A trihydroxyanthraquinone or trihydroxyanthracenedione is any of several isomer

Isomer

In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...

ic organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

s with formula , formally derived from anthraquinone

Anthraquinone

Anthraquinone, also called anthracenedione or dioxoanthracene is an aromatic organic compound with formula . Several isomers are possible, each of which can be viewed as a quinone derivative...

 by replacing three hydrogen

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

 atoms by hydroxyl

Hydroxyl

A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...

 groups. They include several historically important dyes. 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.

From 9,10-anthaquinone

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

• 1,2,3-Trihydroxyanthraquinone (anthragallol)
• 1,2,4-Trihydroxyanthraquinone (purpurin), a component of madder
  Madder
  Rubia is a genus of the madder family Rubiaceae, which contains about 60 species of perennial scrambling or climbing herbs and sub-shrubs native to the Old World, Africa, temperate Asia and America...
  
   root dye.
• 1,2,5-Trihydroxyanthraquinone (oxyanthrarufin)
• 1,2,6-Trihydroxyanthraquinone (flavopurpurin)
• 1,2,7-Trihydroxyanthraquinone (isopurpurin, anthrapurpurin)
• 1,2,8-Trihydroxyanthraquinone (oxychrysazin)
• 1,3,5-Trihydroxyanthraquinone
• 1,3,6-Trihydroxyanthraquinone
• 1,3,7-Trihydroxyanthraquinone
• 1,3,8-Trihydroxyanthraquinone
  1,3,8-Trihydroxyanthraquinone
  1,3,8-Trihydroxyanthraquinone is an organic compound. It is one of many trihydroxyanthraquinone isomers, formally derived from anthraquinone by replacement of three hydrogen atoms by hydroxyl groups....
  
  
• 1,4,5-Trihydroxyanthraquinone
• 1,4,6-Trihydroxyanthraquinone
• 1,6,7-Trihydroxyanthraquinone
• 2,3,6-Trihydroxyanthraquinone

See also

• Hydroxyanthraquinone
  Hydroxyanthraquinone
  A hydroxyanthraquinone is any of several organic compounds with formula C14H9O2, which can be viewed as derivatives of an anthraquinone through replacement of one hydrogen atom by an hydroxyl group ....
  
  
• Dihydroxyanthraquinone
  Dihydroxyanthraquinone
  A dihydroxyanthraquinone is any of several isomeric organic compounds with formula , formally derived from an anthraquinone by replacing two hydrogen atoms by hydroxyl groups. Dihyroxyantraquinones have been studied since the early 1900s, and include some compounds of historical and current...
  
  
• Tetrahydroxyanthraquinone
  Tetrahydroxyanthraquinone
  A tetrahydroxyanthraquinone, also called tetrahydroxyanthradione, is any of several isomeric organic compounds with formula , almost invariably derived from 9,10-anthraquinone by replacing four hydrogen atoms by hydroxyl groups. Only a few of these isomers are commercially significant...
  
  
• Pentahydroxyanthraquinone
• Hexahydroxyanthraquinone
• Heptahydroxyanthraquinone
• Octahydroxyanthraquinone
  Octahydroxyanthraquinone
  Octahydroxyanthraquinone is an organic compound with formula , formally derived from anthraquinone by replacement of 8 hydrogen atoms by hydroxyl groups....