Anthraquinone pigment

Apart from some nonclassified pigments such as Indanthrone Blue (P.131.60), the anthraquinone pigments, which are structurally or synthetically derived from the anthraquinone molecule, can be divided into the following four groups of polycyclic pigments. 

---

This chapter classifies polycyclic pigments by chemical constitution. The resulting classes include aminoanthraquinones, hydroxyanthraquinones, heterocyclic and polycarbocyclic anthraquinone pigments. 

P.Y.193, an anthraquinone pigment which, so far, is produced in Japan has gained only little importance. According to the producer s information the pigment is utilized in printing inks and in plastics. 

The Friedel-Crafts reaction, which proceeds via electrophilic aromatic substitution, as illustrated in the following scheme, is unique to the manufacture of anthanthrone pigments. Most other polycyclic anthraquinone pigments are synthesized via nucleophilic ring closure. 

The exact chemical structure of P.B1.20, an anthraquinone pigment, is not known. P.B1.20 is a specialty product used in camouflage paint. The pigment satisfies cer-... 

RP-HPLC with DAD and MS detection has also been employed for the determination of anthraquinone pigments in the extract of Rubia tinctorum. The names and chemical structures of anthraquinone pigments found in R. tinctorum are compiled in Table 2.110. 

Even the tetrasubstituted diene (117) underwent smooth cycloaddition to p-quinones, thereby opening a convenient route to polyoxygenated anthraquinone pigments, e.g. (117) + (118) - (119). ... 

Aromatic compounds derived from six, seven and eight or more acetate units are also found as metabolites of these fungi. These metabolites include a series of anthraquinone pigments, which are discussed later in Chapter 7. 

A second large group of polyketide metabolites that have been isolated from lichens are heptaketide xanthones. Their structures are mainly based on norli-chexanthone (7.54). An interesting feature of these compounds is the presence of chlorine in several of the metabolites. Lichens also produce some anthraquinone pigments, exemplified by physcion (7.6) from Xanthora species. 

Fujitake, N., J. Azuma, T. Hamasaki, H. Nakajima, and K. Saiki. 1991. Determination of chrysotalunin, a predominant soil anthraquinone pigment, by high-performance liquid chromatography. Geoderma AS 83-91. 

CHCI3). A member of a group of unusual dimeric anthraquinone pigments from the mycelium of the Tasmanian agaric Dermocybe canaria (Basidiomycetes). Some preanthraquinones of the same type occur in Cortinarius sinapicolor and Australian Dermocybe species. 

Stereochemical Studies on Pre-Anthraquinones and Dimeric Anthraquinone Pigments... 

---