Candida parapsilosis ATCC 7330 grown using different culture conditions (inoculum size 4% (v/v), inoculum age 12 h, and harvest time 14 h) from those previously reported (inoculum size 2% (v/v), inoculum age 24 h, and harvest time 44 h) successfully deracemised racemic 1-arylethanols and 4-phenyl-2-butanol to the (R)-enantiomer (ee up to >99%). The deracemisation of racemic 1-aryl ethanol proceeds via (i) enantioselective oxidation of (S)-enantiomer followed by (ii) reduction of the ketone formed to give the racemic alcohol which gets kinetically resolved thus enriching for the (R)-enantiomer from the racemate. This is the first report on the deracemisation of 1-arylethanols using Candida parapsilosis ATTC 7330 via dynamic kinetic resolution. © 2011 Informa UK, Ltd.

Sathyanarayana Naidu Gummadi

Department Of Biotechnology

Anju Chadha

1-ARYLETHANOLS

CANDIDA PARAPSILOSIS

CANDIDA PARAPSILOSIS ATCC 7330

Culture conditions

DERACEMISATION

DYNAMIC KINETIC RESOLUTION

ENANTIOSELECTIVE OXIDATION

HARVEST TIME

INOCULUM SIZE

RACEMIC ALCOHOLS

chirality

Enantiomers

Ethanol

Ketones

Kinetics

yeast

Candida

alcohol

ketone

phenyl group

article

enantiomer

nonhuman

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

Candida parapsilosis ATCC 7330 can also deracemise 1-arylethanols

Biocatalysis and Biotransformation

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.

Fulltext

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

We present an FTIR based assay to monitor the whole cell mediated oxidation of aryl alcohols by measuring the characteristic IR absorption of the hydroxyl group [OH] of the substrate and the carbonyl group [CO] of the corresponding oxidized product. This method expedites the analysis of whole cell mediated catalysis which is usually done by GC and/or HPLC. The FTIR assay had linearity with R2≥0.980 and sensitivity up to 10μM. The accuracy and precision of FTIR assay was found ≥81% and ≥94%, respectively. This assay was validated by GC which exhibited ≥82% accuracy and ≥79% precision. The time of analysis taken by this assay was 2-3min per sample in comparison with 20-40min by GC. © 2015 Elsevier B.V.

Journal of Biotechnology

A fourier transform infrared spectroscopy (FTIR) based assay for Candida parapsilosis ATCC 7330 mediated oxidation of aryl alcohols

Asymmetric reduction of ethyl-4-chloro-3-oxobutanoate to (S)-ethyl-4-chloro-3-hydroxybutanoate in aqueous medium by resting cells of Candida parapsilosis ATCC 7330 was optimized. The influence of culture parameters (inoculum size, inoculum age and biocatalyst harvest time) and reaction parameters (co-substrate, resting cell, pH and substrate concentrations) on the asymmetric reduction were studied. It was found that these parameters significantly influenced the rate of the asymmetric reduction. Under the optimum conditions, the final concentration of (S)-ethyl-4-chloro-3- hydroxybutanoate, enantiomeric excess and the isolated yield of (S)-ethyl-4-chloro-3-hydroxybutanoate were 1.38 M (230 g/l), >99 and 95%, respectively. The space time yield was 115 mmol/lh, which is significantly higher than other whole cell biocatalysts reported so far. © 2009 Society for Industrial Microbiology.

Journal of Industrial Microbiology and Biotechnology

Asymmetric synthesis of (S)-ethyl-4-chloro-3-hydroxybutanoate using Candida parapsilosis ATCC 7330

Deracemisation of racemic alkyl 3-(hetero-2-yl)-3-hydroxypropanoates using whole cells of Candida parapsilosis ATCC 7330 resulted in the formation of the 'S' enantiomer in high enantiomeric excess (up to >99% ee) and isolated yields (up to 75%). © 2007 Elsevier B.V. All rights reserved.

Journal of Molecular Catalysis B: Enzymatic

Preparation of optically pure alkyl 3-(hetero-2-yl)-3-hydroxypropanoates by Candida parapsilosis ATCC 7330 mediated deracemisation

Biocatalytic deracemisation of racemic allylic alcohols by whole cells of Candida parapsilosis ATCC 7330 resulted in the formation of the (R)-enantiomers in high enantiomeric excesses (up to >99%) and isolated yields (up to 79%). © 2008 Elsevier Ltd. All rights reserved.

Tetrahedron Asymmetry

Enantiomerically pure allylic alcohols: preparation by Candida parapsilosis ATCC 7330 mediated deracemisation

Deracemisation of racemic (3E)-alkyl-4-(hetero-2-yl)-2-hydroxybut-3-enoates using Candida parapsilosis ATCC 7330 resulted in the formation of one enantiomer in high enantiomeric excess [up to &gt;99% ee] and isolated yields [up to 79%]. The absolute configuration of the enantiomerically pure (3E)-ethyl-4-(thiophene-2-yl)-2-hydroxybut-3-enoate as determined by 1H NMR of the Mosher esters was found to be (S). © 2007 Elsevier Ltd. All rights reserved.

Preparation of enantiomerically pure (3E)-alkyl-4-(hetero-2-yl)-2-hydroxybut-3-enoates by Candida parapsilosis ATCC 7330 mediated deracemisation and determination of the absolute configuration of (3E)-ethyl-4-(thiophene-2-yl)-2-hydroxybut-3-enoate

Biocatalytic deracemisation of a range of racemic (3E,5E)-alkyl-2-hydroxy-6-arylhexa-3,5-dienoates using Candida parapsilosis ATCC 7330 resulted in pure (S)-enantiomers in yields of up to 80% and ee>99%. © 2007 Elsevier Ltd. All rights reserved.

Tetrahedron

Preparation of optically pure (3E,5E)-alkyl-2-hydroxy-6-arylhexa-3,5-dienoates by Candida parapsilosis ATCC 7330 mediated deracemisation of the racemates

Journal	Biocatalysis and Biotransformation
ISSN	10242422
Open Access	No