Anthraquinones


For the parent molecule 9,10-anthraquinone, see anthraquinone
Anthraquinones are a class of naturally occurring phenolic compounds based on the 9,10-anthraquinone skeleton. They are widely used industrially and occur naturally.

Occurrence in plants

Natural pigments that are derivatives of anthraquinone are found, inter alia, in aloe latex, senna, rhubarb, and cascara buckthorn, fungi, lichens, and some insects. A type II polyketide synthase is responsible for anthraquinone biosynthesis in the bacterium Photorhabdus luminescens. Chorismate, formed by isochorismate synthase in the shikimate pathway, is a precursor of anthraquinones in Morinda citrifolia.
Tests for anthraquinones in natural extracts have been established.

In the production of hydrogen peroxide

A large industrial application of anthraquinones is for the production of hydrogen peroxide. 2-Ethyl-9,10-anthraquinone or a related alkyl derivative is used, rather than anthraquinone itself.
for the anthraquinone process to produce hydrogen peroxide.
Millions of tons of hydrogen peroxide are manufactured by the anthraquinone process.

Pulping

is a water-soluble anthraquinone derivative that was the first anthraquinone derivative discovered to have a catalytic effect in the alkaline pulping processes.

Dyestuff precursor

The 9,10-anthraquinone skeleton occurs in many dyes, such as alizarin. Important derivatives of 9,10-anthraquinone are 1-nitroanthraquinone, anthraquinone-1-sulfonic acid, and the dinitroanthraquinone.
. From the left: C.I.Acid Blue 43
an "acid dye" for wool, C.I. Vat Violet 1, which is applied by transfer printing using sublimation, a blue colorant commonly used in gasoline, and C.I. Disperse Red 60.

Medicine

Derivatives of 9,10-anthraquinone include many important drugs. They include
Natural anthraquinone derivatives tend to have laxative effects. Prolonged use and abuse leads to melanosis coli. 5 anthraquinones have been shown to inhibit the formation of Tau aggregates and dissolve paired helical filaments thought to be critical to Alzheimer's disease progression in both mouse models and in vitro testing but have not been investigated as a therapeutic agent.