scholarly journals Methanol oxidation over copper supported catalysts.

2020 ◽  
Vol 45 (5) ◽  
Author(s):  
L. Leke ◽  
O A. Olawuyi ◽  
S. O Okopi ◽  
T T Weor ◽  
R. P.K. Wells ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Co Adsorption ◽  
Supported Catalyst ◽  
Nitrogen Adsorption ◽  
Copper Catalysts ◽  
High Yield ◽  
Pure Alumina ◽  
Pure Silica ◽  
Oxidation Of Methanol ◽  
High Yields

Oxidation of methanol has been studied over a range of temperature and contact times with a synthesised, 1wt % copper catalysts supported over Al2O3 and SiO2. Characterisation of these catalysts was performed by nitrogen adsorption and porosity measurements (BET), X-Ray Diffraction (XRD), and IR spectroscopy of adsorbed CO. BET measurement revealed surface areas reducing from 105 to 104 m2g-1 for pure alumina to copper supported catalyst while the silica ones reduced from 247 to 240 m2g-1 for pure silica to the copper supported respectively. Pore sizes also reduced from 32 – 23 nm and 23 – 20.3 nm for the alumina and silica catalysts respectively. No crystalline phases from the diffraction patterns of the loaded metals were found to be present on the XRD. CO adsorption studies showed the presence of small cluster metal atoms adsorbed on the surface of the catalysts with Temperature Programmed Reduction (TPR) experiments revealing the presence of partially oxidised and well dispersed Cu atoms. The alumina supported catalyst were more active than the silica ones while for selectivity and yield for formaldehyde, the reverse was the case. The alumina supported significantly showed high yields of Dimethyl ether (DME) while the silica showed high yield for methyl formate (MF) with COx and CH4 detected in very small quantities.

Evaluation of germ plasm for resistant to Soybean mosaic virus (SMV)

2020 ◽  
Vol 21 (1) ◽  
pp. 6-9
Author(s):  
Wuye Ria Andayanie
Keyword(s):  
Abiotic Stress ◽  
Environmental Factors ◽  
Mosaic Virus ◽  
Polyclonal Antibody ◽  
Symptom Severity ◽  
Germ Plasm ◽  
Polyclonal Antibodies ◽  
Soybean Mosaic Virus ◽  
High Yield ◽  
High Yields

Soybean superior varieties with high yields and are resistant to abiotic stress have been largely released, although some varieties grown in the field are not resistant to SMV. In addition, the opportunity to obtain lines of hope as prospective varieties with high yield and resistance to SMV is very small. The method for evaluating soybean germplasm is based on serological observations of 98 accessions of leaf samples from SMV inoculation with T isolate. The evaluation results of 98 accessions based on visual observations showed 31 genotypes reacting very resistant or healthy to mild resistant category to SMV T isolate  with a percentage of symptom severity of 0 −30 %. Among 31 genotypes there are 2 genotypes (PI 200485; M8Grb 44; Mlg 3288) with the category of visually very resistant and resistant, respectively and  Mlg 3288  with the category of mild resistant.  They have a good agronomic appearance with a weight of 100 seeds (˃10 g) and react negatively with polyclonal antibodies to SMV, except Mlg 3288 reaction is not consistent, despite the weight of 100 seeds (˃ 10 g). Leaf samples from 98 accessions revealed various symptoms of SMV infection in the field. This diversity of symptoms is caused by susceptibility to accession, when infection occurs, and environmental factors. Keywords—: soybean; genotipe; Soybean mosaic virus (SMV); disease severity; polyclonal  antibody

Synthetic Routes for 1,4-disubstituted 1,2,3-triazoles: A Review

2019 ◽  
Vol 23 (8) ◽  
pp. 860-900 ◽  
Author(s):  
Chander P. Kaushik ◽  
Jyoti Sangwan ◽  
Raj Luxmi ◽  
Krishan Kumar ◽  
Ashima Pahwa
Keyword(s):  
Solid Phase ◽  
Click Reaction ◽  
Biological Activities ◽  
Triazole Ring ◽  
Copper Catalysts ◽  
Biologically Active ◽  
Pharmaceutical Chemistry ◽  
Biological Targets ◽  
Synthetic Routes ◽  
High Yields

