Calcium(II)-mediated resolution of methyl o-chloromandelate with chiral O,O′-dibenzoyltartaric acid in preparative scale

Abstract We report here the coordination-mediated resolution of methyl o-chloromandelate, which is a key intermediate for clopidogrel, in preparative scale. The reaction of CaO, optically pure (2R, 3R)-O,O′-dibenzoyltartaric acid, and methyl o-chloromandelate in ethanol solution afforded a mixed-ligands calcium(II) complex that was further purified by stirring of the crystals in hot methanol. Methyl (R)-o-chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (71%) by treatment of the complex with acid. At the same time, (2R, 3R)-O,O′-dibenzoyltartaric acid was recovered in 72% yield. In addition, methyl (S)-o-chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (73%) by recovery from the mother liquor and resolution with the same procedure for methyl (R)-o-chloromandelate, except that (2S, 3S)-O,O′-dibenzoyltartaric acid was used as the resolving reagent.

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Efficient Biocatalytic Preparation of Optically Pure (R)-1-[4-(Trifluoromethyl)phenyl]ethanol by Recombinant Whole-Cell-Mediated Reduction

Catalysts ◽

10.3390/catal9040391 ◽

2019 ◽

Vol 9 (4) ◽

pp. 391 ◽

Cited By ~ 2

Author(s):

Ying Chen ◽

Nana Xia ◽

Yuewang Liu ◽

Pu Wang

Keyword(s):

Organic Solvent ◽

Asymmetric Reduction ◽

Enantiomeric Excess ◽

Aqueous System ◽

Cell Membrane Permeability ◽

Buffer Solution ◽

Preparative Scale ◽

Buffer Medium ◽

Polar Organic Solvent ◽

Optically Pure

(R)-1-[4-(Trifluoromethyl)phenyl]ethanol is an important pharmaceutical intermediate of a chemokine CCR5 antagonist. In the present study, a bioprocess for the asymmetric reduction of 4-(trifluoromethyl)acetophenone to (R)-1-[4-(trifluoromethyl)phenyl]ethanol was developed by recombinant Escherichia coli cells with excellent enantioselectivity. In order to overcome the conversion limitation performed in the conventional buffer medium resulting from poor solubility of non-natural substrate, we subsequently established a polar organic solvent-aqueous medium to improve the efficacy. Isopropanol was selected as the most suitable cosolvent candidate, based on the investigation on a substrate solubility test and cell membrane permeability assay in different organic solvent-buffer media. Under the optimum conditions, the preparative-scale asymmetric reduction generated a 99.1% yield with >99.9% product enantiomeric excess (ee) in a 15% (v/v) isopropanol proportion, at 100 mM of 4-(trifluoromethyl)acetophenone within 3 h. Compared to bioconversion in the buffer medium, the developed isopropanol-aqueous system enhanced the substrate concentration by 2-fold with a remarkably improved yield (from 62.5% to 99.1%), and shortened the reaction time by 21 h. Our study gave the first example for a highly enantioselective production of (R)-1-[4-(trifluoromethyl)phenyl]ethanol by a biological method, and the bioreduction of 4-(trifluoromethyl)acetophenone in a polar organic solvent-aqueous system was more efficient than that in the buffer solution only. This process is also scalable and has potential in application.

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Enzymes in organic synthesis. 33. Stereoselective pig liver esterase-catalyzed hydrolyses of meso cyclopentyl-, tetrahydrofuranyl-, and tetrahydrothiophenyl-1,3-diesters

Canadian Journal of Chemistry ◽

10.1139/v85-074 ◽

1985 ◽

Vol 63 (2) ◽

pp. 452-456 ◽

Cited By ~ 29

Author(s):

J. Bryan Jones ◽

R. Scott Hinks ◽

Philip G. Hultin

Keyword(s):

Organic Synthesis ◽

Absolute Configuration ◽

Enantiomeric Excess ◽

Membered Ring ◽

Pig Liver ◽

Pig Liver Esterase ◽

Preparative Scale ◽

Liver Esterase ◽

The Absolute ◽

Enzymes In Organic Synthesis

Preparative-scale pig liver esterase-catalyzed hydrolyses of five-membered ring meso-1,3-diesters are enantiotopically selective. While pro-S enantiotopic selectivity is exhibited in each case, the absolute configuration sense of the hydrolysis in the cyclopentyl series is opposite to that of both the tetrahydrofuranyl and tetrahydrothiophenyl diesters. The enantiomeric excess levels induced are in the 34–46% range.

