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Naphthoquinone
Naphthoquinones constitute a class of organic compounds structurally related to naphthalene. Two isomers are common for the parent naphthoquinones: * 1,2-Naphthoquinone * 1,4-Naphthoquinone Natural products * Alkannin * Hexahydroxy-1,4-naphthalenedione * Juglone * Lapachol * Lawsone * Menatetrenone * 2-Methoxy-1,4-naphthoquinone, a compound found in ''Impatiens'' species * Nigrosporin B * 2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione * Phylloquinone * Plumbagin * 2,3,5,7-Tetrahydroxy-1,4-naphthalenedione * Vitamin K and related compounds Synthetic naphthoquinones * Menadione (2-Methyl-1,4-naphthoquinone), a vitamin K mimic * 5,8-Dihydroxy-1,4-naphthoquinone and dihydroxynaphthoquinones * Atovaquone * Buparvaquone, an antiprotozoal drug used in veterinary medicine * Diazonaphthoquinone, a diazo derivative of naphthoquinone * 1,2-Naphthoquinone, from the biodegradation of naphthalene. See also * Hydroxynaphthoquinone A hydroxynaphthoquinone (formula: ) is any of sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroxynaphthoquinone
A dihydroxynaphthoquinone (formula: ) is any of several organic compounds that can be viewed as derivatives of naphthoquinone through replacement of two hydrogen atoms (H) by hydroxyl groups (OH). The unqualified term "dihydroxynaphthoquinone" usually means a derivative of 1,4-naphthoquinone. Other dihydroxy- compounds can be derived from the two other known isomers, 1,2-naphthoquinone (''ortho''-) and 2,6-naphthoquinone (''amphi''-). Isomers From 1,4-naphthoquinone Due to the symmetry of the parent quinone, there are only nine distinct isomers of dihydroxy-1,4-naphthoquinone: * 2,3-Dihydroxy-1,4-naphthoquinone. * 2,5-Dihydroxy-1,4-naphthoquinone. * 2,6-Dihydroxy-1,4-naphthoquinone. * 2,7-Dihydroxy-1,4-naphthoquinone. * 2,8-Dihydroxy-1,4-naphthoquinone. * 5,6-Dihydroxy-1,4-naphthoquinone. * 5,7-Dihydroxy-1,4-naphthoquinone. * 5,8-Dihydroxy-1,4-naphthoquinone (naphthazarin). J. Khalafy and J.M. Bruce (2002), ''Oxidative dehydrogenation of 1-tetralones: Synthesis of juglone, na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxynaphthoquinone
A hydroxynaphthoquinone (formula: ) is any of several organic compounds that can be viewed as derivatives of a naphthoquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH). In general, the term may mean any naphthoquinone 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 6) is indicated by a multiplier prefix (mono-, di-, tri-, tetra-, penta-, or hexa-). The unqualified term "hydroxynaphthoquinone" usually means a derivative of 1,4-naphthoquinone. Other hydroxy- compounds can be derived from other isomers of the latter, such as 1,2-naphthoquinone and 2,6-naphthoquinone. The IUPAC nomenclature uses dihydronaphthalenedione instead of "naphthoquinone", with the necessary prefixes to indicate the positions of the carbonyl oxygens (=O) — as in 5,8-dihydroxy-1a,8a-dihydronaphthalene-1,4-dione (= 5,8-dihydroxy-1,4-naphthoquinone). The hydroxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naphthoquinones
Naphthoquinones constitute a class of organic compounds structurally related to naphthalene. Two isomers are common for the parent naphthoquinones: * 1,2-Naphthoquinone * 1,4-Naphthoquinone Natural products * Alkannin * Hexahydroxy-1,4-naphthalenedione * Juglone * Lapachol * Lawsone * Menatetrenone * 2-Methoxy-1,4-naphthoquinone, a compound found in '' Impatiens'' species * Nigrosporin B * 2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione * Phylloquinone * Plumbagin * 2,3,5,7-Tetrahydroxy-1,4-naphthalenedione * Vitamin K and related compounds Synthetic naphthoquinones * Menadione (2-Methyl-1,4-naphthoquinone), a vitamin K mimic * 5,8-Dihydroxy-1,4-naphthoquinone and dihydroxynaphthoquinones * Atovaquone * Buparvaquone, an antiprotozoal drug used in veterinary medicine * Diazonaphthoquinone Diazonaphthoquinone (DNQ) is a diazo derivative of naphthoquinone. Upon exposure to light, DNQ converts to a derivative that is susceptible to etching. In this way, DNQ has becom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexahydroxy-1,4-naphthalenedione
