Enantioselective bioreduction of alkyl 2-oxo-4-arylbutanoates and 2-oxo-4-arylbut-3-enoates mediated by Candida parapsilosis ATCC 7330 resulted in the formation of the corresponding (S)-2-hydroxy compounds in high enantiomeric excesses (93-99%) and good isolated yields (58-71%). The absolute configuration of enantiomerically pure ethyl 2-hydroxy-4-(p-methylphenyl)but-3-enoate obtained by the reduction of the corresponding keto ester was assigned by 1H NMR using Mosher's method. © 2004 Elsevier Ltd. All rights reserved.

Anju Chadha

Department Of Biotechnology

Kuttikode Priya

butyric acid derivative

article

asymmetric synthesis

CANDIDA PARAPSILOSIS

chemical analysis

Enantioselectivity

nonhuman

priority journal

proton nuclear magnetic resonance

quantum yield

reduction

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Tetrahedron Asymmetry

The whole cells of Candida parapsilosis ATCC 7330 are a well-established biocatalyst used for oxidation and reduction of various organic compounds to generate chiral synthons. Recombinantly expressed carbonyl reductase (CpCR) from the same strain reduces aryl α–ketoesters to their respective optically pure alcohols but preferentially reduces aliphatic and aryl aldehydes to primary alcohols. The prochiral substrates viz. aryl α-ketoester [Ethyl-2-oxo-4-phenylbutanoate], aryl ketone [Acetophenone] and aliphatic β-ketoester [Ethyl-4,4,4-trifloro-3-oxo-butanoate] get reduced to (R)-alcohols with CpCR while an aryl ketoaldehyde [2-oxo-2-phenylacetaldehyde] gives the (S)-alcohol. The optimal orientation required for the high conversion and desired enantioselectivity was analyzed by docking the α/β ketoesters, ketoaldehyde and a ketone with a modeled CpCR. Aryl α-ketoester, having the lowest free energy (-8.43 kcal/mol), shows the most favorable binding with CpCR (Interaction Energy = 7.9 kcal/mol). Also, the close proximity of aryl α-ketoester to the cofactor NADPH (2.82 Å) facilitates a better Pro-R hydride transfer as compared to other substrates. © 2018 Elsevier B.V.

Molecular Catalysis

Understanding substrate specificity and enantioselectivity of carbonyl reductase from Candida parapsilosis ATCC 7330 (CpCR): Experimental and modeling studies

This review highlights the importance of the biocatalyst, Candida parapsilosis for oxidation and reduction reactions of organic compounds and establishes its versatility to generate a variety of chiral synthons. Appropriately designed reactions using C. parapsilosis effect efficient catalysis of organic transformations such as deracemization, enantioselective reduction of prochiral ketones, imines, and kinetic resolution of racemic alcohols via selective oxidation. This review includes the details of these biotransformations, catalyzed by whole cells (wild type and recombinant strains), purified enzymes (oxidoreductases) and immobilized whole cells of C. parapsilosis. The review presents a bioorganic perspective as it discusses the chemo, regio and stereoselectivity of the biocatalyst along with the structure of the substrates and optical purity of the products. Fermentation scale biocatalysis using whole cells of C. parapsilosis for several biotransformations to synthesize important chiral synthons/industrial chemicals is included. A comparison of C. parapsilosis with other whole cell biocatalysts for biocatalytic deracemization and asymmetric reduction of carbonyl and imine groups in the synthesis of a variety of enantiopure products is presented which will provide a basis for the choice of a biocatalyst for a desired organic transformation. Thus, a wholesome perspective on the present status of C. parapsilosis mediated organic transformations and design of new reactions which can be considered for large scale operations is provided. Taken together, C. parapsilosis can now be considered a ‘reagent’ for the organic transformations discussed here. © 2016 Elsevier Inc.

Bioorganic Chemistry

Candida parapsilosis: A versatile biocatalyst for organic oxidation-reduction reactions

Confocal microscopic studies with the resting cells of yeast, Candida parapsilosis ATCC 7330, a reportedly versatile biocatalyst for redox enzyme mediated preparation of optically pure secondary alcohols in high optical purities [enantiomeric excess (ee) up to >99%] and yields, revealed that the yeast cells had large vacuoles under the experimental conditions studied where the redox reaction takes place. A novel fluorescence method was developed using 1-(6-methoxynaphthalen-2-yl)ethanol to track the site of biotransformation within the cells. This alcohol, itself non-fluorescent, gets oxidized to produce a fluorescent ketone, 1-(6-methoxynaphthalen-2-yl)ethanone. Kinetic studies showed that the reaction occurs spontaneously and the products get released out of the cells in less time [5 mins]. The biotransformation was validated using HPLC.

