ABSTRACT
Alkaloids are nitrogenous secondary metabolites found in plants. Pyrrolidine alkaloids are abundant in the plant kingdom. It has been estimated that about 3% of all plants contain such alkaloids. Many pyrrolizidine alkaloids are carcinogenic. These include alkaloids from plants that are widely consumed, such as those of the Senecio, Petasites, Tussilago, Crotalaria, and Symphytum genera. Alkaloid-containing plants are frequently taken as medicines or herbs or for their psychoactive effects. The most widely consumed alkaloids worldwide are, without a doubt, the methylxanthines. Perhaps the best-known examples of alkaloidal contamination of food come from the epidemics of ergotism that ravaged Europe at intervals throughout the Middle Ages. Alkaloids of therapeutic importance include morphine, vincristine, vinblastine, quinine, atropine, cocaine, pilocarpine, reserpine, colchicine, and a host of others. Accidental exposure to alkaloids can occur because of food contamination; because an alkaloid-containing plant was taken deliberately without the consumer being aware of the danger, or because a misidentified plant was consumed.
