Dactylallene: a novel dietary C15 bromoallene from the Atlantic anaspidean mollusc Aplysia dactylomela

A new C-15 bromoallene, dactylallene (1), was isolated from the digestive gland of the anaspidean mollusc Aplysia dactylomela. The structure was established by using mainly mono and bidimensional NMR techniques, whereas the absolute stereochemistry was determined by X-ray diffractometric analysis. Ichthyotoxicity and antifeedant-activity suggest a defensive role of 1 against predators.