Myrmenaphthol A, Isolated from a Hawaiian Sponge of the Genus .

Four compounds (-) were isolated from a Hawaiian sponge of the genus . Myrmenaphthol A () incorporates two unusual elements into an oxidized steroidal core: a naphthyl AB-ring system and a hydroxy group at C-2. A comparison of the experimental and predicted electronic circular dichroism (ECD) spectra of assigned an configuration to the lone stereocenter (Δ = 0.75; similarity factor 0.8137). Known compounds, cinanthrenol A (), 3,4-dihydroxypregna-5,17-diene-10,2-carbolactone (), and 3,4-dihydroxypregna-5,20-diene-10,2-carbolactone (), were also isolated. Despite literature reports of competitive inhibition at nanomolar levels for , neither nor the structurally related showed any activity against estrogen receptors at the concentrations tested.