Palinurin,a new linear sesterterpene from a marine sponge

Summary The structure of a new linear sesterterpene, palinurin (1), obtained from the marine spongeIrcinia variabilis, was determined by spectral and chemical means.This work was carried out at the Progetto Finalizzato Oceanografia e Fondi Marini, C.N.R., Roma. We thank Professor M. Sarà (University of Genova) for the identification of the sponge, Mr C. Di Pinto for¹H-and¹³C-NMR, Mr G. Scognamiglio for technical assistance.