5303-65-1Relevant academic research and scientific papers
Parallel interconnected kinetic asymmetric transformation (PIKAT) with an immobilized ω-transaminase in neat organic solvent
B?hmer, Wesley,Koenekoop, Lucien,Mutti, Francesco G.,Simon, Timothée
, (2020/05/25)
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.
Structural analysis of the dual-function thioesterase SAV606 unravels the mechanism of Michael addition of glycine to an α,β-unsaturated thioester
Chisuga, Taichi,Miyanaga, Akimasa,Kudo, Fumitaka,Eguchi, Tadashi
, p. 10926 - 10937 (2017/07/06)
Thioesterases catalyze hydrolysis of acyl thioesters to release carboxylic acid or macrocyclization to produce the corresponding macrocycle in the biosynthesis of fatty acids, polyketides, or nonribosomal peptides. Recently, we reported that the thioesterase CmiS1 from Streptomyces sp. MJ635-86F5 catalyzes the Michael addition of glycine to an α,β-unsaturated fatty acyl thioester followed by thioester hydrolysis in the biosynthesis of the macrolactam antibiotic cremimycin. However, the molecular mechanisms of CmiS1-catalyzed reactions are unclear. Here, we report on the functional and structural characterization of the CmiS1 homolog SAV606 from Streptomyces avermitilis MA-4680. In vitro analysis indicated that SAV606 catalyzes the Michael addition of glycine to crotonic acid thioester and subsequent hydrolysis yielding (R)-N-carboxymethyl-3-aminobutyric acid. We also determined the crystal structures of SAV606 both in ligand-free form at 2.4 ? resolution and in complex with (R)-N-car-boxymethyl-3-aminobutyric acid at 2.0 ? resolution. We found that SAV606 adopts an α/β hotdog fold and has an active site at the dimeric interface. Examining the complexed structure, we noted that the substrate-binding loop comprising Tyr-53–Asn-61 recognizes the glycine moiety of (R)-N-carboxymethyl-3-aminobutyric acid. Moreover, we found that SAV606 does not contain an acidic residue at the active site, which is distinct from canonical hotdog thioesterases. Site-directed mutagenesis experiments revealed that His-59 plays a crucial role in both the Michael addition and hydrolysis via a water molecule. These results allow us to propose the reaction mechanism of the SAV606-catalyzed Michael addition and thioester hydrolysis and provide new insight into the multiple functions of a thioesterase family enzyme.
Chiral Phosphinyl Enamines and Their Asymmetric Reduction through Group-Assisted Purification Chemistry Leading to Enantiopure β-Amino Esters/Amides
Qiao, Shuo,Wu, Jianbin,Mo, Junming,Spigener, Preston T.,Zhao, Brian Nlong,Jiang, Bo,Li, Guigen
, p. 2483 - 2488 (2017/10/06)
A series of new chiral N -phosphinyl β-enamino esters and amides were successfully prepared with excellent Z -stereoselectivity (Z / E > 99:1 in nearly all cases). Group-assisted purification chemistry proved to be an efficient method for the asymmetric reduction of the resulting β-enamino esters/amides to give enantiopure β-amino esters/amides. The asymmetric reduction can be controlled efficiently by using a combination of sodium cyanoborohydride and acetic acid.
QUINOLINONE PYRIMIDINES COMPOSITIONS AS MUTANT-ISOCITRATE DEHYDROGENASE INHIBITORS
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Paragraph 0619; 0624; 0625, (2016/04/19)
The invention relates to inhibitors of mutant isocitrate dehydrogenase (mt-IDH) proteins with neomorphic activity useful in the treatment of cell-proliferation disorders and cancers, having the Formula: where A, B, W1, W2, W3, and R1-R6 are described herein.
