Alkaloid

An alkaloid is a nitrogenous organic molecule that has a pharmacological effect on humans and other animals. Alkaloids are found in plants (e.g., in potatoes and tomatoes), animals (e.g., in shellfish) and fungi.

Even though many alkaloids are poisonous (such as strychnine or coniine), some are used in medicine as analgesics (pain relievers) or anaesthetics. Morphine, cocaine, atropine, caffeine, quinine, theophylline, and theobromine are also members of the alkaloid family.