- Chemical constituents from Ginkgo biloba leaves and their cytotoxicity activity
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One novel neoligan glucoside, Ginkgoside B (1), and one new glucose ester, 6-O-(4-hydroxyhydrocinnamoyl)-d-glucopyranose (2), along with nine known compounds (3–11) were isolated from the ethanol extract of Ginkgo biloba leaves. Their structures were elucidated by combination of spectroscopic analyses and alkaline methanolysis. The absolute configuration of compound 1 was determined by single-crystal X-ray diffraction. All the isolated compounds were evaluated for their cytotoxicity activities, and compound 11 exhibited IC50 values of 36.20 and 58.95?μM against 5637 and HeLa cell lines, respectively.
- Shu, Penghua,Sun, Mengyuan,Li, Junping,Zhang, Lingxiang,Xu, Haichang,Lou, Yueyue,Ju, Zhiyu,Wei, Xialan,Wu, Wenming,Sun, Na
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Read Online
- Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
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Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
- Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
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supporting information
p. 20391 - 20399
(2021/08/13)
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- Isolation and characterization of glycosidic tyrosinase inhibitors from typhonium giganteum rhizomes
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A new hydrocinnamoyl glucoside, 1-O-(4-hydroxyhydrocinnamoyl)-β-D-glucopyranose (1), together with fifteen known glycosides, including two phenylethanoid glycosides (2–3), two cinnamoyl glycosides (4–5), six phenolic glycosides (6–11), one lignan glycoside (12) and four megastigmane glycosides (13–16) were isolated from a 95% EtOH extract of the Typhonium giganteum rhizomes. The sixteen glycosides were structurally characterized by NMR, HRESIMS, enzymatic hydrolysis and comparison with literature. Upon evaluating inhibitory activities of compounds 1–16 against mushroom tyrosinase at 25 μM, compounds 10 and 11 exhibited obvious inhibitory activities, with %inhibition values of 20.94±0.59%, 23.28±1.09%, respectively, with arbutin used as the positive control (26.21±0.58%).
- Shu, Penghua,Zhu, Huiqing,Liu, Wanrong,Zhang, Lingxiang,Li, Junping,Yu, Mengzhu,Fei, Yingying,Cai, Shujing,Li, Ruihua,Wei, Xialan,Yi, Wenhan,Xiao, Fugang
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p. 380 - 387
(2021/06/02)
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- Ruthenium-catalyzed intramolecular arene C(sp2)-H amidation for synthesis of 3,4-dihydroquinolin-2(1 H)-ones
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We report the [Ru(p-cymene)(l-proline)Cl] ([Ru1])-catalyzed cyclization of 1,4,2-dioxazol-5-ones to form dihydroquinoline-2-ones in excellent yields with excellent regioselectivity via a formal intramolecular arene C(sp2)-H amidation. The reactions of the 2- and 4-substituted aryl dioxazolones proceeds initially through spirolactamization via electrophilic amidation at the arene site, which is para or ortho to the substituent. A Hammett correlation study showed that the spirolactamization is likely to occur by electrophilic nitrenoid attack at the arene, which is characterized by a negative ρ value of -0.73.
- Au, Chi-Ming,Ling, Cho-Hon,Sun, Wenlong,Yu, Wing-Yiu
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p. 3310 - 3314
(2021/05/29)
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- Hydrogenation reaction method
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The invention relates to a hydrogenation reaction method, and belongs to the technical field of organic synthesis. The hydrogenation reaction method provided by the invention comprises the following steps: carrying out a hydrogen transfer reaction on a hydrogen acceptor compound, pinacol borane and a catalyst in a solvent in the presence of proton hydrogen, so that the hydrogen acceptor compound is subjected to a hydrogenation reaction; the catalyst is one or more than two of a palladium catalyst, an iridium catalyst and a rhodium catalyst; the hydrogen acceptor compound comprises one or morethan two functional groups of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogentriple bonds and epoxy. The method is mild in reaction condition, easy to operate, high in yield, short in reaction time, wide in substrate application range, suitable for carbon-carbon double bonds,carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogen triple bonds and epoxy functional groups, good in selectivity and high in reaction specificity.
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Paragraph 0034; 0057-0060
(2020/05/14)
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- Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
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A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
- Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
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supporting information
p. 4119 - 4129
(2020/08/10)
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- Copper and L-(?)-quebrachitol catalyzed hydroxylation and amination of aryl halides under air
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L-(?)-Quebrachitol, a natural product obtained from waste water of the rubber industry, was utilized as an efficient ligand for the copper-catalyzed hydroxylation and amination of aryl halides to selectively give phenols and aryl amines in water or 95percent ethanol. In addition, the hydroxylation of 2-chloro-4-hydroxybenzoic acid was validated on a 100-g scale under air.
