Marine natural products, with their unique chemical features and pronounced biological activities, have recently provided "lead structures" in the search for new drugs and agrochemicals. The influence on the bioactivity of the size, shape, and degree of ionization of a molecule is afforded by the investigation of the various derivatives of the parent molecule and allows the development of novel drugs or agrochemicals with increased potency, greater selectivity, increased stability, and low toxicity. In this chapter, a rationale of the structure-activity relationships of various series of bioactive secondary metabolites from Indo-Pacific marine invertebrates is reviewed. These include alkaloids, terpenes and polybrominated diphenyl ethers which were subjected to a series of bioassays in search for insecticidal, antibacterial, fungicidal, and cytotoxic lead compounds. From these various biotests, it was observed that the bioactivity of an analogue is not due to general toxicity but rather possesses a degree of specificity on a particular target biomolecule. The relationship between chemical structures and biological activity is related to the specific action of a compound.
- marine natural products
- bioactive metabolites
- Indo-Pacific marine invertebrates