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ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

Applied and Environmental Microbiology ◽

10.1128/aem.70.4.2529-2534.2004 ◽

2004 ◽

Vol 70 (4) ◽

pp. 2529-2534 ◽

Cited By ~ 71

Author(s):

Hyungdon Yun ◽

Seongyop Lim ◽

Byung-Kwan Cho ◽

Byung-Gee Kim

Keyword(s):

Amino Acids ◽

Kinetic Resolution ◽

Specific Activity ◽

Expression System ◽

Enantiomeric Excess ◽

Selective Enrichment ◽

Alcaligenes Denitrificans ◽

Keto Acids ◽

Optically Pure ◽

High Stereoselectivity

ABSTRACT Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for l-β-amino-n-butyric acid (l-β-ABA). The enzyme converts various β-amino acids and amines to the corresponding β-keto acids and ketones by using pyruvate as an amine acceptor. The apparent Km and V max for l-β-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM l-β-ABA, the apparent Km and V max for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM d,l-β-ABA, producing optically pure d-β-ABA (99% enantiomeric excess) with 53% conversion.

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One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination

Molecules ◽

10.3390/molecules23071785 ◽

2018 ◽

Vol 23 (7) ◽

pp. 1785 ◽

Cited By ~ 5

Author(s):

Peter Lankhorst ◽

Jozef van Rijn ◽

Alexander Duchateau

Keyword(s):

1H Nmr ◽

13C Nmr ◽

Quantitative Method ◽

Enantiomeric Excess ◽

Nmr Spectrum ◽

One Dimensional ◽

Nmr Method ◽

Relative Standard ◽

Excess Value ◽

Chiral Solvating Agent

The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons.

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Yeast-Mediated Stereoselective Reduction of α-Acetylbutyrolactone

Applied Sciences ◽

10.3390/app8081334 ◽

2018 ◽

Vol 8 (8) ◽

pp. 1334 ◽

Cited By ~ 7

Author(s):

Wanda Mączka ◽

Katarzyna Wińska ◽

Małgorzata Grabarczyk ◽

Barbara Żarowska

Keyword(s):

Organic Solvent ◽

Yarrowia Lipolytica ◽

Enantiomeric Excess ◽

Deep Eutectic Solvent ◽

Ester Group ◽

Resting Cells ◽

Media Composition ◽

Yeast Strains ◽

Optically Pure ◽

Diastereomeric Excess

α’-1’-Hydroxyethyl-γ-butyrolactone—a product of reduction of α-acetylbutyrolactone possesses two stereogenic centres and two reactive functionalities (an alcohol and an ester group). Additionally, this compound has a similar structure to γ-butyrolactone (GBL) which is psychoactive. In the present work, biotransformation using seven yeast strains was used to obtain anti stereoisomers of α’-1’-hydroxyethyl-γ-butyrolactone. The process was carried out in both growing and resting culture. The effect of media composition and organic solvent addition on stereoselectivity and effectiveness of biotransformation was also studied. After one day of transformation, optically pure (3R,1’R)-hydroxylactone was obtained by means of Yarrowia lipolytica P26A in YPG medium (yeast extract (1%), peptone (2%) and glucose (2%)). In turn, the use of resting cells culture of Candida viswanathi AM120 in the presence of 10% DES (deep eutectic solvent) allowed us to obtain a (3S,1’S)-enantiomer with de = 85% (diastereomeric excess) and ee 76% (enantiomeric excess).

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Bienzymatic Cascade for the Synthesis of an Optically Active O-benzoyl Cyanohydrin

Catalysts ◽

10.3390/catal9060522 ◽

2019 ◽

Vol 9 (6) ◽

pp. 522 ◽

Cited By ~ 4

Author(s):

Laura Leemans ◽

Luuk van Langen ◽

Frank Hollmann ◽

Anett Schallmey

Keyword(s):

Organic Solvent ◽

Manihot Esculenta ◽

Direct Synthesis ◽

Enantiomeric Excess ◽

Candida Antarctica ◽

Optically Active ◽

Candida Antarctica Lipase ◽

Hydroxynitrile Lyase ◽

Lipase A ◽

Optically Pure

A concurrent bienzymatic cascade for the synthesis of optically pure (S)-4-methoxymandelonitrile benzoate ((S)-3) starting from 4-anisaldehyde (1) has been developed. The cascade involves an enantioselective Manihot esculenta hydroxynitrile lyase-catalyzed hydrocyanation of 1, and the subsequent benzoylation of the resulting cyanohydrin (S)-2 catalyzed by Candida antarctica lipase A in organic solvent. To accomplish this new direct synthesis of the protected enantiopure cyanohydrin, both enzymes were immobilized and each biocatalytic step was studied separately in search for a window of compatibility. In addition, potential cross-interactions between the two reactions were identified. Optimization of the cascade resulted in 81% conversion of the aldehyde to the corresponding benzoyl cyanohydrin with 98% enantiomeric excess.

