For the parent molecule 9,10-anthraquinone, see anthraquinone
Anthraquinones (also known as anthraquinonoids) are a class of naturally occurring phenolic compounds based on the 9,10-anthraquinone skeleton. They are widely used industrially and occur naturally.
The name "anthraquinone" was first used by German chemists Carl Graebe and Carl Theodore Liebermann in a 1868 publication describing the chemical synthesis of the red dye alizarin from anthracene, a component of coal tar. This discovery led to the industrial production of alizarin and the impetus for further research on anthraquinone chemistry. [1]
Natural pigments that are derivatives of anthraquinone are found, inter alia, in aloe latex, senna, rhubarb, and cascara buckthorn, fungi, lichens, and some insects. A type II polyketide synthase is responsible for anthraquinone biosynthesis in the bacterium Photorhabdus luminescens . [3] Chorismate, formed by isochorismate synthase in the shikimate pathway, is a precursor of anthraquinones in Morinda citrifolia . [4] Tests for anthraquinones in natural extracts have been established. [5]
A large industrial application of anthraquinones is for the production of hydrogen peroxide. 2-Ethyl-9,10-anthraquinone or a related alkyl derivative is used, rather than anthraquinone itself. [7]
Millions of tons of hydrogen peroxide are manufactured by the anthraquinone process. [8]
Sodium 2-anthraquinonesulfonate (AMS) is a water-soluble anthraquinone derivative that was the first anthraquinone derivative discovered to have a catalytic effect in the alkaline pulping processes. [9]
The 9,10-anthraquinone skeleton occurs in many dyes, such as alizarin. [10] Important derivatives of 9,10-anthraquinone are 1-nitroanthraquinone, anthraquinone-1-sulfonic acid, and the dinitroanthraquinone. [11]
Derivatives of 9,10-anthraquinone include drugs such as the anthracenediones and the anthracycline family of chemotherapy drugs. The latter drugs are derived from the bacterium Streptomyces peucetius , discovered in a soil sample near the Adriatic Sea. Drugs in the anthraquinone family include the prototypical daunorubicin, doxorubicin, mitoxantrone, losoxantrone, and pixantrone. Most of these drugs, with the notable exception of pixantrone, are extremely cardiotoxic, causing irreversible cardiomyopathy, which can limit their practical usefulness in cancer treatment. [11]
The anthracenediones also include
Dantron, emodin, and aloe emodin, and some of the senna glycosides have laxative effects. Prolonged use and abuse leads to melanosis coli. [13] [14]
Soluble anthraquinones such as 9,10-anthraquinone-2,7-disulfonic acid are used as reactants in redox flow batteries, which provide electrical energy storage. [15]
Acridine is an organic compound and a nitrogen heterocycle with the formula C13H9N. Acridines are substituted derivatives of the parent ring. It is a planar molecule that is structurally related to anthracene with one of the central CH groups replaced by nitrogen. Like the related molecules pyridine and quinoline, acridine is mildly basic. It is an almost colorless solid, which crystallizes in needles. There are few commercial applications of acridines; at one time acridine dyes were popular, but they are now relegated to niche applications, such as with acridine orange. The name is a reference to the acrid odour and acrid skin-irritating effect of the compound.
The cumene process is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene, the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR), and independently by Heinrich Hock in 1944.
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.
The quinones are a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C(=O)– groups with any necessary rearrangement of double bonds", resulting in "a fully conjugated cyclic dione structure". The archetypical member of the class is 1,4-benzoquinone or cyclohexadienedione, often called simply "quinone". Other important examples are 1,2-benzoquinone (ortho-quinone), 1,4-naphthoquinone and 9,10-anthraquinone.
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula C
14H
8O
2. Several isomers exist but these terms usually refer to 9,10-anthraquinone wherein the keto groups are located on the central ring. It is used as a digester additive to wood pulp for papermaking. Many anthraquinone derivatives are generated by organisms or synthesised industrially for use as dyes, pharmaceuticals, and catalysts. Anthraquinone is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite.
Anthrone is a tricyclic aromatic ketone. It is used for a common cellulose assay and in the colorimetric determination of carbohydrates.
Triphenylmethanol is an organic compound. It is a white crystalline solid that is insoluble in water and petroleum ether, but well soluble in ethanol, diethyl ether, and benzene. In strongly acidic solutions, it produces an intensely yellow color, due to the formation of a stable "trityl" carbocation. Many derivatives of triphenylmethanol are important dyes.
2-Phenylphenol, or o-phenylphenol, is an organic compound. In terms of structure, it is one of the monohydroxylated isomers of biphenyl. It is a white solid. It is a biocide used as a preservative with E number E231 and under the trade names Dowicide, Torsite, Fungal, Preventol, Nipacide and many others.
3-Nitroaniline is an organic compound with the formula H2NC6H4NO2. A yellow solid, it is a derivative of aniline, carrying a nitro functional group in position 3. It is an isomer of 2-nitroaniline and 4-nitroaniline. It is used as a precursor to dyes.
2,4-Xylidine is an organic compound with the formula C6H3(CH3)2NH2. It is one of several isomeric xylidines. It is a colorless viscous liquid. Commercially significant derivatives include the veterinary drug cymiazole and the colorant Pigment Yellow 81.
2-Ethylanthraquinone is an organic compound that is a derivative of anthraquinone. This pale yellow solid is used in the industrial production of hydrogen peroxide (H2O2).
1,4-Dihydroxyanthraquinone, also called quinizarin or Solvent Orange 86, is an organic compound derived from anthroquinone. Quinizarin is an orange or red-brown crystalline powder. It is formally derived from anthraquinone by replacement of two hydrogen atoms by hydroxyl (OH) groups. It is one of ten dihydroxyanthraquinone isomers and occurs in small amounts in the root of the madder plant, Rubia tinctorum.
A hydroxyanthraquinone (formula: C14H7O2(OH)) is any of several organic compounds that can be viewed as derivatives of an anthraquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH).
9,10-Dihydroxyanthracene is an organic compound with the formula C14H10O2. It is the hydroquinone form of 9,10-anthraquinone (AQ). It formed when AQ is hydrogenated. It is easily dissolved in alkaline solutions and is often called soluble anthraquinone (SAQ).
4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is a pale yellow solid. It is one of three isomers of nitrotoluene.
Hydroxyanthracenes are a class of natural phenolic compounds. They can be found in Cassia alata and Cassia senna.
Violanthrone, also known as dibenzanthrone, is an organic compound that serves as a vat dye and a precursor to other vat dyes. X-ray crystallography confirms that the molecule is planar with C2v symmetry. Isomeric with violanthrone is isoviolanthrone, which has a centrosymmetric structure.
Dibromoanthanthrone is a scarlet or orange-red-hue synthetic organic colourant.
4-Chlorophenol is an organic compound with the formula C6H4ClOH. It is one of three monochlorophenol isomers. It is a colorless or white solid that melts easily and exhibits significant solubility in water. Its pKa is 9.14.
Disperse Red 60, or 1-amino-4-hydroxy-2-phenoxyanthraquinone, is a popular disperse dye of the anthraquinone family of dyes. It is a dark red solid that is insoluble in water but soluble in dichloromethane.