Showing 1-30 of 290 results for "o-quinone"
Dong Lin et al.
Molecular nutrition & food research, 59(12), 2395-2406 (2015-09-01)
Catechol moieties are commonly present in dietary natural products that exert cancer chemopreventive activity. While the oxidative conversion of catechols into their corresponding o-quinones is generally considered to contribute to their cancer chemopreventive effects, the mechanism of the intracellular conversion...
Frank D Gilliland et al.
Cancer research, 62(8), 2248-2252 (2002-04-17)
Inactivation of the p16(INK4a) tumor suppressor gene and O(6)-methylguanine-DNA methyltransferase (MGMT) DNA repair gene by aberrant promoter methylation appears to be an important step in respiratory carcinogenesis after exposure to tobacco smoke and radon progeny. The determinants of aberrant promoter...
Li Zhang et al.
The Journal of biological chemistry, 286(29), 25644-25654 (2011-05-31)
Polycyclic aromatic hydrocarbons (PAH) are environmental and tobacco carcinogens. Metabolic activation of intermediate PAH trans-dihydrodiols by aldo-keto reductases (AKRs) leads to the formation of electrophilic and redox-active o-quinones. We investigated whether O-methylation by human recombinant soluble catechol-O-methyltransferase (S-COMT) is a...
Rayjean J Hung et al.
Carcinogenesis, 25(6), 973-978 (2004-01-20)
Tobacco smoking and occupational exposure are major risk factors of bladder cancer via exposure to polycyclic aromatic hydrocarbons (PAHs) and aromatic amines, which lead to oxidative stress and DNA damage. Several enzymes, which play key roles in oxidative stress are...
N S Waleh et al.
Carcinogenesis, 19(8), 1333-1337 (1998-09-23)
Transient transfection studies of human HepG2 and mouse Hepa hepatocarcinoma cells with a reporter gene construct regulated by a human antioxidant responsive element (ARE) from the NQO1 gene demonstrated that the element is responsive to low oxygen conditions. The antioxidant...
Neli Hevir-Kene et al.
Chemico-biological interactions, 234, 309-319 (2014-12-02)
Estrogens have important roles in the pathogenesis of endometrial cancer. They can have carcinogenic effects through stimulation of cell proliferation or formation of DNA-damaging species. To characterize model cell lines of endometrial cancer, we determined the expression profiles of the...
H S Radeke et al.
Chemistry & biology, 6(9), 639-647 (1999-09-01)
The marine sponge metabolite (-)-ilimaquinone has antimicrobial, anti-HIV, anti-inflammatory and antimitotic activities, inhibits the cytotoxicity of ricin and diptheria toxin, and selectively fragments the Golgi apparatus. The range of activities demonstrated by this natural product provides a unique opportunity for...
Terri S Armstrong et al.
Neuro-oncology, 11(6), 825-832 (2009-01-31)
A benefit of temozolomide (TMZ) is that myelotoxicity is uncommon. Recently, several small series have reported significant myelotoxicity resulting in treatment delays or death. The ability to predict risk of myelotoxicity may influence patient care. We retrospectively reviewed 680 malignant...
Yuji Tanaka et al.
Journal of gastroenterology and hepatology, 27(11), 1711-1717 (2012-05-18)
Hepatic excessive iron may play a role in the pathogenesis of non-alcoholic steatohepatitis (NASH). Nrf2 is a master regulator of antioxidative responses. However, the role of Nrf2 in lipid and iron homeostasis remains unclear. Accordingly, it was examined how Nrf2...
Y Li et al.
The Journal of biological chemistry, 267(21), 15097-15104 (1992-07-25)
Deletion mutagenesis and transfection studies into hepatic (mouse hepatoma (Hepa-1) and human hepatoblastoma (Hep-G2)) and nonhepatic (HeLa) cells indicated that high levels of expression of the human NAD(P)H:quinone oxidoreductase gene in tumor cells and its induction by beta-naphthoflavone and 3-(2)-tert-butyl-4-hydroxyanisole...
