A dihydroxyanthraquinone 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

9,10-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 two

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. Dihyroxyantraquinones have been studied since the early 1900s, and include some compounds of historical and current importance. The isomers differ in the position of the hydroxyl groups, and of the

carbonyl In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a ...

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

s (=O) of the underlying anthraquinone.

Isomers

From 9,10-anthraquinone

The unqualified term "dihydroxyanthraquinone" usually means a hydroxy derivative of

. The dihydroxy-9,10-anthraquinone

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

occurs widely in natural products, and is an important feature of the anthracycline antitumour antibiotics. In particular, 1,8-Dihydroxy-9,10-anthraquinone is the precursor for the important topical antipsoriatic drug anthralin, 1,8-dihydroxy-9-anthrone, There are 28 ways of choosing two of the 8 possible hydrogens, but because of the four-fold symmetry of the 9,10-anthraquinone core there are only 10 distinct isomers. * 1,2-Dihydroxyanthraquinone (alizarin) * 1,3-Dihydroxyanthraquinone (purpuroxanthin, xantopurpurin) * 1,4-Dihydroxyanthraquinone (quinizarin) * 1,5-Dihydroxyanthraquinone (anthrarufin) * 1,6-Dihydroxyanthraquinone * 1,7-Dihydroxyanthraquinone * 1,8-Dihydroxyanthraquinone (dantron, chrysazin) * 2,3-Dihydroxyanthraquinone (histazarin) * 2,6-Dihydroxyanthraquinone (anthraflavic acid) * 2,7-Dihydroxyanthraquinone (isoanthraflavic acid)

From other anthraquinones

There are also many dihydroxy derivatives of other anthraquinones, such as 1,2-anthraquinone, 1,4-anthraquinone, and 2,6-anthraquinone.

References

{{Anthraquinone

Isomers

From 9,10-anthraquinone

From other anthraquinones

See also

References