated C1- and C4-oxidized, MtLPMO9B C1-oxidized and MtLPMO9C C4-oxidized gluco-oligosaccharides from cellulose. The recently published MtLPMO9A oxidized, next to cellulose, xylan, β-(1 → 3, 1 → 4)-glucan and xyloglucan. In addition, MtLPMO9C oxidized, to a minor extent, xyloglucan and β-(1 → 3, 1 → 4)-glucan from oat spelt at the C4 position. In total, 34 Reducing Agents, mainly plant-derived flavonoids and lignin-building blocks, were studied for their ability to promote LPMO activity. Reducing Agents with a 1,2-benzenediol or 1,2,3-benzenetriol moiety gave the highest release of oxidized and non-oxidized gluco-oligosaccharides from cellulose for all three MtLPMOs. Low activities toward cellulose were observed in the presence of monophenols and sulfur-containing compounds. Several of the most powerful LPMO Reducing Agents of this study serve as lignin building blocks or protective flavonoids in plant biomass. Our findings support the hypothesis that LPMOs do not only vary in their C1-/C4-regioselectivity and substrate specificity, but also in their Reducing Agent specificity. This work strongly supports the idea that the activity of LPMOs toward lignocellulosic biomass does not only depend on the ability to degrade plant polysaccharides like cellulose, but also on their specificity toward plant-derived Reducing Agents in situ.
Anwarul Hasan - One of the best experts on this subject based on the ideXlab platform.
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biosynthesis and characterization of graphene by using non toxic Reducing Agent from allium cepa extract anti bacterial properties
International Journal of Biological Macromolecules, 2019Co-Authors: Noorunnisa P Khanam, Anwarul HasanAbstract:Graphene based materials have attracted huge interest in recent years due to their outstanding properties and applications in various fields including bioengineering, electronics, nanotechnology, composite materials and many more. Despite numerous reports on synthesis of graphene, the mass production of high quality graphene in an inexpensive and eco-friendly method has remained as a challenge. In this work, we present a simple and green method for biosynthesis of graphene by using nontoxic Reducing Agent from Allium Cepa (onion) extracts. Modified Hummers' method was used to synthesis the Graphene oxide (G0) and extracts from Allium Cepa was used as Reducing Agent. The prepared graphene was analyzed by Raman spectroscopy, XRD, FTIR, SEM, TEM and XPS. The experimental results showed that GO was successfully reduced to graphene using onion extract. The Raman spectroscopy results, XPS results and XRD results confirmed the reduction of GO to graphene. The SEM and TEM results also reconfirmed the reduction of GO into graphene, where GO exhibited different morphologies, i.e. hexagonal larger sheets than graphene. The antibacterial properties of the graphene were studied against two gram-negative and gram-positive bacteria. Graphene inhibited cell growth, which proves that our prepared graphene can be useful as an antimicrobial Agent against different microorganisms. This work thus reports the design of a novel, facile synthetic route for a new production method of graphene.
Wenbin Hu - One of the best experts on this subject based on the ideXlab platform.
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role of additives in electroless copper plating using hypophosphite as Reducing Agent
Surface & Coatings Technology, 2012Co-Authors: Kechao Zhou, Wenbin Hu, Dou ZhangAbstract:Abstract In electroless copper plating baths using hypophosphite as the Reducing Agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K 4 Fe(CN) 6 were used to improve the microstructure and properties of copper deposits obtained from electroless copper plating bath using hypophosphite as the Reducing Agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67 × 10 − 5 M or more. The deposition rate increased and the electrical resistivity of the copper deposits decreased slightly with the addition of PEG to the plating solution. The electrical resistivity of copper deposits decreased to 2.85 μΩ cm with 1.67 × 10 − 5 M PEG and 4.70 × 10 − 6 M K 4 Fe(CN) 6 in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current–voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode.
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electroless copper plating on pet fabrics using hypophosphite as Reducing Agent
Surface & Coatings Technology, 2007Co-Authors: Yating Wu, Bin Shen, Wenbin HuAbstract:Abstract Electroless copper plating on PET fabrics using hypophosphite as Reducing Agent was investigated. A continuous copper deposition could be obtained as the nickel ion concentration and temperature were more than 0.0030 M and 65 °C, respectively. The deposition rate increased obviously with the increase of temperature, pH and nickel ion concentration. Potassium ferrocyanide (K4Fe(CN)6) was used to improve the properties of the copper deposits. The addition of K4Fe(CN)6 to the plating solution could reduce the deposition rate and make the deposits become more compact, which led to lower surface resistance of copper-coated fabrics. The copper deposit had an intensified (111) plane orientation with the addition of K4Fe(CN)6 to the plating bath. The conductive fabrics could be prepared at the optimum condition with 0.0038M nickel ions and 2 ppm K4Fe(CN)6. As the copper weight on the fabric was 40 g/m2, the shielding effectiveness (SE) of copper-coated fabrics was more than 85 dB at frequency ranging from 100 MHz to 20 GHz.
Matthias Frommhagen - One of the best experts on this subject based on the ideXlab platform.
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Lytic polysaccharide monooxygenases from Myceliophthora thermophila C1 differ in substrate preference and Reducing Agent specificity.
Biotechnology for biofuels, 2016Co-Authors: Matthias Frommhagen, Jaap Visser, Martijn J. Koetsier, Sandra W.a. Hinz, Adrie H. Westphal, Jean-paul Vincken, Willem J. H. Van Berkel, Mirjam A. Kabel, Harry GruppenAbstract:Lytic polysaccharide monooxgygenases (LPMOs) are known to boost the hydrolytic breakdown of lignocellulosic biomass, especially cellulose, due to their oxidative mechanism. For their activity, LPMOs require an electron donor for Reducing the divalent copper cofactor. LPMO activities are mainly investigated with ascorbic acid as a Reducing Agent, but little is known about the effect of plant-derived Reducing Agents on LPMOs activity. Here, we show that three LPMOs from the fungus Myceliophthora thermophila C1, MtLPMO9A, MtLPMO9B and MtLPMO9C, differ in their substrate preference, C1-/C4-regioselectivity and Reducing Agent specificity. MtLPMO9A generated C1- and C4-oxidized, MtLPMO9B C1-oxidized and MtLPMO9C C4-oxidized gluco-oligosaccharides from cellulose. The recently published MtLPMO9A oxidized, next to cellulose, xylan, β-(1 → 3, 1 → 4)-glucan and xyloglucan. In addition, MtLPMO9C oxidized, to a minor extent, xyloglucan and β-(1 → 3, 1 → 4)-glucan from oat spelt at the C4 position. In total, 34 Reducing Agents, mainly plant-derived flavonoids and lignin-building blocks, were studied for their ability to promote LPMO activity. Reducing Agents with a 1,2-benzenediol or 1,2,3-benzenetriol moiety gave the highest release of oxidized and non-oxidized gluco-oligosaccharides from cellulose for all three MtLPMOs. Low activities toward cellulose were observed in the presence of monophenols and sulfur-containing compounds. Several of the most powerful LPMO Reducing Agents of this study serve as lignin building blocks or protective flavonoids in plant biomass. Our findings support the hypothesis that LPMOs do not only vary in their C1-/C4-regioselectivity and substrate specificity, but also in their Reducing Agent specificity. This work strongly supports the idea that the activity of LPMOs toward lignocellulosic biomass does not only depend on the ability to degrade plant polysaccharides like cellulose, but also on their specificity toward plant-derived Reducing Agents in situ.