Spinochrome E, 2,3,5,6,7,8-Hexahydroxy-1,4-naphthalenedione, also called hexahydroxynaphthoquinone is a polyhydroxylated 1,4-naphthoquinones, pigments found in sea urchin shell ("test"), spine, gonads, coelomic fluid, and eggs, of sea urchin commonly known as spinochromes. These natural phenolic compounds are quinones that are known to have pharmacological properties. The several hydroxyl groups are appropriate for free-radical scavenging, which diminishes ROS and prevents redox imbalance. Mechanisms are described such as scavenging of reactive oxygen species (ROS), interaction with lipid peroxide radicals, chelation of metal ions, inhibition of lipid peroxidation and regulation of the cell redox potential. Spinochrome E formula shows that have one extra hydroxyl group that Echinochrome A and it is formally derived from naphthoquinone (1,4-naphtalenedione) through replacement of all six hydrogen atoms by hydroxyl (OH) groups. The numerical prefixes "2,3,5,6,7,8" are super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawsone
Lawsone (2-hydroxy-1,4-naphthoquinone), also known as hennotannic acid, is a red-orange dye present in the leaves of the henna plant (''Lawsonia inermis''), for which it is named, as well as in the flower of water hyacinth (''Eichhornia crassipes''). Humans have used henna extracts containing lawsone as hair and skin dyes for more than 5,000 years. Lawsone reacts chemically with the protein keratin in skin and hair via Michael addition, resulting in a strong permanent stain that lasts until the skin or hair is shed. The darker colored ink is due to more lawsone-keratin interactions occurring, which evidently break down as the concentration of lawsone decreases and the tattoo fades. Lawsone strongly absorbs UV light, and aqueous extracts can be effective sunless tanning and sunscreens. Lawsone is a 1,4-naphthoquinone derivative. Lawsone isolation from ''Lawsonia Inermis'' can be difficult due to its easily biodegradable nature. Isolation involves four steps: # extraction with an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazonaphthoquinone
Diazonaphthoquinone (DNQ) is a diazo derivative of naphthoquinone. Upon exposure to light, DNQ converts to a derivative that is susceptible to etching. In this way, DNQ has become an important reagent in photoresist technology in the semiconductor industry. Diazonaphthoquinone sulfonic acid esters are components of common photoresist materials. Such photoresists are used in the manufacture of semiconductors. In this application DNQs are mixed with Novolac resin, a type of phenolic polymer. The DNQ functions as a dissolution inhibitor. During the masking/patterning process, portions of the photoresist film are exposed to light while others remain unexposed. In the unexposed regions of the resist film, the DNQ acts as a dissolution inhibitor and the resist remains insoluble in the aqueous base developer. In the exposed regions, the DNQ forms a ketene, which, in turn, reacts with ambient water to form a base soluble indene carboxylic acid. The exposed regions of the photoresist f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juglone
Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) is an organic compound with the molecular formula C10H6O3. In the food industry, juglone is also known as C.I. Natural Brown 7 and C.I. 75500. It is insoluble in benzene but soluble in dioxane, from which it crystallizes as yellow needles. It is an isomer of lawsone, which is the staining compound in the henna leaf. Juglone occurs naturally in the leaves, roots, husks, fruit ( the epicarp), and bark of plants in the Juglandaceae family, particularly the black walnut (''Juglans nigra''), and is toxic or growth-stunting to many types of plants. It is sometimes used as an herbicide, as a dye for cloth and inks, and as a coloring agent for foods and cosmetics. History The harmful effects of walnut trees on other plants have been observed for at least two millennia. The ancient civilizations of Greece and Rome used the walnut for its cytotoxic properties as did residents of the American South for easily gathering fish when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione
2,3,5,6,8-Pentahydroxy-1,4-naphthalenedione, also called 2,3,5,6,8-pentahydroxy-1,4-naphthoquinone or spinochrome D, is an organic compound with formula , formally derived from 1,4-naphthoquinone through the replacement of five hydrogen atoms by hydroxyl (OH) groups. Spinochrome D occurs naturally as a brownish red pigment in the shell and spines of sea urchins such as the Japanese ''aka-uni'' ('' Pseudocentrotus depressus''). Chika KURODA and Masae OKAJIMA (1967), ''Studies on the Derivatives of Naphthoquinones, XVIII. The pigments of sea urchins, XIII''. Proc. Japan Acad., volume 43, pages 41--44Online versionaccessed on 2010-02-01. It is soluble in diethyl ether and crystallizes as brownish red needles that sublime at 285−295 °C. The compound gives a yellowish brown solution when treated with sodium hydroxide, a bluish green solution with ferric chloride, and a violet precipitate with lead acetate. It forms a five-fold acetate ester, ()5, that crystallizes from meth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5,8-Dihydroxy-1,4-naphthoquinone
