Pseudopterosin Biosynthesis: Aromatization of the Diterpene Cyclase Product, Elisabethatriene

Putative precursors in pseudopterosin biosynthesis, the hydrocarbons isoelisabethatriene (10) and erogorgiaene (11), have been identified from an extract of Pseudopterogorgia elisabethae collected in the Florida Keys. Biosynthetic experiments designed to test the utilization of these compounds in pseudopterosin production revealed that erogorgiaene is transformed to pseudopterosins A–D. Together with our previous data, it is now apparent that early steps in pseudopterosin biosynthesis involve the cyclization of geranylgeranyl diphosphate to elisabethatriene followed by the dehydrogenation and aromatization to erogorgiaene.