Bioorganic studies on marine natural products--diverse chemical structures and bioactivities.

The discovery of new molecules contributes to the development of basic scientific concepts, leads to valuable drug-oriented compounds, and suggests possible new pharmacological reagents. Newly discovered substances can even be responsible for the creation of new scientific fields. Due to the radically different habitats of marine organisms, several notable examples of secondary metabolites from marine organisms have been isolated. Two of the most remarkable properties of these compounds are their structural and physiological diversities. These bioactive compounds are candidates for drugs or biological probes for physiological studies. Palytoxin is a polyol compound that shows extreme acute toxicity. Halichondrins are remarkable antitumor macrolides from sponge. Pinnatoxins, potent shellfish poisons, cause food poisoning. This paper describes bioorganic studies on such newly discovered wonders of nature. Several bioactive marine alkaloids and important substances involved in dynamic ecological systems are also described. Copyright (c) 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.