- Continuous Flow Bioamination of Ketones in Organic Solvents at Controlled Water Activity using Immobilized ω-Transaminases
-
Compared with biocatalysis in aqueous media, the use of enzymes in neat organic solvents enables increased solubility of hydrophobic substrates and can lead to more favorable thermodynamic equilibria, avoidance of possible hydrolytic side reactions and easier product recovery. ω-Transaminases from Arthrobacter sp. (AsR?ωTA) and Chromobacterium violaceum (Cv?ωTA) were immobilized on controlled porosity glass metal-ion affinity beads (EziG) and applied in neat organic solvents for the amination of 1-phenoxypropan-2-one with 2-propylamine. The reaction system was investigated in terms of type of carrier material, organic solvents and reaction temperature. Optimal conditions were found with more hydrophobic carrier materials and toluene as reaction solvent. The system's water activity (aw) was controlled via salt hydrate pairs during both the biocatalyst immobilization step and the progress of the reaction in different non-polar solvents. Notably, the two immobilized ωTAs displayed different optimal values of aw, namely 0.7 for EziG3?AsR?ωTA and 0.2 for EziG3?Cv?ωTA. In general, high catalytic activity was observed in various organic solvents even when a high substrate concentration (450–550 mM) and only one equivalent of 2-propylamine were applied. Under batch conditions, a chemical turnover (TTN) above 13000 was obtained over four subsequent reaction cycles with the same batch of EziG-immobilized ωTA. Finally, the applicability of the immobilized biocatalyst in neat organic solvents was further demonstrated in a continuous flow packed-bed reactor. The flow reactor showed excellent performance without observable loss of enzymatic catalytic activity over several days of operation. In general, ca. 70% conversion was obtained in 72 hours using a 1.82 mL flow reactor and toluene as flow solvent, thus affording a space-time yield of 1.99 g L?1 h?1. Conversion reached above 90% when the reaction was run up to 120 hours. (Figure presented.).
- B?hmer, Wesley,Engelmark Cassimjee, Karim,Mutti, Francesco G.,Volkov, Alexey
-
-
Read Online
- A Chemoenzymatic Cascade Combining a Hydration Catalyst with an Amine Dehydrogenase: Synthesis of Chiral Amines
-
The combination of biocatalysis and transition-metal catalysis can complement synthetic gaps only in a chemical or biological process. However, the intrinsic mutual deactivation between enzymatic and chemical species is a significant challenge in a single
- Chang, Fengwei,Chen, Qipeng,Liu, Guohua,Wang, Chengyi,Zhang, Yongjin
-
supporting information
(2022/01/19)
-
- GPhos Ligand Enables Production of Chiral N-Arylamines in a Telescoped Transaminase-Buchwald-Hartwig Amination Cascade in the Presence of Excess Amine Donor
-
The combination of biocatalysis and chemocatalysis can be more powerful than either technique alone. However, combining the two is challenging due to typically very different reaction conditions. Herein, chiral N-aryl amines, key features of many active pharmaceutical ingredients, are accessed in excellent enantioselectivity (typically>99.5 % ee) by combining transaminases with the Buchwald-Hartwig amination. By employing a bi-phasic buffer-toluene system as well as the ligand GPhos, the telescoped cascade proceeded with up to 89 % overall conversion in the presence of excess alanine. No coupling to alanine was observed.
