Continuous Diastereomeric Kinetic Resolution—Silybins A and B

The natural diastereomeric mixture of silybins A and B is often used (and considered) as a single flavonolignan isolated from the fruit extract of milk thistle (Silybum marianum), silymarin. However, optically pure silybin diastereomers are required for the evaluation of their biological activity. The separation of silybin diastereomers by standard chromatographic methods is not trivial. Preparative chemoenzymatic resolution of silybin diastereomers has been published, but its optimization and scale-up are needed. Here we present a continuous flow reactor for the chemoenzymatic kinetic resolution of silybin diastereomers catalyzed by Candida antarctica lipase B (CALB) immobilized on acrylic resin beads (Novozym® 435). Temperature, flow rate, and starting material concentration were varied to determine optimal reaction conditions. The variables observed were conversion and diastereomeric ratio. Optimal conditions were chosen to allow kilogram-scale reactions and were determined to be −5 °C, 8 g/L silybin, and a flow rate of 16 mL/min. No significant carrier degradation was observed after approximately 30 cycles (30 days). Under optimal conditions and using a 1000 × 15 mm column, 20 g of silybin per day can be easily processed, yielding 6.7 and 5.6 g of silybin A and silybin B, respectively. Further scale-up depends only on the size of the reactor.

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Rapid Determination of Optimal Conditions in a Continuous Flow Reactor Using Process Analytical Technology

Processes ◽

10.3390/pr2010024 ◽

2013 ◽

Vol 2 (1) ◽

pp. 24-33 ◽

Cited By ~ 3

Author(s):

Michael Roberto ◽

Thomas Dearing ◽

Charles Branham ◽

Olav Bleie ◽

Brian Marquardt

Keyword(s):

Continuous Flow ◽

Flow Reactor ◽

Process Analytical Technology ◽

Rapid Determination ◽

Optimal Conditions ◽

Continuous Flow Reactor ◽

Analytical Technology

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Suzuki–Miyaura Coupling Using Monolithic Pd Reactors and Scaling-Up by Series Connection of the Reactors

Catalysts ◽

10.3390/catal9030300 ◽

2019 ◽

Vol 9 (3) ◽

pp. 300 ◽

Cited By ~ 6

Author(s):

Aiichiro Nagaki ◽

Katsuyuki Hirose ◽

Yuya Moriwaki ◽

Masahiro Takumi ◽

Yusuke Takahashi ◽

...

Keyword(s):

Pressure Drop ◽

Flow Rate ◽

Flow Reactor ◽

Scale Up ◽

Good Method ◽

Aryl Halides ◽

Series Connection ◽

Pore Sizes ◽

Polymer Monolith ◽

Increase In Productivity

The space integration of the lithiation of aryl halides, the borylation of aryllithiums, and Suzuki–Miyaura coupling using a Pd catalyst supported by a polymer monolith flow reactor without using an intentionally added base was achieved. To scale up the process, a series connection of the monolith Pd reactor was examined. To suppress the increase in the pressure drop caused by the series connection, a monolith reactor having larger pore sizes was developed by varying the temperature of the monolith preparation. The monolithic Pd reactor having larger pore sizes enabled Suzuki–Miyaura coupling at a higher flow rate because of a lower pressure drop and, therefore, an increase in productivity. The present study indicates that series connection of the reactors with a higher flow rate serves as a good method for increasing the productivity without decreasing the yields.

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Enantioselective extraction of unprotected amino acids coupled with racemization

Nature Communications ◽

10.1038/s41467-020-20402-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haofei Huang ◽

Yingji Jin ◽

Mukesh E. Shirbhate ◽

Dayoung Kang ◽

Misun Choi ◽

...

