New C21 Δ20 pregnanes, inhibitors of mitochondrial respiratory chain, from Indopacific octocoral Carijoa sp.

Two new compounds, pregnanes 1 and 2, the known pregnane 3 and a series of known chlorinated prostanoids (4–9) have been isolated from the Indian octocoral Carijoa sp. Their structures have been elucidated by spectroscopic methods, mainly by 1D and 2D NMR. The new compounds were potent inhibitors of the mitochondrial respiratory chain.