scholarly journals Immobilization and Biochemical Properties of the Enantioselective Recombinant NStcI Esterase of Aspergillus nidulans

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Carolina Peña-Montes ◽  
María Elena Mondragón-Tintor ◽  
José Augusto Castro-Rodríguez ◽  
Ismael Bustos-Jaimes ◽  
Arturo Navarro-Ocaña ◽  
...  
Keyword(s):  
Kinetic Resolution ◽  
Storage Stability ◽  
Enantiomeric Excess ◽  
Residual Activity ◽  
Biochemical Properties ◽  
Maximum Activity ◽  
Acyl Donor ◽  
Initial Activity ◽  
Enzymatic Kinetic Resolution ◽  
Repeated Use

The recombinant NStcI A. nidulans esterase was adsorbed on Accurel MP1000, where protein yield and immobilization efficiency were 42.48% and 81.94%, respectively. Storage stability test at 4°C and RT showed 100% of residual activity after 40 days at both temperatures. The biocatalyst retains more than 70% of its initial activity after 3 cycles of repeated use. Biochemical properties of this new biocatalyst were obtained. Maximum activity was achieved at pH 11 and 30°C, while the best stability was observed with the pH between 9 and 11 at 40°C. NStcI thermostability was increased after immobilization, as it retained 47.5% of its initial activity after 1 h at 60°C, while the free enzyme under the same conditions displayed no activity. NStcI preserved 70% of its initial activity in 100% hexane after 72 h. Enzymatic kinetic resolution of (R,S)-1-phenylethanol was chosen as model reaction, using vinyl acetate as acyl donor. After optimization of reaction parameters, the highest possible conversion (42%) was reached at 37°C, aw of 0.07, and 120 h of bioconversion in hexane with an enantiomeric excess of 71.7%. NStcI has selectivity for (R)-enantiomer. The obtained E value (31.3) is in the range considered useful to resolve enantiomeric mixtures.

Carbodiimide for Covalent α-Amylase Immobilization onto Magnetic Nanoparticles

2017 ◽  
Vol 16 (05n06) ◽  
pp. 1750015 ◽  
Author(s):  
Zeinab Mortazavi Milani ◽  
Razieh Jalal ◽  
Elaheh K. Goharshadi
Keyword(s):  
Residual Activity ◽  
Maximum Activity ◽  
Covalent Attachment ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Operational Conditions ◽  
Transmission Electron ◽  
Repeated Batch ◽  
Repeated Use ◽  
Co Precipitation

Covalent cross-linking of enzymes to magnetite (Fe3O4) nanoparticles (MNPs) is one of the useful enzyme immobilization methods which provides repeated use of the catalyst, facilitates enzyme separation from the reaction mixture, and sometimes improves biocatalysts stability. The aim of this study was to immobilize [Formula: see text]-amylase onto MNPs via covalent attachment using carbodiimide (CDI) molecules. MNPs were synthesized by the co-precipitation method. The size and the structure of the particles were characterized by X-ray diffraction and transmission electron microscopy. The effects of different operational conditions of direct [Formula: see text]-amylase binding on MNPs in the presence of CDI were investigated by using the shaking method. Fourier transform infrared spectroscopy was used to confirm the success of immobilization. The optimum conditions and catalytic properties of immobilized [Formula: see text]-amylase were also evaluated. The efficiency of immobilization and the residual activity of the immobilized [Formula: see text]-amylase were dependent on the mass ratio of MNPs: CDI: [Formula: see text]-amylase and the immobilization temperature. The optimum pH for the free and immobilized amylase was 6. The free and immobilized [Formula: see text]-amylase showed maximum activity at 20[Formula: see text]C and 35[Formula: see text]C, respectively. The immobilized [Formula: see text]-amylase was more thermostable than the free one. The retained activity for free [Formula: see text]-amylase after 19 storage days was 57.7% whereas it was 100% for the immobilized [Formula: see text]-amylase. In repeated batch experiments, the immobilized [Formula: see text]-amylase retained a residual activity of 45% after 11 repeated uses. The [Formula: see text] and [Formula: see text] values for the immobilized enzyme were larger than those of the free enzyme. The immobilization of [Formula: see text]-amylase on MNPs using CDI improves its stability and reusability.

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.

Optimization of Chiral Resolution of (+/-)-1-Phenylethanol by Statistical Methods

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Ganapati D. Yadav ◽  
Jyoti B. Sontakke
Keyword(s):  
Kinetic Resolution ◽  
Batch Reactor ◽  
Immobilized Lipase ◽  
Enantiomeric Excess ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Acyl Donor ◽  
Reaction Conditions ◽  
Optimum Reaction ◽  
Synthetic Intermediate

Optically active 1-phenylethanol is used as a chiral building block and synthetic intermediate in pharmaceutical and fine-chemical industries. Lipase - catalyzed kinetic resolution of (R,S)-1-phenylethanol with vinyl acetate as an acyl donor and Candida antarctica immobilized lipase as a biocatalyst in a batch reactor was optimized using Response Surface Methodology (RSM). Four-factor-five-level central composite rotatable design (CCRD) was employed to evaluate the effect of synthesis parameters such as speed of agitation, enzyme loading, temperature and acyl donor/alcohol molar ratio, on conversion, enantiomeric excess (ee), enantioselectivity and initial rate. Optimum reaction conditions obtained were; mole ratio of acyl donor: ester of 2:1, temperature of 42.5 °C, catalyst loading of 1.6x10-3 g.cm-3 and speed of agitation of 336 rpm. Analysis of variance was performed to determine significantly affecting variables and interactions between the process parameters.

