2,3,5,7-Tetrahydroxy-1,4-naphthalenedione

2,3,5,7-Tetraahydroxy-1,4-naphthalenedione, also called 2,3,5,7-tetrahydroxynaphthoquinone or spinochrome B, is an organic compound with formula C
₁₀H
₆O
₄, formally derived from 1,4-naphthoquinone through the replacement of four hydrogen atoms by hydroxyl (OH) groups.

2,3,5,7-Tetrahydroxy-1,4-naphthalenedione

Names
IUPAC name 1,4,5,7-tetrahydroxynaphthalene-2,3-dione
Identifiers
3D model (JSmol)	Interactive image Interactive image
ChemSpider	14617131^Y
PubChem CID	324101
CompTox Dashboard (EPA)	DTXSID30314748
InChI InChI=1S/C10H6O6/c11-3-1-4-6(5(12)2-3)8(14)10(16)9(15)7(4)13/h1-2,11-12,15-16H^Y Key: RWRKDUHFUYRCIT-UHFFFAOYSA-N^Y InChI=1/C10H6O6/c11-3-1-4-6(5(12)2-3)8(14)10(16)9(15)7(4)13/h1-2,11-12,15-16H Key: RWRKDUHFUYRCIT-UHFFFAOYAA
SMILES O=C(C1=C2C(O)=CC(O)=C1)C(O)=C(O)C2=O Oc1cc(O)c2c(c1)C(=O)C(\O)=C(\O)C2=O
Properties
Chemical formula	C10H6O6
Molar mass	222.15 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 B occurs naturally as pigment in the shell and spines of sea urchins such as the Japanese dull red species aka-uni (Pseudocentrotus depressus), the greenish-black murasaki-uni (Heliocidaris crassispina), and the brown bafun-uni (Strongylocentrotus pulcherrimus).[1][2] It is soluble in methanol and crystallizes as bright red needles that sublime above 200 °C.[2]

The compound gives a greenish yellow solution when treated with sodium hydroxide, a green solution with ferric chloride, and a green precipitate with lead acetate. It forms a fourfold acetate ester, C
₁₀H
₂O
₂(CH
₃COO)₄, that crystallizes from methanol as yellow needles that melt at 157 °C.[2]

See also

• Hexahydroxynaphthoquinone (spinochrome E)
• 2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione (spinochrome D)

References

1. Chika KURODA and Masae OKAJIMA (1958), Studies on the Derivatives of Naphthoquinones, XIV. The pigments of sea urchins, IX. Proc. Japan Acad., volume 34, pages 616--618. Online version accessed on 2010-02-01. Pigment M₂ is drawn as 2,3,6,8-thNQ but that is the same as 2,3,5,7-thNQ. The genus Heliocedaris should be Heliocidaris and the species purcherrmus should be pulcherrimus.
2. 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.