Marine alkaloids. Part 4. A formamide, flustrabromine, from the marine bryozoan Flustra foliacea

Abstract

The isolation and structure elucidation of a marine alkaloid from the bryozoan Flustra foliacea is described. The alkaloid, 6-bromo-2-(1,1-dimethylallyl)-N^b-formyl-N^b-methyltryptamine (1), has been shown to consist of two rotameric forms reflecting hindered rotation around the carbon–nitrogen bond of the formamide function. Further-more, each rotamer exists in equilibrium with an intramolecularly associated form where the amide nitrogen is associated with the aromatic system.