Versiquinazolines A-K, Fumiquinazoline-Type Alkaloids from the Gorgonian-Derived Fungus Aspergillus versicolor LZD-14-1

J Nat Prod. 2016 Nov 23;79(11):2941-2952. doi: 10.1021/acs.jnatprod.6b00801. Epub 2016 Nov 10.

Abstract

Eleven fumiquinazoline-type alkaloids, namely, versiquinazolines A-K (1-11), along with cottoquinazolines B-D, were isolated from the gorgonian-derived fungus Aspergillus versicolor LZD-14-1. Their structures were determined by extensive analyses of the spectroscopic data (1D and 2D NMR, HRESIMS), in addition to the experimental and calculated ECD data and X-ray single-crystal diffraction analysis for the assignments of the absolute configurations. Versiquinazolines A, B, and F (1, 2, and 6), bearing a methanediamine or an aminomethanol unit and representing a unique subtype of fumiquinazolines, were found from nature for the first time. Possible biogenetic relationships of the versiquinazolines are postulated. In addition, the structures of cottoquinazolines B (12), D (13), and C (14) should be revised to the enantiomers. Compounds 1, 2, 7, and 11 exhibited inhibitory activities against thioredoxin reductase (IC50 values ranging from 12 to 20 μM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / isolation & purification*
  • Alkaloids / pharmacology
  • Aspergillus / chemistry*
  • Crystallography, X-Ray
  • Molecular Conformation
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Quinazolines / chemistry
  • Quinazolines / isolation & purification*
  • Quinazolines / pharmacology
  • Stereoisomerism
  • Thioredoxin-Disulfide Reductase / antagonists & inhibitors

Substances

  • Alkaloids
  • Quinazolines
  • cottoquinazoline B
  • cottoquinazoline D
  • Thioredoxin-Disulfide Reductase