Chemical variation in the tropical seaweed Stypopodium zonale (dictyotaceae)

Five separate collections of the tropical seaweed Stypopodium zonale were analysed for ten secondary metabolites using a combination of high performance liquid chromatography and proton nuclear magnetic resonance spectrometry. Shallow water populations from the Caribbean were found to possess similar metabolite profiles from year to year and from widely diverse locations. Stypopodium zonale from the South Pacific (Palau) contained similar structure types; however, the profile was qualitatively and quantitatively dissimilar to the Caribbean algae. A deep water Caribbean form of S. zonale was found to contain two metabolites, epitaondiol and 6a-desmethyl-6-acetylatomaric acid, not observed in the other extracts. This latter population is morphologically and anatomically distinct from the other S. zonale Caribbean populations.