Ruberythric acid

Rubia tinctorum roots Alizarin, alizarin glucoside, purpurin, pseudopurpurin, lucidin glucoside, lucidin primeveroside, munjistin, ruberythric acid EtOH/H20, H2S04 A ACN B ammonium formate/FA with EDTA 250, 254 nm/ESI (+) Post column modification of eluent (5% NH3 in H20) for NI mode... 

Madder lake, lac dye, cochineal Alizarin, purpurin, ruberythric acid, lucidin, laccaic acid A, carminic acid hci/h2o, n amyl alcohol, MeOH H20/MeOH with AcOH 250, 280 nm/ ESI( ) HPLC optimization... 

Detailed examination of another madder preparation proved that the sample can be premordanted with alum. [ 19] After hydrolysis performed with hydrochloric acid and extraction with M-amyl alcohol, only four colourants are found alizarin, purpurin, and probably lucidin and ruberythric acid. Additionally, signals at m/z 525 and 539 are observed in the mass spectrum. Analysis of the preparation by inductively coupled plasma mass spectrometry (ICP MS) shows that aluminium and calcium are the main inorganic components of the sample. This is why it was suggested that the signal at m/z 539 can be attributed to the complex of aluminium with alizarin, and the second one, observed at m/z 525, to an aluminium-calcium cluster. 

N.A. Rubia tinctorum L. Anthraquinone derivatives, ruberythric acid, alzarin, purpurin, indoid, asperuloside, resin, calcium.99 Treat kidney and bladder stones. 

Turkey Red.—Alizarin is the chief constituent of the coloring matter Turkey red, which has been known since ancient times and which was obtained from the root of the madder plant, Rubia tinctorum L. The substance is of special interest because the determination of its constitution was one of the early triumphs of organic chemistry and because it was the first natural dye to be synthetically prepared. The name is derived from the oriental name for the madder, viz., alizari. In the madder root it is present as a glucoside known as ruberythric acid, which, on hydrolysis by fermentation or by boiling with acids, yields glucose and alizarin. Alizarin is a solid which sublimes as orange red needles, m.p. 289°, insoluble in water but slightly soluble in alcohol. 

What structure or structures are possible for ruberythric acid How can any uncertainties be cleared up ... 

Alizarin is one of the few natural dyestuffs which have been prepared synthetically, and is probably the only one which is prepared artificially on the large scale. It occurs generally as a glucoside, ruberythric acid CggH gOu [1, 2] in madder, the root of Rubia tincforium, and also in some other plants. 

Ruberythric acid splits up by boiling with dilute acid, or by fermentation, glucose and alizarin being formed. 

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]. 

Ruberythric acid (l-Hydroxyanthraquinone-2-O-B-D-primeveroside) Structure R] = OH, R2 = O-B-D-primeveroside, R3 = R4 = H... 

The most important dyestuff in the madder root is alizarin. In the plant it occurs as a glycoside, bonded to glucose and xylose (ruberythric acid or alizarin-2-O-/1-primeveroside). The structure was elucidated in 1868 by Carl Graebe and Carl Liebermann (two students of Adolf von Baeyer) at the Berliner Gewerbe-akademie (Berlin Trade Academy). 

By the hydrolysis of ruberythric acid, it was concluded that alizarin must be a dihydroxy-compound. Distillation over zinc dust gave anthracene. 

Since oxidation of alizarin with manganese dioxide and sulfuric acid also gave purpurin, only one possibility remained for the structure of alizarin. Further work allowed then also to assign the structure of ruberythric acid. 

The anthraquinones of madder, Rubia tinctoria (Rubiaceae), are well known. Most of the anthraquinones occur as glycosides within the plant. One of these, ruberythric acid (67), a diglucoside, can be converted to alizarin (62) by hydrolysis. Many biosynthetic studies have been carried out... 

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