Natural Products Chemistry in Marine Ascidians of the Genus Aplidium

Ascidians (tunicates) are widely recognized as one of the most prolific producers of bioactive natural products in the marine environment. In particular, ascidians of the genus Aplidium are renowned for the variability in the metabolites that they content. The non-nitrogenous compounds are dominated by the presence of meroterpenoids exemplified by the longithorones. Among the nitrogen containing group, nucleosides, cyclic peptides and a high variety of alkaloids can be mentioned. In this review the most interesting aspects of structure elucidation and bioactivity of the natural products from species of the genus Aplidium reported up to the end of 2004 will be presented.