Biochemical properties of the alkaline lipase of Bacillus flexus XJU-1 and its detergent compatibility

Biologia ◽  
2014 ◽  
Vol 69 (9) ◽  
Author(s):  
Francois Niyonzima ◽  
Sunil More
Keyword(s):  
Sodium Dodecyl ◽  
Tween 80 ◽  
Relative Activity ◽  
Biochemical Properties ◽  
Maximum Activity ◽  
Liquid Chromatography Mass Spectrometry ◽  
Initial Activity ◽  
Detergent Compatibility ◽  
Bacillus Flexus ◽  
Stain Removal

AbstractThe possibility of using Bacillus flexus XJU-1 lipase in detergent preparations was studied. The enzyme was monomeric protein as confirmed by liquid chromatography-mass spectrometry and its molecular weight was 15.95 kDa. The lipase showed optimum activity at pH 10.0 and was 100% stable for 24 h at pH 10.0 and 11.0. It exhibited maximum activity at 70°C and retained more than 70% of the initial activity at 60, 70 and 80°C for 24 h. The activity was stimulated by Ca2+, Ba2+, Mg2+ and Co2+, whereas 50% of the initial activity was lost with Fe3+ and Hg2+. The activity was inhibited by 10 mM N-bromosuccinimide and tosyl-L-lysylchloromethylketone, while N-ethylmaleimide, phenylmethylsulphonylfluoride and urea did not show any effect. The enzyme significantly hydrolysed olive, cottonseed, sunflower, groundnut, and gingelly oils. With p-nitrophenyl palmitate, Vmax and Km were 62.5 U/mL and 2.25 mM, respectively. The lipase maintained its stability in Tween-80, Triton-100 and H2O2 at 1%, but an activation of 10% and a reduction of 15% in relative activity were observed with NaClO and sodium dodecyl sulphate, respectively. The enzyme retained maximum storage stability for 20 days at −20, 4 and 30°C. In the presence of 0.7% (w/v) Ariel, Henko, Super wheel, Tide plus and Rin, a retention of more than 84.90% initial activity was recorded after 24 h at 60°C. The supplementation of the lipase to the detergents improved the olive oil stain removal. These properties suggested the present enzyme as a potential additive for detergent preparations.

scholarly journals Effect of Reaction Parameters on the Lipase-Catalyzed Kinetic Resolution of (RS )-Metoprolol

2020 ◽  
Vol 20 (1) ◽  
pp. 20
Author(s):  
Mariani Rajin ◽  
Asiah Binti Zulkifli ◽  
Sariah Abang ◽  
S.M Anissuzzaman ◽  
Azlina Harun Kamaruddin
Keyword(s):  
Adrenergic Receptor ◽  
Kinetic Resolution ◽  
Beta Blockers ◽  
Enantiomeric Excess ◽  
Acyl Donor ◽  
Market Demand ◽  
Disease Treatment ◽  
Enantiomeric Ratio ◽  
Candida Antarctica B ◽  
Candida Antarctica B Lipase

Racemic metoprolol is a selective ß1-blocker, which is used in cardiovascular disease treatment. It has been found that (S)-metoprolol has a higher affinity to bind the ß-adrenergic receptor compared to (R)-metoprolol. Moreover, the regulatory authorities’ high market demand and guidelines have increased the preference for single enantiomer drugs. In this work, the lipase-catalyzed kinetic resolution of racemic metoprolol was performed to obtain the desired enantiomer. The type of lipase, acyl donor, and solvent were screened out. This was achieved by Candida antarctica B lipase-catalyzed transesterification of racemic metoprolol in hexane and vinyl acetate as the solvent and an acyl donor, which gave maximum conversion of (S)-metoprolol (XS) of 52%, enantiomeric excess of substrate, (ees) of 92% and product (eeP) of 90% with enantiomeric ratio (E) of 62. This method can be considered as green chemistry, which can be applied to produce other enantiopure beta-blockers.

