NMR analysis of chiral alcohols and amines: development of an environmentally benign “in tube” procedure with high efficiency and improved detection limit

2011 ◽  
Vol 13 (7) ◽  
pp. 1735 ◽  
Author(s):  
Nikolay V. Orlov ◽  
Valentine P. Ananikov
Keyword(s):  
Detection Limit ◽  
High Efficiency ◽  
Environmentally Benign ◽  
Chiral Alcohols ◽  
Nmr Analysis

scholarly journals Kinetic resolution of indolines by asymmetric hydroxylamine formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Wang ◽  
Ran Lu ◽  
Chuangchuang He ◽  
Lei Liu
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Synthesis ◽  
Late Stage ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Environmentally Benign ◽  
Secondary Amines

AbstractCatalytic kinetic resolution of amines represents a longstanding challenge in chemical synthesis. Here, we described a kinetic resolution of secondary amines through oxygenation to produce enantiopure hydroxylamines involving N–O bond formation. The economic and practical titanium-catalyzed asymmetric oxygenation with environmentally benign hydrogen peroxide as oxidant is applicable to a range of racemic indolines with multiple stereocenters and diverse substituent patterns in high efficiency with efficient chemoselectivity and enantio-discrimination. Late-stage asymmetric oxygenation of bioactive molecules that are otherwise difficult to synthesize was also explored.

Separation of phenols from oils using deep eutectic solvents and ionic liquids

2020 ◽  
Vol 92 (10) ◽  
pp. 1717-1731
Author(s):  
Yucui Hou ◽  
Zhi Feng ◽  
Jaime Ruben Sossa Cuellar ◽  
Weize Wu
Keyword(s):  
Ionic Liquids ◽  
Phenolic Compounds ◽  
High Efficiency ◽  
Deep Eutectic Solvents ◽  
Environmentally Benign ◽  
Organic Chemical ◽  
Environmental Friendliness ◽  
Oil Mixtures ◽  
Organic Chemical Industry

AbstractPhenolic compounds are important basic materials for the organic chemical industry, such as pesticides, medicines and preservatives. Phenolic compounds can be obtained from biomass, coal and petroleum via pyrolysis and liquefaction, but they are mixtures in oil. The traditional methods to separate phenols from oil using alkaline washing are not environmentally benign. To solve the problems, deep eutectic solvents (DESs) and ionic liquids (ILs) have been developed to separate phenols from oil, which shows high efficiency and environmental friendliness. In this article, we summarized the properties of DESs and ILs and the applications of DESs and ILs in the separation of phenols and oil. There are two ways in which DESs and ILs are used in these applications: (1) DESs formed in situ using different hydrogen bonding acceptors including quaternary ammonium salts, zwitterions, imidazoles and amides; (2) DESs and ILs used as extractants. The effect of water on the separation, mass transfer dynamics in the separation process, removal of neutral oil entrained in DESs, phase diagrams of phenol + oil + extractant during extraction, are also discussed. In the last, we analyze general trends for the separation and evaluate the problematic or challenging aspects in the separation of phenols from oil mixtures.

Ionic liquid promoted and mediated green preparation of arylbispyranylmethane and pyran derivatives and their hybrid with a pyrimidine nucleoside

2009 ◽  
Vol 2009 (8) ◽  
pp. 473-477 ◽  
Author(s):  
Xinying Zhang ◽  
Yingying Qu ◽  
Xuesen Fan ◽  
Xia Wang ◽  
Jianji Wang
Keyword(s):  
Ionic Liquid ◽  
High Efficiency ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
Pyrimidine Nucleoside ◽  
Reaction Conditions ◽  
Operation Process ◽  
Antiviral Activities ◽  
Benign Nature ◽  
High Yields

The utilisation of an ionic liquid-[bmim][BF4] as both reaction medium and promoter for the reaction between aldehyde and 4-hydroxy-6-methylpyran-2-one is described. Without any added catalyst, this reaction was realised efficiently to give arylbispyranylmethane derivatives in high yields. Alternatively, when this reaction was carried out in the presence of acetic anhydride, fused pyran derivatives were obtained. These two novel procedures have advantages such as an environmentally benign nature, high efficiency, simple operation process and mild reaction conditions. As an application, these procedures were used in the preparation of novel 5-substituted pyrimidine nucleoside derivatives with potential antiviral activities.

