23357-52-0Relevant academic research and scientific papers
Engineering the large pocket of an (S)-selective transaminase for asymmetric synthesis of (S)-1-amino-1-phenylpropane
Liu, He,Wang, Hualei,Wei, Dongzhi,Xie, Youyu,Xu, Feng,Xu, Xiangyang,Yang, Lin
, p. 2461 - 2470 (2021/04/22)
Amine transaminases offer an environmentally benign chiral amine asymmetric synthesis route. However, their catalytic efficiency towards bulky chiral amine asymmetric synthesis is limited by the natural geometric structure of the small pocket, representing a great challenge for industrial applications. Here, we rationally engineered the large binding pocket of an (S)-selective ?-transaminase BPTA fromParaburkholderia phymatumto relieve the inherent restriction caused by the small pocket and efficiently transform the prochiral aryl alkyl ketone 1-propiophenone with a small substituent larger than the methyl group. Based on combined molecular docking and dynamic simulation analyses, we identified a non-classical substrate conformation, located in the active site with steric hindrance and undesired interactions, to be responsible for the low catalytic efficiency. By relieving the steric barrier with W82A, we improved the specific activity by 14-times compared to WT. A p-p stacking interaction was then introduced by M78F and I284F to strengthen the binding affinity with a large binding pocket to balance the undesired interactions generated by F44. T440Q further enhanced the substrate affinity by providing a more hydrophobic and flexible environment close to the active site entry. Finally, we constructed a quadruple variant M78F/W82A/I284F/T440Q to generate the most productive substrate conformation. The 1-propiophenone catalytic efficiency of the mutant was enhanced by more than 470-times in terms ofkcat/KM, and the conversion increased from 1.3 to 94.4% compared with that of WT, without any stereoselectivity loss (ee > 99.9%). Meanwhile, the obtained mutant also showed significant activity improvements towards various aryl alkyl ketones with a small substituent larger than the methyl group ranging between 104- and 230-fold, demonstrating great potential for the efficient synthesis of enantiopure aryl alkyl amines with steric hindrance in the small binding pocket.
Kinetic Resolution of Racemic Primary Amines Using Geobacillus stearothermophilus Amine Dehydrogenase Variant
Tseliou, Vasilis,Knaus, Tanja,Vilím, Jan,Masman, Marcelo F.,Mutti, Francesco G.
, p. 2184 - 2188 (2020/03/11)
A NADH-dependent engineered amine dehydrogenase from Geobacillus stearothermophilus (LE-AmDH-v1) was applied together with a NADH-oxidase from Streptococcus mutans (NOx) for the kinetic resolution of pharmaceutically relevant racemic α-chiral primary amines. The reaction conditions (e. g., pH, temperature, type of buffer) were optimised to yield S-configured amines with up to >99 % ee.
Kinetic Resolution and Deracemization of Racemic Amines Using a Reductive Aminase
Aleku, Godwin A.,Mangas-Sanchez, Juan,Citoler, Joan,France, Scott P.,Montgomery, Sarah L.,Heath, Rachel S.,Thompson, Matthew P.,Turner, Nicholas J.
, p. 515 - 519 (2018/02/15)
The NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm) was combined with an NADPH oxidase (NOX) to develop a redox system that recycles the co-factor. The AspRedAm-NOX system was applied initially for the kinetic resolution of a variety of racemic secondary and primary amines to yield S-configured amines with enantiomeric excess (ee) values up to 99 %. The addition of ammonia borane to this system enabled the efficient deracemization of racemic amines, including the pharmaceutical drug rasagiline and the natural product salsolidine, with conversions up to >98 % and >99 % ee Furthermore, by using the AspRedAm W210A variant it was possible to generate the opposite R enantiomers with efficiency comparable to, or even better than, the wildtype AspRedAm.
Simultaneous engineering of an enzyme's entrance tunnel and active site: The case of monoamine oxidase MAO-N
Li, Guangyue,Yao, Peiyuan,Gong, Rui,Li, Jinlong,Liu, Pi,Lonsdale, Richard,Wu, Qiaqing,Lin, Jianping,Zhu, Dunming,Reetz, Manfred T.
, p. 4093 - 4099 (2017/07/10)
A new directed evolution approach is presented to enhance the activity of an enzyme and to manipulate stereoselectivity by focusing iterative saturation mutagenesis (ISM) simultaneously on residues lining the entrance tunnel and the binding pocket. This combined mutagenesis strategy was applied successfully to the monoamine oxidase from Aspergillus Niger (MAO-N) in the reaction of sterically demanding substrates which are of interest in the synthesis of chiral pharmaceuticals based on the benzo-piperidine scaffold. Reversal of enantioselectivity of Turner-type deracemization was achieved in the synthesis of (S)-1,2,3,4-tetrahydro-1-methyl-isoquinoline, (S)-1,2,3,4-tetrahydro-1-ethylisoquinoline and (S)-1,2,3,4-tetrahydro-1-isopropylisoquinoline. Extensive molecular dynamics simulations indicate that the altered catalytic profile is due to increased hydrophobicity of the entrance tunnel acting in concert with the altered shape of the binding pocket.
