Three-steps in one-pot: whole-cell biocatalytic synthesis of enantiopure (+)- and (−)-pinoresinol via kinetic resolution. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Ricklefs, Esther; Girhard, Marco; Urlacher, Vlada
• Is Part Of: Microbial cell factories. Volume 15:Issue 1(2016)
• Page Start: 1
• Page End: 11
• Publication Date: 2016-12
• Subjects: Laccase -- Vanillyl-alcohol oxidase -- Pinoresinol reductase -- Pinoresinol lariciresinol reductase -- Eugenol -- Coniferyl alcohol -- Pinoresinol -- Lignan -- Biocatalysis -- Kinetic resolution; Microbial biotechnology -- Periodicals; Recombinant proteins -- Synthesis -- Periodicals; 660.62
• DOI: 10.1186/s12934-016-0472-0
• Languages: English
• ISSNs: 1475-2859

Abstract

Abstract Background Pinoresinol is a high-value plant-derived lignan with multiple health supporting effects. Enantiomerically pure pinoresinol can be isolated from natural sources, but with low efficiency. Most chemical and biocatalytic approaches that have been described for the synthesis of pinoresinol furnish the racemic mixture. In this study we devised a three-step biocatalytic cascade for the production of enantiomerically pure pinoresinol from the cheap compound eugenol. Two consecutive oxidations of eugenol through vanillyl-alcohol oxidase and laccase are followed by kinetic resolution of racemic pinoresinol by enantiospecific pinoresinol reductases. Results The addition of the enantiospecific pinoresinol reductase fromArabidopsis thaliana for kinetic resolution of (±)-pinoresinol to an in vitro cascade involving the vanillyl-alcohol oxidase fromPenicillium simplicissimum and the bacterial laccase CgL1 fromCorynebacterium glutamicum resulted in increasing ee values for (+)-pinoresinol; however, an ee value of 34 % was achieved in the best case. The ee value could be increased up to ≥99 % by applyingEscherichia coli -based whole-cell biocatalysts. The optimized process operated in a one-pot "two-cell" sequential mode and yielded 876 µM (+)-pinoresinol with an ee value of 98 %. Switching the reductase to the enantiospecific pinoresinol lariciresinol reductase fromForsythia intermedia enabled the production of 610 µM (−)-pinoresinol with an ee value of 97 %. Conclusion A new approach for the synthesis of enantiomerically pure (+)- and (−)-pinoresinol is described that combines three biotransformation steps in one pot. By switching the reductase in the last step, the whole-cell biocatalysts can be directed to produce either (+)- or (−)-pinoresinol. The products of the reductases' activity, (−)-lariciresinol and (−)-secoisolariciresinol, are valuable precursors that can also be applied for the synthesis of further lignans.