Keyword(s):

Aqueous Solution ◽

Amino Acids ◽

Kinetic Resolution ◽

Flow Reactor ◽

Building Blocks ◽

Selective Extraction ◽

Organic Layer ◽

Acidic Aqueous Solution ◽

Enantioselective Extraction ◽

Optically Pure

AbstractScalable and economical methods for the production of optically pure amino acids, both natural and unnatural, are essential for their use as synthetic building blocks. Currently, enzymatic dynamic kinetic resolution (DKR) underpins some of the most effective processes. Here we report the development of enantioselective extraction coupled with racemization (EECR) for the chirality conversion of underivatized amino acids. In this process, the catalytic racemization of amino acids in a basic aqueous solution is coupled with the selective extraction of one enantiomer into an organic layer. Back-extraction from the organic layer to an acidic aqueous solution then completes the deracemization of the amino acid. The automation of the EECR process in a recycling flow reactor is also demonstrated. Continuous EECR is made possible by the sterically hindered chiral ketone extractant 5, which prevents the coextraction of the copper racemization catalyst because of its nonplanar geometry. Furthermore, the extractant 5 unexpectedly forms imines with amino acids faster and with greater enantioselectivity than less bulky derivatives, even though 5 cannot participate in intramolecular resonance-assisted hydrogen bonding. These features may allow EECR to challenge the preponderance of enzymatic DKR in the production of enantiomerically enriched amino acids.

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Photocatalytic abatement of o-xylene using adsorption enhanced ZnO/GAC catalyst in a continuous flow reactor: Catalytic potential, Fate of o-xylene and its by-products

Global NEST Journal ◽

10.30955/gnj.002297 ◽

2017 ◽

Vol 19 (3) ◽

pp. 479-488 ◽

Cited By ~ 5

Keyword(s):

Flow Reactor ◽

Optimal Conditions ◽

Breakthrough Time ◽

Removal Capacity ◽

Catalytic Potential ◽

Continuous Flow Reactor ◽

Efficient Option ◽

Methanoic Acid ◽

By Products ◽

Maximum Removal

Photocatalytic abatement of o-xylene was investigated by immobilized ZnO on granular activated carbon (ZnO/GAC) under UV irradiation. Immobilization of ZnO increased the breakthrough time and removal capacity by 51 and 57%, respectively, in optimal conditions. The catalytic potential of the ZnO/GAC (86.5%) for o-xylene removal was far greater than simple GAC (13.5%), at the optimum condition. The maximum removal capacity with ZnO/GAC (3.12g o-xylene /gZnO/GAC) was observed at 100 °C, while the maximum removal capacity of simple GAC (1.37 g o-xylene/g GAC) was observed a t 20 °C. The main intermediates of the o-xylene oxidation in photocatalytic process with GAC were methanoic acid, o-nitro-p-cresol, phenylmethanal, and methyl di-phenyl-methane. ZnO/GAC can highly catalyze the degradation of o-xylene in the presence of UV, with methanoic acid being the major intermediate desorbed from the bed. The results demonstrated that the ZnO/GAC is an efficient option for the removal of VOCs and biohazards emitted from industrial streams.

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Renewable Energy from Agricultural Waste

Revista de Chimie ◽

10.37358/rc.18.6.6325 ◽

2018 ◽

Vol 69 (6) ◽

pp. 1363-1366 ◽

Cited By ~ 1

Author(s):

Stefania Daniela Bran ◽

Petre Chipurici ◽

Mariana Bran ◽

Alexandru Vlaicu

Keyword(s):

Saccharomyces Cerevisiae ◽

Gas Chromatography ◽

Continuous Flow ◽

Laboratory Experiments ◽

Fermentation Process ◽

Flow Reactor ◽

Agricultural Waste ◽

Continuous Flow Reactor ◽

Natural Support ◽

Co2 Flow

This paper has aimed at evaluating the concentration of bioethanol obtained using sunflower stem as natural support, molasses as carbon source and Saccharomyces cerevisiae yeast in a continuous flow reactor. The natural support was tested to investigate the immobilization/growth of S. cerevisiae yeast. The concentration of bioethanol produced by fermentation was analyzed by gas chromatography using two methods: aqueous solutions and extraction in organic phase. The CO2 flow obtained during the fermentation process was considered to estimate when the yeast was deactivated. The laboratory experiments have highlighted that the use of plant-based wastes to bioconversion in ethanol could be a non-pollutant and sustainable alternative.

