Dysidiolide: a novel protein phosphatase inhibitor from the Caribbean sponge Dysidea etheria de Laubenfels

A novel cdc25A inhibitor was isolated from the marine sponge Dysidea etheria de Laubenfels as the search for new protein phosphatase inhibitors from marine organisms continues. Named dysidiolide, the inhibitor is a sesterterpene gamma-hydroxybutenolide, whose structure represents an unusual cyclization of a C(sub 25) isoprenoid. Dysidiolide inhibited the dephosphorylation of p-nitrophenol phosphate by cdc25A with an IC(sub 50) of 9.4 (mu)M. This represents the first account of a cdc25A active compound isolated from a natural source.