Anthraquinone dyes chemical properties

Included in this grouping are D C Green No. 5 (13), a water-soluble sulfonate, D C Green No. 6 (14), an unsulfonated water-insoluble compound, and D C Violet No. 2 (29), a water-insoluble hydroxyanthraquinone. Anthraquinone color additives, in general, are light stable and have good physical and chemical properties for use in cosmetics (see Dyes, ANTHRAQUINONE). 

Due to the laxative properties of A., a number of drugs, such as Radix Rhei, Cortex Frangulae, Fructus and Folia Sermae are used pharmaceutically. A few A., such as carminic acid and alizarin, are still used to some extent as dyes. [J.Schripsema D.Dagnino Anthraquinones Elucidation of the substitution pattern of 9,10-Anthraquinones through chemical shifts of peri-hydroxyl protons Phytochemistry 42 (1996) 177-184]... 

In chlorophenols the aromatic ring of phenol is substituted with one to five chlorine atoms. They have antimicrobial properties and are therefore used as fungicides, herbicides, insecticides, and algicides. Chlorophenols are precursors of agricultural chemicals, pharmaceuticals (e.g.clofibrate), biocides and of anthraquinone dyes. 

In the dyestuff industry, anthraquinone still ranks high as an intermediate for the production of dyes and pigments having properties unattainable by any other class of dyes or pigments. Its cost is relatively high and will remain so because of the equipment and operations involved in its manufacture. As of May 1991, anthraquinone sold for 4.4/kg in ton quantities. In the United States and abroad, anthraquinone is manufactured by a few large chemical companies (62). At present, only two processes for its production come into consideration manufacture by the Friedel-Crafts reaction utilizing benzene, phthahc anhydride, and anhydrous aluminum chloride, and by the vapor-phase catalytic oxidation of anthracene the latter method is preferred. 

Naphthoquinone Derivatives, These dyes are generally not very colorfast and sometimes also fade. Anthraquinone derivatives have better properties (see Dyes, ANTHRAQUINONE). New developments are based on compounds that combine the chemical structure of phenothiazine or phenoselenazine derivatives with benzoquinone or naphthoquinone units (16). These dyes show good chemical stability. Naphthoquinone derivatives have yet to find a practical application as dyes in WORM disks because of the high expenditure for synthesis due to low yields. 

Reactive Dyes. These dyes form a covalent bond with the fiber, usually cotton, although they are used to a small extent on wool and nylon. This class of dyes, first introduced commercially in 1956 by ICI, made it possible to achieve extremely high washfastness properties by relatively simple dyeing methods. A marked advantage of reactive dyes over direct dyes is that their chemical structures are much simpler, their absorption spectra show narrower absorption bands, and the dyeings are brighter. The principal chemical classes of reactive dyes are azo (including metallized azo), triphendioxazine, phthalocyanine, formazan, and anthraquinone (see Section 3.1). 

The cytotoxic properties of anthraquinones result from their binding to cellular DNA [222,223]. The planarity of the dye allows an intercalation between the DNA base pairs while its redox properties may be used for the formation of reactive radical or radical-ion intermediates in biological systems. The chemical and biological activity exhibited by anthraquinone derivatives is significantly affected by the different substituents at the planar ring system [224-227]. Thus, side chains usually carry one or two positive charges, in order to establish an electrostatic interaction with the phosphate backbone... 

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