Metabolites from the sponge plakortis simplex. II. : Isolation of four bioactive lactone compounds and of a novel related amino acid

Abstract

Seven lactone metabolites namely the known plakortones B-D ( 1-3) the novel plakortones E ( 4) and F ( 5) and two novel δ-lactones, named simplactones A ( 6) and B ( 7) have been isolated from the Caribbean sponge Plakortis simplex, and their structures characterized by spectroscopic and chemical means. In addition the unprecedented amino acid 8 has been isolated from the same source, and a hypothesis of its biogenetic relationship with simplactones is herein reported. Plakortones B-F and compound 8 exhibited in vitro cytotoxic activity on WEHI 164, murine fibrosarcoma cell line.