Ascidians are a potential taxonomic group such as sponges and nudibranchis producing compounds of biological activity. Since the 80's, the antitumor, antibacterial, antithrombotic and antileukemic capacity in different species of the group. Currently,
the order new  compounds have been found and many species of this group, especially  belong to Aplodoubranchia order -  Eudistoma, Aplidium, Didemnum and Lissoclinum genus.  From South Western Atlantic, Phallusia nigra, Symplegma rubra and Polyclinum sp were the species that showed some potential for new drugs.