The active constituents of plants have only relatively recently been isolated. The active constituents in plants are the chemicals that have a medicinal effect on the body. These are the active ingredients of the plant, the chemicals that have a marked, definable physiological and therefore, possibly medical activity upon the body. These constituents and their actions within the body are also referred to as their pharmacology. They have been divided into 16 main groups: Alkaloids, Anthocyanins, Anthraquinones, Cardiac Glycosides, Coumarins, Cyanogenic Glycosides, Flavonoids, Glucosilinates, Phenols, Saponins, and Tannins