Naphthazarin, often called 5,8-dihydroxy-1,4-naphthoquinone or 5,8-dihydroxy-1,4-naphthalenedione (IUPAC), is a naturally occurringThomson R.H. Naturally Occurring Quinones. Academic Press, London (1971). Quoted by Khalafy and Bruce.Thomson R.H. Naturally Occurring Quinones III. Chapman and Hall, London (1987). Quoted by Khalafy and Bruce. organic compound with formula , formally derived from 1,4-naphthoquinone through replacement of two hydrogen atoms by hydroxyl (OH) groups. It is thus one of many dihydroxynaphthoquinone structural isomers. Naphthazarin is soluble in 1,4-dioxane from which it crystallizes as deep red needles that melt at 228−232 °C. Synthesis Naphtharazin can be prepared by condensation of 1,4-dimethoxybenzene with 2,3-dichloromaleic anhydride followed by reductive dechlorination and reoxidation.Lewis J.R. and Paul J.J.(1977). Z. Naturforsch., B, 32: 1473. Quoted by Khalafy and Bruce.Huot R. and Brassard P. (1974). Can. J. Chem., 52: 838. Quoted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,3,5,7-Tetrahydroxy-1,4-naphthalenedione
2,3,5,7-Tetraahydroxy-1,4-naphthalenedione, also called 2,3,5,7-tetrahydroxynaphthoquinone or spinochrome B, is an organic compound with formula , formally derived from 1,4-naphthoquinone through the replacement of four hydrogen atoms by hydroxyl (OH) groups. Spinochrome B occurs naturally as pigment in the shell and spines of sea urchins such as the Japanese dull red species ''aka-uni'' ('' Pseudocentrotus depressus''), the greenish-black ''murasaki-uni'' ('' Heliocidaris crassispina''), and the brown ''bafun-uni'' ('' Strongylocentrotus pulcherrimus''). Chika KURODA and Masae OKAJIMA (1958), ''Studies on the Derivatives of Naphthoquinones, XIV. The pigments of sea urchins, IX''. Proc. Japan Acad., volume 34, pages 616--618Online versionaccessed on 2010-02-01. Pigment M2 is drawn as 2,3,6,8-thNQ but that is the same as 2,3,5,7-thNQ. The genus ''Heliocedaris'' should be ''Heliocidaris'' and the species ''purcherrmus'' should be ''pulcherrimus''. Chika KURODA and Masae OKAJIMA (1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Naphthoquinone
1,2-Naphthoquinone or ''ortho''-naphthoquinone is a polycyclic aromatic organic compound with formula . This yellow solid is prepared by oxidation of 1-amino-2-hydroxynaphthalene with ferric chloride. Occurrence This diketone (an ortho- quinone) is a metabolite of naphthalene. It arises from the naphthalene-1,2-oxide. It is also found in diesel exhaust particles. The accumulation of this toxic metabolite in rats from doses of naphthalene has been shown to cause eye damage, including the formation of cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble ...s. See also * 1,4-Naphthoquinone, an isomer of 1,2-naphthoquinone References External links * * {{DEFAULTSORT:Naphthoquinone, 1, 2- 1,2-Naphthoquinones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menadione
Menadione is a natural organic compound with the formula C6H4(CO)2C2H(CH3). It is an analog of 1,4-naphthoquinone with a methyl group in the 2-position. It is sometimes called vitamin K3. Use is allowed as a nutritional supplement in animal feed because of its vitamin K activity. Biochemistry Menadione is converted to vitamin K2 (specifically, MK-4) by the prenyltransferase action of vertebrate UBIAD1. This reaction requires the hydroquinone (reduced) form of K3, menadiol, produced by an unidentified enzyme. Menadione is also a circulating form of vitamin K, produced in small amounts (1–5%) after intestinal absorption of K1 and K2. This circulation explains the uneven tissue distribution of MK-4, especially since menadione can penetrate the blood–brain barrier. The cleavage enzyme is yet to be identified. Terminology The compound is variously known as vitamin K3 and provitamin K3. Proponents of the latter name generally argue that the compound is not a real vitamin due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
