2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione

2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione, also called 2,3,5,6,8-pentahydroxy-1,4-naphthoquinone or spinochrome D, is an organic compound with formula C
₁₀H
₆O
₅, formally derived from 1,4-naphthoquinone through the replacement of five hydrogen atoms by hydroxyl (OH) groups.

2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione

Identifiers
3D model (JSmol)	Interactive image Interactive image
ChEMBL	ChEMBL452666^Y
ChemSpider	10287017^Y
PubChem CID	10444193
InChI InChI=1S/C10H6O7/c11-2-1-3(12)6(13)5-4(2)7(14)9(16)10(17)8(5)15/h1,11-13,16-17H^Y Key: HYVDWYISUNRFCU-UHFFFAOYSA-N^Y InChI=1/C10H6O7/c11-2-1-3(12)6(13)5-4(2)7(14)9(16)10(17)8(5)15/h1,11-13,16-17H Key: HYVDWYISUNRFCU-UHFFFAOYAZ
SMILES O=C(C1=C2C(O)=C(O)C(O)=C1O)C(O)=CC2=O Oc1c(O)cc(O)c2C(=O)C(\O)=C(\O)C(=O)c12
Properties
Chemical formula	C10H6O7
Molar mass	238.15 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is ^YN ?)
Infobox references

Spinochrome D occurs naturally as a brownish red pigment in the shell and spines of sea urchins such as the Japanese aka-uni (Pseudocentrotus depressus).[1] It is soluble in diethyl ether and crystallizes as brownish red needles that sublime at 285−295 °C.[1]

The compound gives a yellowish brown solution when treated with sodium hydroxide, a bluish green solution with ferric chloride, and a violet precipitate with lead acetate. It forms a five-fold acetate ester, C
₁₀HO
₂(CH
₃COO)₅, that crystallizes from methanol as yellow needles that melt at 185−186 °C.[1]

See also

• Hexahydroxynaphthoquinone (spinochrome E)
• 2,3,5,7-Tetrahydroxy-1,4-naphthoquinone (spinochrome B)

References

1. Chika KURODA and Masae OKAJIMA (1967), Studies on the Derivatives of Naphthoquinones, XVIII. The pigments of sea urchins, XIII. Proc. Japan Acad., volume 43, pages 41--44. Online version accessed on 2010-02-01.