C Jamora et al.
Cell, 91(5), 617-626 (1997-12-11)
We have previously shown that ilimaquinone (IQ), a marine sponge metabolite, causes complete vesiculation of the Golgi stacks. By reconstituting the IQ-mediated vesiculation of the Golgi apparatus in permeabilized cells, we now demonstrate that this process does not require ARF...
Yuting Li et al.
Food chemistry, 244, 25-28 (2017-11-10)
o-Benzoquinones, formed during oxidation of polyphenols, react with amines through a Michael addition. In the present study, the ability of 4-methylbenzoquinone (4MBQ) to trap Nε-(carboxymethyl)lysine (CML) through a Michael addition with the amine groups on CML was investigated at different...
J S Elmendorf et al.
The Journal of biological chemistry, 273(21), 13289-13296 (1998-05-28)
Guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) treatment of permeabilized adipocytes results in GLUT4 translocation similar to that elicited by insulin treatment. However, although the selective phosphatidylinositol 3-kinase inhibitor, wortmannin, completely prevented insulin-stimulated GLUT4 translocation, it was without effect on GTPgammaS-stimulated GLUT4 translocation. In...
Robert A Kanaly et al.
Chemosphere, 92(11), 1442-1449 (2013-04-25)
Transformation of 9,10-phenanthrenedione, a cytotoxic derivative of phenanthrene, was shown to occur by a soil bacterium belonging to the genus Sphingobium. Phenanthrene-grown cells of this strain were exposed to 50mgL(-1) 9,10-phenanthrenedione in liquid cultures, extracted, and extracts were analyzed by...
Ye Zhang et al.
The Journal of biological chemistry, 279(41), 42545-42551 (2004-07-31)
Tumor suppressor p53 has been implicated in cell stress response and determines cell fate of either growth arrest or apoptosis. Heat shock proteins (Hsps) expressed under stress usually confer survival protection to the cell or interruption in the apoptotic pathways....
Jie Li et al.
Journal of agricultural and food chemistry, 65(39), 8634-8642 (2017-09-15)
Bioassay-guided phytochemical investigation of a commercially available maqui berry (Aristotelia chilensis) extract used in botanical dietary supplement products led to the isolation of 16 compounds, including one phenolic molecule, 1, discovered for the first time from a natural source, along...
K Tabakovic et al.
Chemical research in toxicology, 7(5), 696-701 (1994-09-01)
Reaction of lysine with estrone 3,4-o-quinone gave a complex mixture of products. Six compounds were isolated and identified using spectroscopic techniques. Among the reaction products isolated were 4-hydroxyestrone (2), 3-aminoisoestrone (3), 3-(N-pentyl-5-amino)-isoestrone (4), 1-lysylestrone 3,4-o-iminoquinone (5), and two dimeric products...
Da-Li Zhang et al.
Organic letters, 15(6), 1162-1165 (2013-03-05)
An oxygen-insertion reaction that transforms an o-quinone and a conjugated α-diketone substrate into an anhydride product or derivative under catalytic hydrogenation conditions is reported. The experiments and computations indicate that the oxygen insertion proceeds via a radical mechanism mediated by...
Roman Vozdek et al.
Biochimica et biophysica acta, 1834(12), 2691-2701 (2013-10-09)
O-Acetylserine(thiol)lyases (OAS-TLs) play a pivotal role in a sulfur assimilation pathway incorporating sulfide into amino acids in microorganisms and plants, however, these enzymes have not been found in the animal kingdom. Interestingly, the genome of the roundworm Caenorhabditis elegans contains...
Kazuhiro Saihara et al.
Biochemistry, 56(50), 6615-6625 (2017-12-01)
Pyrroloquinoline quinone (PQQ), a redox-active o-quinone found in various foods and mammalian tissues, has received an increasing amount of attention because of a number of health benefits that can be attributed to its ability to enhance mitochondrial biogenesis. However, its...
Selvanathan Arumugam et al.
