Biosynthesis of oxygenated brasilane terpene glycosides involves a promiscuous N-acetylglucosamine transferase

Chem Commun (Camb). 2020 Oct 21;56(82):12419-12422. doi: 10.1039/d0cc03950k. Epub 2020 Sep 16.

Abstract

Investigation of the metabolome of the ascomycete Annulohypoxylon truncatum led to the identification of novel oxygenated brasilane glycosides and the revision of the stereochemistry of the brasilane A octahydro-1H-indene core scaffold to trans. The bra biosynthetic gene cluster containing five genes (braA-braE) was identified and verified by heterologous expression experiments in Aspergillus oryzae demonstrating that BraC is a multifunctional P450 monooxygenase. In vitro studies of BraB revealed it to be a very rare fungal UDP-GlcNAc dependent N-acetylglucosamine transferase. UDP-glucose is also accepted as a donor, and a broad acceptor substrate tolerance for various primary and secondary alcohols was observed.

MeSH terms

  • Ascomycota / genetics
  • Ascomycota / metabolism
  • Aspergillus oryzae / metabolism
  • Cytochrome P-450 Enzyme System / genetics
  • Glycosides / biosynthesis*
  • Glycosides / chemistry
  • Multigene Family
  • N-Acetylglucosaminyltransferases / genetics
  • N-Acetylglucosaminyltransferases / metabolism*
  • Oxygen / chemistry*
  • Sesquiterpenes / chemistry
  • Sesquiterpenes / metabolism*
  • Stereoisomerism
  • Substrate Specificity
  • Terpenes / chemistry

Substances

  • Glycosides
  • Sesquiterpenes
  • Terpenes
  • brasilane
  • Cytochrome P-450 Enzyme System
  • N-Acetylglucosaminyltransferases
  • UDP-N-acetylglucosamine transferase
  • Oxygen