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.

Anju Chadha

Department Of Biotechnology

Pula Mahajabeen

acetaldehyde

Cyclohexane derivative

diketone

KETOL

ketone

article

Biocatalyst

biotransformation

CANDIDA PARAPSILOSIS

catalysis

enantiomer

Enantioselectivity

FUNGAL CELL

nonhuman

priority journal

reduction

Whole cell

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

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

Selectivity between primary and secondary alcohols was observed in oxidation using whole cells of Candida parapsilosis ATCC 7330, where the secondary alcohol was preferentially oxidized. In racemic sec alcohols, the 'R' enantiomer was selectively oxidized to the corresponding keto alcohol (yield = 18-54%) leaving the 'S' diol (yield = 31-69% and enantiomeric excess from 14% to >99%). A biphasic system consisting of isooctane-water (48 : 2 v/v) was used as a medium for biotransformation at 25 °C. This is the first report of the regio- and enantio-selective oxidation of diols using C. parapsilosis ATCC 7330. © The Royal Society of Chemistry 2014.

RSC Advances

Regio- and enantio-selective oxidation of diols by Candida parapsilosis ATCC 7330

Biocatalytic preparation of various substituted N-phenylacetamides was carried out for the first time using whole cells of Candida parapsilosis ATCC 7330 under mild reaction conditions with excellent conversions (up to 93%) and good yields (up to 81%). Arylamine N-acetyltransferase (NAT) from whole cells of Candida parapsilosis ATCC 7330 is implicated in the N-acylation which is known to transfer the acetyl group from acetyl CoA (coenzyme A) to aromatic amines. Mechanistic investigation carried out using deuterated ethanol to find the source of acetyl CoA revealed that the reaction proceeds through the formation of acetaldehyde in situ, which is a potential source for the acetyl group of cytoplasmic acetyl CoA. Furthermore, experiments on regioselectivity, carried out with 2-phenylenediamine (2-PDA) resulted in a cyclised product 2-methyl benzimidazole (conversion 99%). The biocatalyst also mediates the cyclization of 3-(phenylamino)cyclohex-2-enones in the presence of the in situ generated acetaldehyde to form acridine-1,8-diones (conversion up to 70%), which is a green process reported here for the first time. © The Royal Society of Chemistry 2013.

A novel green route for the synthesis of N-phenylacetamides, benzimidazoles and acridinediones using Candida parapsilosis ATCC 7330

The aerobic oxidative kinetic resolution of racemic α-hydroxy ketones was accomplished using a chiral Zn-quinine complex as the catalyst in the presence of molecular oxygen. The resulting optimized reaction conditions were applied to resolute different types of racemic α-hydroxy ketones and a maximum of 9.2 selectivity (s) was obtained with 88% ee for the recovered α-hydroxy ketone. © 2011 Elsevier Ltd. All rights reserved.

Chiral Zn-catalyzed aerobic oxidative kinetic resolution of α-hydroxy ketones

Zn(II)-DABCO complex is used as an efficient catalyst for the aerobic oxidation of benzoins to benzils in the presence of molecular oxygen. Usage of chiral zinc complex as catalyst resulted in enantioselective oxidative kinetic resolution of racemic benzoin to yield enantiomerically enriched benzoins. © 2010 Elsevier Ltd. All rights reserved.

Tetrahedron Letters

Zinc-catalyzed aerobic oxidation of benzoins and its extension to enantioselective oxidation

Whole cells of Candida parapsilosis ATCC 7330 were used for the resolution of N-acetyl amino acid esters. Excellent enantioselectivities (E = 40 to >500) were achieved for the resolution of N-protected protein and non-protein amino acid esters giving good yields (28-50%) and high enantiomeric excesses (up to >99%) for both enantiomers. © 2010 Elsevier Ltd. All rights reserved.

Resolution of N-protected amino acid esters using whole cells of Candida parapsilosis ATCC 7330

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

Journal	Data powered by TypesetTetrahedron Asymmetry
Publisher	Data powered by TypesetElsevier Ltd
ISSN	09574166
Open Access	No