Chapter 9 - Bioactive Natural Products from Marine-Derived Fungi: An Update

Abstract

Abstract In the search for novel and bioactive molecules for drug discovery, marine-derived natural resources are becoming an important research area. The worldwide marine pharmaceutical pipeline consists of three FDA-approved drugs namely cytarabine, vidarabine, and ziconotide, whereas, the current clinical pipeline includes 13 marine-derived compounds that are either in Phase I, Phase II, or Phase III clinical trials. On the other hand the preclinical pipeline continues to feed to clinical pipeline hundreds of novel marine-derived compounds [1]. Terrestrial sources have been intensively investigated for their metabolites, and even marine bacteria offered a considerable number of bioactive natural products. The reason behind the marine-fungi producing diverse metabolites is that these organisms inhabit severe marine environment of high pressure with low nutrients, low temperature, high salt concentration, and absence of light, which is obviously different from the conditions on earth's surface. Therefore, to compete in this environment, it is possible for marine fungi to produce unique secondary metabolites [2,3]. Until 2005, nearly 35 drugs that originated from fungi were identified being used as antibacterial, immunosuppressive, and other therapeutic agents [1,4]. Further, it is important to mention about the discovery of antibacterial drug cephalosporin C, which was originally isolated from the marine fungus Cephalosporium acremonium [5]. Despite the discovery of such important drugs from fungi, the number of bioactive natural products originated from marine fungi increased extremely slowly for long time. It is only during last decade that researchers have focused on marine-derived fungi to search for novel bioactive secondary metabolites that could potentially be used as drugs. Currently, hundreds of structurally unique and biologically active compounds have been reported from marine fungi [6,7]. The purpose to write a chapter on the topic above is to highlight the products of this wonderful natural machinery and to provide a comprehensive data on the reported bioactive compounds of marine-derived fungi, which may help the researchers to develop potential drugs. This chapter comprehensively describes the isolation, characterization, and biological studies of more than 500 substances from marine-derived fungi, published during a period of 7 years, that is, 2006–2012.