1,2,7-Trihydroxy anthraquinone

Anthracyclinones The anthraquinone 1, available from the commercial dyestuff l,4,5-trihydroxy-9,10-anthraquinone, reacts regiospecifically because of the halo substituent with 2-methoxybutadiene to give 2. The product can be converted by ketalization and oxidation into the quinone 3, a known precursor to anthracyclinones. 

Emodin (= Archin Frangula emodin Frangulic acid Rheum emodin 1,3,8-Trihydroxy-6-methyl-9,1 Clan thracenedione) (anthraquinone)... 

A modifier Step 1 procedure was used to dimerize 1,3,8-trihydroxy-3-methyl-anthraquinone, (IV), as illustrated in Eq. 2 and described by the author. 

Emodin (l,6,8-trihydroxy-3-methylanthraquinone), the active principle of Polygonum cuspidatum (Polygonaceae), was reported to be an inhibitor of the p56 -PTK activity from bovine thymus, with an IC50 of 18.5 pM. When the hydroxyl functions at C-6 or C-8 were blocked by methylation or glycosylation, respectively, the effect disappeared. The inhibition was competitive with respect to ATP and non competitive with respect to the substrate [64]. In a bioassay-guided separation of the anthraquinones found in rhizomes of another Polygonaceae species, rhubarb Rheum... 

Dinitroaloeemodine, C H,N,0,—not found in Beil or CA through 1956 Trinitroaloeemodine, C,jH,NjO,—not found in Beil or CA through I956 Tetranitroaloeemodine or 1,3,6,8-Tetronitro-4,5,2 -trihydroxy-2-methyl-anthraquinone (Called in Beil 1.3.6.8-Tetranitro-4.5,2 -trioxy-2-methyl-anthrachinon or Tetranitro-aloeemodin), qq... 

Further examples of the sulfonation of phenols by this method are the preparation of l,4-dihydroxyanthraquinone-2-sulfonic acid from quinazirin189 and of 1,3,4-trihydroxy-anthraquinone-2-sulfonic acid from purpurin.190... 

If the sulphonation step is prolonged all the anthraquinones are almost exclusively converted into 2,6- and 2,7 anthraquinone disulphonic acids. After dilution of this reaction mixture to 40% sulphuric acid, saturating the solution with salts can precipitate the compounds. After fusion with base a mixture of 1,2,6- en 1,2,7-trihydroxy anthraquinones is obtained that leads to a more yellowish red on fabrics that have been impregnated with aluminium mordant [20],... 

Some anthraquinones isolated from Rubia tinctorum are believed to be artefacts for example the anthraquinones which show the presence of a 2-methoxymethyl or 2-ethoxymethyl group. These anthraquinones have been formed during the extraction of lucidin with boiling methanol or ethanol [4,68,97]. According to Schweppe the anthraquinones purpurin (1,2,4-trihydroxy anthraquinone) and purpuroxanthin (1,3-dihydroxy-anthaquinone) are formed from respectively pseudopurpurin (3-carboxy-1,2,4-trihydroxyanthraquinone) and munjistin (2-carboxy-l,3-dihydroxy-anthraquinone) during drying of the roots [3]. Some anthraquinones were only isolated once from Rubia tinctorum. It is thus doubtful whether these... 

Fuming sulfuric acid attained importance as an oxidizing agent for the introduction of hydroxyl groups in anthraquinone derivatives in the production of a variety of alizarin dyes. Thus, fuming sulfuric acid at low temperatures may be used to convert alizarin and other hydroxy derivatives of anthraquinone to trihydroxy or up to hexahydroxy derivatives. 

See Sodium 2-anthraquinone sulfonate Anthraquinone, 1,4,5,8-tetramino-. See 1,4,5,8-Tetraaminoanthraquinone Anthraquinone, 1,3,8-trihydroxy-6-methyl-. See Emodin... 

CAS 518-82-1 EINECS/ELINCS 208-258-8 Synonyms 9,10-Anthracenedione, 1,3,8-trihydroxy-6-methyl- Anthraquinone, 1,3,8-trihydroxy-6-methyl- Cl 75440 Cl natural yellow 14 Emodol... 

Alizarin blue was prepared from nitroalizarin, glycerol, and sulphuric acid by M. Prud homme, anthragallol (anthracene brown, i a 3-trihydroxy-anthraquinone) from pyrogallol and phthalic anhydride by C. Seuberlich, di- (or tetra-) azo dyes by Caro and Schraube, rhodamine from ammonium thiocyanate and chloracetic acid by M. Nencki, rocelline or echtrot (naphthalene sulphonic azonaphthol) by Roussin (1877) and Caro and Griess, and methylene blue by Caro (1877). ... 

Morindons l,2,5-trihydroxy-6-methylanthraqui-none, an orange-red anthraquinone, m.p. 285°C (from glacial acetic). M. occurs in the roots, bark and wood of Morinda species. In some Asian countries, particularly India, it was earlier used extensively as a natural dye. 

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