- Heckmann, Christian M.,Paradisi, Francesca
-
supporting information
p. 16616 - 16620
(2021/10/12)
-
- Iterative Alanine Scanning Mutagenesis Confers Aromatic Ketone Specificity and Activity of L-Amine Dehydrogenases
-
Direct reductive amination of prochiral ketones catalyzed by amine dehydrogenases is attractive in the synthesis of active pharmaceutical ingredients. Here, we report the protein engineering of L-Bacillus cereus amine dehydrogenase to allow reactivity on synthetically useful aromatic ketone substrates using an iterative, multiple-site alanine scanning mutagenesis approach. Mutagenesis libraries based on molecular docking, iterative alanine scanning, and double-proximity filter approach significantly expand the scope of active pharmaceutical ingredients relevant building blocks. The eventual quintuple mutant (A115G/T136A/L42A/V296A/V293A) showed reactivity toward aromatic ketones 12 a (5-phenyl-pentan-2-one) and 13 a (6-phenyl-hexan-2-one), which have not been reported to serve as targets of reductive amination by currently available amine dehydrogenases. Docking simulation and tunnel analysis provided valuable insights into the source of the acquired specificity and activity.
- Mu, Xiaoqing,Wu, Tao,Mao, Yong,Zhao, Yilei,Xu, Yan,Nie, Yao
-
p. 5243 - 5253
(2021/11/16)
-
- Parallel interconnected kinetic asymmetric transformation (PIKAT) with an immobilized ω-transaminase in neat organic solvent
-
Comprising approximately 40% of the commercially available optically active drugs, α-chiral amines are pivotal for pharmaceutical manufacture. In this context, the enzymatic asymmetric amination of ketones represents a more sustainable alternative than traditional chemical procedures for chiral amine synthesis. Notable advantages are higher atom-economy and selectivity, shorter synthesis routes, milder reaction conditions and the elimination of toxic catalysts. A parallel interconnected kinetic asymmetric transformation (PIKAT) is a cascade in which one or two enzymes use the same cofactor to convert two reagents into more useful products. Herein, we describe a PIKAT catalyzed by an immobilized ω-transaminase (ωTA) in neat toluene, which concurrently combines an asymmetric transamination of a ketone with an anti-parallel kinetic resolution of an amine racemate. The applicability of the PIKAT was tested on a set of prochiral ketones and racemic α-chiral amines in a 1:2 molar ratio, which yielded elevated conversions (up to >99%) and enantiomeric excess (ee, up to >99%) for the desired products. The progress of the conversion and ee was also monitored in a selected case. This is the first report of a PIKAT using an immobilized ωTA in a non-aqueous environment.
- B?hmer, Wesley,Koenekoop, Lucien,Mutti, Francesco G.,Simon, Timothée
-
-
- Upgraded Bioelectrocatalytic N2 Fixation: From N2 to Chiral Amine Intermediates
-
Enantiomerically pure chiral amines are of increasing value in the preparation of bioactive compounds, pharmaceuticals, and agrochemicals. ω-Transaminase (ω-TA) is an ideal catalyst for asymmetric amination because of its excellent enantioselectivity and wide substrate scope. To shift the equilibrium of reactions catalyzed by ω-TA to the side of the amine product, an upgraded N2 fixation system based on bioelectrocatalysis was developed to realize the conversion from N2 to chiral amine intermediates. The produced NH3 was in situ reacted with l-alanine dehydrogenase to generate alanine with NADH as a coenzyme. ω-TA transferred the amino group from alanine to ketone substrates and finally produced the desired chiral amine intermediates. The cathode of the upgraded N2 fixation system supplied enough reducing power to synchronously realize the regeneration of reduced methyl viologen (MV?+) and NADH for the nitrogenase and l-alanine dehydrogenase. The coproduct, pyruvate, was consumed by l-alanine dehydrogenase to regenerate alanine and push the equilibrium to the side of amine. After 10 h of reaction, the concentration of 1-methyl-3-phenylpropylamine achieved 0.54 mM with the 27.6% highest faradaic efficiency and >99% enantiomeric excess (eep). Because of the wide substrate scope and excellent enantioselectivity of ω-TA, the upgraded N2 fixation system has great potential to produce a variety of chiral amine intermediates for pharmaceuticals and other applications.
- Chen, Hui,Cai, Rong,Patel, Janki,Dong, Fangyuan,Chen, Hsiaonung,Minteer, Shelley D.
