Microbial antitumor drugs: natural products of microbial origin as anticancer agents.

This review discusses the role of microbial secondary metabolites produced by organisms from all three domains of life (the Archaea, Prokarya and Eukarya) as sources of pure natural products or derivatives of natural products, and as leads for novel synthetic compounds that may have the potential to ameliorate cancer. Drugs for which a microbe has either been identified as the producer of the active component or has been associated with its production based on circumstantial evidence are discussed. In addition, the impact of the increase in available genomic information and manipulation is discussed, along with some relevant examples, leading to the realization that the potential of microbes as sources of new leads/agents or as biological probes is large.