Juglone

Juglone

Names
IUPAC name 5-Hydroxy-1,4-naphthalenedione
Other names 5-Hydroxy-1,4-naphthoquinone 5-Hydroxy-p-naphthoquinone Regianin 5-Hydroxynaphthoquinone Nucin NCI 2323 Oil Red BS C.I. Natural Brown 7
Identifiers
CAS Number	481-39-0 Y
3D model (Jmol)	Interactive image
ChemSpider	3674 N
ECHA InfoCard	100.006.880
PubChem CID	3806
RTECS number	QJ5775000
UNII	W6Q80SK9L6 Y
InChI InChI=1S/C10H6O3/c11-7-4-5-9(13)10-6(7)2-1-3-8(10)12/h1-5,12H N Key: KQPYUDDGWXQXHS-UHFFFAOYSA-N N InChI=1/C10H6O3/c11-7-4-5-9(13)10-6(7)2-1-3-8(10)12/h1-5,12H Key: KQPYUDDGWXQXHS-UHFFFAOYAH
SMILES O=C\2c1c(c(O)ccc1)C(=O)/C=C/2
Properties
Chemical formula	C10H6O3
Molar mass	174.16 g·mol−1
Appearance	Yellow solid
Melting point	162 to 163 °C (324 to 325 °F; 435 to 436 K)
Solubility in water	Slightly sol.
Hazards
R-phrases	R25
S-phrases	S28 S45
Related compounds
Related compounds	quinone
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) 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. It is insoluble in benzene but soluble in dioxane, from which it crystallizes as yellow needles. It is an isomer of lawsone, which is the staining compound in the henna leaf.

Juglone occurs naturally in the leaves, roots, husks, fruit (the epicarp), and bark of plants in the Juglandaceae family, particularly the black walnut (Juglans nigra), and is toxic or growth-stunting to many types of plants. It is sometimes used as an herbicide, as a dye for cloth and inks, and as a coloring agent for foods and cosmetics.

The harmful effects of walnut trees on other plants have been observed for at least two millennia. The ancient civilizations of Greece and Rome used the walnut for its cytotoxic properties as did residents of the American South for easily gathering fish when they threw cut husks into the water with the fish. However, juglone was not isolated until the 1850s. Two men, A. Vogel Jr. and C. Reischauer, were able to isolate the compound from the walnut tree in 1851. The compound was known as nucin at that time. Juglone was then synthesized and characterized for the first time in 1887 by A. Bernthsen and A. Semper. It was not until 1928 the compound was identified and confirmed to be toxic to other plants by E.F. Davis.

The use of walnut tree has historically been used within the field of traditional medicine. In America during the early 1900s, doctors prescribed juglone for the treatment of various skin diseases.