Sponges are multicellular, heterotrophic parazoan organisms, characterized by the possession of unique feeding system among the animals. They are the most primitive types of animals in existence, featuring a cell-based organization where different cells have different tasks, but do not form tissues. Sponges (Porifera) are a predominantly marine phylum living from the intertidal to the abyssal (deepest ocean) zone. There are approximately 8500 described species of sponges worldwide with a prominent role in many reef coral communities. Several ecological studies reported have shown that secondary metabolites isolated from sponges often serve defensive purposes to protect them from threats such as predator attacks, biofouling, microbial infections, and overgrowth by other sessile organisms. In the recent years, interest in marine sponges has risen considerably due to presence of high number of interesting biologically active natural products. More than 5300 different natural products are known from sponges and their associated microorganisms, and every year hundreds of new substances are discovered. In addition to the unusual nucleosides, other classes of substances such as bioactive terpenes, sterols, fatty acids, alkaloids, cyclic peptides, peroxides, and amino acid derivatives (which are frequently halogenated) have been described from sponges or from their associated microorganisms. Many of these natural products from sponges have shown a wide range of pharmacological activities such as anticancer, antifungal, antiviral, anthelmintic, antiprotozoal, anti-inflammatory, immunosuppressive, neurosuppressive, and antifouling activities. This chapter covers extensive work published regarding new compounds isolated from marine sponges and biological activities associated with them.
Part of the book: Biological Resources of Water