Motobamide, an Antitrypanosomal Cyclic Peptide from a sp. Marine Cyanobacterium.

Motobamide (), a new cyclic peptide containing a -prenylated cyclotryptophan residue, was isolated from a marine sp. cyanobacterium. Its planar structure was established by spectroscopic and MS/MS analyses. The absolute configuration was elucidated based on a combination of chemical degradations, chiral-phase HPLC analyses, spectroscopic analyses, and computational chemistry. Motobamide () moderately inhibited the growth of bloodstream forms of (IC 2.3 μM). However, it exhibited a weaker cytotoxicity against normal human cells (IC 55 μM).