-
p. 4963 - 4971
(2019/03/26)
-
- An Ammonium-Formate-Driven Trienzymatic Cascade for ω-Transaminase-Catalyzed (R)-Selective Amination
-
(R)-Amination mediated by (R)-specific ω-transaminases generally requires costly d-alanine in excess to obtain the desired chiral amines in high yield. Herein, a one-pot, trienzymatic cascade comprising an (R)-specific ω-transaminase, an amine dehydrogenase, and a formate dehydrogenase was developed for the economical and eco-friendly synthesis of (R)-chiral amines. Using inexpensive ammonium formate as the sole sacrificial agent, the established cascade system enabled efficient ω-transaminase-mediated (R)-amination of various ketones, with high conversions and excellent ee (>99%); water and CO2 were the only waste products.
- Chen, Fei-Fei,Liu, Lei,Wu, Jian-Ping,Xu, Jian-He,Zhang, Yu-Hui,Zhang, Zhi-Jun,Zheng, Gao-Wei
-
p. 14987 - 14993
(2019/12/02)
-
- n-Butylamine as an alternative amine donor for the stereoselective biocatalytic transamination of ketones
-
Formal reductive amination has been a main focus of biocatalysis research in recent times. Among the enzymes able to perform this transformation, pyridoxal-5′-phosphate-dependent transaminases have shown the greatest promise in terms of extensive substrate scope and industrial application. Despite concerted research efforts in this area, there exist relatively few options regarding efficient amino donor co-substrates capable of allowing high conversion and atom efficiency with stable enzyme systems. Herein we describe the implementation of the recently described spuC gene, coding for a putrescine transaminase, exploiting its unusual amine donor tolerance to allow use of inexpensive and readily-available n-butylamine as an alternative to traditional methods. Via the integration of SpuC homologues with tandem co-product removal and cofactor regeneration enzymes, high conversion could be achieved with just 1.5 equivalents of the amine with products displaying excellent enantiopurity.
- Slabu, Iustina,Galman, James L.,Iglesias, Cesar,Weise, Nicholas J.,Lloyd, Richard C.,Turner, Nicholas J.
-
-
- In vitro biocatalytic pathway design: Orthogonal network for the quantitative and stereospecific amination of alcohols
-
The direct and efficient conversion of alcohols into amines is a pivotal transformation in chemistry. Here, we present an artificial, oxidation-reduction, biocatalytic network that employs five enzymes (alcohol dehydrogenase, NADP-oxidase, catalase, amine dehydrogenase and formate dehydrogenase) in two concurrent and orthogonal cycles. The NADP-dependent oxidative cycle converts a diverse range of aromatic and aliphatic alcohol substrates to the carbonyl compound intermediates, whereas the NAD-dependent reductive aminating cycle generates the related amine products with >99% enantiomeric excess (R) and up to >99% conversion. The elevated conversions stem from the favorable thermodynamic equilibrium (K′eq = 1.88 × 1042 and 1.48 × 1041 for the amination of primary and secondary alcohols, respectively). This biocatalytic network possesses elevated atom efficiency, since the reaction buffer (ammonium formate) is both the aminating agent and the source of reducing equivalents. Additionally, only dioxygen is needed, whereas water and carbonate are the by-products. For the oxidative step, we have employed three variants of the NADP-dependent alcohol dehydrogenase from Thermoanaerobacter ethanolicus and we have elucidated the origin of the stereoselective properties of these variants with the aid of in silico computational models.
- Knaus, Tanja,Cariati, Luca,Masman, Marcelo F,Mutti, Francesco G.
