Hydroxyanthraquinone
In organic chemistry hydroxyanthraquinones refers to compounds with the formula C12H8−nn2 where n ≥ 1. Almost all hydroxyanthraquinones are derivative of 9,10-anthraquinone.
Isomers
One peculiarity of the hydroxyanthraquinones is the relative obscurity of the monohydroxy derivatives. Most hydroxyanthraquinones have two or more hydroxy groups.
Dihydroxy
Dihydroxyanthraquinones have the formula. The dyes alizarin and quinizarin are prominent examples.
Trihydroxy
Trihydroxyanthraquinones have the formula. 1,2,4-Trihydroxyanthraquinone, commonly called purpurin, is a naturally occurring red/yellow dye.
Tetrahydroxy
Tetrahydroxyanthraquinones have the formula. The dye quinalizarin (1,2,5,8-tetrahydroxyanthraquinone is one example.
Hexahydroxy
Hexahydroxyanthraquinones have the formula.1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone occurs in nature.