9 research outputs found
Enantioselective Synthesis of Pharmaceutically Relevant Bulky Arylbutylamines Using Engineered Transaminases
ATAs engineered for having an enlarged small binding pocket were applied for the synthesis of enantiomerically pure (R)âbenzo[1,3]dioxolâ5âylâbutylamine, a chiral component of human leukocyte elastase inhibitor DMP 777 (Lâ694,458). Kinetic resolution of the racemic amine was performed by using the L59A variant of the (S)âselective ATA from Chromobacterium violaceum (CvâATA), providing the residual (R)âenantiomer in excellent yield and >99% ee. At moderate enzyme loading and absence of coâsolvent, high volumetric productivity of 0.22 mol Lâ»Âč hâ»Âč (42.5 g Lâ»Âč hâ»Âč) was achieved. Complementarily, the (S)âenantiomer was generated via kinetic resolution using the (R)âselective ATAâ117âRd11 from Arthrobacter sp. with acetone as the amino acceptor. In an alternative approach, we employed ATAâ117âRd11 for the asymmetric amination of the prochiral ketone precursor, which at 86% conversion gave the (R)âbenzo[1,3]dioxolâ5âylâbutylamine with excellent >99% ee. We further evaluated the utility of CvâATA L59A for the asymmetric synthesis of pharmaceutically relevant (S)â1âphenylbutanâ1âamine, a chiral component of the deubiquitinase inhibitor degrasyn (WP1130). The enzyme showed good tolerance to high concentrations of isopropylamine, producing (S)â1âphenylbutanâ1âamine in enantiomerically pure form (>99% ee)
Power to participants:Methodological and ethical reflections from a decade of adolescent advisory groups in South Africa
Biocatalytic Transamination of Aldolase-Derived 3-Hydroxy Ketones
Although optical pure amino alcohols are in high demand due to their widespread applicability, they still remain challenging to synthesize, since commonly elaborated protection strategies are required. Here, a multi-enzymatic methodology is presented that circumvents this obstacle furnishing enantioenriched 1,3-amino alcohols out of commodity chemicals. A Type I aldolase forged the carbon backbone with an enantioenriched aldol motif, which was subsequently subjected to enzymatic transamination. A panel of 194 TAs was tested on diverse nine aldol products prepared through different nucleophiles and electrophiles. Due to the availability of (R)- and (S)-selective TAs, both diastereomers of the 1,3-amino alcohol motif were accessible. A two-step process enabled the synthesis of the desired amino alcohols with up to three chiral centers with de up to >97 in the final products. (Figure presented.).This research was funded in part by the Austrian Science Fund (FWF) [J 4242-B21]. M. P. acknowledges funding by the Austrian FWF through an Erwin Schrödinger fellowship and by grants PID2021-122166OBâI00 and PCI2018-092937 funded by MCIN/AEI/10.13039/501100011033, and by âERDF A way of making Europeâ and under the ERACoBioTech (European Union's Horizon 2020 research and innovation programme under grant agreement No [722361]. The authors wish to thank Goran Djordjic for technical assistance and Klaus Zangger for NMR measurements and valuable discussions. The University of Graz and BioHealth Graz are acknowledged for financial support.Peer reviewe
Synthesis of Deoxysugars from Aliphatic 뱉Ketoacids and Aldoses Catalyzed by Thermostable Transketolase Variants from Geobacillus stearothermophilus
International audienceWe described a strategy for the enzymatic synthesis of 1-deoxy and 1,2-deoxyketoses from the aliphatic α-ketoacids, pyruvate and 2-oxobutyrate, as donors and natural aldoses of variable chain length as acceptors, catalyzed by thermostable transketolase variants from Geobacillus stearothermophilus (TKgst). Analytical studies have been carried out on a panel of TKgst variants with the appropriate substrates allowing to select the best combinations and to apply it to the preparative scale synthesis of 1-deoxy and 1,2-deoxyketoses obtained with good to excellent isolated yields (61%â86%). To optimize the strategy, and as a proof of principle, the α-ketoacids pyruvate and 2-oxobutyrate were generated inâ
