Targeted Isolation of Asperheptatides from a Coral-Derived Fungus Using LC-MS/MS-Based Molecular Networking and Antitubercular Activities of Modified Cinnamate Derivatives

J Nat Prod. 2021 Jan 22;84(1):11-19. doi: 10.1021/acs.jnatprod.0c00804. Epub 2020 Dec 24.

Abstract

Under the guidance of MS/MS-based molecular networking, four new cycloheptapeptides, namely, asperheptatides A-D (1-4), were isolated together with three known analogues, asperversiamide A-C (5-7), from the coral-derived fungus Aspergillus versicolor. The planar structures of the two major compounds, asperheptatides A and B (1 and 2), were determined by comprehensive spectroscopic data analysis. The absolute configurations of the amino acid residues were determined by advanced Marfey's method. The two structurally related trace metabolites, asperheptatides C and D (3 and 4), were characterized by ESI-MS/MS fragmentation methods. A series of new derivatives (8-26) of asperversiamide A (5) were semisynthesized. The antitubercular activities of 1, 2, and 5-26 against Mycobacterium tuberculosis H37Ra were also evaluated. Compounds 9, 13, 23, and 24 showed moderate activities with MIC values of 12.5 μM, representing a potential new class of antitubercular agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / chemistry*
  • Animals
  • Anthozoa / microbiology*
  • Antitubercular Agents / chemistry*
  • Aspergillus / chemistry*
  • Chromatography, Liquid
  • Cinnamates / chemistry*
  • Cinnamates / pharmacology
  • Molecular Structure
  • Mycobacterium tuberculosis / chemistry*
  • Peptides, Cyclic / chemistry*
  • Peptides, Cyclic / metabolism
  • Spectrum Analysis
  • Tandem Mass Spectrometry

Substances

  • Antitubercular Agents
  • Cinnamates
  • Peptides, Cyclic
  • asperversiamide C

Supplementary concepts

  • Aspergillus versicolor