Madder plant, alizarin production

The fiber is first treated with metal salts (mordanted). Highly adhesive, basic metal compounds are formed on the fiber. These compounds are capable of producing insoluble colored complexes (lakes) with certain azo and anthraquinone derivatives. Alizarin is the best-known anthraquinone derivative for this process (see Section 2.3). It used to be isolated from the root of the madder plant but has now been replaced by the synthetic product. Suitable azo dyes contain, e.g., hydroxyl or carboxyl groups in the position ortho to the azo group on one or both of the aromatic nuclei. The shade of the dyeing depends on the type of metallic mordant used. Alizarin with aluminum or calcium salts produces the well-known Turkey red. 

Industrial Importance.—The synthesis of alizarin by Graebe and Liebermann was the first case of a common natural dye being prepared in the laboratory. As the synthesis starts with anthracene, a substance obtained in good yields from coal tar, it affords at once a cheap commercial source for the synthetic preparation of a natural product. Hardly any synthesis that has been worked out in the laboratory has had such an immediate effect upon industry as this one, and in addition to this it exerted a strong influence upon similar syntheses of other dyes. In 1868 Turkey red was a very common and valuable dye and the growth of the madder plant, in France especially, was an important industry. In their original paper Graebe and Liebermann make this statement ... 

ABSTRACT The roots of Rubia tinctorum L. (madder) are the source of a natural dye. In this review for the first time all the different information on Rubia tinctorum available in the literature is summarised. The dye components are anthraquinones which probably contribute to the resistance of the plant against fungi in the soil. Madder roots have been used to dye textiles in many parts of the world since ancient times and an overview of the historical development, cultivation, harvesting and dyeing techniques of madder is given. The anthraquinone alizarin, the hydrolysis product of ruberythric acid, is supposed to be the main dye component of Rubia tinctorum. The chemical synthesis of alizarin and the biosynthesis of the anthraquinones in Rubia tinctorum are described. As far as the purification, structure elucidation and structures of isolated compounds are concerned, the review confines itself to the anthraquinones of madder. Finally the pharmacology and medicinal uses of madder and pure anthraquinones are discussed. This review supplements and updates earlier partial reviews on madder or anthraquinones by Schweppe, Thomson and Wijnsma. 

The roots of Rubia tinctorum L. (madder) are the source of a natural dye and they have been used to dye textiles in many parts of the world since ancient times [1], The dye components are anthraquinones [1] with alizarin, the hydrolysis product of ruberythric acid, being the main dye component of Rubia tinctorum. The anthraquinones probably contribute to the resistance of the plant against fungi in the soil [2]. 

Madder dyes plant dyes from madder Rubm tinctorum) and other members of the madder fanuly Rubiaceae). Important representatives are the gjyt sidically bound components, alizarin and purpurin. M. d. were chiefly used to make madder en el, a colored paint with outstanding fastness to light. Now the product is made almost exclusively from qmthetic alizarin. 

Another important organic red color that has served since ancient times for dyeing textile materials is madder. This colorant is derived from the roots of Rubia tinctorum and other plants in the Rubiaceae family it consists of a mixture of alizarin, purpurin, and pseudopurpurin, and thus one might expect that the natural product would yield a variety of shades. It was described by Strabo, Dioscorides, Pliny the Elder, and in the Tahnud. It has been identified on Egyptian textiles as early as 1300 BCE and in six paint pots of Greco-Roman origin that are now in the British Museum. In addition, textiles dyed with madder were sold at the St. Denis... 

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