Molecular Aspects of Fungal Bioactive Polyketides

Abstract

Secondary metabolites often have obscure or unknown functions in organisms but have considerable importance for mankind due to their broad range of useful antibiotic, pharmaceutical as well as toxic activities (Yu and Keller 2005). The products of fungal metabolic pathways include important pharmaceuticals such as Penicillin, cyclosporine and statins, as well as potent poisons including aatoxins (e.g., aatoxin B1) and trichothecenes (Keller et al. 2005). Harold Raistrick was the rst to initiate systematic study of fungal secondary metabolites in 1922 and was successful in characterizing more than 200 fungal metabolites (Keller et al. 2005). However, the major breakthrough in fungal metabolite research was achieved in 1929, when the rst broad-spectrum antibiotic Penicillin was discovered from fungus Penicillium notatum (alias Penicillium chrysogenum) by Alexander Fleming (Fleming 1929, Bennett 2001). The discovery of Penicillin and its clinical use initiated extensive screening programs for microbial bioactive metabolites (Keller et al. 2005). More than half of the molecules isolated and characterized between 1993 and 2001 show antibacterial, antifungal, or antitumour activity (Pelaez 2005), thereby illustrating that natural products are the most important source of anticancer and anti-infective agents (Da Rocha et al. 2001).