1,2,4-Trihydroxyanthraquinone
1,2,4-Trihydroxyanthraquinone, commonly called purpurin, is an anthraquinone. It is a naturally occurring red/yellow dye. It is formally derived from 9,10-anthraquinone by replacement of three hydrogen atoms by hydroxyl (OH) groups.
Purpurin is also called verantin, smoke Brown G, hydroxylizaric acid, and C.I. 58205. It is a minor component of the classical lake pigment "madder lake" or Rose Madder.
History
Madder root has been used for dying cloth at least since 1500 BC. Purpurin and alizarin were isolated from the root by Pierre Robiquet and Colin, two French chemists, in 1826. They were identified as anthracene derivatives by Gräbe and Liebermann in 1868. They also synthesized alizarin from bromoanthraquinone, which, together with the conversion of alizarin into purpurin published previously by M. F. De Lalande, provided the first synthetic route to purpurin. The positions of the OH groups were determined by Bayer and Caro in 1874–1875.
Natural occurrence
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and may require a mordant to improve the fastness of the dye on the fiber.
Both dyes and pigments are colored because they absorb some wavelengths of light more than others. In contrast to dyes, pigments are insoluble and have no affinity for the substrate. Some dyes can be precipitated with an inert salt to produce a lake pigment, and based on the salt used they could be aluminum lake, calcium lake or barium lake pigments.They are of many types as we know that indigo is a type of plant which was rashly cultivated in bangal by the Britishers as to make different color of dye.
Natural
The majority of natural dyes are from plant sources: roots, berries, bark, leaves, and wood, fungi, and lichens. Textile dyeing dates back to the Neolithic period. Throughout history, people have dyed their textiles using common, locally available materials. Scarce dyestuffs that produced brilliant and permanent colors such as the natural invertebrate dyes Tyrian purple and crimson kermes were highly prized luxury items in the ancient and medieval world. Plant-based dyes such as woad, indigo, saffron, and madder were raised commercially and were important trade goods in the economies of Asia and Europe. Across Asia and Africa, patterned fabrics were produced using resist dyeing techniques to control the absorption of color in piece-dyed cloth. Dyes from the New World such as cochineal and logwood were brought to Europe by the Spanish treasure fleets, and the dyestuffs of Europe were carried by colonists to America.
Dye (disambiguation)
A dye is a colored substance that has an affinity to the substrate to which it is being applied.
Dye or Dyes may also refer to:
See also
Dye (surname)
Dye is a surname. Notable people with the surname include:
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