A new phenyl ethanone (1-[4-(1,4-diamino-heptyl)-phenyl]-ethanone (1))and two known sterols (stigmasterol (2) and β–sitosterol (3))were succesfully isolated from methanolic extract of Acanthaster planci collected from the East Coast of Peninsular Malaysia. The chemical structures of compounds 1-3 were deduced on the basis of extensive spectral data (1D and 2D NMR), MS and IR spectroscopy techniques; as well as in comparison the data with those reported in the literature.Compounds 1-3were not toxic towards HepG2 cells and displayed as a potential peroxissome proliferator activated receptor (PPAR) ligand.