there are three known analogous structures of atx which have different toxicity: antillatoxin b (8-demethyl-antillatoxin) and dh-atx (8-demethyl-8,9-dihydro-antillatoxin), and various stereoisomers of antillatoxin a. these various structures have been found to be less toxic than antillatoxin a. synthetic versions of antillatoxin have been produced with conformational variations of the lipophilic side chain. all of these structures drastically changed the toxins activity. structures where the c7-c8=c9 bond angle was closer to 180 showed lower levels of toxicity in cell cultures. structures that added a bulky side group to the c5 position also showed dramatic decreases in toxicity, including loss of activity.