Anticancer Compounds from Marine Microorganisms

Abstract

Since the discovery of penicillin from fungus by Alexander Fleming in 1928, scientists have been seeking to isolate pharmaceutical agents from terrestrial microorganisms. While more than 100 blockbuster drugs have been derived from terrestrial microorganisms, the rate for new drug discovery has decreased. Thus, it is crucial that new groups of microorganisms from unexplored or underexploited habitats be pursued as sources of novel bioactive metabolites. Despite covering 70% of the Earth’s surface, the oceans have been largely ignored as a source of biomedical potential. As part of our ongoing program to develop the biomedical potential of marine microorganisms, we have focused considerable attention on the marine actinomycetes. As marine environmental conditions are extremely different from terrestrial ones, it is surmised that marine actinomycetes have different characteristics from those of terrestrial counterparts and, therefore, might produce different types of bioactive compounds. We isolated more than 3,000 strains of marine actinomycetes from the marine samples such as deep sea and shallow water sediments, plants and invertebrates. We have established that about 10% of isolates show some bioactivity in our assays such as cytotoxicity, antifungal, antimicrobial, and enzyme inhibitory activities. From the bioactive isolates several new actinomycetes have been identified and a variety of bioactive molecules were characterized. We present here the discovery of anticancer compounds from marine microorganisms, especially marine-derived actinomycetes. The isolation, structure determination, and anticancer activities of the compounds from marine actinomycetes will be the focus of this presentation.