situ from the corresponding d-amino acids d-alanine and d-homoalanine respectively, using a thermostable d-amino acid oxidase dAAO4536 that was selected from a screening of 55 putative DAAOs provided by Prozomix Limited. Hence, a one-pot one step procedure was performed at 50â°C by coupling dAAO4536 and the best TKgst variant H102L/L118I/H474S in the presence of d-alanine or d-homoalanine as α-ketoacids precursors and d-erythrose as acceptor substrate. The corresponding 1-deoxy and 1,2-dideoxyketoses were isolated with good yields (64% and 72% respectively, out of two steps)
Enantioselective Synthesis of Pharmaceutically Relevant Bulky Arylbutylamines Using Engineered Transaminases
ATAs engineered for having an enlarged small binding pocket were applied for the synthesis of enantiomerically pure (R)-benzo[1,3]dioxol-5-yl-butylamine, a chiral component of human leukocyte elastase inhibitor DMP 777 (L-694,458). Kinetic resolution of the racemic amine was performed by using the L59A variant of the (S)-selective ATA from Chromobacterium violaceum (Cv-ATA), providing the residual (R)-enantiomer in excellent yield and >99% ee. At moderate enzyme loading and absence of co-solvent, high volumetric productivity of 0.22 mol L-1 h(-1) (42.5 g L-1 h(-1)) was achieved. Complementarily, the (S)-enantiomer was generated via kinetic resolution using the (R)-selective ATA-117-Rd11 from Arthrobacter sp. with acetone as the amino acceptor. In an alternative approach, we employed ATA-117-Rd11 for the asymmetric amination of the prochiral ketone precursor, which at 86% conversion gave the (R)-benzo[1,3]dioxol-5-yl-butylamine with excellent >99% ee. We further evaluated the utility of Cv-ATA L59A for the asymmetric synthesis of pharmaceutically relevant (S)-1-phenylbutan-1-amine, a chiral component of the deubiquitinase inhibitor degrasyn (WP1130). The enzyme showed good tolerance to high concentrations of isopropylamine, producing (S)-1-phenylbutan-1-amine in enantiomerically pure form (>99% ee)
Biocatalytic Synthesis of Homochiral 2-Hydroxy-4-butyrolactone Derivatives by Tandem Aldol Addition and Carbonyl Reduction
Chiral 2-hydroxy acids and 2-hydroxy-4-butyrolactone derivatives are structural motifs often found in fine and commodity chemicals. Here, we report a tandem biocatalytic stereodivergent route for the preparation of these compounds using three stereoselective aldolases and two stereocomplementary ketoreductases using simple and achiral starting materials. The strategy comprises (i) aldol addition reaction of 2-oxoacids to aldehydes using two aldolases from E. coli, 3-methyl-2-oxobutanoate hydroxymethyltransferase (KPHMTEcoli), 2-keto-3-deoxy-l-rhamnonate aldolase (YfaUEcoli), and trans-o-hydroxybenzylidene pyruvate hydratase-aldolase from Pseudomonas putida (HBPAPputida) and (ii) subsequent 2-oxogroup reduction of the aldol adduct by ketopantoate reductase from E. coli (KPREcoli) and a Î1-piperidine-2-carboxylate/Î1-pyrroline-2-carboxylate reductase from Pseudomonas syringae pv. tomato DSM 50315 (DpkAPsyrin) with uncovered promiscuous ketoreductase activity. A total of 29 structurally diverse compounds were prepared: both enantiomers of 2-hydroxy-4-butyrolactone (>99% ee), 21 2-hydroxy-3-substituted-4-butyrolactones with the (2R,3S), (2S,3S), (2R,3R), or (2S,3R) configuration (from 60:40 to 98:2 dr), and 6 2-hydroxy-4-substituted-4-butyrolactones with the (2S,4R) configuration (from 87:13 to 98:2 dr). Conversions of aldol adducts varied from 32 to 98%, while quantitative