Latrunculin,a new 2-thiazolidinone macrolide from the marine sponge latrunculia magnifica

Three new toxins were isolated from the Red Sea sponge $\text{Latrunculia magnifica}$ A full structure determination of these toxins, by spectroscopic methods, was aided by an X-ray diffraction analysis of a crystalline derivative ($\text{1}$b) of latrunculin-A. The Latrunculins exhibit a new class of 14 and 16 membered macrolides to which the rare 2-thiazolidinone moiety is attached. A biogenesis of these biologically active compounds is put forward.