(+/-)-Gelliusines A and B, two diastereomeric brominated tris-indole alkaloids from a deep water New Caledonian marine sponge (Gellius or Orina sp.)

Abstract

Two new diastereomeric brominated tris-indole alkaloids occurring as enantiomeric pairs, (±)-gelliusine A (I) and its isomer (±)-gelliusine B, have been isolated from a deep water New Caledonian sponge (Gellius or Orina sp.), whose crude ext. exhibited cytotoxicity against KB cells. Their structures were elucidated by spectroscopic methods including one- and two-dimensional NMR spectroscopy. The major compd., I, which showed very weak cytotoxicity, proved to be active at the serotonin receptor