ABSTRACT
Secondary metabolites are produced when the rapid growth of the culture is completed. These have no obvious function in the growth of the producing organisms and often are produced as a family of structurally related compounds. Fungi are exceptionally prolific producers of secondary metabolites. It has been speculated that these compounds give some form of selective advantage to the producing organism in nature. The evidence in support of this hypothesis comes from the fact that the secondary metabolites possess wide range of biological activities. The secondary metabolites produced by fungi include antibiotics such as penicillins [1] and cephalosporins; the antifungals echinocandins [2,3] and pneumocandins [4]; cholesterol-lowering agents like lovastatin [5] and mevastatin [6]; the immunosuppressive agent cyclosporin [7]; alkaloids such as lysergic acid, ergotamine, and bromocriptine [8]; toxins like aflatoxin [9] and paraherquamide [10]; and asperlicin [11], a nonpeptide potent specific inhibitor of neurotransmitter cholecystokinin. Interestingly, mevastatin [12] and cyclosporin [13] were originally isolated as antifungal agents and paraherquamide was later shown to have anthelmintic activity [14]. For more discussion on secondary metabolites, see Chapter 1.
