Waiakeamide, a Cyclic Hexapeptide from the Sponge Ircinia dendroides¹

Abstract

From the sponge, Ircinia dendroides, collected in Indonesia we isolated a new cyclic hexapeptide, waiakeamide (1). Its structure, consisting of three proline residues, two methionine sulfoxides, and one thiazolylphenylalanine, was elucidated by spectral analysis and chemical degradation. Isolation and structural elucidation of waiakeamide is described. Investigation of an Indonesian collection of I. dendroides yielded a new cyclic hexapeptide, waiakeamide (1). Its structure, encompassing three proline residues, two methionine sulfoxides, and one thiazolylphenylalanine, was elucidated by spectral analysis and chemical degradation.