scholarly journals ω-Transaminase-Mediated Asymmetric Synthesis of (S)-1-(4-Trifluoromethylphenyl)Ethylamine

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 307
Author(s):  
Carlos J. C. Rodrigues ◽  
Manuel Ferrer ◽  
Carla C. C. R. de Carvalho
Keyword(s):  
Enzyme Activity ◽  
Organic Phase ◽  
Process Development ◽  
Enzyme Reaction ◽  
Building Blocks ◽  
Inhibitory Effect ◽  
Chiral Amines ◽  
Phase System ◽  
Two Phase ◽  
Chiral Amine

The pivotal role played by ω-transaminases (ω-TAs) in the synthesis of chiral amines used as building blocks for drugs and pharmaceuticals is widely recognized. However, chiral bulky amines are challenging to produce. Herein, a ω-TA (TR8) from a marine bacterium was used to synthesize a fluorine chiral amine from a bulky ketone. An analysis of the reaction conditions for process development showed that isopropylamine concentrations above 75 mM had an inhibitory effect on the enzyme. Five different organic solvents were investigated as co-solvents for the ketone (the amine acceptor), among which 25–30% (v/v) dimethyl sulfoxide (DMSO) produced the highest enzyme activity. The reaction reached equilibrium after 18 h at 30% of conversion. An in situ product removal (ISPR) approach using an aqueous organic two-phase system was tested to mitigate product inhibition. However, the enzyme activity initially decreased because the ketone substrate preferentially partitioned into the organic phase, n-hexadecane. Consequently, DMSO was added to the system to increase substrate mass transfer without affecting the ability of the organic phase to prevent inhibition of the enzyme activity by the product. Thus, the enzyme reaction was maintained, and the product amount was increased for a 62 h reaction time. The investigated ω-TA can be used in the bioconversion of bulky ketones to chiral amines for future bioprocess applications.

scholarly journals Optimization of Aqueous Two-Phase System (ATPS) of Recombinant Bromelain by Response Surface Methodology

2018 ◽  
Vol 7 (4.30) ◽  
pp. 377
Author(s):  
Zatul Iffah Mohd Arshad ◽  
Azura Amid
Keyword(s):  
Response Surface Methodology ◽  
Enzyme Activity ◽  
Partition Coefficient ◽  
Response Surface ◽  
Potassium Phosphate ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Crude Sample ◽  
Face Centered

Recombinant bromelain is a protease that was partially purified using aqueous two-phase system (ATPS). The process variables (pH, PEG 6000 and potassium phosphate concentration) were optimized on enzyme activity and partition coefficient using response surface methodology (RSM) based on a face-centered central composite design (FCCCD) model. The optimum conditions for purification were at 18.47% [w/w] PEG6000 and 13% [w/w] potassium phosphate, pH 7.0 with enzyme activity was obtained as 0.272±0.0036 unit m/L, and partition coefficient as 1.394±0.093. The recombinant bromelain was preferentially partitioned into the top phase and the band was reduced in contrast to crude sample on SDS-PAGE gel.

scholarly journals Label-Free Direct Visual Analysis of Hydrolytic Enzyme Activity Using Aqueous Two-Phase System Droplet Phase Transitions

2014 ◽  
Vol 86 (8) ◽  
pp. 4052-4057 ◽  
Author(s):  
David Lai ◽  
John P. Frampton ◽  
Michael Tsuei ◽  
Albert Kao ◽  
Shuichi Takayama
Keyword(s):  
Enzyme Activity ◽  
Phase Transitions ◽  
Visual Analysis ◽  
Hydrolytic Enzyme ◽  
Phase System ◽  
Label Free ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Droplet Phase

scholarly journals Lipase-Catalyzed Production of Sorbitol Laurate in a “2-in-1” Deep Eutectic System: Factors Affecting the Synthesis and Scalability

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2759
Author(s):  
André Delavault ◽  
Oleksandra Opochenska ◽  
Laura Laneque ◽  
Hannah Soergel ◽  
Claudia Muhle-Goll ◽  
...  
Keyword(s):  
De Novo ◽  
Choline Chloride ◽  
Building Blocks ◽  
Flash Chromatography ◽  
Phase System ◽  
Eutectic System ◽  
Two Phase ◽  
Factors Affecting ◽  
Ester Formation ◽  
Wide Range

