Alkaloid

"The alkaloids are bitter-tasting, natural nitrogen-containing compounds found particularly in plants. The name is derived from their characteristic basic properties (alkali-like), which are induced by the lone electron pair of nitrogen. As with acyclic amines, the (Lewis) basic nature of the alkaloids, in con junction with their particular three-dimensional architecture, gives rise to often potent phys iological activity. We have already noted some examples of this behavior in the narcotics morphine and heroin, the psychoactive lysergic acid and LSD, and the antibiotic penicillins."