The present volume deals mainly with compounds which have been detected as natural microbial products. Part 1 of this volume introduces the general aspects of the overproduction of metabolites and the concepts and genetics of secondary metabolism. Compounds such as nucleosides, nucleotides, coenzymes, vitamins and lipids are dealt with in part 2. Part 3 then is devoted to products and antibiotics with uses im medicine, veterinary medicine, plant protection and metabolites with antitumor activity. Several secondary metabolites have found uses in human and animal health care. With 244 figs., 109 tabs.