Catalytic Promiscuity of Transaminases: Preparation of Enantioenriched β-Fluoroamines by Formal Tandem Hydrodefluorination/Deamination
Cuetos, Aníbal,García-Ramos, Marina,Fischereder, Eva-Maria,Díaz-Rodríguez, Alba,Grogan, Gideon,Gotor, Vicente,Kroutil, Wolfgang,Lavandera, Iván
supporting information, p. 3144 - 3147 (2016/03/12)
Transaminases are valuable enzymes for industrial biocatalysis and enable the preparation of optically pure amines. For these transformations they require either an amine donor (amination of ketones) or an amine acceptor (deamination of racemic amines). Herein transaminases are shown to react with aromatic β-fluoroamines, thus leading to simultaneous enantioselective dehalogenation and deamination to form the corresponding acetophenone derivatives in the absence of an amine acceptor. A series of racemic β-fluoroamines was resolved in a kinetic resolution by tandem hydrodefluorination/deamination, thus giving the corresponding amines with up to greater than 99 % ee. This protocol is the first example of exploiting the catalytic promiscuity of transaminases as a tool for novel transformations.
Synthesis of oxazolidin-2-ones and imidazolidin-2-ones directly from 1,3-diols or 3-amino alcohols using iodobenzene dichloride and sodium azide
He, Tian,Gao, Wen-Chao,Wang, Wei-Kun,Zhang, Chi
, p. 1113 - 1118 (2014/04/03)
A general and efficient method for the synthesis of oxazolidin-2-ones and imidazolidin-2-ones directly from 1,3-diols and 3-amino alcohols has been developed using the same reagent combination of iodobenzene dichloride (PhICl2) and sodium azide (NaN3).
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.
Expanding dynamic kinetic protocols: Transaminase-catalyzed synthesis of α-substituted β-amino ester derivatives
Cuetos, Anibal,Lavandera, Ivan,Gotor, Vicente
supporting information, p. 10688 - 10690 (2013/11/06)
Several α-alkylated β-amino esters have been obtained via DKR processes employing a kit of transaminases and isopropylamine as an amino donor in aqueous medium under mild conditions. Thus, while acyclic α-alkyl-β-keto esters afforded excellent conversions and enantioselectivities, although usually low diastereoselectivities, using more constrained cyclic β-keto esters high to excellent inductions were obtained.
Amination of ketones by employing two new (S)-selective ω-transaminases and the his-tagged ω-TA from Vibrio fluvialis
Mutti, Francesco G.,Fuchs, Christine S.,Pressnitz, Desiree,Turrini, Nikolaus G.,Sattler, Johann H.,Lerchner, Alexandra,Skerra, Arne,Kroutil, Wolfgang
experimental part, p. 1003 - 1007 (2012/04/04)
Two recently identified (S)-selective ω-transaminases (ω-TAs) that originate from Paracoccus denitrificans (Strep-PD-ωTA, cloned with an N-terminal Strep-tag II) and Pseudomonas fluorescens (PF-ωTA) were employed for the asymmetric amination of selected prochiral ketones. The substrates tested were transformed into optically pure amines (>99 % ee) with high conversion (up to >99 %). The ω-TAs led to higher conversion in the absence of dimethyl sulfoxide as a cosolvent than in its presence (15 %, v/v). Additionally, it was shown that a His-tagged recombinant transaminase from Vibrio fluvialis (His-VF-ωTA, cloned with an N-terminal His 6-tag) showed for a single substrate, ethyl acetoacetate, significantly higher stereoselectivity for the amination compared to the corresponding commercial enzyme preparation (>99 vs. 50 %). The (S)-selective ω-transaminases (ω-TAs) from Paracoccus denitrificans and Pseudomonas fluorescens transformed various ketones into optically pure amines (>99 % ee). These enzymes extend the substrate spectrum of highly (S)-stereoselective ω-TAs. Copyright
Asymmetric bio-amination of ketones in organic solvents
Mutti, Francesco G.,Kroutil, Wolfgang
supporting information, p. 3409 - 3413 (2013/02/25)
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.
