- Activation of the phase II enzymes for neuroprotection by ginger active constituent 6-dehydrogingerdione in PC12 cells
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The cellular endogenous antioxidant system plays pivotal roles in counteracting or retarding the pathogenesis of many neurodegenerative diseases. Molecules with the ability to enhance the antioxidant defense thus are promising candidates for neuroprotective drugs. 6-Dehydrogingerdione (6-DG), one of the major components of dietary ginger, has received increasing attention due to its multiple pharmacological activities. However, how this pleiotropic molecule works on the neuronal system has not been studied. This paper reports that 6-DG efficiently scavenges various free radicals in vitro and displays remarkable cytoprotection against oxidative stress-induced neuronal cell damage in the neuron-like rat pheochromocytoma cell line, PC12 cells. Pretreatment of PC12 cells with 6-DG significantly up-regulates a panel of phase II genes as well as the corresponding gene products, such as glutathione, heme oxygenase, NAD(P)H:quinone oxidoreductase, and thioredoxin reductase. Mechanistic study indicates that activation of the Keap1-Nrf2-ARE pathway is the molecular basis for the cytoprotection of 6-DG. This is the first revelation of this novel mechanism of 6-DG as an Nrf2 activator against oxidative injury, providing the potential therapeutic use of 6-DG as neuroprotective agent.
- Yao, Juan,Ge, Chunpo,Duan, Dongzhu,Zhang, Baoxin,Cui, Xuemei,Peng, Shoujiao,Liu, Yaping,Fang, Jianguo
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Read Online
- 2-Methylene-(22E)-25-Hexanoyl-24-OXO-26,27-Cyclo-22-Dehydro-19-Nor-Vitamin D Analogs
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This invention discloses 2-methylene-(22E)-25-hexanoyl-24-oxo-26,27-cyclo-22-dehydro-19-nor-vitamin D analogs, and specifically 2-methylene-(22E)-25-hexanoyl-24-oxo-26,27-cyclo-22-dehydro-19-nor-1α-hydroxyvitamin D3, and pharmaceutical uses therefor. This compound exhibits relatively high transcription activity as well as pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. This compound also shows low activity in vivo on bone calcium mobilization, and therefore may be used to treat autoimmune disorders or inflammatory diseases in humans as well as renal osteodystrophy. This compound may also be used for the treatment or prevention of obesity.
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Page/Page column 5
(2013/02/28)
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- 2-Methylene-(22E)-25-(1-Methylene-Hexyl)-26,27-Cyclo-22-Dehydro-19-Nor-Vitamin D Analogs
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This invention discloses 2-methylene-(22E)-25-(1-methylene-hexyl)-26,27-cyclo-22-dehydro-19-nor-vitamin D analogs, and specifically 2-methylene-(22E)-25-(1-methylene-hexyl)-26,27-cyclo-22-dehydro-19-nor-1α,24(R)-dihydroxyvitamin D3, and pharmaceutical uses therefor. This compound exhibits relatively high transcription activity as well as pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. This compound also shows lower activity in vivo on bone calcium mobilization and intestinal calcium transport activity compared to the native hormone 1α,25-dihydroxyvitamin D3, and therefore may be used to treat autoimmune disorders or inflammatory diseases in humans as well as renal osteodystrophy. This compound may also be used for the treatment or prevention of obesity.
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Page/Page column 6; 8
(2010/02/17)
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- Promiscuous substrate binding explains the enzymatic stereoand regiocontrolled synthesis of enantiopure hydroxy ketones and diols
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Regio- and stereoselective reductions of several diketones to afford enantiopure hydroxy ketones or diols were accomplished using isolated alcohol dehydrogenases (ADHs). Results could be rationalised taking into account different (promiscuous) substrate-binding modes in the active site of the enzyme. Furthermore, interesting natural cyclic diketones were also reduced with high regio- and stereoselectivity. Some of the 1,2 and 1,3-diketones used in this study were reduced by employing a low excess of the hydrogen donor (2-propanol) due to the quasi-irreversibility of these ADH-catalysed processes. Thus, using lower quantities of co-substrate, scale-up could be easily achieved.
- Kurina-Sanz, Marcela,Bisogno, Fabricio R.,Lavandera, Ivan,Orden, Alejandro A.,Gotor, Vicente
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supporting information; experimental part
p. 1842 - 1848
(2011/02/25)
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- Ethyl-branched aldehydes, ketones, and diketones from caimans (Caiman and Paleosuchus; Crocodylia, Reptilia)
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Secretions from the paracloacal glands of alligators (Alligator spp.) and caimans (Caiman spp., Melanosuchus niger, and Paleosuchus spp.) were examined by GC-MS. The secretions of the common caiman (C. crocodilus), the broad-snouted caiman (C. latirostris), the yacare caiman (C. yacare), the dwarf caiman (P. palpebrosus), and the smooth-fronted caiman (P. trigonatus) yielded a new family of 43 aliphatic carbonyl compounds that includes aldehydes, ketones, and β-diketones with an ethyl branch adjacent to the carbonyl group. The identification of these glandular components and the syntheses and stereochemical investigations of selected compounds are described.