-
p. 8313 - 8325
(2017/10/19)
-
- Two-Enzyme Hydrogen-Borrowing Amination of Alcohols Enabled by a Cofactor-Switched Alcohol Dehydrogenase
-
The NADPH-dependent secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus (TeSADH), displaying broad substrate specificity and low enantioselectivity, was engineered to accept NADH as a cofactor. The engineered TeSADH showed a >10 000-fold switch from NADPH towards NADH compared to the wildtype enzyme. This TeSADH variant was applied to a biocatalytic hydrogen-borrowing system that employed catalytic amounts of NAD+, ammonia, and an amine dehydrogenase, which thereby enabled the conversion a range of alcohols into chiral amines.
- Thompson, Matthew P.,Turner, Nicholas J.
-
p. 3833 - 3836
(2017/09/25)
-
- Vicinal Diamines as Smart Cosubstrates in the Transaminase-Catalyzed Asymmetric Amination of Ketones
-
Transaminases (TAs) have recently been established as catalysts for the asymmetric, reductive amination of prochiral ketones. Depending on the ketone substrate and the amine donor (the cosubstrate), equilibrium constants may limit high conversions; thus, methods to overcome this limitation are required. Removal of the co-product from the reaction equilibrium through spontaneous, intramolecular reactions has provided a successful solution to this problem; therefore, these amine donors have been named “smart cosubstrates”. Here, we present a comparison of various bifunctional amine donors including vicinal diamines as potential structural cosubstrate motifs. Upon TA-catalyzed deamination of 1,2-diamines, spontaneous dimerization of the resulting α-aminoketones and oxidation gave heteroaromatic pyrazines.
- Payer, Stefan E.,Schrittwieser, Joerg H.,Kroutil, Wolfgang
-
supporting information
p. 2553 - 2559
(2017/05/12)
-
- Biocatalytic transamination with near-stoichiometric inexpensive amine donors mediated by bifunctional mono- and di-amine transaminases
-
The discovery and characterisation of enzymes with both monoamine and diamine transaminase activity is reported, allowing conversion of a wide range of target ketone substrates with just a small excess of amine donor. The diamine co-substrates (putrescine, cadaverine or spermidine) are bio-derived and the enzyme system results in very little waste, making it a greener strategy for the production of valuable amine fine chemicals and pharmaceuticals.
- Galman, James L.,Slabu, Iustina,Weise, Nicholas J.,Iglesias, Cesar,Parmeggiani, Fabio,Lloyd, Richard C.,Turner, Nicholas J.
-
supporting information
p. 361 - 366
(2017/08/14)
-
- Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades
-
α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product.
- Mutti, Francesco G.,Knaus, Tanja,Scrutton, Nigel S.,Breuer, Michael,Turner, Nicholas J.
-
p. 1525 - 1529
(2015/10/05)
-
- Continuous flow synthesis of chiral amines in organic solvents: Immobilization of E. coli cells containing both ω-transaminase and PLP
-
E. coli cells containing overexpressed (R)-selective ω-transaminase and the cofactor PLP were immobilized on methacrylate beads suitable for continuous flow applications. The use of an organic solvent suppresses leaching of PLP from the cells; no addition
- Andrade, Leandro H.,Kroutil, Wolfgang,Jamison, Timothy F.
-
supporting information
p. 6092 - 6095
(2015/02/19)
-
- Investigation of one-enzyme systems in the ω-transaminase-catalyzed synthesis of chiral amines
-
ω-Transaminase (TA) catalyzed asymmetric syntheses of amines were carried out in the one enzyme systems with wild-type enzymes (S)-TA from Pseudomonas aeruginosa, (S)-TA from Paracoccus denitrificans and (R)-TA from Aspergillus terreus. The scope of amine donors and aromatic carbonyl substrates was thoroughly explored. Among the range of potential amino donors, 2-propylamine, 2-butylamine and 1-phenylethylamine were found as promising candidates, which gave superior conversions in the amination reactions compared to other donors. Various prochiral aromatic ketones were accepted as substrates by the investigated enzymes. In most cases, good to excellent conversions (up to 98%) to the amine products with excellent e.e.-values (>99.9% for (S) or (R)) were obtained by the action of a single enzyme and an appropriate amino donor. (S)-TA from Paracoccus denitrificans was found to accept bulky ketones, e.g. 1-indanone, α- and β-tetralone or 2-acetonaphthone, in the asymmetric amination. In some cases the enantiomeric excesses in the amination reactions were dependent on the amino donor. More-over, the influence of the pH, temperature and cosolvents on the outcome of reactions was additionally investigated.
