Wainunuamide, a histidine-containing proline-rich cyclic heptapeptide isolated from the Fijian marine sponge Stylotella aurantium

The isolation and Structure determination of an unusual cyclic heptapeptide. wainunuamide, from a Fijian marine sponge, Stylotella aurantium, is reported. The peptide contains three proline residues and a histidine residue, which is rare in cyclic peptides and has only Previously been reported in a cyclic peptide isolated from the cyanobacterium Oscillatoria agardhii, suggesting a possible source of the peptide. Wainunuamide is found to have weak cytotoxic activity. (C) 2001 Elsevier Science Ltd. All rights reserved.