Himalaquinones A-G, Angucyclinone-Derived Metabolites Produced by the Himalayan Isolate Streptomyces sp. PU-MM59

J Nat Prod. 2021 Jul 23;84(7):1930-1940. doi: 10.1021/acs.jnatprod.1c00192. Epub 2021 Jun 25.

Abstract

Himalaquinones A-G, seven new anthraquinone-derived metabolites, were obtained from the Himalayan-based Streptomyces sp. PU-MM59. The chemical structures of the new compounds were identified based on cumulative analyses of HRESIMS and NMR spectra. Himalaquinones A-F were determined to be unique anthraquinones that contained unusual C-4a 3-methylbut-3-enoic acid aromatic substitutions, while himalaquinone G was identified as a new 5,6-dihydrodiol-bearing angucyclinone. Comparative bioactivity assessment (antimicrobial, cancer cell line cytotoxicity, impact on 4E-BP1 phosphorylation, and effect on axolotl embryo tail regeneration) revealed cytotoxic landomycin and saquayamycin analogues to inhibit 4E-BP1p and inhibit regeneration. In contrast, himalaquinone G, while also cytotoxic and a regeneration inhibitor, did not affect 4E-BP1p status at the doses tested. As such, this work implicates a unique mechanism for himalaquinone G and possibly other 5,6-dihydrodiol-bearing angucyclinones.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ambystoma mexicanum
  • Aminoglycosides / isolation & purification
  • Aminoglycosides / pharmacology
  • Animals
  • Anthraquinones / isolation & purification
  • Anthraquinones / pharmacology*
  • Antineoplastic Agents / isolation & purification
  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Pakistan
  • Soil Microbiology
  • Streptomyces / chemistry*

Substances

  • Aminoglycosides
  • Anthraquinones
  • Antineoplastic Agents
  • angucyclinone
  • saquayamycin