a bitter, yellow alkaloid, CHNO·6HO or CHNO·6HO, obtained from barberry and other plants: it is used as a dye and as a drug in treating malaria, fever, or skin ulcers
See berberine in American Heritage Dictionary 4
(bûrˈbə-rēnˌ)
noun
A bitter-tasting yellow alkaloid, C20H19NO5, obtained from several plants such as goldenseal and having medical uses as an antipyretic and antibacterial agent.