WHY ARE THERE MEDICINAL CHEMICALS IN PLANTS?
The chemicals from plants that have medicinal value are called phytochemicals. These are part of a class of chemicals produced by plants that are known as secondary metabolites. They are chemicals not essential to the ordinary life activities of the plant, such as photosynthesis. Secondary metabolites are probably defensive in nature. Since plants are stationary, they engage in ‘chemical warfare’ in order to survive. Penicillin, produced by a mold, wards off predators. We have adapted it for medicinal use. Richard Schulteis, the father of modern ethnobotany has said that “plants live by their chemical wits.” The largest groups of phytochemicals are the alkaloids. These include caffeine, nicotine, and cocaine from the coca leaf. Their discovery by aboriginal peoples was probably by trial and error. It was usual for an aboriginal practitioner in the Americas or Australia to be familiar with more than 150 different medicinal plants in his/her realm. ….. III. TOTEMS AND SYMBOLS Virtually