- Fesko, Kateryna,Steiner, Kerstin,Breinbauer, Rolf,Schwab, Helmut,Schuermann, Martin,Strohmeier, Gernot A.
-
p. 103 - 110
(2013/10/22)
-
- Asymmetric bio-amination of ketones in organic solvents
-
ω-Transaminases, employed as a lyophilised crude cell-free extract, were successfully employed in organic solvent for the asymmetric amination of ketones without the need for immobilisation. Best activity was found for methyl tert-butyl ether (MTBE) at a water activity of 0.6. The ω-transaminases (9 different enzymes) accepted efficiently 2-propylamine as amine donor when used in the solvent, which is not the case when they are used in aqueous solution. The bio-amination in organic solvent showed several advantages such as higher reaction rates (up to 17-fold), general acceptance of 2-propylamine as amine donor, simple work-up procedure (i.e., no basification and extraction required), easy recycling of the catalyst and lack of substrate inhibition. The biocatalysts maintained their excellent stereoselectivity in MTBE allowing the preparation of optically pure amines (ee >99%) with up to >99% conversion.
- Mutti, Francesco G.,Kroutil, Wolfgang
-
supporting information
p. 3409 - 3413
(2013/02/25)
-
- Stereoselectivity of four (R)-selective transaminases for the asymmetric amination of ketones
-
Four (R)-ω-transaminases originating from Hyphomonas neptunium (HN-ωTA), Aspergillus terreus (AT-ωTA) and Arthrobacter sp. (ArR-ωTA), as well as an evolved transaminase (ArRmut11-ωTA) were successfully employed for the amination of prochiral ketones leading to optically pure (R)-amines. The first three transaminases displayed perfect stereoselectivity for the amination of all substrates tested (ee >99%). Furthermore, the transaminase AT-ωTA led in most cases to better conversion than ArR-ωTA and HN-ωTA using D-alanine as amine donor. α-Tetralone, which was the only substrate not accepted by HN-ωTA, ArR-ωTA, and AT-ωTA, was successfully transformed with perfect enantioselectivity (ee >99%) into the corresponding optically pure amine employing the variant ArRmut11-ωTA. Copyright
- Mutti, Francesco G.,Fuchs, Christine S.,Pressnitz, Desiree,Sattler, Johann H.,Kroutil, Wolfgang
-
experimental part
p. 3227 - 3233
(2012/01/03)
-
- Asymmetric synthesis of optically pure pharmacologically relevant amines employing ω-transaminases
-
Various ω-transaminases were tested for the synthesis of enantiomerically pure amines from the corresponding ketones employing D- or L-alanine as amino donor and lactate dehydrogenase to remove the side-product pyruvate to shift the unfavourable reaction equilibrium to the product side. Both enantiomers, (R)- and (S)-amines, could be prepared with up to 99% ee and >99% conversions within 24 h at 50 mM substrate concentration. The activity and stereoselectivity of the amination reaction depended on the ω-transaminase and substrate employed; furthermore the co-solvent significantly influenced both the stereoselectivity and activity of the transaminases. Best results were obtained by employing ATA-117 to obtain the (R)-enantiomer and ATA-113 or ATA-103 to access the (S)-enantiomer with 15% v v-1 DMSO.
