The isolation, structure elucidation, biological activities, total synthesis, and biosynthesis of the marine prostanoids such as clavulones, chlorovulones and punaglandins are described. These marine prostanoids have unique structural features and show strong antileukemic activities. Owing to their biosynthetic route which is different from those of the mammalian prostaglandins, the marine prostanoids are recognized as a new series of arachidonic acid cascade.