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ChemInform Abstract: Synthesis of Optically Pure α-Alkylated α-Amino Acids and a Single-Step Method for Enantiomeric Excess Determination.

ChemInform ◽

10.1002/chin.198841319 ◽

1988 ◽

Vol 19 (41) ◽

Author(s):

W. H. KRUIZINGA ◽

J. BOLSTER ◽

R. M. KELLOGG ◽

J. KAMPHUIS ◽

W. H. J. BOESTEN ◽

...

Keyword(s):

Amino Acids ◽

Enantiomeric Excess ◽

Single Step ◽

Step Method ◽

Optically Pure

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Synthesis of optically pure .alpha.-alkylated .alpha.-amino acids and a single-step method for enantiomeric excess determination [Erratum to document cited in CA108(19):166035p]

The Journal of Organic Chemistry ◽

10.1021/jo00257a047 ◽

1988 ◽

Vol 53 (22) ◽

pp. 5392-5392 ◽

Cited By ~ 1

Author(s):

Wim H. Kruizinga ◽

John Bolster ◽

Richard M. Kellogg ◽

Johan Kamphuis ◽

Wilhelmus H. J. Boesten ◽

...

Keyword(s):

Amino Acids ◽

Enantiomeric Excess ◽

Single Step ◽

Step Method ◽

Optically Pure

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ChemInform Abstract: Chiral Synthesis via Organoboranes. Part 17. Preparation of α-Chiral α′-Alkynyl Ketones of High Enantiomeric Excess from Optically Pure Organyl(1-alkynyl)borinic Esters.

ChemInform ◽

10.1002/chin.198839171 ◽

1988 ◽

Vol 19 (39) ◽

Author(s):

H. C. BROWN ◽

A. K. GUPTA ◽

J. V. N. V. PRASAD ◽

M. SREBNIK

Keyword(s):

Enantiomeric Excess ◽

Chiral Synthesis ◽

Optically Pure

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Protein Engineering of a Nitrilase from Burkholderia cenocepacia J2315 for Efficient and Enantioselective Production of (R)-o-Chloromandelic Acid

Applied and Environmental Microbiology ◽

10.1128/aem.02688-15 ◽

2015 ◽

Vol 81 (24) ◽

pp. 8469-8477 ◽

Cited By ~ 13

Author(s):

Hualei Wang ◽

Wenyuan Gao ◽

Huihui Sun ◽

Lifeng Chen ◽

Lujia Zhang ◽

...

Keyword(s):

Protein Engineering ◽

Hot Spots ◽

Enantiomeric Excess ◽

Random Mutagenesis ◽

Burkholderia Cenocepacia ◽

Saturation Mutagenesis ◽

Wild Type ◽

High Concentration ◽

Content Type ◽

Optically Pure

ABSTRACTThe nitrilase-mediated pathway has significant advantages in the production of optically pure aromatic α-hydroxy carboxylic acids. However, low enantioselectivity and activity are observed on hydrolyzingo-chloromandelonitrile to produce optically pure (R)-o-chloromandelic acid. In the present study, a protein engineering approach was successfully used to enhance the performance of nitrilase obtained fromBurkholderia cenocepaciastrain J2315 (BCJ2315) in hydrolyzingo-chloromandelonitrile. Four hot spots (T49, I113, Y199, and T310) responsible for the enantioselectivity and activity of BCJ2315 were identified by random mutagenesis. An effective double mutant (I113M/Y199G [encoding the replacement of I with M at position 113 and Y with G at position 199]), which demonstrated remarkably enhanced enantioselectivity (99.1% enantiomeric excess [ee] compared to 89.2%eefor the wild type) and relative activity (360% of the wild type), was created by two rounds of site saturation mutagenesis, first at each of the four hot spots and subsequently at position 199 for combination with the selected beneficial mutation I113M. Notably, this mutant also demonstrated dramatically enhanced enantioselectivity and activity toward other mandelonitrile derivatives and, thus, broadened the substrate scope of this nitrilase. Using an ethyl acetate-water (1:9) biphasic system,o-chloromandelonitrile (500 mM) was completely hydrolyzed in 3 h by this mutant with a small amount of biocatalyst (10 g/liter wet cells), resulting in a high concentration of (R)-o-chloromandelic acid with 98.7%ee, to our knowledge the highest ever reported. This result highlights a promising method for industrial production of optically pure (R)-o-chloromandelic acid. Insight into the source of enantioselectivity and activity was gained by homology modeling and molecular docking experiments.

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