scholarly journals Biocatalysis in continuous-flow mode: A case-study in the enzymatic kinetic resolution of secondary alcohols via acylation and deacylation reactions mediated by Novozym 435®

Biocatalysis ◽  
2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Juliana Christina Thomas ◽  
Martha Daniela Burich ◽  
Pamela Taisline Bandeira ◽  
Alfredo Ricardo Marques de Oliveira ◽  
Leandro Piovan
Keyword(s):  
Continuous Flow ◽  
Energy Use ◽  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Flow Mode ◽  
Enzymatic Reactions ◽  
Secondary Alcohols ◽  
Batch Mode ◽  
Enzymatic Kinetic Resolution

AbstractEnzymatic kinetic resolution reactions are a well-established way to achieve optically active compounds. When enzymatic reactions are combined to continuous-flow methodologies, other benefits are added, including reproducibility, optimized energy use, minimized waste generation, among others. In this context, we herein report a case study involving lipase-mediated transesterification by acylation and deacylation reactions of secondary alcohols/esters in batch and continuous-flow modes. Acylation reactions were performed with high values of enantiomeric excess (72 up to >99%) and enantioselectivity (E > 200) for both batch and continuous-flow modes. On the other hand, for deacylation reactions using n-butanol as nucleophile, enatiomeric excess ranged between 38 to >99% and E from 6 to >200 were observed for batch mode. For deacylation reactions in continuous-flow mode, results were disappointing, as in some cases, very low or no conversion was observed. Enantiomeric excess ranged from 16 to >99% and enantioselectivity from 5 to >200 were observed. In terms of productivity, continuous-flow mode reactions were superior in both strategies (acylation: r from 1.1 up to 18.1-fold higher, deacylation: 2.8 up to 7.4- fold higher in continuous-flow than in batch mode).

scholarly journals Tailored sol–gel immobilized lipase preparates for the enzymatic kinetic resolution of heteroaromatic alcohols in batch and continuous flow systems

RSC Advances ◽  
2017 ◽  
Vol 7 (83) ◽  
pp. 52977-52987 ◽  
Author(s):  
Mădălina Elena Moisă ◽  
Cristina Georgiana Spelmezan ◽  
Cristina Paul ◽  
Judith Hajnal Bartha-Vári ◽  
László Csaba Bencze ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Immobilized Lipase ◽  
Sol Gel ◽  
Flow Mode ◽  
Batch Mode ◽  
Flow Reactors ◽  
Immobilized Lipases ◽  
Enzymatic Kinetic Resolution ◽  
Continuous Flow Reactors

The EKR of some heteroaromatic secondary ethanols with tailored sol–gel immobilized lipases in batch and continuous-flow reactors was studied. The productivity in continuous-flow mode is higher than in batch mode.

scholarly journals CALB Immobilized onto Magnetic Nanoparticles for Efficient Kinetic Resolution of Racemic Secondary Alcohols: Long-Term Stability and Reusability

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 490 ◽  
Author(s):  
Xiu Xing ◽  
Jun-Qi Jia ◽  
Jing-Fan Zhang ◽  
Zi-Wen Zhou ◽  
Jun Li ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Particles ◽  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Secondary Alcohols ◽  
Optimal Conditions ◽  
Long Term Stability ◽  
Enzymatic Kinetic Resolution ◽  
Functionalized Magnetic Nanoparticles ◽  
Co Precipitation

