Paltolides A-C, Anabaenopeptin-Type Peptides from the Palau Sponge Theonella swinhoei

Three new anabacnopeptin-like peptides, named paltolides A-C, were isolated from a deep-water specimen of the marine sponge Theonella swinhoei from Palau. Paltolides belong to a rare subgroup of sponge-derived anabaenopeptins, that have in common a C-terminal tryptophan residue linked 10 the epsilon-amine of' a lysine bearing, a i) configuration. The structures of paltolides A-C were determined by NMR and tandem MS techniques. Paltolide A is the first anabaenopeptin structures where a non-N-methylated amino acid precedes the C-terminal residue.