| Section2 = }} Lanthionine is a nonproteinogenic amino acid with the chemical formula (HOOC-CH(NH2)-CH2-S-CH2-CH(NH2)-COOH). As the monosulfide analog of cystine, lanthionine is composed of two alanine residues that are crosslinked on their β-carbon atoms by a thioether linkage. Background In 1941, lanthionine was first isolated from the treatment of wool with sodium carbonate and was first synthesized from cysteine and β-chloroalanine. Lanthionines are found widely in nature and… (More on Lanthionine)