ISOLATING BIOACTIVE COMPOUNDS FROM MARINE ORGANISMS

The strategies used for isolation and structural elucidation of pharma cologically active metabolites from marine organisms are discussed, wi th examples of cytotoxic and antihistaminic compounds from marine equi noderms, sponges, gorgonians, ascidians, and tunicates from the author 's laboratory. Special attention will be paid to isolation procedures adapted to the physical and chemical characteristics of the compounds isolated, particularly to their polarity and lipo-or hydrophilic chara cter. Examples of isolation from water-soluble material of highly pola r metabolites such as saponins, polyhydroxysteroids, alkaloids, and am ino acids will be presented. Sesquiterpene quinones, polypropionates, peptides, and depsipeptides from the extracts of medium or low polarit y are also described. The relevance of recent spectroscopic techniques -especially exhaustive 2D NMR and MS analysis-in the structural elucid ation of complex structures and the usefulness of new reagents for the assignment of absolute configuration by H-1 NMR are presented.