High Quality Content by WIKIPEDIA articles! Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) or 5-hydroxynaphthoquinone, is an organic compound with the molecular formula C10H6O3. In the food industry, juglone is also known as C.I. Natural Brown 7 and C.I. 75500. Other names in industry are Nucin, Regianin, NCI 2323, and Oil Red BS.