1,3-Dihydroxyanthraquinone, also called purpuroxanthin or xanthopurpurin, is an organic compound with formula C14H8O4 that occurs in the plant Rubia cordifolia (Indian madder). It is one of ten dihydroxyanthraquinone isomers. Its molecular structure can be viewed as being derived from an

Rubia cordifolia, often known as common madder or Indian madder, is a species of flowering plant in the coffee family, Rubiaceae. It has been cultivated for a red pigment derived from roots. Common names of this plant include manjistha in Sanskrit, Marathi, Kannada and Bengali, majit

Rubia is the type genus of the Rubiaceae family of flowering plants, which also contains coffee. It contains around 80 species of perennial scrambling or climbing herbs and subshrubs native to the Old World. The genus and its best-known species are commonly known as madder, e.g. Rubia