In organic chemistry hydroxyanthraquinones refers to compounds with the formula C12H8−n(OH)n(CO)2 where n ≥ 1.
[3][4][5] One peculiarity of the hydroxyanthraquinones is the relative obscurity of the monohydroxy derivatives.
The dyes alizarin (1,2-Dihydroxyanthraquinone) and quinizarin are prominent examples.
1,2,4-Trihydroxyanthraquinone, commonly called purpurin, is a naturally occurring red/yellow dye.
Dihydroxyanthraquinones have the formula C12H2(OH)6(CO)2.1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone (rufigallol) occurs in nature.