Noun
A coloring principle, C14H6O2(OH)2, found in madder, and now produced artificially from anthracene. It produces the Turkish reds.
Source: Webster's dictionaryHe injected the dyes alizarin blue and indophenol blue into laboratory animals and established after their death that various organs had been colored to different degrees. Source: Internet
In organs with high oxygen saturation, indophenol was retained; in organs with medium saturation, indophenol was reduced, but not alizarin blue. Source: Internet
The roots of this plant have been used since ancient times to extract alizarin and purpurin, two red dyes used for coloring clothes. Source: Internet