Colonial Zoanthid, alkaloids from

Our group in Pakistan has also isolated an alkaloid zoanthaminone (10) C30H39NO6, [a]D 30° (CHCI3), (M+) m/z 509.2882, by extensive solvent-solvent fractionation of the ethanolic extract of a colonial zoanthid collected from the intertidal rocks of the Karachi coast. The structure of the alkaloid was solved by single-crystal X-ray diffraction analysis and was found to be a C-ll keto analog of zoanthamine (5) (23). 

C. Alkaloids of Unknown Biosynthetic Origin from a Colonial Zoanthid. 237... 

Chemical investigations on a new species of a colonial zoanthid of the genus Zoanthus collected in the Bay of Bengal and from the Karachi coast of the Arabian Ocean have resulted in the isolation of a new class of alkaloids of unknown biosynthetic origin. The colonial zoanthids occur as dense mats on intertidal rocks along the coast of the Indian subcontinent. The animals can eject jets of water when they are disturbed. If the spray comes in contact with a victim s eyes, it causes tears followed by prolonged redness and pain. 

Alkaloids from colonial zoanthids such as zoanthamine, zoanthamide, 28-deoxyzoanthenamine, and others form a new class of alkaloids of unknown biosynthetic origin, although some structural features suggest a triterpenoid origin (20-23). 

Alkaloids isolated from an unidentified colonial zoanthid have also exhibited interesting biological activities. Zoanthamine (5), zoanthenamine (6), zoanthamide (7), and 28-deoxyzoanthenamine (8) possess inhibitory activity in the phorbol myristate acetate (PMA)-induced mouse ear inflammation assay, as well as analgesic activity (22). Zoanthamine (5) also exhibited strong nematicidal activity against the root-knot nematode (Meloidogyne javanica) and antibacterial activity (41). 

---