Androsamide, a Cyclic Tetrapeptide from a Marine Nocardiopsis sp., Suppresses Motility of Colorectal Cancer Cells.

A cyclic tetrapeptide, androsamide (1), was isolated from a marine actinomycete of the genus Nocardiopsis, strain CNT-189. The planar structure of 1 was assigned by the interpretation of 1D and 2D NMR spectroscopic data. The absolute configurations of constituent amino acids of 1 were determined by application of the Marfey's and advanced Marfey's methods. Androsamide (1) strongly suppressed the motility of Caco2 cells caused by epithelial-mesenchymal transition.