Madagascar Vinblastine and Vincristine are two alkaloids isolated from Catharanthus roseus, the rosy periwinkle from Madagascar.
Alkaloids are a major class of natural products that have a physiological effect in other organisms.
They characteristically contain carbon, hydrogen, nitrogen, and in many cases, oxygen. Because of their potent pharmacological effects, alkaloids are the basis for many drugs. C. roseus is in the Apocynaceae family, which is composed of dicots, usually shrubs or herbs, that have either opposite or whorled entire leaves. An attractive plant, it is cultivated worldwide as an ornamental. In the 1950s, Eli Lilly and Company, while screening natural products in bioassays, discovered that a leaf extract from C. roseus could affect the progress of leukemia.