N-Heterocyclic compounds like 1,2,3-triazoles serve as a key scaffolds among organic compounds having diverse applications in the field of drug discovery, bioconjugation, material science, liquid crystals, pharmaceutical chemistry and solid phase organic synthesis. Various drugs containing 1,2,3-triazole ring which are commonly available in market includes Rufinamide, Cefatrizine, Tazobactam etc., Stability to acidic/basic hydrolysis along with significant dipole moment support triazole moiety for appreciable participation in hydrogen bonding and dipole-dipole interactions with biological targets. Huisgen 1,3-dipolar azide-alkyne cycloaddition culminate into a mixture of 1,4 and 1,5- disubstituted 1,2,3-triazoles. In 2001, Sharpless and Meldal came across with a copper(I) catalyzed regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles by cycloaddition between azides and terminal alkynes. This azide-alkyne cycloaddition has been labelled as a one of the important key click reaction. Click synthesis describes chemical reactions that are simple to perform, gives high selectivity, wide in scope, fast reaction rate and high yields. Click reactions are not single specific reaction, but serve as a pathway for construction of simple to complex molecules from a variety of starting materials. In the last few decades, 1,2,3-triazoles attracted attention of researchers all over the world because of their broad spectrum of biological activities. Keeping in view the biological importance of 1,2,3-triazole, in this review we focus on the various synthetic routes for the syntheisis of 1,4-disubstituted 1,2,3-triazoles. This review involves various synthetic protocols which involves copper and non-copper catalysts, different solvents as well as substrates. It will boost synthetic chemists to explore new pathway for the development of newer biologically active 1,2,3-triazoles.

scholarly journals Performance of Strawberry Varieties Developed for Perennial Matted-Row Production in Annual Plasticulture in a Cold Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1407
Author(s):  
Courtney A. Weber
Keyword(s):  
Large Scale ◽  
Fruit Size ◽  
Weather Conditions ◽  
Cold Climate ◽  
Annual Production ◽  
High Yield ◽  
Production Cycle ◽  
Late Season ◽  
Berry Weight ◽  
High Yields

Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.

Direct conversion of cellulose to high-yield methyl lactate over Ga-doped Zn/H-nanozeolite Y catalysts in supercritical methanol

2017 ◽  
Vol 19 (8) ◽  
pp. 1969-1982 ◽  
Author(s):  
Deepak Verma ◽  
Rizki Insyani ◽  
Young-Woong Suh ◽  
Seung Min Kim ◽  
Seok Ki Kim ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Value Added ◽  
Direct Conversion ◽  
High Yield ◽  
Supercritical Methanol ◽  
Methyl Lactate ◽  
High Yields

For realizing sustainable bio-based refineries, it is crucial to obtain high yields of value-added chemicalsviadirect conversion of cellulose and lignocellulosic biomass.

scholarly journals Multi-curie production of gallium-68 on a biomedical cyclotron and automated radiolabelling of PSMA-11 and DOTATATE

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
High Yield ◽  
Clinical Use ◽  
Automated Production ◽  
Automated Method ◽  
Gallium 68 ◽  
High Yields ◽  
High Level ◽  
Mev Protons ◽  
Very High

Abstract Background With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE. Results Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected > 370 GBq (> 10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (> 98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (> 95%) and with apparent molar activities (9–25 MBq/nmol) sufficient for clinical use. Conclusions We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient to supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.

High yield and greener C–H difluoromethylation reactions using copper iodide nanoparticles/boron nitride nanosheets as a versatile and recyclable heterogeneous catalyst

2021 ◽  
Author(s):  
Udayakumar Veerabagu ◽  
Gowsika Jaikumar ◽  
Fushen Lu ◽  
Franck Quero
Keyword(s):  
Boron Nitride ◽  
Heterogeneous Catalyst ◽  
High Efficiency ◽  
High Yield ◽  
Copper Iodide ◽  
Boron Nitride Nanosheets ◽  
Greener Synthesis ◽  
High Yields ◽  
Recyclable Heterogeneous Catalyst

The 3 wt% CuI/BNNS catalyst exhibited high efficiency for C–H difluoromethylation reactions and enabled greener synthesis at high yields using cyrene as a solvent. Furthermore, the catalyst could be easily recovered and recycled for at least five cycles.

scholarly journals Synthesis of a Novel Series of Cu(I) Complexes Bearing Alkylated 1,3,5-Triaza-7-phosphaadamantane as Homogeneous and Carbon-Supported Catalysts for the Synthesis of 1- and 2-Substituted-1,2,3-triazoles

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2702
Author(s):  
Ivy L. Librando ◽  
Abdallah G. Mahmoud ◽  
Sónia A. C. Carabineiro ◽  
M. Fátima C. Guedes da Silva ◽  
Carlos F. G. C. Geraldes ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Sodium Azide ◽  
Supported Catalysts ◽  
Cycloaddition Reaction ◽  
Water Soluble ◽  
Terminal Alkynes ◽  
One Pot ◽  
Catalytic Systems ◽  
Immobilized Catalyst ◽  
High Yields

