Biocatalytic cascades towards iminosugar scaffolds reveals promiscuous activity of shikimate dehydrogenases

Abstract

Protecting group-free chemoenzymatic and biocatalytic cascade synthesis of iminosugars from sugar aminopolyols has been achieved using Galactose oxidase F2 and chemical or enzymatic imine reduction. Putative iminosugar oxidoreductases were identified through genome mining, with several shikimate dehydrogenases (SDH) found to effect iminosugar formation. The SDH catalysed transformation is the first example of such activity on an iminosugar scaffold, and provides support for the reduction of iminosugar intermediates by endogenous enzymes in iminosugar biosynthesis.