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Biocatalytic Process (biocatalytic + process)
Selected AbstractsEfficient Tandem Biocatalytic Process for the Kinetic Resolution of Aromatic ,-Amino AcidsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Bian Wu Abstract We describe a simple and efficient enzymatic tandem reaction for the preparation of enantiomerically pure , -phenylalanine and its analogues from the corresponding racemates. In this process, phenylalanine aminomutase (PAM) catalyzes the stereoselective isomerization of (R)- , -phenylalanines to (S)- , -phenylalanines, which are in situ transformed to cinnamic acids by phenylalanine ammonia lyase (PAL). Preparative scale conversions are done with a mutated PAM with enhanced catalytic activity. [source] Chiral alcohol production by NADH-dependent phenylacetaldehyde reductase coupled with in situ regeneration of NADHFEBS JOURNAL, Issue 9 2002Nobuya Itoh Phenylacetaldehyde reductase (PAR) produced by styrene-assimilating Corynebacterium strain ST-10 was used to synthesize chiral alcohols. This enzyme with a broad substrate range reduced various prochiral aromatic ketones and ,-ketoesters to yield optically active secondary alcohols with an enantiomeric purity of more than 98% enantiomeric excess (e.e.). The Escherichia coli recombinant cells which expressed the par gene could efficiently produce important pharmaceutical intermediates; (R)-2-chloro-1-(3-chlorophenyl)ethanol (28 mg·mL,1) from m -chlorophenacyl chloride, ethyl (R)-4-chloro-3-hydroxy butanoate) (28 mg·mL,1) from ethyl 4-chloro-3-oxobutanoate and (S)- N-tert -butoxycarbonyl(Boc)-3-pyrrolidinol from N -Boc-3-pyrrolidinone (51 mg·mL,1), with more than 86% yields. The high yields were due to the fact that PAR could concomitantly reproduce NADH in the presence of 3,7% (v/v) 2-propanol in the reaction mixture. This biocatalytic process provided one of the best asymmetric reductions ever reported. [source] Captopril and its synthesis from chiral intermediatesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2001R Chirumamilla Abstract Captopril is an antihypertensive agent that inhibits the angiotensin-converting enzyme of the renin,angiotensin system. Chiral intermediates are used in the synthesis of the drug. These intermediates are obtained by resolution of racemic compounds or by chemical, biocatalytic methods and or by asymmetric synthesis by biocatalytic process. This article reviews the various chemical and biochemical processes involved in the synthesis of the chiral drug, including the pharmacological action of captopril. © 2001 Society of Chemical Industry [source] Application of immobilized bovine enterokinase in repetitive fusion protein cleavage for the production of mucin 1BIOTECHNOLOGY JOURNAL, Issue 11 2009Tina Kubitzki Abstract Bovine enterokinase is a serine protease that catalyzes the hydrolysis of peptide bonds and plays a key role in mammalian metabolism. Because of its high specificity towards the amino acid sequence (Asp)4 -Lys, enterokinase is a potential tool for the cleavage of fusion proteins, which are gaining more importance in biopharmaceutical production. A candidate for adaptive cancer immunotherapy is mucin 1, which is produced recombinantly as a fusion protein in CHO cells. Here, we present the first repetitive application of immobilized enterokinase for the cleavage of the mucin fusion protein. The immobilization enables a facile biocatalytic process due to simplified separation of the biocatalyst and the target protein. Immobilized enterokinase was applied in a maximum of 18 repetitive reactions. The enzyme utilization (total turnover number) was increased significantly 419-fold compared to unbound enzyme by both immobilization and optimization of process conditions. Slight enzyme inactivation throughout the reaction cycles was observed, but was compensated by adjusting the process time accordingly. Thus, complete fusion protein cleavage was achieved. Furthermore, we obtained isolated mucin 1 with a purity of more than 90% by applying a simple and efficient purification process. The presented results demonstrate enterokinase to be an attractive tool for fusion protein cleavage. [source] Application of modeling and simulation tools for the evaluation of biocatalytic processes: A future perspectiveBIOTECHNOLOGY PROGRESS, Issue 6 2009Gürkan Sin Abstract Modeling and simulation techniques have for some time been an important feature of biocatalysis research, often applied as a complement to experimental studies. In this short review, we report on the state-of-the-art process and kinetic modeling for biocatalysis with the aim of identifying future research needs. We have particularly focused on four aspects of modeling: (i) the model purpose, (ii) the process model boundary, (iii) the model structure, and (iv) the model identification procedure. First, one finds that most of the existing models describe biocatalyst behavior in terms of enzyme selectivity, mechanism, and reaction kinetics. More recently, work has focused on extending these models to obtain process flowsheet descriptions. Second, biocatalysis models remain at a relatively low level of complexity compared with the trends observed in other engineering disciplines. Hence, there is certainly room for additional development, i.e., detailed mixing and hydrodynamics, more process units (e.g., biorefinery). Third, biocatalysis models have been only partially subjected to formal statistical analysis. In particular, uncertainty analysis is needed to ascertain reliability of the predictions of the process model, which is necessary to make sound engineering decisions (e.g., the optimal process flowsheet, control strategy, etc). In summary, for modeling studies to be more mature and successful, one needs to introduce Good Modeling Practice and that asks for (i) a standardized and systematic guideline for model development, (ii) formal identifiability analysis, and (iii) uncertainty analysis. This will advance the utility of models in biocatalysis for more rigorous application within process design, optimization, and control strategy evaluation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] | |||||||||||||