Trihydroxyanthraquinone

A trihydroxyanthraquinone or trihydroxyanthracenedione is any of several isomeric organic compounds with formula (C₁₂H₅(OH)₃)(CO)₂, 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]
• 1,6,7-Trihydroxyanthraquinone
• 2,3,6-Trihydroxyanthraquinone

See also

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