The marine animal commonly known as the "firefoms" is dangerous for humans because if they are carelessly handled with bare hands, serious dermatitis results. However the toxic substance of these animals has remained unknown in a long while. We isolated as a novel amphipathic substance, named complanine, from an amphinomid polycheates, Eurythoe complanata. The structure of complanine was spectroscopically revealed to be a trimethylammonium with an unsaturated carbon chain. The total synthesis of (-)-complanine was also accomplished by a synthon approach, by using a chiral malic acid as a starting material. The stereochemistry of this molecule was determined to have an R configuration. Syntheses of the related compounds, neocomplanines, were also achieved. From a biological point of view, complanine enhanced PKC activity in combination with TPA in the presence of Ca^<2+> in vitro; this result suggest that it could bind PKC at the same site as phosphatidylserine. This may explain the molecular mechanism behind its inflammation-inducing activity.
