Microbial Stereoselective One-Step Conversion of Diols to Chiral Lactones in Yeast Cultures

Filip Boratyński,Ewa Szczepańska,Teresa Olejniczak,Jakub Pannek

doi:10.3390/catal5042068

Abstract

It has been shown that whole cells of different strains of yeast catalyze stereoselective oxidation of meso diols to the corresponding chiral lactones. Among screening-scale experiments, Candida pelliculosa ZP22 was selected as the most effective biocatalyst for the oxidation of monocyclic diols 3a–b with respect to the ratio of high conversion to stereoselectivity. This strain was used in the preparative oxidation, affording enantiomerically-enriched isomers of lactones: (+)-(3aR,7aS)-cis-hexahydro-1(3H) -isobenzofuranone (2a) and (+)-(3aS,4,7,7aR)-cis-tetrahydro-1(3H)-isobenzofuranone (2b). Scaling up the culture growth, as well as biotransformation conditions has been successfully accomplished. Among more bulky substrates, bicyclic diol 3d was totally converted into enantiomerically-pure exo-bridged (+)-(3aR,4S,7R,7aS)-cis-tetrahydro-4,7-methanoisobenzofuran -1(3H)-one (2d) by Yarrovia lipolytica AR71. Microbial oxidation of diol 3f by Candida sake AM908 and Rhodotorula rubra AM4 afforded optically-pure cis-3-butylhexahydro-1(3H) -isobenzofuranone (2f), however with low conversion.

Highlights

The most dynamically-developing field of research on the border of chemistry and biology is biocatalysis, namely the application of microorganisms or isolated enzymes to carry out chemical transformations in a stereospecific way [1,2,3,4,5,6]
Reactions of low-reactive chemicals and reactions of non-activated areas of the molecule are possible. This usually leads to products that are very difficult to obtain by chemical synthesis
The substrate for biotransformation, diol 3f, was synthesized by the reduction of corresponding lactone 2f, which was previously obtained from anhydride 1a in a three-step synthesis described by us earlier [43] (Scheme 2)

Summary

Introduction

The most dynamically-developing field of research on the border of chemistry and biology is biocatalysis, namely the application of microorganisms or isolated enzymes to carry out chemical transformations in a stereospecific way [1,2,3,4,5,6]. Biocatalysis allows stereochemical control of reactions and often provides chiral compounds. Reactions of low-reactive chemicals and reactions of non-activated areas of the molecule are possible. This usually leads to products that are very difficult to obtain by chemical synthesis. Biotransformation as an environmentally-friendly process requires mild conditions (temperature, pH), decreases the consumption of chemicals and reduces side reactions and toxic chemical waste

Objectives

Results

Conclusion