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Thermocatalytic Hydrodeoxygenation and Depolymerization of Waste Lignin to Oxygenates and Biofuels in a Continuous Flow Reactor at Atmospheric Pressure

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.0c02102 ◽

2020 ◽

Vol 8 (35) ◽

pp. 13195-13205 ◽

Cited By ~ 2

Author(s):

Swathi Mukundan ◽

Daria Boffito ◽

Abhijit Shrotri ◽

Luqman Atanda ◽

Jorge Beltramini ◽

...

Keyword(s):

Atmospheric Pressure ◽

Continuous Flow ◽

Flow Reactor ◽

Continuous Flow Reactor

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Effect of Aspect Ratio on the Mixing Performance in the Kenics Static Mixer

Processes ◽

10.3390/pr9030464 ◽

2021 ◽

Vol 9 (3) ◽

pp. 464

Author(s):

Xingren Jiang ◽

Ning Yang ◽

Rijie Wang

Keyword(s):

Pharmaceutical Industry ◽

Aspect Ratio ◽

Flow Reactor ◽

Mixing Time ◽

Continuous Process ◽

Scale Up ◽

Influence Factors ◽

Continuous Manufacturing ◽

Static Mixer ◽

Mixing Performance

Continuous manufacturing has received increasing interest because of the advantages of intrinsic safety and enhanced mass transfer in the pharmaceutical industry. However, the difficulty for scale-up has limited the application of continuous manufacturing for a long time. Recently, the tubular flow reactor equipped with the Kenics static mixer appears to be a solution for the continuous process scale-up. Although many influence factors on the mixing performance in the Kenics static mixer have been investigated, little research has been carried out on the aspect ratio. In this study, we used the coefficient of variation as the mixing evaluation index to investigate the effect of the aspect ratio (0.2–2) on the Kenics static mixer’s mixing performance. The results indicate that a low aspect ratio helps obtain a shorter mixing time and mixer length. This study suggests that adjusting the aspect ratio of the Kenics static mixer can be a new strategy for the scale-up of a continuous process in the pharmaceutical industry.

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Scale-up of a photochemical flow reactor for the production of lignin-coated titanium dioxide as a sunscreen ingredient

Journal of Photochemistry and Photobiology ◽

10.1016/j.jpap.2021.100040 ◽

2021 ◽

pp. 100040

Author(s):

Kelsey Fournier ◽

Nancy Marina ◽

Neeraj Joshi ◽

Vincent R. Berthiaume ◽

Sara Currie ◽

...

Keyword(s):

Titanium Dioxide ◽

Flow Reactor ◽

Scale Up

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Preparation, Characterization, and Activity of Pd/PSS-Modified Membranes in the Low Temperature Dry Reforming of Methane with and without Addition of Extra Steam

Membranes ◽

10.3390/membranes11070518 ◽

2021 ◽

Vol 11 (7) ◽

pp. 518

Author(s):

Cecilia Mateos-Pedrero ◽

Miguel A. Soria ◽

Antonio Guerrero-Ruíz ◽

Inmaculada Rodríguez-Ramos

Keyword(s):

Low Temperature ◽

Flow Reactor ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Porous Stainless Steel ◽

Pd Membrane ◽

Continuous Flow Reactor ◽

Oxidation In Air ◽

H2 Yield ◽

Water Gas

The external surface of a commercial porous stainless steel (PSS) was modified by either oxidation in air at varying temperatures (600, 700, and 800 °C) or coating with different oxides (SiO2, Al2O3, and ZrO2). Among them, PSS-ZrO2 appears as the most suitable carrier for the synthesis of the Pd membrane. A composite Pd membrane supported on the PSS-ZrO2 substrate was prepared by the electroless plating deposition method. Supported Ru catalysts were first evaluated for the low-temperature methane dry reforming (DRM) reaction in a continuous flow reactor (CR). Ru/ZrO2-La2O3 catalyst was found to be active and stable, so it was used in a membrane reactor (MR), which enhances the methane conversions above the equilibrium values. The influence of adding H2O to the feed of DRM was investigated over a Ru/ZrO2-La2O3 catalyst in the MR. Activity results are compared with those measured in a CR. The addition of H2O into the feed favors other reactions such as Water-Gas Shift (RWGS) and Steam Reforming (SR), which occur together with DRM, resulting in a dramatic decrease of CO2 conversion and CO production, but a marked increase of H2 yield.

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