ABSTRACT
The natural world is particularly rich in potential lead compounds. Folk medicine and the records of ancient civilizations often give useful hints about which plants are most likely to contain useful lead compounds. The venoms of snakes and spiders have been particularly useful as lead compounds. Lead compounds obtained from microorganisms have also been useful in other fields of medicine. Another example is the fungal metabolite lovastatin, which was the lead compound for a series of drugs that lower cholesterol levels. CC-1065 is too toxic to be used itself, but it has been used as a lead compound for other anticancer agents. The natural agonists for receptors can be used as lead compounds for synthetic agonists that may demonstrate greater selectivity between receptor types and subtypes than the natural ligand. Furthermore, the active compounds are often highly complex in structure making them difficult to synthesize.