- Koszelewski, Dominik,Lavandera, Ivan,Clay, Dorina,Rozzell, David,Kroutil, Wolfgang
-
scheme or table
p. 2761 - 2766
(2009/10/06)
-
- Formal asymmetric biocatalytic reductive amination
-
All for one: A combination of three biocatalysts (ω-transaminase, alanine dehydrogenase, and an enzyme such as formate dehydrogenase for cofactor recycling) catalyze a cascade to achieve the asymmetric transformation of a ketone into a primary α-chiral unprotected amine through a formal stereoselective reductive amination (see scheme). Only ammonia and the reducing agent (formate) are consumed during this reaction. (Chemical Equation Presented).
- Koszelewski, Dominik,Lavandera, Ivan,Clay, Dorina,Guebitz, Georg M.,Rozzell, David,Kroutil, Wolfgang
-
supporting information; experimental part
p. 9337 - 9340
(2009/05/15)
-
- Discovery of pyrazolopyrimidines as the first class of allosteric agonists for the high affinity nicotinic acid receptor GPR109A
-
Pyrazolopyrimidines were discovered as the first class of allosteric agonists for the high affinity nicotinic acid receptor GPR109A. In addition to its intrinsic activity, compound 9n significantly enhances nicotinic acid binding to the receptor, thereby
- Shen, Hong C.,Taggart, Andrew K.P.,Wilsie, Larissa C.,Waters, M. Gerard,Hammond, Milton L.,Tata, James R.,Colletti, Steven L.
-
scheme or table
p. 4948 - 4951
(2009/05/07)
-
- Aminoalcohol derivatives
-
The present invention relates to a compound formula [I]: wherein R1 is hydrogen or halogen, R2 is hydrogen or an amino protective group, R3 is hydrogen or lower alkyl, X is bond, —CH2— or —O—, and Y is ?in which R4 is lower alkoxycarbonyl, ?in which R5 is carboxy(lower)alkyl, etc., ?in which R6 is hydroxy, etc., and so on, or a salt thereof. The compound [I] of the present invention and pharmaceutically acceptable salts thereof are useful for the prophylactic and/or the therapeutic treatment of pollakiurea or urinary incontinence.
- -
-
Page/Page column 17
(2010/02/07)
-
- AMINOALCOHOL DERIVATIVES AND THEIR USE AS BETA-3 ADRENERGIC RECEPTOR AGONISTS
-
The present invention relates to a compound formula [I] or a salt thereof. The compound [I] of the present invention and pharmaceutically acceptable salts thereof are useful for the prophylactic and/or the therapeutic treatment of pollakiurea or urinary incontinence.
- -
-
Page/Page column 49
(2010/02/07)
-
- Design of scytalone dehydratase inhibitors as rice blast fungicides: (N- phenoxypropyl)-carboxamides
-
Insights gained from a crystal structure of scytalone dehydratase led to the design of carboxamide inhibitors with a phenoxypropyl group substituted on the nitrogen atom. Potent enzyme inhibitors were synthesized around this motif, the best of which provided excellent control of rice blast disease in greenhouse assays and outdoor field trials.
- Jordan, Douglas B.,Lessen, Thomas A.,Wawrzak, Zdzislaw,Bisaha, John J.,Gehret, Troy C.,Hansen, Stephen L.,Schwartz, Rand S.,Basarab, Gregory S.
-
p. 1607 - 1612
(2007/10/03)
-
- Purine derivatives
-
A compound of formula (I), or a pharmaceutically acceptable salt thereof: STR1 wherein X is hydrogen, amino, halogen, hydroxy, lower alkoxy or lower alkyl andR 1 is STR2 wherein Y is methylene or a valence bond, R 2 and R 5 is H or lower, straight or branched alkyl,R 3 is H or lower alkyl, orR 2 and R 3 can together form a cyclobutyl, cyclopentyl, cyclohexyl or phenyl ring,Z is oxygen, methylene, sulphur, sulphonyl or a valence bond,R 4 is H, lower alkyl, aralkyl, a mono or bicyclic aromatic system optionally substituted with various groups.The compounds have been found useful for treating central nervous system ailments.
- -
-
-