Surfactants, such as glycolipids, are specialty compounds that can be encountered daily in cleaning agents, pharmaceuticals or even in food. Due to their wide range of applications and, more notably, their presence in hygiene products, the demand is continuously increasing worldwide. The established chemical synthesis of glycolipids presents several disadvantages, such as lack of specificity and selectivity. Moreover, the solubility of polyols, such as sugars or sugar alcohols, in organic solvents is rather low. The enzymatic synthesis of these compounds is, however, possible in nearly water-free media using inexpensive and renewable building blocks. Using lipases, ester formation can be achieved under mild conditions. We propose, herein, a “2-in-1” system that overcomes solubility problems, as a Deep Eutectic System (DES) made of sorbitol and choline chloride replaces either a purely organic or aqueous medium. For the first time, 16 commercially available lipase formulations were compared, and the factors affecting the conversion were investigated to optimize this process, owing to a newly developed High-Performance Liquid Chromatography-Evaporative Light Scattering Detector (HPLC-ELSD) method for quantification. Thus, using 50 g/L of lipase formulation Novozym 435® at 50 °C, the optimized synthesis of sorbitol laurate (SL) allowed to achieve 28% molar conversion of 0.5 M of vinyl laurate to its sugar alcohol monoester when the DES contained 5 wt.% water. After 48h, the de novo synthesized glycolipid was separated from the media by liquid–liquid extraction, purified by flash-chromatography and characterized thoroughly by one- and two-dimensional Nuclear Magnetic Resonance (NMR) experiments combined to Mass Spectrometry (MS). In completion, we provide initial proof of scalability for this process. Using a 2.5 L stirred tank reactor (STR) allowed a batch production reaching 25 g/L in a highly viscous two-phase system.

scholarly journals In vitro Antioxidant and Antibacterial Activities of Quinoa Flavonoids Extracted by Ethanol-Ammonium Sulfate Aqueous Two-Phase System

2021 ◽  
Vol 25 (06) ◽  
pp. 1187-1196
Author(s):  
Xiaoyong Wu
Keyword(s):  
Free Radicals ◽  
Vitamin C ◽  
Mass Fraction ◽  
Oxygen Free Radicals ◽  
Inhibitory Effect ◽  
Extraction Rate ◽  
Phase System ◽  
Phase Extraction ◽  
Two Phase ◽  
Scavenging Effect

Quinoa (Chenopodium quinoa Willd.) is a functional and ideal food for human nutrition and an Andean seed-producing crop. In this study, ultrasonic-assisted extraction of total flavonoids in Quinoa with ethanol (C2H5OH)-ammonium sulfate ((NH4)2SO4) aqueous two-phase system was performed based on the Box-Behnken experimental design principle. The highest extraction rate of TFQ under the condition of 28% C2H5OH -14% (NH4)2SO4 aqueous two-phase extraction system was used to analyze the variance of TFQ extraction rate as the response value. The multiple quadratic linear regression equation was obtained by a three-factor three-level response surface method. The extraction rate= 74.28+1.78 A+0.10 B+0.38 C+0.20 AB+0.05 AC+0.05 BC+1.000E-002 A2-0.94 B2-0.69 C2. The response surface analysis showed that the best extraction conditions of aqueous two-phase were the crude TFQ mass fraction 20.6%, pH 7.18, NaCl mass fraction 2.23% and the maximum value predicted by the extraction rate model was 75.929 3% (P=0.994). The average extraction rate of TFQ was 75.3%, according to the optimal two-aqueous phase extraction conditions. The ETFQ has varying degree of scavenging effect on hydroxyl radical, oxygen free radicals, nitrite and ·ABTS+ compared with vitamin C. Among them, the scavenging effect of the ETFQ on hydroxyl radical, oxygen free radicals and ·ABTS+ was greater than vitamin C, except nitrite. Also, the ETFQ has the strongest inhibitory effect on E. coli and Bacillus subtilis, and the inhibitory rate can reach up to high dose 97.59 and 98.44%, MIC is 1.56 mg/mL; the second is the inhibition of S. aureus, MIC is 6.25 mg/mL. It has the weakest inhibitory effect on Salmonella. The antibacterial rate was positively correlated with the ETFQ mass concentration. The results help to discover the medicinal effects of quinoa in addition to nutrition to carry out more in-depth research and increase economic value. © 2021 Friends Science Publishers

Prevention of Lipid Inhibition in Anaerobic Processes by Introducing a Two-Phase System

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1189-1200 ◽  
Author(s):  
Toshiya Komatsu ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo
Keyword(s):  
Single Phase ◽  
Inhibitory Effect ◽  
Phase System ◽  
Long Chain Fatty Acids ◽  
Beta Oxidation ◽  
Two Phase ◽  
Anaerobic Processes ◽  
Ph Values ◽  
Acidogenic Reactor ◽  
Oxidation Degradation

The inhibitory effect of lipids and prevention of this inhibition in a two-phase anaerobic process were examined using laboratory-scale reactors and batch experiments. Lipids were satisfactorily degraded in a two-phase anaerobic filter while in a single-phase system, inhibition resulted in poor lipid degradation. Unsaturated long-chain fatty acids (LFAs) had a greater inhibitory effect than saturated LFAs. Methane production as well as beta-oxidation (degradation of saturated LFAs) were inhibited by unsaturated LFAs. The saturation of unsaturated LFAs was not inhibited, and palmitate (C16:0) was accumulated in the degradation of oleate (C18:l) or linoleate (C18:2). Greater inhibition was observed at low pH values. Continuous operation of a suspended-growth acidogenic reactor showed that hydraulic retention times (HRTs) of no less than 8 hours were necessary to mitigate the inhibition in a two-phase process. The fact that saturation of oleate occurred at HRTs no less than 8 hours suggests that the saturation of unsaturated LFAs in an acidogenic reactor is essential in the prevention of lipid inhibition in two-phase anaerobic processes.

