There are several examples of marine
organisms whose metabolic
profiles differ among conspecifics inhabiting the same region. We
have analyzed the metabolic profile of each colony of a Theonella
swinhoei marine sponge with a yellow interior and noticed
the patchy distribution of one metabolite. This compound was isolated
and its structure was studied by a combination of spectrometric analyses
and chemical degradation, showing it to be a congener in the theonellamide
class of bicyclic peptides. Theonellamides had previously been isolated
by us only from T. swinhoei with a white interior
and not from those with a yellow interior.