(R)- SELECTIVE AMINATION
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Paragraph 0120; 0121; 0122, (2016/03/22)
The present invention relates to a method for the enzymatic synthesis of enantiomerically enriched (R)-amines of general formula [1][c] from the corresponding ketones of the general formula [1][a] by using novel transaminases. These novel transaminases are selected from two different groups: either from a group of some 20 proteins with sequences as specified herein, or from a group of proteins having transaminase activity and isolated from a microorganism selected from the group of organisms consisting of Rahnella aquatilis, Ochrobactrum anthropi, Ochrobactrum tritici, Sinorhizobium morelense, Curtobacterium pusiffium, Paecilomyces lilacinus, Microbacterium ginsengisoli, Microbacterium trichothecenolyticum, Pseudomonas citronellolis, Yersinia kristensenii, Achromobacter spanius, Achromobacter insolitus, Mycobacterium fortuitum, Mycobacterium frederiksbergense, Mycobacterium sacrum, Mycobacterium fluoranthenivorans, Burkhoideria sp., Burkhoideria tropica, Cosmospora episphaeria, and Fusarium oxysporum.
Palladium/Lewis Acid Co-catalyzed Divergent Asymmetric Ring-Opening Reactions of Azabenzonorbornadienes with Alcohols
Yang, Fan,Chen, Jingchao,Xu, Jianbin,Ma, Fujie,Zhou, Yongyun,Shinde, Madhuri Vikas,Fan, Baomin
, p. 4832 - 4835 (2016/10/14)
By fine tuning the combinations of chiral palladium catalysts and Lewis acids, both the additional and reductive asymmetric ring-opening reactions of azabenzonorbornadienes with alcohols were accomplished with good chemoselectivity, regioselectivity, and enantioselectivity. It was proven that the reductive ring-opening products were generated through a transfer-hydrogenation process with alcohols as hydrogen source.
A Single Lipase-Catalysed One-Pot Protocol Combining Aminolysis Resolution and Aza-Michael Addition: An Easy and Efficient Way to Synthesise β-Amino Acid Esters
Xu, Fan,Wu, Qiongsi,Chen, Xiaoyang,Lin, Xianfu,Wu, Qi
, p. 5393 - 5401 (2015/08/24)
A novel one-pot protocol combining aza-Michael addition and aminolysis resolution was developed to obtain chiral β-amino acid esters with lipase B from Candida antarctica (CAL-B) as the only catalyst. This method is conducted under mild reaction conditions and is very easy to handle. After a series of detailed optimization studies, ten racemic aromatic or aliphatic amines were subjected to this one-pot procedure, and twelve chiral β-amino acid esters and ten chiral amides were successfully synthesised with excellent ee values in theoretical yields. Scaled-up procedures also worked without apparent reduction in reaction rate or enantioselectivity, which makes this method suitable for large-scale production of chiral β-amino acid esters. A one-pot protocol for simultaneous synthesis of chiral β-amino acid esters and amides was developed by combining single lipase B from Candida antarctica (CAL-B) catalysed aza-Michael addition and aminolysis resolution. This method requires mild reaction conditions and is very easy to handle. Chiral β-amino acid esters and chiral amides were obtained with excellent ee values and in theoretical yields.
Substrate profile of an ω-transaminase from Burkholderia vietnamiensis and its potential for the production of optically pure amines and unnatural amino acids
Jiang, Jinju,Chen, Xi,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
, p. 32 - 39 (2014/01/06)
A new (S)-enantioselective ω-transaminase (ω-TA) gene from Burkholderia vietnamiensis G4 was functionally expressed in Escherichia coli BL21 (DE3), and the purified recombinant N-terminal His-tagged ω-TA (HBV-ω-TA) had a dimeric structure with optimum pH and temperature of 8.4 and 40 C, respectively. The enzyme showed higher activities toward aromatic amines than aliphatic amines and (S)-1-methylbenzylamine ((S)-α-MBA) was the most active amino donor. For amino acceptor, keto acids, keto esters and aldehydes were more reactive than ketones with pyruvate ethyl ester being most active. Several chiral amines and unnatural amino acids or esters were synthesized using HBV-ω-TA as the catalyst and isopropylamine or (S)-α-MBA as amino donor. Notably, HBV-ω-TA catalyzed the amino transfer to β-keto esters to give optically pure β-amino acid esters. In addition, glyoxylate was used as amino acceptor for the first time in the kinetic resolution of racemic amines and optically pure amines, such as (R)-1-methylbenzylamine, (R)-1-phenylpropylamine, (R)-2-amino-4-phenylbutane and (R)-1-aminotetraline, were obtained.
How the mode of Candida antarctica lipase B immobilization affects the continuous-flow kinetic resolution of racemic amines at various temperatures
Boros, Zoltán,Falus, Péter,Márkus, Mária,Weiser, Diána,Oláh, Márk,Hornyánszky, Gábor,Nagy, József,Poppe, László
, p. 119 - 125 (2013/01/15)
The effect of temperature on enantiomeric ratio (E) and specific reaction rate (rflow) in the continuous-flow mode acetylation of (±)-1-phenylethanamine (rac-1a), (±)-4-phenylbutan-2-amine (rac-1b) and (±)-1,2,3,4-tetrahydro-1-naphthalenamine (rac-1c) by variously immobilized Candida antarctica lipase B biocatalysts was studied in the 0-70 °C range. In the continuous-flow kinetic resolutions with differently immobilized CaLB biocatalysts, the character of temperature effect depended significantly both on the substrate and on the mode of immobilization. Alteration of E in the kinetic resolutions of three differently flexible amines rac-1a-c as a function of temperature was rationalized by the various flexibility of the lipase in its different forms. Our results indicated that the optimal method of immobilization depended both on the nature of the substrate and the reaction conditions.
Step-efficient access to chiral primary amines
Nugent, Thomas C.,Marinova, Sofiya M.
, p. 153 - 166 (2013/02/25)
Routes to enantioenriched amines are outlined that employ reductive amination and carbanion addition methods. The strategies require either one or two reaction steps from prochiral carbonyl compounds for the synthesis of the corresponding chiral primary amines. Georg Thieme Verlag Stuttgart New York.
