Chapter 10 - Mushrooms: A Source of Exciting Bioactive Compounds

Abstract

Abstract Over several centuries, natural products being major molecular structural resources have played an important role for discovery of drugs. Aspirin the antipyretic and analgesic drug, taxol the anti-cancer drug, artemisinin the antimalarial drug, and huperzine A and tacrin the anti-Alzheimer's disease drugs together with many antibiotics and penicillins are the typical examples. A great number of the chemical structure novelties of natural products have been isolated and the chiral centers of these compounds are advantageous as most of the natural products occur as single enantiomers; and only one of the enantiomers of many chiral drugs are active for their biological activity. Statistical data demonstrate that the origins of half of the drugs approved were natural products between 1994 and 2007. In 2008, however, 225 new drugs from the natural products were developed and almost 38% and 18% of them are used as anticancer and anti-infective drugs, respectively. In the past century, almost 200,000 natural compounds have been obtained from various natural products and some of them are used as natural drugs. Recently, the discovery or synthesis of new biologically active compounds has increasingly become difficult. At this time, interest in mushrooms as a potential source of bioactive compounds has occurred and much research investigating bioactivity has been investigated in the last two decades in detail. Up to date, lectins, polysaccharides, polysaccharide-protein complexes, polysaccharide-peptides, lanostane-type triterpenoids, phenolic, and flavonoid-structured compounds indicating anticancer, antioxidant, antitumour, antiviral, antibacterial, antifungal, anti-inflammatory, anti-imunomodulatory activities have been isolated from the mushroom species. Recently, mushrooms have been especially used as immunomodulators and antitumor agents. Medicinal mushrooms are the sources of polysaccharides that prevent the cancer and increase the strength of the immune system. Since the treatment of all types of cancers diseases has challenges, mushrooms may become very important source of drugs for modern medicine to find cures particularly for the cancer diseases. The published papers on mushroom species studied for their chemistry together with their biological activities in the last two decades were evaluated in this chapter. Particularly, the studies comprise the last decade. Briefly, polysaccharides, terpenoids, steroids, phenolics, and alkaloids isolated from the mushroom species are discussed together with their biological activities.