conversions were achieved by both ketoreductases, with global isolated yields between 20 and 45% for most of the examples. One-pot one-step cascade reactions were successfully conducted achieving isolated yields from 30 to 57%.Grant PID2021-122166OB-I00 funded by MCIN/AEI/10.13039/501100011033 and âERDF A way of making Europeâ. C.J.M. acknowledges a PhD contract (i.e., Ayudas para Contratos Predoctorales para la FormaciĂłn de Doctores) BES-2016-079447 funded by MCIN/AEI/10.13039/501100011033. The authors wish to thank Dr. Lothar Fink, from Frankfurt University, for the X-ray structure determination with Cu Kα radiation. The authors thankfully acknowledge the use of the computational resources of the Consorci de Serveis Universitaris de Catalunya (CSUC).Peer reviewe
Synthesis of Îł-Hydroxy-α-amino Acid Derivatives by Enzymatic Tandem Aldol AdditionâTransamination Reactions
Three enzymatic routes toward Îł-hydroxy-α-amino acids by tandem aldol additionâtransamination one-pot two-step reactions are reported. The approaches feature an enantioselective aldol addition of pyruvate to various nonaromatic aldehydes catalyzed by trans-o-hydroxybenzylidene pyruvate hydratase-aldolase (HBPA) from Pseudomonas putida. This affords chiral 4-hydroxy-2-oxo acids, which were subsequently enantioselectively aminated using S-selective transaminases. Three transamination processes were investigated involving different amine donors and transaminases: (i) l-Ala as an amine donor with pyruvate recycling, (ii) a benzylamine donor using benzaldehyde lyase from Pseudomonas fluorescens Biovar I (BAL) to transform the benzaldehyde formed into benzoin, minimizing equilibrium limitations, and (iii) l-Glu as an amine donor with a double cascade comprising branched-chain α-amino acid aminotransferase (BCAT) and aspartate amino transferase (AspAT), both from E. coli, using l-Asp as a substrate to regenerate l-Glu. The Îł-hydroxy-α-amino acids thus obtained were transformed into chiral α-amino-Îł-butyrolactones, structural motifs found in many biologically active compounds and valuable intermediates for the synthesis of pharmaceutical agents.This project has received funding from the Ministerio de Ciencia e InnovaciĂłn (MICIN), cofinanced by the Fondo Europeo de Desarrollo Regional (FEDER) (grants RTI2018-094637-B-I00 to P.C. and PGC2018-095808-B-I00 to T.P.), and ProgramaciĂłn Conjunta Internacional (PCI2018-092937), through the EU initiative ERA CoBioTech under grant agreement No [722361] to P.C and S.J.Ch.) (Tralaminol).Peer reviewe
Regiodivergent Radical Termination for Intermolecular Biocatalytic CâC Bond Formation
Radical hydrofunctionalizations
of electronically unbiased dienes
are challenging to render regioselective, because the products are
nearly identical in energy. Here, we report two engineered FMN-dependent
âeneâ-reductases (EREDs) that catalyze regiodivergent
hydroalkylations of cyclic and linear dienes. While previous studies
focused exclusively on the stereoselectivity of alkene hydroalkylation,
this work highlights that EREDs can control the regioselectivity of
hydrogen atom transfer, providing a method for selectively preparing
constitutional isomers that would be challenging to prepare using
traditional synthetic methods. Engineering the ERED from Gluconabacter sp. (GluER) furnished a variant that favors the Îł,ÎŽ-unsaturated
ketone, while an engineered variant from a commercial ERED panel favors
the Ύ,Δ-unsaturated ketone. The effect of beneficial mutations
has been investigated using substrate docking studies and the mechanism
probed by isotope labeling experiments. A variety of α-bromo
ketones can be coupled with cyclic and linear dienes. These interesting
building blocks can also be further modified to generate difficult-to-access
heterocyclic compounds