Two new luffarin derivatives from the Adriatic Sea sponge Fasciospongia cavernosa

Together with the known luffarin V and 6Z-luffarin V, two new sesterterpenes (1a and 2), related to luffarins have been isolated from the sponge Fasciospongia cavernosa, collected in the Northern Adriatic Sea. The structures of the new compounds were proposed on the basis of spectroscopic data. The absolute stereochemistry of compound 1a was determined by application of Mosher's method.