Research progress on chemical defensive substances from soft corals (Sinularia flexibilis) and Gorgonians (Plexaura homomalla) Diterpenoids from a kind of soft coral Lobophytum sp. Chemical constituents from Xisha soft coral Lobophytum sp. Research progress on cembranoid type ring diterpenes Studies on the Chemical Constituents of the Soft Coral (Clavularia inflata Scheuk var. luzoniana)