Treasures from the Sea: Discovery and Total Synthesis of Ammosamides

Out of the blue : Ammosamides A ( 1 ) and B ( 2 ) were isolated from a marine streptomycete collected at a depth of more than 1600 m. By employing a blue‐fluorescent diaminocoumarin conjugate of 2 (see structure), myosin was identified as a cellular target of these antiproliferative natural products. The total synthesis of 1 and 2 has now been completed, thus allowing further elaboration of the chemical biology of these fascinating compounds.