The Journal of organic chemistry, 75(21), 7338-7346 (2010-10-12)
4-Hydroxy-6-methylene-2,4-cyclohexadien-1-one (1) and 4-methoxy-6-methylene-2,4-cyclohexadien-1-one (2) were generated by efficient (Φ = 0.3) photodehydration of 2-(hydroxymethyl)benzene-1,4-diol (3a) and 2-(hydroxymethyl)-4-methoxyphenol (4a), respectively. o-Quinone methides 1 and 2 can be quantitatively trapped as Diels-Alder adducts with ethyl vinyl ether or intercepted by good...
F Kader et al.
Journal of agricultural and food chemistry, 47(11), 4625-4630 (1999-12-20)
Caffeic acid o-quinone (CQ) was prepared by oxidation of caffeic acid with o-chloranil in organic media. The reaction between the purified CQ and cyanidin 3-glucoside (Cy 3-glc, o-diphenolic anthocyanin) was monitored by HPLC, and quantitative analyses were performed to establish...
Ethan Alden-Danforth et al.
Organic letters, 10(21), 4951-4953 (2008-10-15)
The catalytic, enantioselective, [4 + 2] cycloaddition reaction of ortho-quinone methides with silyl ketene acetals is described. This mechanistically interesting reaction, initiated by a chiral cinchona alkaloid-derived ammonium fluoride "precatalyst" complex, affords a variety of alkyl- and aryl-substituted 3,4-dihydrocoumarin products...
The synthesis of highly stable o-and p-quinone methides.
Nakayama J, et al
Chemistry Letters (Jpn), 6(7), 789-792 (1977)
Naganjaneyulu Bodipati et al.
Organic & biomolecular chemistry, 10(10), 1958-1961 (2012-01-31)
Highly reactive o-benzoquinone monoimines were chemically generated and successfully trapped with electron-rich olefins that led to the synthesis of hitherto unknown 1,4-benzoxazine derivatives. This unprecedented transformation was achieved by the oxidation of o-aminophenols bearing appropriate functionality on the arene residue...
Teshome B Gherezghiher et al.
Chemico-biological interactions, 196(1-2), 1-10 (2012-02-01)
o-Quinone forming estrogens and selective estrogen receptor modulators (SERMs) have been associated with carcinogenesis. LY2066948, a novel SERM in development by Eli Lilly for the treatment of uterine fibroids and myomas, has structural similarity to the equine estrogen equilenin present...
Katsuhisa Sakano et al.
Biochemical pharmacology, 68(9), 1869-1878 (2004-09-29)
Melatonin, an indolic pineal hormone, is produced primarily at night in mammals and is important in controlling biological rhythms. Although melatonin is known to be effective as a free radical scavenger and has an anti-cancer effect, carcinogenic properties have also...
Carol A Shultz et al.
Chemical research in toxicology, 24(12), 2153-2166 (2011-09-14)
Polycyclic aromatic hydrocarbons (PAHs) are suspect human lung carcinogens and can be metabolically activated to remote quinones, for example, benzo[a]pyrene-1,6-dione (B[a]P-1,6-dione) and B[a]P-3,6-dione by the action of either P450 monooxygenase or peroxidases, and to non-K region o-quinones, for example B[a]P-7,8-dione...
Deshan Yu et al.
Biochemistry, 41(39), 11888-11894 (2002-09-25)
Polycyclic aromatic hydrocarbons (PAHs) require metabolic activation to exert their carcinogenic effects. PAH trans-dihydrodiol proximate carcinogens are oxidized by aldo-keto reductases (AKRs) to their corresponding reactive and redox-active o-quinones which may have the properties of initiators and promoters. To determine...
Ruichuan Yin et al.
Scientific reports, 3, 1269-1269 (2013-02-23)
Polyhalogenated quinones are a class of carcinogenic intermediates. We found recently that the highly reactive and biologically/environmentally important ·OH can be produced by polyhalogenated quinones and H₂O₂ independent of transition metal ions. However, it is not clear whether this unusual...

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