PREUPLOTIN, A PUTATIVE BIOGENETIC PRECURSOR OF THE EUPLOTINS, BIOACTIVE SESQUITERPENOIDS OF THE MARINE CILIATED PROTIST EUPLOTES-CRASSUS

Strains of the marine ciliated protist Euplotes crassus typically cont ain preuplotin oxymethylene)hex-5-enylidene]-6-methylhept-5-enal} 4. T his represents the C-12 deprenyl analogue of udoteal, the feeding-dete rrent of tropical seaweeds of the genus Udotea. Euplotes crassus typic ally contains also the O-cyclized form euplotin C 3 which may bethough t to descend biogenetically from preuplotin together with euplotins A and B previously isolated from highly-productive strains of this cilia te as likely adjuvant factors of its adaptive radiation.