The N-alkylation of 1,3,5-triaza-7-phosphaadamantane (PTA) with ortho-, meta- and para-substituted nitrobenzyl bromide under mild conditions afforded three hydrophilic PTA ammonium salts, which were used to obtain a new set of seven water-soluble copper(I) complexes. The new compounds were fully characterized and their catalytic activity was investigated for the low power microwave assisted one-pot azide–alkyne cycloaddition reaction in homogeneous aqueous medium to obtain disubstituted 1,2,3-triazoles. The most active catalysts were immobilized on activated carbon (AC), multi-walled carbon nanotubes (CNT), as well as surface functionalized AC and CNT, with the most efficient support being the CNT treated with nitric acid and NaOH. In the presence of the immobilized catalyst, several 1,4-disubstituted-1,2,3-triazoles were obtained from the reaction of terminal alkynes, organic halides and sodium azide in moderate yields up to 80%. Furthermore, the catalyzed reaction of terminal alkynes, formaldehyde and sodium azide afforded 2-hydroxymethyl-2H-1,2,3-triazoles in high yields up to 99%. The immobilized catalyst can be recovered and recycled through simple workup steps and reused up to five consecutive cycles without a marked loss in activity. The described catalytic systems proceed with a broad substrate scope, under microwave irradiation in aqueous medium and according to “click rules”.

scholarly journals A method for the generation of pseudotyped virus particles bearing SARS coronavirus spike protein in high yields

2021 ◽  
Author(s):  
Yoichiro Fujioka ◽  
Sayaka Kashiwagi ◽  
Aiko Yoshida ◽  
Aya O. Satoh ◽  
Mari Fujioka ◽  
...  
Keyword(s):  
Global Economy ◽  
Expression System ◽  
Antiviral Agents ◽  
Production Method ◽  
Spike Protein ◽  
High Yield ◽  
Pseudotyped Virus ◽  
Efficient Production ◽  
Live Virus ◽  
High Yields

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has threatened human health and the global economy. Development of additional vaccines and therapeutics is urgently required, but such development with live virus must be conducted with biosafety level 3 confinement. Pseudotyped viruses have been widely adopted for studies of virus entry and pharmaceutical development to overcome this restriction. Here we describe a modified protocol to generate vesicular stomatitis virus (VSV) pseudotyped with SARS-CoV or SARS-CoV-2 Spike protein in high yield. We found that pseudovirions produced with the conventional transient expression system lacked coronavirus Spike protein at their surface as a result of inhibition of parental VSV infection by overexpression of this protein. Establishment of stable cell lines with an optimal expression level of coronavirus Spike protein allowed the efficient production of progeny pseudoviruses decorated with Spike protein. This improved VSV pseudovirus production method should facilitate studies of coronavirus entry and development of antiviral agents.

scholarly journals Epimerization-free C-term Activation of Peptide Fragments by Ball-Milling

2020 ◽  
Author(s):  
Yves Yeboue ◽  
Marion Jean ◽  
Gilles Subra ◽  
Jean Martinez ◽  
Frédéric Lamaty ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ball Milling ◽  
High Yield ◽  
Coupling Agents ◽  
Peptide Fragment ◽  
Peptide Fragments ◽  
Solution Synthesis ◽  
High Yields ◽  
Synthesis Approach ◽  
Yield And Purity

Ball-milling enabled to perform [2+1], [2+2], and [2+3] peptide couplings with high yields and, if any, very low epimerization. Very good results were obtained with peptide fragments containing highly epimerization-prone and/or highly hindered amino acids at C-term such as phenylglycine, cysteine and valine. Ball-milling was clearly identified as the key element to obtain both high yield and purity along with low epimerization. Indeed, the ball-milling conditions proved to be superior to the classical solution synthesis approach on a various array of widely used coupling agents. These results open avenues for the development of highly efficient, convergent and flexible peptide synthesis strategies based on peptide fragment couplings mediated by ball-milling.

scholarly journals Epimerization-free C-term Activation of Peptide Fragments by Ball-Milling

2020 ◽  
Author(s):  
Yves Yeboue ◽  
Marion Jean ◽  
Gilles Subra ◽  
Jean Martinez ◽  
Frédéric Lamaty ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ball Milling ◽  
High Yield ◽  
Coupling Agents ◽  
Peptide Fragment ◽  
Peptide Fragments ◽  
Solution Synthesis ◽  
High Yields ◽  
Synthesis Approach ◽  
Yield And Purity

Ball-milling enabled to perform [2+1], [2+2], and [2+3] peptide couplings with high yields and, if any, very low epimerization. Very good results were obtained with peptide fragments containing highly epimerization-prone and/or highly hindered amino acids at C-term such as phenylglycine, cysteine and valine. Ball-milling was clearly identified as the key element to obtain both high yield and purity along with low epimerization. Indeed, the ball-milling conditions proved to be superior to the classical solution synthesis approach on a various array of widely used coupling agents. These results open avenues for the development of highly efficient, convergent and flexible peptide synthesis strategies based on peptide fragment couplings mediated by ball-milling.

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