Bromination of Butyl Rubber in the Presence of Electrophilic Solvents and Oxidizing Agents

2000 ◽  
Vol 73 (2) ◽  
pp. 356-365 ◽  
Author(s):  
Gabor Kaszas
Keyword(s):  
Organic Phase ◽  
Hydrogen Bromide ◽  
Butyl Rubber ◽  
Phase System ◽  
Two Phase ◽  
Oxidizing Agents ◽  
Consecutive Reactions ◽  
Highly Uniform ◽  
Rate Controlling Step

Abstract Bromination of 1,4-isoprene units in butyl rubber proceeds by substitution leading to the formation of hydrogen bromide as byproduct. In-situ conversion of HBr back to bromine is possible by the use of oxidizing agents but the reaction is very slow and oxidation of the polymer may occur. The reaction is complex and is typically conducted in a two-phase system. It has been found that the rate-controlling step is the bromination of the 1,4-isoprene unit in the organic phase, and not the oxidation of HBr to Br2 in the water phase or the mass transfer of HBr or Br2 between phases. Increasing the electrophilicity of the organic phase dramatically increased the overall rate. A 90–95 wt % conversion of bromine was achieved in one minute. Side or consecutive reactions (oxidation of the polymer, hydrobromination of the unsaturation, rearrangement or dehydrohalogenation of the main product) could be avoided, allowing the synthesis of a highly uniform material.

Separation of vanadium(V) using N235 by three-phase system in concentrated HCl media

2017 ◽  
Vol 95 (6) ◽  
pp. 717-722 ◽  
Author(s):  
Chun Shen ◽  
Yimin Zhang ◽  
Jing Huang ◽  
Shenxu Bao ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Organic Phase ◽  
Extraction Efficiency ◽  
Inhibitory Effect ◽  
Phase System ◽  
Phase Form ◽  
The Third ◽  
Third Phase ◽  
Vanadium Extraction ◽  
Three Phase ◽  
Ftir Spectral Analysis

The third phase formed in the process of extracting vanadium in a N235/HCl system was usually regarded as a limit to the throughput of the plant. To have a deep insight on this problem, the formation of the third phase in the extraction of vanadium by tertiary amine N235 in the concentrated HCl system was studied. The optimum parameters of three-phase system extraction were determined, and FTIR analysis was carried out to characterize the structure of extracted complexes and analyze the mechanism of formation and elimination of the third phase. The results showed that vanadium extraction efficiency was 86.5% with 20% v/v N235 and a phase ratio (O:A) of 1:2 in 2 min at 25 °C, though an obvious third phase was found within the experimental HCl concentration range. Cl− is the participant in the process of increasing the vanadium extraction efficiency, whereas H+ has an inhibitory effect on vanadium extraction. Meanwhile, the structure of the extracted complex was confirmed as (R3N)m(HCl)m+x·([Formula: see text])·(H2O)n through a solvation mechanism with molecular association, which was further proved by FTIR spectral analysis. Furthermore, the limited solubility of the ion-extracted complexes in the nonpolar solvent kerosene made the third-phase form. The third phase disappeared when phase modifier (about 5% v/v TBP) was added into the organic phase, as the polarity of the organic phase increased.

An Emulsion Polymerization Process for Soluble and Electrically Conductive Polyaniline

1997 ◽  
Vol 488 ◽  
Author(s):  
P. J. Kinlen ◽  
Y. Ding ◽  
C. R. Graham ◽  
J. Liu ◽  
E. E. Remsen
Keyword(s):  
Molecular Weight ◽  
Organic Acid ◽  
Organic Solvents ◽  
Organic Phase ◽  
Sulfonic Acid ◽  
Direct Synthesis ◽  
Water Soluble ◽  
Polymerization Process ◽  
Phase System ◽  
Two Phase

AbstractA new emulsion process has been developed for the direct synthesis of the emeraldine salt of polyaniline (PANI) that is soluble in organic solvents. The process entails forming an emulsion composed of water, a water soluble organic solvent (e.g., 2-butoxyethanol), a water insoluble organic acid (e.g., dinonylnaphthalene sulfonic acid) and aniline. Aniline is protonated by the organic acid to form a salt which partitions into the organic phase. As oxidant (ammonium peroxydisulfate) is added, PANI salt forms in the organic phase and remains soluble. As the reaction proceeds, the reaction mixture changes from an emulsion to a two phase system, the soluble PANI remaining in the organic phase. With dinonylnaphthalene sulfonic acid (DNNSA) as the organic acid, the resulting product is truly soluble in organic solvents such as xylene and toluene(not a dispersion), of high molecular weight (Mw >22,000), film forming and miscible with many polymers such as polyurethanes, epoxies and phenoxy resins. As cast, the polyaniline film is only moderately conductive, (10−5 S/cm), however treatment of the film with surfactants such as benzyltriethylammonium chloride (BTEAC) or low molecular weight alcohols and ketones such as methanol and acetone increases the conductivity 2–3 orders of magnitude.

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