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Hydrogen peroxide driven biocatalysis

A review of the biotransformations of priority pharmaceuticals in biological wastewater treatment processes.

Flavin-dependent ‘ene’-reductases (EREDs) are exquisite catalysts for effecting stereoselective reductions. Although these reactions typically proceed through a hydride transfer mechanism, we recently found that EREDs can also catalyse reductive dehalogenations and cyclizations via single electron transfer mechanisms. Here, we demonstrate that these enzymes can catalyse redox-neutral radical cyclizations to produce enantioenriched oxindoles from α-haloamides. This transformation is a C–C bond-forming reaction currently unknown in nature and one for which there are no catalytic asymmetric examples. Mechanistic studies indicate the reaction proceeds via the flavin semiquinone/quinone redox couple, where ground-state flavin semiquinone provides the electron for substrate reduction and flavin quinone oxidizes the vinylogous α-amido radical formed after cyclization. This mechanistic manifold was previously unknown for this enzyme family, highlighting the versatility of EREDs in asymmetric synthesis. Flavin-dependent ‘ene’-reductases have now been shown to catalyse redox-neutral radical cyclizations of α-haloamides to form enantioenriched oxindoles. Mechanistic studies indicate the reaction proceeds via the flavin semiquinone/quinone redox couple, where a ground state flavin semiquinone provides the electron for substrate reduction and flavin quinone oxidizes the radical formed after cyclization.

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Asymmetric redox-neutral radical cyclization catalysed by flavin-dependent ‘ene’-reductases

Biocatalysis in drug discovery and development.

Given the high costs and stoichiometric amounts of reduced nicotinamide adenine dinucleotide (NADH) required by the many oxidoreductases used for organic synthesis and the pharmaceutical industry, ...

Efficient NADH Regeneration by a Redox Polymer-Immobilized Enzymatic System

http://digital.csic.es/bitstream/10261/155825/1/Oxidoreductases_industrial_biotransformations_2017_CC.pdf

Ib Winckelmann

Papers

Oxidoreductases on their way to industrial biotransformations