Plants as Sources of Drugs

Plants have a historically important role as sources of prescription drugs in western medicine, and their active principles also serve as templates for synthetic drug optimization and provide intermediates that are used in the production of semi-synthetic drugs. Worldwide, hundreds of higher plants are cultivated for substances useful in medicine and pharmacy. Although the anticancer agent taxol (paclitaxel) is the first naturally occurring plant-derived drug to have gained the approval of the U.S. Food and Drug Administration for more than 25 years, analogs of other plant constituents such as artemisinin, camptothecin, and forskolin are currently under development for drug use in western medicine. Another recent development has occurred in Western Europe, where there is currently a well-developed phytomedicinal market, with extractives of many plants being used for therapeutic purposes. An underlying concern with the production of plant-derived drugs is the question of supply, which must be stable and reliable, and frequently necessitates cultivation rather than collection in the wild. Information on the cultivation, constituents, and therapeutic uses of two examples of important medicinal plants (Panax ginseng; Korean ginseng and Ginkgo biloba; Ginkgo) will be provided in this chapter.