New bromoterpenes from the red alga Laurencia luzonensis.

Extraction of a sample of Laurencia luzonensis collected off the coast of Kudaka Island, Okinawa, yielded the known sesquiterpenes palisol (1), palisadin B (2), palisadin A (3), pacifigorgiol (4), and aplysistatin (5), together with five new bromosesquiterpenes, isopalisol (6), luzonensol (7), luzonensol acetate (8), luzonensin (9), and (3Z,6E)-1-bromo-2-hydroxy-3,7,11-trimethyldodeca-3,6,10-triene (10). In addition, a new bromoditerpene of unusual structure, 3-bromobarekoxide (11), possessing a seven-membered ring fused to trans-decalin, was isolated.