The use of antibiotics in the treatment by antibacterial and antifungal chemo therapy, has become standard practice since the end of World War Two and has had an enormous impact on healthcare throughout the world. Compounds belonging to this class have also reached an important place in the medical treatment of human cancer. Although, the discovery of most of these agents came from more or less sophisticated screening programs of soil microrganisms, many of the important antibiotics used today in clinical practice are derived from the original biosynthetic products by the application of often...