Briaexcavatolides X–Z, three new briarane-related derivatives from the gorgonian coral Briareum excavatum

Three new polyoxygenated briarane-type diterpenoids, briaexcavatolides X–Z (), have been isolated from the gorgonian coral Briareum excavatum. The structures, including the relative configurations of briaranes , were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The configuration of briarane was further supported by molecular mechanics calculations.