New acetogenin katsuurallene from Laurencia saitoicollected from Katsuura, Japan

We examined the chemical constitution of the red alga Laurencia saitoiPerestenko, collected from Katsuura, Boso Peninsula, Chiba Prefecture, Japan. This specimen produced a new polyhalogenated acetogenin, named katsuurallene (1), which structure was determined by the spectral methods, along with known diterpene, deoxyparguerol (2) and triterpene, thyrsiferol (3). In this paper we describe the structural elucidation of katsuurallene together with some biological activities.