生物碱

Alkaloids are a diverse class of compounds, often containing a basic nitrogen atom, which are produced by a large variety of organisms including bacteria, fungi, plants and animals.  The boundary between alkaloids and other nitrogen-containing natural compounds is not always clear-cut and the role of alkaloids in living organisms is often unclear, but most relate to a protective function. Many alkaloids and their derivatives have historically been used in medicine, agriculture and as psychoactive substances.