Is an α-amino acid that is used in the biosynthesis of proteins. As an essential amino acid, it is not synthesized in animals, hence it must be ingested as lysine or lysine-containing proteins. In plants and most bacteria, it is synthesized from aspartic acid (aspartate) It is a precursor for piperidine. Responsible for bitter principles in lupine (legume family) In lycopodium, is a widely used homeopathic medicine for the liver, urinary and digestive disorders