Searching for a high efficiency and environmental benign reagent to leach ion-adsorption rare earths based on the zeta potential of clay particles

2018 ◽  
Vol 20 (19) ◽  
pp. 4528-4536 ◽  
Author(s):  
Lifen Yang ◽  
Dashan Wang ◽  
Cuicui Li ◽  
Yuanyuan Sun ◽  
Xuezhen Zhou ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Rare Earths ◽  
Aluminum Sulfate ◽  
High Efficiency ◽  
Specific Adsorption ◽  
Environmentally Benign ◽  
Ion Adsorption ◽  
Clay Particles ◽  
Highly Efficient

Aluminum sulfate is the best reagent for highly efficient and environmentally benign leaching of IAREs because of its specific adsorption towards CPs.

scholarly journals Marine Toxins Detection by Biosensors Based on Aptamers

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 1 ◽  
Author(s):  
Wei Ye ◽  
Taomei Liu ◽  
Weimin Zhang ◽  
Muzi Zhu ◽  
Zhaoming Liu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Rapid Development ◽  
High Sensitivity ◽  
Detection Methods ◽  
Marine Toxins ◽  
Time Saving ◽  
Low Detection Limit ◽  
The Future

Marine toxins cause great harm to human health through seafood, therefore, it is urgent to exploit new marine toxins detection methods with the merits of high sensitivity and specificity, low detection limit, convenience, and high efficiency. Aptasensors have emerged to replace classical detection methods for marine toxins detection. The rapid development of molecular biological approaches, sequencing technology, material science, electronics and chemical science boost the preparation and application of aptasensors. Taken together, the aptamer-based biosensors would be the best candidate for detection of the marine toxins with the merits of high sensitivity and specificity, convenience, time-saving, relatively low cost, extremely low detection limit, and high throughput, which have reduced the detection limit of marine toxins from nM to fM. This article reviews the detection of marine toxins by aptamer-based biosensors, as well as the selection approach for the systematic evolution of ligands by exponential enrichment (SELEX), the aptamer sequences. Moreover, the newest aptasensors and the future prospective are also discussed, which would provide thereotical basis for the future development of marine toxins detection by aptasensors.

scholarly journals Nanostructured copper selenide as an ultrasensitive and selective non-enzymatic glucose sensor

2021 ◽  
Author(s):  
Siddesh Umapathi ◽  
Harish Singh ◽  
Jahangir Masud ◽  
Manashi Nath
Keyword(s):  
Detection Limit ◽  
High Efficiency ◽  
Glucose Sensor ◽  
High Sensitivity ◽  
Copper Selenide ◽  
Glucose Detection ◽  
Applied Potential ◽  
Detection Range ◽  
Low Detection Limit ◽  
Linear Detection

CuSe nanostructures exhibit high-efficiency for glucose detection with high sensitivity (19.419 mA mM−1 cm−2) and selectivity at low applied potential (0.15 V vs. Ag|AgCl), low detection limit (0.196 μM) and linear detection range (100 nM to 40 μM).

scholarly journals Ratiometric Colorimetric Detection of Nitrite Realized by Stringing Nanozyme Catalysis and Diazotization Together

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 280
Author(s):  
Mengzhu Wang ◽  
Peng Liu ◽  
Hengjia Zhu ◽  
Bangxiang Liu ◽  
Xiangheng Niu
Keyword(s):  
Detection Limit ◽  
Signal Analysis ◽  
High Efficiency ◽  
Colorimetric Assay ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Health It ◽  
Practical Applications ◽  
Higher Sensitivity

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3–133.3 μM with good specificity was realized, providing a detection limit down to 0.2 μM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.