In this study, an immobilization strategy for magnetic cross-linking enzyme aggregates of lipase B from Candida antarctica (CALB) was developed and investigated. Magnetic particles were prepared by conventional co-precipitation. The magnetic nanoparticles were modified with 3-aminopropyltriethoxysilane (APTES) to obtain surface amino-functionalized magnetic nanoparticles (APTES–Fe3O4) as immobilization materials. Glutaraldehyde was used as a crosslinker to covalently bind CALB to APTES–Fe3O4. The optimal conditions of immobilization of lipase and resolution of racemic 1-phenylethanol were investigated. Under optimal conditions, esters could be obtained with conversion of 50%, enantiomeric excess of product (eep) > 99%, enantiomeric excess of substrate (ees) > 99%, and enantiomeric ratio (E) > 1000. The magnetic CALB CLEAs were successfully used for enzymatic kinetic resolution of fifteen secondary alcohols. Compared with Novozym 435, the magnetic CALB CLEAs exhibited a better enantioselectivity for most substrates. The conversion was still greater than 49% after the magnetic CALB CLEAs had been reused 10 times in a 48 h reaction cycle; both ees and eep were close to 99%. Furthermore, there was little decrease in catalytic activity and enantioselectivity after being stored at −20 °C for 90 days.

Different Types of Microbial Fuel Cell (MFC) Systems for Simultaneous Electricity Generation and Pollutant Removal

2015 ◽  
Vol 74 (3) ◽  
Author(s):  
S. M. Zain ◽  
N. L. Ching ◽  
S. Jusoh ◽  
S. Y. Yunus
Keyword(s):  
Nitrogen Removal ◽  
Continuous Flow ◽  
Electricity Generation ◽  
Pollutant Removal ◽  
Flow Mode ◽  
Oxidizing Agent ◽  
Batch Mode ◽  
Carbon And Nitrogen ◽  
Different Types ◽  
The Relationship

The aim of this study is to identify the relationship between the rate of electricity generation and the rate of carbon and nitrogen removal from wastewater using different MFC processes.  Determining whether the generation of electricity using MFC process could be related to the rate of pollutant removal from wastewater is noteworthy. Three types of MFC process configurations include the batch mode (SS), a continuous flow of influent with ferricyanide (PF) as the oxidizing agent and a continuous flow of influent with oxygen (PU) as the oxidizing agent. The highest quantity of electricity generation was achieved using the continuous flow mode with ferricyanide (0.833 V), followed by the continuous flow mode with oxygen (0.589 V) and the batch mode (0.352 V). The highest efficiency of carbon removal is also achieved by the continuous flow mode with ferricyanide (87%), followed by the continuous flow mode with oxygen (51%) and the batch mode (46%). Moreover, the continuous flow mode with ferricyanide produced the highest efficiency for nitrogen removal (63%), followed by the continuous flow mode with oxygen (54%) and the batch mode (27%).

scholarly journals Immobilized Whole-Cell Transaminase Biocatalysts for Continuous-Flow Kinetic Resolution of Amines

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 438 ◽  
Author(s):  
Zsófia Molnár ◽  
Emese Farkas ◽  
Ágnes Lakó ◽  
Balázs Erdélyi ◽  
Wolfgang Kroutil ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Sol Gel ◽  
Chiral Amines ◽  
Flow Mode ◽  
Immobilized Cell ◽  
Hollow Silica ◽  
E Coli ◽  
Sol Gel Process ◽  
Racemic Amines

Immobilization of transaminases creates promising biocatalysts for production of chiral amines in batch or continuous-flow mode reactions. E. coli cells containing overexpressed transaminases of various selectivities and hollow silica microspheres as supporting agent were immobilized by an improved sol-gel process to produce immobilized transaminase biocatalysts with suitable stability and mechanical properties for continuous-flow applications. The immobilized cell-based transaminase biocatalyst proved to be durable and easy-to-use in kinetic resolution of four racemic amines 1a–d. The batch and continuous-flow mode kinetic resolutions with transaminase biocatalyst of opposite stereopreference provided access to both enantiomers of the corresponding amines. By using the most suitable immobilized transaminase biocatalysts, this study describes the first transaminase-based approach for the production of both pure enantiomers of 1-(3,4-dimethoxyphenyl)ethan-1-amine 1d.

scholarly journals Efficient and Stable Magnetic Chitosan-Lipase B from Candida Antarctica Bioconjugates in the Enzymatic Kinetic Resolution of Racemic Heteroarylethanols

