Anthraquinone, 1,8-dihydroxy

Water, drinking Add sample to 1,2-dihydroxy-anthraquinone-3-sulphonic acid in phosphate buffer. Polarographic analyser 2 xg/L No data Quentel et al. 1994... 

Dinitr o-l,8-dihydroxy anthraquinone, lt-yel cryst flakes, mp - not reported (Ref 3)... 

Hydroxy- and 1,8-dihydroxy-anthraquinones form neutral 2 1 complexes (209) with divalent metals such as copper and zinc, whilst 1,4- and 1,5-dihydroxyanthraquinones form polymeric complexes (210) and (211), respectively. The latter are virtually insoluble in a wide range of organic solvents and have been used for the mass pigmentation of synthetic polymers. The parent compounds have also found application as mordant dyestuffs, e.g. (212), (213) and (214). 

Acylation of 1-amino- or 1,5-diaminoanthraquinones yields yellow vat dyes and affords red to ruby colored dyes when 1,4-diaminoanthraquinones are used. Use of 4,8-diamino-l,5-dihydroxy-anthraquinones gives violet to blue dyes. The relatively low lightfastness of the yellow acylaminoanthraquinones may be improved greatly by using azodiphenyl-4,4 -dicarboxv 1 ic acid. Acylaminoanthraquinones are relatively sensitive to atmospheric conditions. 

Technical Observations-. The dyes, prepared from 1,5- and 1,8-dihydroxy-anthraquinone by tHe above procedure, are so similar that frequently a mixture of the two is used. The SE dye can be prepared without isolating the intermediate disulfo dye (alizarin saphirol B), the reduced solution from the hydrosulfide reduction being treated directly with sodium sulfide. 

This theoretical example of a QSAR assessment is presented to exhibit FDA s current approach to using S AR as a tool in the safety evaluation of substances proposed for use as food contact materials. If anthrafurin (1,6-dihydroxy anthraquinone CASRN 117-12-4 Fig. 7.3) were expected to be an impurity in a food contact material, an immediate initial concern would be raised due to reports in the literature of positive results in the bacterial reverse mutation assay and other in vitro genetic toxicity tests. A literature search did not identify relevant carcinogenicity data for anthrafurin. 

Mitro-l, 2-dihydroxy anthraquinone, golden-yel ndls (from ale or glac acet ac), mp 289° (dec) (Ref 2)... 

Nitro-1,4-dihydroxy anthraquinone, red crysts (from glac acet ac), mp 244-45°... 

The anthranoid compounds, which can be chemically described as dihydroxy-anthraquinones, -dianthrones and -anthrones, possess a laxative... 

Beilstein Handbook Referenoe) 9,10-Anthracenedione, 1,5-dihydroxy- Anthraquinone, 1,5-dihydroxy- Anthrarufin BRN 1881718 CCRIS 3150 1,5-... 

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... 

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