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Tetrahydroxyanthraquinone
A tetrahydroxyanthraquinone, also called tetrahydroxyanthradione, is any of several isomeric organic compounds with formula , almost invariably derived from 9,10- anthraquinone by replacing four hydrogen atoms by hydroxyl groups. Only a few of these isomers are commercially significant.Hans-Samuel Bien, Josef Stawitz, Klaus Wunderlich “Anthraquinone Dyes and Intermediates” Ullmann's Encyclopedia of Industrial Chemistry 2002 Wiley-VCH, Weinheim. These are 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin), 1,4,5,8-tetrahydroxyanthraquinone, and 1,2,3,4-tetrahydroxyanthraquinone (Alizarine Bordeaux).Hugh Alister McGuigan (1921), ''An introduction to chemical pharmacology; pharmacodynamics in relation to chemistry''. P. Blakiston's son, PhiladelphiaOnline versionat archive.org, accessed on 2010-01-30. See also *Hydroxyanthraquinone *Tetrahydroxybenzoquinone Tetrahydroxy-1,4-benzoquinone, also called tetrahydroxy-''p''-benzoquinone, tetrahydroxybenzoquinone, or tetrahydroxyquinone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinalizarin
Quinalizarin or 1,2,5,8-tetrahydroxyanthraquinone is an organic compound with formula . It is one of many tetrahydroxyanthraquinone isomers, formally derived from anthraquinone by replacement of four hydrogen atoms by hydroxyl (OH) groups. Quinalizarin is an inhibitor of the enzyme protein kinase CK2. It is more potent and selective than emodin. It is also a potent catechol O-methyltransferase (COMT) inhibitor. See also * 1,4-Dihydroxyanthraquinone (quinizarin) * Alizarin Alizarin (also known as 1,2-dihydroxyanthraquinone, Mordant Red 11, C.I. 58000, and Turkey Red) is an organic compound with formula that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Histori ..., a related simpler dye References 3-Hydroxypropenals Catechol-O-methyltransferase inhibitors Catechols Hydroquinones Tetrahydroxyanthraquinones {{Ketone-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which '' bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Livin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It 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. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyanthraquinone
A hydroxyanthraquinone (formula: C14H9O2(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). The IUPAC nomenclature recommends hydroxyanthracenedione. Usually "hydroxyanthraquinone" refers to a derivative of 9,10-anthraquinone. Quoted by Khalafy and Bruce. Quoted by Khalafy and Bruce. Isomers In general, the term may mean any anthraquinone derivative where any number ''n'' of hydrogens have been replaced by ''n'' hydroxyls, so that the formula is . In this case, the number ''n'' (which is between 1 and 8) is indicated by a multiplier prefix A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy''. Particu ... (mono-, di-, tri-, up to octa-). Additional hydroxy- compounds can be derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydroxybenzoquinone
Tetrahydroxy-1,4-benzoquinone, also called tetrahydroxy-''p''-benzoquinone, tetrahydroxybenzoquinone, or tetrahydroxyquinone (THBQ, THQ), is an organic compound with formula . Its molecular structure consists of a cyclohexadiene ring with four hydroxyl groups and two ketone groups in opposite (''para'') positions. The compound gives a light red solution in water, and crystallizes as the glistening bluish-black (but non-conducting) dihydrate . The compound can be synthesized from glyoxal or from ''myo''-inositol, a natural compound widely present in plants. THBQ forms an adduct with 4,4′-bipyridine in a 2:3 ratio. Salts of THBQ Like most phenols, THBQ is acidic and easily loses the four hydrogen ions from the hydroxyl groups, yielding anions such as and . The latter is symmetric and aromatic, as the double bonds and negative charges are evenly distributed over the six CO groups. The calcium salt is the dark purple pigment produced from inositol by ''Chromohalobacter be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
