Netamines O-S, Five New Tricyclic Guanidine Alkaloids from the Madagascar Sponge Biemna laboutei, and Their Antimalarial Activities

Chem Biodivers. 2015 Nov;12(11):1725-33. doi: 10.1002/cbdv.201400350.

Abstract

In our continuing program to isolate new compounds from the Madagascar sponge Biemna laboutei, five new tricyclic guanidine alkaloids, netamines O - S (1-5, resp.), have been identified together with the known compounds netamine E (6) and mirabilin J (7). The structures of all new netamines were assigned on the basis of spectroscopic analyses. Their relative configurations were established by analysis of ROESY data and comparison with literature data. Netamines O, P, and Q, which were isolated in sufficient quantities, were tested for their cytotoxic activities against KB cells and their activities against the malaria parasite Plasmodium falciparum. Netamines O and Q were found to be moderately cytotoxic. Netamines O, P, and Q exhibited antiplasmodial activities with IC₅₀ values of 16.99 ± 4.12, 32.62 ± 3.44, and 8.37 ± 1.35 μM, respectively.

Keywords: Antiplasmodial activity; Biemna laboutei; Cytotoxic activity; Guanidine alkaloids; Netamines O - S.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / isolation & purification
  • Alkaloids / pharmacology*
  • Animals
  • Antimalarials / chemistry
  • Antimalarials / isolation & purification
  • Antimalarials / pharmacology*
  • Dose-Response Relationship, Drug
  • Guanidines / chemistry
  • Guanidines / isolation & purification
  • Guanidines / pharmacology*
  • Madagascar
  • Molecular Conformation
  • Parasitic Sensitivity Tests
  • Plasmodium falciparum / drug effects*
  • Porifera / chemistry*
  • Structure-Activity Relationship

Substances

  • Alkaloids
  • Antimalarials
  • Guanidines