Montmorillonite K-10 clay as reusable heterogeneous catalyst for the microwave-mediated solventless synthesis of phthalazinetetraones

2007 ◽  
Vol 85 (2) ◽  
pp. 81-84 ◽  
Author(s):  
Davood Habibi ◽  
Nosratollah Mahmoodi ◽  
Omid Marvi
Keyword(s):  
Present Method ◽  
High Efficiency ◽  
Reaction Times ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Clay Catalyst ◽  
Solventless Synthesis ◽  
Operational Simplicity

Different phthalazino[2,3-b]phthalazine-5,7,12,14-tetraones were synthesized in a simple and environmentally benign method from the reaction of some phthalic anhydrides with semicarbazide or thiosemicarbazide using montmorillonite K-10 clay as solid heterogeneous acidic catalyst and microwaves under solvent-free conditions in good yields and short reaction times. The present method has many obvious advantages compared with those reported in the literature, including high efficiency, higher yield, operational simplicity, environmental benignity, and the possibility of recycling the solid clay. The solid clay catalyst used in the first cycle of the reactions was successfully recovered and reused in the second cycle, showing a gradual decrease in activity.Key words: montmorillonite K-10 clay, microwave, solvent-free condition, phthalazinetetraones, semicarbazide, thiosemicarbazide.

Eliminating turbidity in drinking water using the mucilage of a common cactus

2012 ◽  
Vol 12 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Thomas Pichler ◽  
Kevin Young ◽  
Norma Alcantar
Keyword(s):  
High Efficiency ◽  
Cost Effective ◽  
Green Technology ◽  
Environmentally Benign ◽  
Aluminium Sulfate ◽  
Cactus Mucilage ◽  
Natural Spring ◽  
High Polarity ◽  
Settling Rates ◽  
Unique Surface

Diced Nopal cladodes (pads) have been used for the treatment of turbid natural spring waters in Latin America. To investigate this phenomenon, the mucilage derived from the species Opuntia ficus-indica was investigated. Comparison against the commonly used synthetic flocculant, aluminium sulfate (Al2(SO4)3) demonstrated the high efficiency of the cactus to eliminate turbidity. The mucilage extract increased particulate settling rates 330% compared with aluminium sulfate, at dosage concentrations of 3 mg L−1, while its performance was equivalent at doses 0.3% of the required Al2(SO4)3 concentration. The cactus mucilage, which consists of complex carbohydrates and sugars, has unique surface activity characteristics that make it an ideal candidate for enhancing dispersion properties, creating emulsifications, and for reducing the surface tension of high polarity liquids. These results indicated that the Nopal cactus mucilage has the potential to be the basis for a new ‘green’ technology, which is environmentally benign and cost-effective.

scholarly journals Efficient PCR-Based Amplification of Diverse Alcohol Dehydrogenase Genes from Metagenomes for Improving Biocatalysis: Screening of Gene-Specific Amplicons from Metagenomes

2014 ◽  
Vol 80 (20) ◽  
pp. 6280-6289 ◽  
Author(s):  
Nobuya Itoh ◽  
Satomi Kariya ◽  
Junji Kurokawa
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Alcohol Dehydrogenase ◽  
High Efficiency ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Chiral Alcohols ◽  
Biotechnological Potential ◽  
Content Type ◽  
Enzyme Product

ABSTRACTScreening of gene-specific amplicons from metagenomes (S-GAM) has tremendous biotechnological potential. We used this approach to isolate alcohol dehydrogenase (adh) genes from metagenomes based on theLeifsoniaspeciesadhgene (lsadh), the enzyme product of which can produce various chiral alcohols. A primer combination was synthesized by reference to homologs oflsadh, and PCR was used to amplify nearly full-lengthadhgenes from metagenomic DNAs. Alladhpreparations were fused withlsadhat the terminal region and used to constructEscherichia coliplasmid libraries. Of the approximately 2,000 colonies obtained, 1,200 clones were identified asadhpositive (∼60%). Finally, 40adhgenes,Hladh-001 toHladh-040 (forhomologousLeifsoniaadh), were identified from 223 clones with high efficiency, which were randomly sequenced from the 1,200 clones. TheHladhgenes obtained via this approach encoded a wide variety of amino acid sequences (8 to 99%). After screening, the enzymes obtained (HLADH-012 and HLADH-021) were confirmed to be superior to LSADH in some respects for the production of anti-Prelog chiral alcohols.

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