Impact of Natural Products on Developing New Anti-Cancer Agents

Plants have a long history of use in the treatment of cancer, and above 3,000 plant species have been identified that can be used against cancer. The first plant-derived agents to advance into clinical use was vinca alkaloids vinblastine and vincristine that were isolated from the Madagascar. Plants and sessile marine organisms release toxic substances that suppress the growth of neighboring species. The cell-to-cell signaling mechanism, known as quorum-sensing, exerted by bacteria to control their density of population growth and biofilm formation, involves the excretion of so-called quorum-sensing compounds. The toxic metabolite, rhizoxin,originally isolated from a rhizopus fungus contaminating rice seedlings, has actually been found to be produced by the endo-symbiotic bacterial species. It has significant implications in development of agents with improved pharmacological properties. Waldmann has developed a new concept for the design of combinatorial libraries based on natural products that is called BIOS.