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Scientific Reports

Direct observation of redox reactions in Candida parapsilosis ATCC 7330 by Confocal microscopic studies

Enantiomerically pure β- and γ-nitro alcohols were prepared from their respective nitro ketones by asymmetric reduction mediated by the biocatalyst, Candida parapsilosis ATCC 7330 under optimized reaction conditions (ee up to >99%; yields up to 76%). This biocatalyst exhibits high chemoselectivity and reduces the keto group in preference to nitro group along with good enantioselectivity to produce enantiomerically enriched nitro alkanols. The asymmetric reduction of aliphatic nitro ketones was carried out in water with ethanol as cosolvent and glucose as cosubstrate using the whole cells of Candida parapsilosis ATCC 7330 in much lesser time (4 h). For the first time, the biocatalytic asymmetric reduction of the following ketones is reported here: 1-nitro-butan-2-one, 1-nitro-pentan-2-one, 3-methyl-1-nitro-butan-2-one and 1-cyclohexyl-2-nitroethanone to produce (R)-alcohols [ee up to 79%, yield up to 74%] and 1-nitro-hexan-2-one and 1-nitro-heptan-2-one to produce (S)-alcohols [ee up to 81%, yield up to 76%]. © The Royal Society of Chemistry.

RSC Advances

Enantio- &amp; chemo-selective preparation of enantiomerically enriched aliphatic nitro alcohols using Candida parapsilosis ATCC 7330

Enantiomerically enriched hydroxy ketones were prepared by the reduction of the corresponding diketones with excellent enantiomeric excess (98%) and in good yields (up to 75%) using whole cells of Candida parapsilosis ATCC 7330. Cyclic diketones, such as 1,2-cyclohexanedione and 1,4-cyclohexanedione, resulted in hydroxy ketones as products. Cyclohexane-1,3-dione and 5,5-dimethylcyclohexane-1,3-dione gave dimerised products, such as 2,2′-(ethane-1,1-diyl)bis(3-hydroxycyclohex-2-enone) and 2,2′-(ethane-1,1-diyl)bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) with acetaldehyde generated in situ from whole cells of Candida parapsilosis ATCC 7330, which is reported here for the first time. © 2015 Elsevier Ltd. All rights reserved.

Regio- and enantioselective reduction of diketones: Preparation of enantiomerically pure hydroxy ketones catalysed by Candida parapsilosis ATCC 7330

A highly enantioselective preparation (92-99% enantiomeric excess, 100% conversion) of various 4-aryl-2-hydroxy but-3-enoic carboxylic acid esters from the corresponding 4-phenyl-2-keto but-3-enoic acid esters mediated by plant cell cultures of Daucus carota under mild and environmentally benign conditions in aqueous medium is described. © 2003 Elsevier B.V. All rights reserved.

Journal of Molecular Catalysis B: Enzymatic

Highly stereoselective reduction of 4-Aryl-2-oxo but-3-enoic carboxylic esters by plant cell culture of Daucus carota

Biocatalytic deracemisaton of the racemic ethyl ester of 2-hydroxy-4-phenylbutanoic acid gives the (S)-enantiomer exclusively in >99% e.e. and 85-90% yield. Ethyl and methyl esters of mandelic acid and the methyl ester of 2-hydroxy-4-phenylbutanoic acid also gave the (S)-enantiomer exclusively. Whole cells of Candida parapsilosis (ATCC 7330) were used to effect this biotansformation. © 2002 Published by Elsevier Science Ltd.

Biocatalytic deracemisation of α-hydroxy esters: High yield preparation of (S)-ethyl 2-hydroxy-4-phenylbutanoate from the racemate

The Journal of Organic Chemistry

Biocatalytic Asymmetric Hydrogen Transfer EmployingRhodococcus ruberDSM 44541

The Scientific World JOURNAL

Ch-ch-ch-ch-ch-changes

Biotransformations in Organic Chemistry

Asymmetric reduction of alkyl 2-oxo-4-arylbutanoates and -but-3-enoates by Candida parapsilosis ATCC 7330: Assignment of the absolute configuration of ethyl 2-hydroxy-4-(p-methylphenyl)but-3-enoate by 1H NMR

Journal	Tetrahedron Asymmetry
ISSN	09574166
Open Access	No