Two new spongian diterpene analogues isolated from the marine sponge sp.

Two new marine natural compounds, 3β-acetoxy-15-hydroxyspongia-12-en () and 3-methylspongia-3,12-dien-16-one (), were isolated from the marine sponge sp., collected in Pulau-Pulau. Compounds and represent new chemical entities of the known spongian diterpene family. Compound is a new 3-acetoxyspongia and compound presents an unreported rearranged 3-methylspongia-3-en. Their structures, including relative configurations, were fully elucidated based on 1D and 2D NMR analyses, as well as HRESTOFMS experiments. No significant bioactivities were found for these compounds. This work reports two new chemical structures, compounds and , together with the first isolation of spongian diterpenes from genus.