A trihydroxyanthraquinone or trihydroxyanthracenedione is any of several

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

s with formula , formally derived from

anthraquinone Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxo ...

by replacing three

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

atoms by

hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

groups. They include several historically important dyes. Wahl, Andre; Atack, F. W (1919) ''The Manufacture Of Organic Dyestuffs''. G. Bell And Sons, Limited
Online version
accessed on 2010-01-22. 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. 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. CRC (1996), ''Dictionary of organic compounds'', Volume 1 CRC Pres
Online version
at books.google.com, accessed on 2010-01-22. * 1,2,3-Trihydroxyanthraquinone (anthragallol) *

1,2,4-Trihydroxyanthraquinone 1,2,4-Trihydroxyanthraquinone, commonly called purpurin, is an anthraquinone. It is a naturally occurring red/yellow dye. It is formally derived from 9,10-anthraquinone by replacement of three hydrogen atoms by hydroxyl (OH) groups. Purpurin is ...

(purpurin), a component of

madder ''Rubia'' is the type genus of the Rubiaceae family of flowering plants, which also contains coffee. It contains around 80 species of perennial scrambling or climbing herbs and subshrubs native to the Old World. The genus and its best-known spe ...

References

{{Aromatic-stub

Isomers

From 9,10-anthraquinone

See also

References