Title:  Juglone 
CAS Registry Number:  481-39-0 
CAS Name:  5-Hydroxy-1,4-naphthalenedione 
Additional Names:  5-hydroxy-1,4-naphthoquinone;  8-hydroxy-1,4-naphthoquinone;  C.I. 75500;  C.I. Natural Brown 7;  nucin;  regianin 
Molecular Formula:  C10H6O3 
Molecular Weight:  174.15 
Percent Composition:  C 68.97%, H 3.47%, O 27.56% 
Literature References:  Coloring matter occurring in various Juglandaceae spp:  Brissemoret, Combes, Compt. Rend. 141, 838 (1905).  Isoln from walnut shells:  Combes, Bull. Soc. Chim. 1(4), 800 (1907).  Isoln and description of sedative properties in fish, mammals:  B. A. Westfall et al., Science 134, 1617 (1961).  Isoln from pecans and identification as inhibitory agent of mycelial growth of Fusicladium effusum:  P. A. Hedin et al., J. Agric. Food Chem. 28, 340 (1980).  Synthesis:  Bernthsen, Semper, Ber. 20, 938 (1887); Willstätter, Wheeler, Ber. 47, 2798 (1914); Teuber, Götz, Ber. 87, 1236 (1954); C. Grundmann, Synthesis 1977, 644.  Tumor-promoting activity study:  B. L. Van Duuren et al., J. Med. Chem. 21, 26 (1978).  Use as pH indicator:  S. S. Sawhney, B. M. L. Bhatia, J. Indian Chem. Soc. 57, 438 (1980). 
Properties:  Yellow needles from benzene + petr ether, mp 155°.  Sublimes.  Absorption max (methanol):  420 nm (log e 3.56).  Volatile with steam.  Slightly sol in hot water; freely sol in chloroform, benzene; sol in alcohol, ether; sol in aq solns of alkalies giving a purplish-red soln. 
Melting point:  mp 155° 
Absorption maximum:  Absorption max (methanol):  420 nm (log e 3.56)   |