Chemical defensive substances of soft corals and gorgonians

Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.