Amygalin (from Greek: ἀμυγδάλη, almond), C20H27NO11, also known as laevomandelonitrile or laetrile, is a glycoside initially isolated from the seeds of the tree Prunus dulcis, also known as bitter almonds, by Pierre-Jean Robiquet and A. F. Boutron-Charlard in 1803, and subsequently investigated by Liebig and Wöhler in 1830, and others. Several other related species in the genus of Prunus, including apricot (Prunus armeniaca), also contain amygdalin. Some sources claim Ernst T. Krebs was the discoverer of the substance, and Krebs is generally credited with popularizing it as a purported cancer cure and as "Vitamin B17."