Trihydroxyanthraquinone Explained

A trihydroxyanthraquinone or trihydroxyanthracenedione is any of several isomeric organic compounds with formula, formally derived from anthraquinone by replacing three hydrogen atoms by hydroxyl groups. They include several historically important dyes.^{[1] [2]} The isomers may differ in the parent anthraquinone isomer and/or of the three hydroxyl groups.

In general there are 56 ways of choosing three out of the 8 hydrogens. However, if the underlying core is symmetrical, some of these choices will give identical molecules.

Isomers

From 9,10-anthraquinone

Due to the symmetry of the 9,10-anthraquinone core, there are only 14 isomers.^[3]

• 1,2,3-Trihydroxyanthraquinone (anthragallol)^[2]
• 1,2,4-Trihydroxyanthraquinone (purpurin), a component of madder root dye.
• 1,2,5-Trihydroxyanthraquinone (oxyanthrarufin)
• 1,2,6-Trihydroxyanthraquinone (flavopurpurin)^[2]
• 1,2,7-Trihydroxyanthraquinone (isopurpurin, anthrapurpurin)^[2]
• 1,2,8-Trihydroxyanthraquinone (oxychrysazin)
  • • • • • 1,3,5-Trihydroxyanthraquinone 1,3,6-Trihydroxyanthraquinone 1,3,7-Trihydroxyanthraquinone 1,3,8-Trihydroxyanthraquinone 1,4,5-Trihydroxyanthraquinone 1,4,6-Trihydroxyanthraquinone^[4]

See also

• Hydroxyanthraquinone
• Dihydroxyanthraquinone
• Tetrahydroxyanthraquinone
• Pentahydroxyanthraquinone
• Hexahydroxyanthraquinone
• Heptahydroxyanthraquinone
• Octahydroxyanthraquinone^[1]

Notes and References

1. Wahl, Andre; Atack, F. W (1919) The Manufacture Of Organic Dyestuffs. G. Bell And Sons, Limited. Online version accessed on 2010-01-22.
2. Hugh Alister McGuigan (1921), An introduction to chemical pharmacology; pharmacodynamics in relation to chemistry. P. Blakiston's son, Philadelphia. Online version at archive.org, accessed on 2010-01-30.
3. CRC (1996), Dictionary of organic compounds, Volume 1 CRC Press Online version at books.google.com, accessed on 2010-01-22.
4. M. L. Crossley (1918), 1,4,6-TRIHYDROXYANTHRAQUINONE J. Am. Chem. Soc., volume 40 issue 2, pages 404–406