Identification of Sternbin and Naringenin as Detoxified Metabolites from the Rice Flavanone Phytoalexin Sakuranetin by Pyricularia oryzae

Chem Biodivers. 2017 Feb;14(2). doi: 10.1002/cbdv.201600240. Epub 2017 Jan 21.

Abstract

Sakuranetin (1) is a flavanone phytoalexin that has been reported to play an important role in disease resistance in rice plants. The rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) has been reported to metabolize 1 to lower its antifungal activity. Here, two flavanones, sternbin (2) and naringenin (3), were identified as metabolites of 1 in P. oryzae suspension culture by liquid chromatography tandem mass spectrometry (LC/MS/MS). The inhibition of 1, 2, and 3 on P. oryzae mycelial growth were 45%, 19%, and 19%, respectively, at a concentration of 100 μm. Thus, 2 and 3 are detoxified metabolites of 1 by P. oryzae.

Keywords: Pyricularia oryzae; Flavonoid; Phytoalexin; Rice.

MeSH terms

  • Antifungal Agents / pharmacology*
  • Ascomycota / pathogenicity*
  • Disease Resistance
  • Flavanones / metabolism*
  • Flavonoids / metabolism*
  • Inactivation, Metabolic
  • Oryza / metabolism*
  • Oryza / microbiology*
  • Plant Diseases / microbiology
  • Plant Leaves / metabolism
  • Plant Leaves / microbiology

Substances

  • Antifungal Agents
  • Flavanones
  • Flavonoids
  • sakuranetin
  • naringenin