Shark repellent lipophilic constituents in the defense secretion of the Moses sole (Pardachirus marmoratus).

The defense secretion of Moses sole (Pardachirus marmoratus), the fish known to repel sharks, contains lipophilic ichthyotoxins in addition to pardaxin, a peptidic ichthyotoxin. Pardaxin has previously been regarded as the only factor responsible for the shark repellency of the secretion. On the basis of the shark repellent activity observed with the lipophile, it is considered to participate in the repellency of the secretion. Further separation of the toxic lipophile yielded five steroid monoglycosides, named mosesins. Their structures have been elucidated by nuclear magnetic resonance spectroscopy and corroborated by correlating them spectroscopically or chemically to cholic acid or to pavoninins, the related glycosides isolated from the secretion of the congeneric peacock sole, P. pavoninus.