New pentacyclic sesterterpenes, lintenolide A (2 a, b) and lintenolide B (3 a, b), have been characterized from the caribbean sponge Cacospongia cf. linteiformis. The structure elucidation of these compounds was accomplished by using 2D NMR experiments, including H-1-H-1 (COSY), H-1-C-13 (HETCORR and COLOC) and rotating frame NOE (ROESY). Compounds showed high ichthyotoxicity and antifeedant activity, which suggest their potential role as natural feeding deterrents.