Optimization of process parameters and kinetic modeling for the enantioselective kinetic resolution of (R,S)-2-pentanol

2017 ◽  
Vol 42 (6) ◽  
Author(s):  
Aslı Soyer Malyemez ◽  
Emine Bayraktar ◽  
Ülkü Mehmetoğlu
Keyword(s):  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Reaction Rates ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Acyl Donor ◽  
Optimum Conditions ◽  
Optimization Of Process Parameters ◽  
Maximum Reaction ◽  
Working Volume

AbstractIntroduction:In order to product (S)-2-pentanol which have been used as a key chiral intermediate required in the synthesis of several potential anti-Alzhemeir drugs, the effects of enzyme, acyl donor, substrate concentration and acyl donor/racemic-2-pentanol mole ratio were investigated on the kinetic resolution of racemic-2-pentanol.Methods:Reactions were performed in a bioreactor of 50 mL capacity with a working volume of 30 mL on an orbital shaker at 150 rpm and at 30°C. Production parameters were investigated with different type of enzyme and acyl donor.Results:The optimum conditions were obtained with Novozyme 435 and vinyl butyrate with the 50% conversion, 99% of enantiomeric excess for the substrate at 30 min. Optimum conditions are 1500 mM substrate and 4 mg/mL enzyme concentrations and 24.88 mM/min maximum initial reaction rate. It was obtained that Ping-Pong bi-bi mechanism was the appropriate reaction kinetic. Kinetic parameters were determined with Polymath 6.1 software as 4.16 mmol/min/g enzyme maximum reaction rates, 103.73 mM Km for (R)-2-pentanol and 51.18 mM Km for vinyl butyrate.Conclusion:(S)-2-pentanol was obtained with 99% of enantiomeric excess. These data will be clear up to product (S)-2-pentanol at larger industrial scales in future.

scholarly journals Biocatalytic synthesis of (S)-Practolol, a selective β-blocker

Biocatalysis ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Sachin Mulik ◽  
Saptarshi Ghosh ◽  
Jayeeta Bhaumik ◽  
Uttam C. Banerjee
Keyword(s):  
Adrenergic Receptor ◽  
Kinetic Resolution ◽  
Sol Gel ◽  
Enantiomeric Excess ◽  
Green Technology ◽  
Chemoenzymatic Synthesis ◽  
Acyl Donor ◽  
Pseudomonas Cepacia ◽  
Reaction Parameters ◽  
Β Blocker

AbstractThe present study describes an efficient chemoenzymatic synthesis of enantiopure (S)-Practolol, a selective β-adrenergic receptor blocker. Prior to the synthesis of the target, a synthetic protocol for (RS)-N-4-(3-chloro-2-hydroxypropoxy)phenylacetamide, an essential precursor, was developed. Various commercial lipases were screened for the kinetic resolution of (RS)- N-4-(3-chloro-2-hydroxypropoxy)phenylacetamide using toluene as solvent and vinyl acetate as an acyl donor. Among various lipases screened, Pseudomonas cepacia sol-gel AK showed the highest enantioselectivity (96% enantiomeric excess with 50% conversion), affording (S)-1-(4-acetamidophenoxy)-3-chloropropan-2-yl acetate. Optimization of the reaction parameters was carried out in order to find the best-suited conditions for the biocatalysis. Furthermore, the enantiopure intermediate was hydrolyzed and the resulting product was reacted with isopropylamine to afford (S)-Practolol. This biocatalytic procedure depicts a green technology for the synthesis of (S)-Practolol with better yield and enantiomeric excess.

scholarly journals The production of enantiomerically pure 1-phenylethanol by enzymatic kinetic resolution method using response surface methodology

2020 ◽  
Vol 44 (5) ◽  
pp. 1352-1365
Author(s):  
Ayşe BOZAN ◽  
Rahime SONGÜR ◽  
Ülkü MEHMETOĞLU
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
High Performance ◽  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Reaction Parameters ◽  
Enantiomerically Pure ◽  
Enzymatic Kinetic Resolution ◽  
Optimum Reaction

As the enantiomers of 1-phenylethanol are valuable intermediates in several industries, the lipase catalyzed kinetic resolution of (R,S) -1-phenylethanol is a relevant research topic. In this study, the goal was to determine the optimum reaction parameters to produce enantiomerically pure 1-phenylethanol by lipase (Novozyme 435) catalyzed kinetic resolution using response surface methodology (RSM). Reactions were performed with 40–400 mM (R,S)-1-phenylethanol, 120–1200 mM vinyl acetate and 2–22 mg/ mL biocatalyst concentrations (BCL), at 20–60 °C and with a stirring rate of 50–400 rpm for 5–120 min. The samples were analyzed using high performance liquid chromatography (HPLC) with a Chiralcel OB column. Optimum reaction parameters to reach 100% enantiomeric excess for the substrate (ees) were determined as follows: substrate concentration (Cs): 240 mM, BCL: 11 mg/mL, at 42 °C with a reaction time of 75 min. Model validation was performed using these conditions and ees was calculated as 100%, which indicates the predicted model was efficient and accurate. When compared to the literature, it was observed that the reaction time decreased significantly. This is an important result considering the industrial scale perspective.

scholarly journals Preparation of (R)-1-(2-Naphthyl)ethylamine by Enzymatic Kinetic Resolution with A New Acyl Donor

2012 ◽  
Vol 32 (03) ◽  
pp. 526 ◽  
Author(s):  
Simin Fu ◽  
Gang Xu ◽  
Yongjun Chen ◽  
Jianping Wu ◽  
Lirong Yang
Keyword(s):  
Kinetic Resolution ◽  
Acyl Donor ◽  
Enzymatic Kinetic Resolution

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).

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