Structure–activity relationship studies of gymnocin-A

The structural elements required for cytotoxicity of gymnocin-A, a polycyclic ether isolated from the red tide-forming dinoflagellate, Karenia mikimotoi, were investigated by the total synthesis and evaluation of the structural analogues. The results of the structure–activity relationship studies indicated that the α,β-unsaturated aldehyde functionality of the side chain as well as the molecular length were needed for exhibiting the cytotoxicity of gymnocin-A.