Anthraquinoids

On the basis of the kind and the position of their substituents and their color range, the anthraquinoid disperse dyes maybe classified as follows ... 

Indigo is the most important vat dye, dating back to ancient times and produced on an industrial scale since 1880. To replace the indigo dyes, the indanthrone (21) class of dyes was developed. Indanthrone has superior characteristics as a vat dye and became a key material for further development of anthraquinoid vat dyes. There exist a variety of anthraquinone vat dyes differing in the chromophoric system. The color-structure relationship of vat dyes have been rationalized by the Pariser-Parr-Pople molecular orbital (PPP MO) method. Some examples of commercialized anthraquinoid vat dyes are shown in Scheme 6.14... 

I. Surowiec, B. Szostek and M. Trojanowicz, HPLC MS of anthraquinoids, flavonoids, and their degradation products in analysis of natural dyes in archeological objects, J. Sep. Sci., 30, 2070 2079 (2007). 

Aerobic biodegradation processes often show unsatisfying results because a number of azo dyes are resistant to aerobic microbiological attack. The main process for removal of dyes in the aerobic part of a CWWT is based on an adsorption of the dyes on the biomass. Further problems in the destruction of chromophores result during the treatment of phthalocyanine dyes, anthraquinoid dyes, and vat and sulfur dyes, which contain rather persistent chromophores. 

Nepenthes raffsiana Masilus Zhu Long Cao (Pitcher plant) (root, stem) Flavonoids, anthraquinoids, amino acids, phenols.57 As a poultice to treat stomachache and dysentery. Internally to treat remittent fever. 

Anthocyanins Anthranil acid Anthranol Anthraquinoids Anthraquinone derivative Anthraquinones... 

By mixing the reddish blue C.I. DisperseBlue 366 with C.I. DisperseBlue 165 [56] or heteroarylazo dyes [57], technically equivalent replacement products [13] for the anthraquinoid Disperse Blue 56 were obtained. The red dye 24 has been similarly used as a substitute [26] for the anthraquinoid C.I. Disperse Red 60, 60765 [1741858-5],... 

On the basis of their chemical constitutions the anthraquinoid vat dyes may be classified in the following major groups acylaminoanthraquinones, anthraqui-noneazoles, anthrimides and other linked anthraquinones, anthrimidocarbazoles, phthaloylacridones, benzanthrone dyes, indanthrones, and other polycondensed ring systems. 

The leuco compounds of anthraquinoid dyes have a high affinity for the cellulose fiber and give dyeings that meet the highest fastness requirements in use and processing. 

Commercial anthraquinoid vat dyes are dye preparations that consist of a vat-table colored pigment and a dispersing agent. Such vattablepigments are polycyclic quinoid compounds that contain two or more carbonyl groups in a closed system of conjugated double bonds (Section 3.4). 

The rate of vatting depends not only on the concentration of dye and reducing agent but also on the crystal form, surface, and dispersion of the pigment (i.e., on its finish quality [51]). Leuco compounds are soluble in alkali. In the case of anthraquinoid vat dyes, the pH of the vat is about 13. At lower values the risk of vat acid sediments exists. Reduction is usually performed at 50-60°C. At higher temperature, over-reduction of certain dyes can occur (i.e., reductive destruction of the dye molecule). 

The leuco esters of vat dyes are anthraquinoid or indigoid vat dyes (Section 3.4) that have been made water soluble by reduction and esterification of the hydroxyl groups with sulfuric acid. These dyes are used mainly for dyeing high-quality articles of cellulose fibers in light colors and polyester-cellulose blends to moderate depths of shade [58], [59, p. 568],... 

Anthraquinoid compounds have also been employed as mediators for reduction of dispersed organic compounds, particularly for dyestuffs used in dyeing of cellulose fibers in 0.1 M NaOH [67], The reduction efficiency is characterized by comparing the maximum cathodic current of the anthraquinoid solution containing the dyestuff with the cathodic peak current without reducible vat dye. The limiting current density depends on the diffusion transport of the anthraquinoid compound, whereas the addition of dispersed dyestuff has a minor influence. 

Hallas, G., Chemistry of Anthraquinoid, Polycyclic, and Miscellaneous Colorants, Chapter 6, in Shore, J., Colorants and Auxiliaries-Organic Chemistry, Properties and Applications, Vol. 1 (Colorants), Society of Dyers and Colourists, Manchester, England, p. 20, 1990. 

Natural dyes are almost entirely napthoquinoid, anthraquinoid, or flavonoid compounds having one or more hydroxyls as the primary functional group. Considerable variation in structure occurs among natural dyes, and a single HPLC system that could separate all natural dye samples was not found. Nevertheless, several workable systems were found in which all dye components eluted except for indigo-carmine, which eluted with the solvent, and indigo and turmeric, which remained on the column. For an isocratic system, we consider this situation to be very satisfactory. 

Anthraquinoid dyes are of enormous technological importance, and much work has been done in devising syntheses of large ring systems embodying the quinone structure. Several examples of anthraquinoid dyes are ... 

Ueno Y, Ueno I, Sato N, litoi Y, Saito M, Enomoto M, Tsunoda H (1971) Toxicological Approach to (-H) Rugulosin, an Anthraquinoid Mycotoxin of Penicillium rugulosum Thom. Japan J Exp Med 41 177... 

Vat dyes are of two types—indigoid (e.g., indigo) and anthraquinoid—and are mainly available in die blue and green shade range. These dyes are useful as replacements for metal-containing fiber-reactive and direct dyes for turquoise and green shades. 

Darvekar, M. Ghorpade, B. Vankar, P. S. Microwave assisted improved syntheses of indigoid and anthraquinoid dyes. Asian J. Chem. 2004,16, 965-970. 

Anthraquinoids (alizarin, purpurin, carminic acid, kermesic acid) [149] Dyes from Rubia spp. and cochineal Pazyryk textiles, 500-200 b.c. APCI operating in positive-ion mode, single quadrupole analyzer... 

Anthraquinoids (purpurin, munjistin) [154] Madder Greek painting materials, Hellenistic period (second to third century b.c.) and Roman period (second century a.d.) ESI operating in negative-ion mode, single qnadmpole analyzer with SIM acquisition mode... 

LDI-MS Anthraquinoids (purpnrin, psendopnrpnrin) Madder [171] Roman cosmetics 337-nm pulsed nitrogen laser (20 Hz) in positive- and negative-ion modes TOF analyzer... 

Franck, B. The biosynthesis of ergochromes. In The Biosynthesis of Mycotoxins (P. S. Steyn ed.), pp. 157-191. Academic Press, New York 1980 Leistner, E. Biosynthesis of plant quinones. In The Biochemistry of Plants, Vol. 7, Secondary Plant Products (E. E. Conn, ed.), pp. 403-423. Academic Press, New York 1981 Sankawa, U. The biosynthesis of anthraquinoid mycotoxins from Penicillium islandicum Sopp and related fungi. In The Biosynthesis of Mycotoxins (P. S. Steyn, ed.),pp. 357-394. Academic Press, New York 1980... 

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