IODOCIONIN, A NEW CYTOTOXIC IODINATED METABOLITE ISOLATED FROM THE MEDITERRANEAN ASCIDIAN CIONA EDWARDSII

Tyrosine-derived halometabolites frequently occur in marine organisms and are known to play basic functions related to the survival of the living creatures producing them.1 Bromine is by far the halogen most frequently found in these metabolites; for example, bromotyrosine derivatives are constantly detected among the secondary metabolites of the Demospongiae; thus, they have been used for taxonomic purposes.2-4 Iodinated halometabolites, biosynthetically related to tyrosine, are much less widespread in the marine environment, since they have been isolated just in a few algae, microorganisms and marine invertebrates;5 however, recent research indicates this number will increase in the future. Many of the isolated and identified iodine-containing metabolites exhibited biological activities.6 A chemical investigation of secondary metabolites from the Mediterranean ascidia Ciona edwardsii has been performed and a new iodinated derivative, named iodocionin (1) has been isolated and chemically characterized. Structure of 1 has been elucidated through extensive spectroscopic analysis (1D- and 2D-NMR, and MS). Tests in vitro have been performed by Abteilung für Angewandte Molekularbiologie, Institut für Physiologische Chemie, in order to evaluate the capability of compound 1 to affect cells viability; these studies demonstrated that iodocionin exhibits acute toxicity against lymphoma cells with an IC50 of 7.75 μg/ml.