- Krueckert, Karsten,Flachsbarth, Birte,Schulz, Stefan,Hentschel, Ute,Weldon, Paul J.
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p. 863 - 870
(2008/09/20)
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- Mild conversion of β-diketones and β-ketoesters to carboxylic acids
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A mild protocol for the conversion of β-ketoesters and β-diketones to carboxylic acids with use of CAN in CH3CN is described. The method is compatible with a number of functional groups, and can generate carboxylic acids under neutral conditions at room temperature. The reaction is fast and general, providing an alternative method to the commonly used malonic ester acid preparation. Initial mechanistic studies show that initial oxidation of the enol form of the β-dicarbonyl initiates the reaction. The presence of nitrate as an oxidant ligand or as an additive is critical for success of the reaction.
- Zhang, Yang,Jiao, Jingliang,Flowers II, Robert A.
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p. 4516 - 4520
(2007/10/03)
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- Method for preparing chiral diphosphines
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The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
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- Asymmetric hydrogenation method of a ketonic compound and derivative
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The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
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- Synthesis of 1,3-Dicarbonyl Compounds by the Oxidation of 3-Hydroxycarbonyl Compounds with Corey-Kim Reagent
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A new method for the preparation of various 1,3-dicarbonyl compounds is described.Oxidation of 3-hydroxycarbonyl compounds without substituent at C-2 position by the Corey-Kim reagent (N-chlorosuccinimide-dimethyl sulfide) afforded the stable dimethylsulfonium methylides, which on reductive desulfurization by zinc-acetic acid furnished the 1,3-dicarbonyl derivatives.On the other hand, the same treatment of 2-mono-, or 2,2-disubstituted 3-hydroxy-carbonyl compounds gave directly the corresponding 1,3-dicarbonyl analogous, respectively.
- Katayama, Sadamu,Fukuda, Kinue,Watanabe, Toshio,Yamauchi, Masashige
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p. 178 - 183
(2007/10/02)
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- Regio- and Enantio-selective Reduction of α,γ-Diketones by Fermenting Baker's Yeast
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Reduction of various numbers of 2,4 alkanediones by fermenting baker's yeast has been found to be highly regio- and enantioselective, resulting in the formation of 2-hydroxy-4-alkanones.In some cases, optical purities of the products exceeded over 99percent as determined by HPLC analysis of MTPA esters.The highest yield was obtained when the reaction was carried out at pH 8 with low substrate concentration.As the representative β-hydroxyketones, the absolute configuration of (+)-2-hydroxy-4-octanone (2d) and (+)-3-hydroxy-1-phenyl-1-butanone (2h) was unambiguously determined to be (S) by comparing the specific rotation of diol derivatives with those of authentic specimens.
- Ohta, Hiromichi,Ozaki, Kazuhiko,Tsuchihashi, Gen-ichi
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p. 2499 - 2502
(2007/10/02)
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- Degradation Mechanism of Poly(vinyl alcohol) by Successive Reactions of Secondary Alcohol Oxidase and β-Diketone Hydrolase from Pseudomonas sp.
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The secondary alcohol oxidase from Pseudomonas sp. catalyzed the oxidation of various vinyl alcohol oligomers with the molecular weight of 220 to 1500 and of β-ketols such as 5-hydroxy-3-heptanone, 4-hydroxy-2-nonanone, 3-hydroxy-5-nonanone, 6-hydroxy-4-nonanone, 7-hydroxy-5-dodecanone, and 8-hydroxy-6-tridecanone. β-Diketone hydrolase from the same strain catalyzed the hydrolysis of various aliphatic β-diketones such as 1-phenyl-1,3-butanedione and 1-phenyl-2,4-pentanedione. 4,6-Nonanediol, used as a low molecular weight model of poly(vinyl alcohol) (PVA), was oxidized to 4,6-nonanedione by way of 6-hydroxy-44nonanone by secondary alcohol oxidase. 4,6-Nonanedione was hydrolyzed to 2-pentanone and n-butyric acid by β-diketone hydrolase.These reactions were stoichiometric.The presence of the β-diketone structure in PVA oxidized by secondary alcohol oxidase was confirmed by spectral experiments.The ratio of the amount of carboxyl groups in the degraded PVA to that of carbonyl groups in the oxidized PVA became more than 0.5.A pathway for the enzymatic degradation of PVA was proposed.
- Sakai, Kiyofumi,Hamada, Nobutake,Watanabe, Yasuto
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p. 989 - 996
(2007/10/02)
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