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 350 ◽  
Author(s):  
Cristina Georgiana Spelmezan ◽  
László Csaba Bencze ◽  
Gabriel Katona ◽  
Florin Dan Irimie ◽  
Csaba Paizs ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Vinyl Acetate ◽  
Kinetic Resolution ◽  
Covalent Binding ◽  
Enantiomeric Excess ◽  
Candida Antarctica ◽  
Optimal Conditions ◽  
Lipase B ◽  
Magnetic Chitosan ◽  
Enzymatic Kinetic Resolution

Lipase B from Candida antarctica immobilized by covalent binding on sebacoyl-activated chitosan-coated magnetic nanoparticles proved to be an efficient biocatalyst (49.2–50% conversion in 3–16 h and >96% enantiomeric excess) for the enzymatic kinetic resolution of some racemic heteroarylethanols through transesterification with vinyl acetate. Under optimal conditions (vinyl acetate, n-hexane, 45 °C), the biocatalyst remains active after 10 cycles.

Overview: Enzyme-catalyzed Enantioselective Biotransformation of Chiral Active Compounds Used in Hypertension Treatment

2020 ◽  
Vol 24 (23) ◽  
pp. 2782-2791
Author(s):  
Joanna Chałupka ◽  
Adam Sikora ◽  
Aleksandra Kozicka ◽  
Michał Piotr Marszałł
Keyword(s):  
Kinetic Resolution ◽  
Enzymatic Reactions ◽  
Reaction Conditions ◽  
Enantiomerically Pure ◽  
Pharmaceutical Ingredients ◽  
Enzymatic Kinetic Resolution ◽  
Treatment Of Hypertension ◽  
Pure Compounds ◽  
Β Blockers ◽  
Asymmetric Carbon

Enzymatic kinetic resolution is one of the methods which allows for the synthesis of enantiomerically pure various active pharmaceutical ingredients. In contrast to chemical routes, enzymatic reactions have characteristics, including mild reaction conditions, a few byproducts, and relatively high activity of the used enzymes. β-adrenolytic drugs are widely used in the treatment of hypertension and cardiovascular disorders. Due to the fact that β- blockers possess an asymmetric carbon atom in their structure, they are presented in two enantiomeric forms. It was reported by many studies that only the (S)-enantiomers of these drugs possess the desired therapeutic effect, whereas the administration of the racemate may cause dangerous side effects, such as bronchoconstriction or diabetes. Nevertheless, β- blockers are still commercially available drugs mainly used in medicine as racemates, whereas there are several methods that are widely used in order to obtain enantiomerically pure compounds.

Chemoenzymatic Dynamic Kinetic Resolution of Amines in Fully Continuous-Flow Mode

2018 ◽  
Vol 20 (24) ◽  
pp. 8052-8056 ◽  
Author(s):  
Emese Farkas ◽  
Márk Oláh ◽  
Attila Földi ◽  
János Kóti ◽  
János Éles ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Flow Mode ◽  
Dynamic Kinetic Resolution

Enzymatic kinetic resolution of secondary alcohols by esterification with FA under vacuum

2003 ◽  
Vol 80 (7) ◽  
pp. 659-663 ◽  
Author(s):  
Roxana Irimescu ◽  
Takao Saito ◽  
Katsuya Kato
Keyword(s):  
Kinetic Resolution ◽  
Secondary Alcohols ◽  
Enzymatic Kinetic Resolution

Enzymatic Kinetic Resolution of Secondary Alcohols Using an Ionic Anhydride Generated In Situ

ChemSusChem ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 296-302 ◽  
Author(s):  
Ângelo Rocha ◽  
Raquel Teixeira ◽  
Nuno M. T. Lourenço ◽  
Carlos A. M. Afonso
Keyword(s):  
Kinetic Resolution ◽  
Secondary Alcohols ◽  
Enzymatic Kinetic Resolution
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