Marine Drug Discovery Home

The Center for Marine Biomedical and Biotechnology Research at Harbor Branch Oceanographic Institute has an extensive collection of frozen invertebrates which are used for marine natural products drug discovery research. These samples have been collected primarily through the use of the Institute’s research vessel, The R/V Seward Johnson and the Johnson-Sea-Links I and II human occupied submersibles. The wide diversity of marine habitats which have been sampled include: deep continental and island slopes; deep and shallow reefs; coral banks and walls; rhodolith banks; caves; grass beds; oyster and mussel beds; kelp forests; mangrove lagoons, inland salt lakes; shipwrecks; pilings and jetties.

Two strategies have been used in collecting specimens for drug discovery research. The first is to maximize taxonomic diversity. In this process, an emphasis is placed on collecting specimens which are related, but different, from those which are known to have bioactive natural products. The second emphasis is to evaluate ecological factors such as consumer pressure, growth form (e.g. thin encrusting vs. massive), level of resource competition, presence or absence of biofouling, etc. and relate this to expression of secondary metabolism. For instance, we have observed a higher percentage of cytotoxic active agents in thin encrusting sponges. One possible role for these compounds may be to allow for continued colonization of relatively large surface areas. We have also observed a greater percentage of active compounds in invertebrate consortia (e.g. where two invertebrates grow in association). For example, the sponges Spongosorites sp. and Thrombus sp. are in almost all instances found in association with Vermetid molluscs and both possess potent bioactive compounds. Interestingly, we have also observed that organisms which are conspicuously colored and live in habitats with limited or no ambient light often possess interesting secondary metabolites (Dercitus sp. and Spongosorites sp.). Such organisms are also targeted for collection.

Secondary metabolites from these organisms have been isolated by our natural products chemistry group. The HBOI Pure Compound Library consists of approximately 150 pure marine natural products that have been discovered at HBOI. Some of the compounds are already known to be potent cytotoxic agents while others have not been fully characterized as to their biological properties. The HBOI peak library currently consists of approximately 2500 materials.