Australin E Isolated from the Soft Coral Cladiella sp Collected in Pohnpei Activates the Inositol 5-Phosphatase SHIP1

Four new diterpenoids, australins E-H (1-4), have been isolated from the marine soft coral Cladiella sp. collected in Pohnpei. The structures of 1-4 were elucidated by analysis of their NMR and mass spectrometry data combined with an X-ray diffraction analysis of australin E (1). Australin E (1) activates the inositol 5-phosphatase SHIP1 in vitro.