Raikovenal, a new sesquiterpenoid favouring adaptive radiation of the marine ciliate Euplotes raikovi, and its putative biogenetic precursor, preraikovenal

The new-skeleton sesquiterpenoid raikovenal 1a, isolated from the marine ciliate Euplotes raikovi and likely to originate biogenetically from co-existing preraikovenal 2a, can be seen to favour its adaptive radiation by selectively killing the predacious ciliate Litonotus Iamella.