Sesquiterpenoid quinone isolated from the marine sponge, Hippiospongia metachromia; naturally occurring as ()-form. Inhibits cellular secretions by selective breakdown of the Golgi apparatus. Isoln and structure determn: R. T. Luibrand et al., Tetrahedron 35, 609 (1979). Revised stereochemistry: R. J. Capon, J. K. MacLeod, J. Org. Chem. 52, 5059 (1987). Total stereosynthesis: S. D. Bruner et al., ibid. 60, 1114 (1995); increased yield: S. Poigny et al., ibid. 63, 5890 (1998). Photoaffinity study on cellular targets: H. S. Radeke, M. N. L. Snapper, Bioorg. Med. Chem. 6, 1227 (1998). Mechanism of action studies: P. A. Takizawa et al., Cell 73, 1079 (1993); H. S. Radeke et al., Chem. Biol. 6, 639 (1999). Use as inhibitor of protein secretion: P. A. Feldman et al., J. Membr. Biol. 155, 275 (1997).