Prodrug not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. Many herbal extracts historically used in medicine contain glycosides (sugar derivatives) of the active agent, which are hydrolyzed in the intestines to release the active and more bioavailable aglycone. For example, salicin is a β-D-glucopyranoside that is cleaved by esterases to release salicylic acid. Aspirin, acetylsalicylic acid, first made by Felix Hoffmann at Bayer in 1897, is a synthetic prodrug of salicylic acid. However, in other cases, such as codeine and morphine,
Ellagic acid heart disease, and other medical problems. Ellagic acid has been identified by the U.S. Food and Drug Administration as a "fake cancer 'cure' consumers should avoid". A number of U.S.-based sellers of dietary supplements have received Warning Letters from the Food and Drug Administration for promoting ellagic acid with claims that violate the Federal Food, Drug, and Cosmetic Act. Urolithins, such as urolithin A, are microflora human metabolites of dietary ellagic acid derivatives that are under study as anti-cancer agents. Claims that ellagic acid can treat or prevent cancer in humans have not been proven. Ellagic acid Ellagic acid is