Marine natural products: potentiality and challenge in drug discovery

Natural products have historically played a major role in the pharmaceutical industry, either directly as drug substances or as inspiration for synthesis or semi-synthesis of novel analogues. Natural products have significant advantages compared to libraries of conventional synthetic molecules, characterized by enormous scaffold diversity and structural complexity that have been ‘optimised’ by evolution to function in biological systems. The marine environment is extremely multiform, representing an important source of diversity and an enormous reserve of new bioactive compounds. The chemistry of these molecules is a challenge considering their structural novelty and complexity, however increasing attentions are drawn in understanding their biological activity, aiming to explore their potential application in various areas of biomedicine. In the search for novel metabolites from marine sources, the combination of isolation procedures, dereplication step, MS- and bioassay-guided isolation, represent a useful approach for the discovery of new bioactive natural products. Examples will include metabolites from marine invertebrates, mainly sponges, and microbial sources, such as fungi