Tricyclic guanidine alkaloids from the marine sponge Acanthella cavernosa that stabilize the tumor suppressor PDCD4

Mar Drugs. 2014 Aug 21;12(8):4593-601. doi: 10.3390/md12084593.

Abstract

A cell-based high-throughput screen that assessed the cellular stability of a tumor suppressor protein PDCD4 (Programmed cell death 4) was used to identify a new guanidine-containing marine alkaloid mirabilin K (3), as well as the known compounds mirabilin G (1) and netamine M (2). The structures of these tricyclic guanidine alkaloids were established from extensive spectroscopic analyses. Compounds 1 and 2 inhibited cellular degradation of PDCD4 with EC50 values of 1.8 μg/mL and 2.8 μg/mL, respectively. Mirabilin G (1) and netamine M (2) are the first marine natural products reported to stabilize PDCD4 under tumor promoting conditions.

Publication types

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

MeSH terms

  • Alkaloids / chemistry*
  • Alkaloids / pharmacology*
  • Animals
  • Apoptosis Regulatory Proteins / metabolism*
  • Guanidine / chemistry*
  • Guanidine / pharmacology*
  • HEK293 Cells
  • Humans
  • Oleanolic Acid / analogs & derivatives
  • Oleanolic Acid / chemistry
  • Porifera / chemistry*
  • RNA-Binding Proteins / metabolism*
  • Saponins / chemistry
  • Tumor Suppressor Proteins / metabolism*

Substances

  • Alkaloids
  • Apoptosis Regulatory Proteins
  • PDCD4 protein, human
  • RNA-Binding Proteins
  • Saponins
  • Tumor Suppressor Proteins
  • mirabilin
  • Oleanolic Acid
  • Guanidine