Isarubrolones Containing a Pyridooxazinium Unit from Streptomyces as Autophagy Activators

J Nat Prod. 2019 May 24;82(5):1149-1154. doi: 10.1021/acs.jnatprod.8b00857. Epub 2019 May 9.

Abstract

Isarubrolones are bioactive polycyclic tropoloalkaloids from Streptomyces. Three new isarubrolones (2-4), together with the known isarubrolone C (1) and isatropolones A (5) and C (6, 3( R)-hydroxyisatropolone A), were identified from Streptomyces sp. CPCC 204095. The structures of these compounds were determined using a combination of mass spectrometry, 1D and 2D NMR spectroscopy, and ECD. Compounds 3 and 4 feature a pyridooxazinium unit, which is rarely seen in natural products. Compound 6 could conjugate with amino acids or amines to expand the structural diversity of isarubrolones with a pentacyclic or hexacyclic core. Importantly, 1 and 3-6 were found to induce complete autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / isolation & purification*
  • Alkaloids / pharmacology
  • Autophagy / drug effects*
  • Hep G2 Cells
  • Humans
  • Magnetic Resonance Spectroscopy
  • Streptomyces / chemistry*
  • Tropolone / isolation & purification*

Substances

  • Alkaloids
  • Tropolone