- Bao, Xuefei,Chen, Guoliang,Dong, Jinhua,Du, Fangyu,Li, Hui,Liang, Xinjie,Wu, Ying,Zhang, Yongsheng
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supporting information
(2020/08/03)
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- Method for preparing p-hydroxyphenylpropionic acid by using tubular reactor
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The invention belongs to the field of drug synthesis, and relates to a method for preparing p-hydroxyphenylpropionic acid by using a tubular reactor. The method is characterized in that p-hydroxyphenylpropionic acid is subjected to high temperature gas phase synthesis by using a tubular reactor; the structure of the reactor, the reaction temperature, the material ratio and the residence time are investigated to obtain the influence of the fluid flow field in the tubular reactor on the chemical reaction and the product yield so as to achieve the optimal process parameters; with the applicationof the tubular reactor to prepare the p-hydroxyphenylpropionic acid, the problems of long reaction time, more by-products and low yield of the traditional process are solved; and the tubular reactor has large heat transfer and mass transfer area, and the operation of the high temperature gas phase synthesis of the p-hydroxyphenylpropionic acid with the tubular reactor is continuous, such that theadvantages of the reactor are fully utilized, the production efficiency is high, the economic value of the product is large, and the industrial application prospect is good.
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Paragraph 0023; 0026-0030
(2019/07/01)
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- Application of quebrachitol in hydrolysis reaction of copper-catalyzed aryl halide
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The invention belongs to the technical field of drug synthesis, and provides application of quebrachitol in a hydrolysis reaction of a copper-catalyzed aryl halide. According to the hydrolysis reaction, copper serves as a catalyst, quebrachitol serves as a ligand, and the hydrolysis reaction is carried out on the aryl halide. The invention further provides a catalytic system of the hydrolysis reaction of the aryl halide. The reaction system comprises the copper catalyst, the quebrachitol, alkali and water, and the system is environmentally friendly and is suitable for industrial application.
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Paragraph 0060-0062
(2019/07/16)
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- Site-Selective, Remote sp3 C?H Carboxylation Enabled by the Merger of Photoredox and Nickel Catalysis
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A photoinduced carboxylation of alkyl halides with CO2 at remote sp3 C?H sites enabled by the merger of photoredox and Ni catalysis is described. This protocol features a predictable reactivity and site selectivity that can be modulated by the ligand backbone. Preliminary studies reinforce a rationale based on a dynamic displacement of the catalyst throughout the alkyl side chain.
- Sahoo, Basudev,Bellotti, Peter,Juliá-Hernández, Francisco,Meng, Qing-Yuan,Crespi, Stefano,K?nig, Burkhard,Martin, Ruben
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p. 9001 - 9005
(2019/06/24)
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- Rapid “Mix-and-Stir” Preparation of Well-Defined Palladium on Carbon Catalysts for Efficient Practical Use
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A facile direct deposition approach for the preparation of recyclable Pd/C catalysts simply by stirring a solution of tris(dibenzylideneacetone)dipalladium(0) with a suitable carbon material was evaluated. An extraordinarily rapid catalyst preparation procedure (0 centers onto the highly accessible surface area and the avoidance of ill-defined PdII/Pd0 states.
- Yakukhnov, Sergey A.,Pentsak, Evgeniy O.,Galkin, Konstantin I.,Mironenko, Roman M.,Drozdov, Vladimir A.,Likholobov, Vladimir A.,Ananikov, Valentine P.
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p. 1869 - 1873
(2018/04/30)
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- Design, synthesis and in combo antidiabetic bioevaluation of multitarget phenylpropanoic acids
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We have synthesized a small series of five 3-[4-arylmethoxy)phenyl]propanoic acids employing an easy and short synthetic pathway. The compounds were tested in vitro against a set of four protein targets identified as key elements in diabetes: G protein-coupled receptor 40 (GPR40), aldose reductase (AKR1B1), peroxisome proliferator-activated receptor gama (PPARγ) and solute carrier family 2 (facilitated glucose transporter), member 4 (GLUT-4). Compound 1 displayed an EC50 value of 0.075 μM against GPR40 and was an AKR1B1 inhibitor, showing IC50 = 7.4 μM. Compounds 2 and 3 act as slightly AKR1B1 inhibitors, potent GPR40 agonists and showed an increase of 2 to 4-times in the mRNA expression of PPARγ, as well as the GLUT-4 levels. Docking studies were conducted in order to explain the polypharmacological mode of action and the interaction binding mode of the most active molecules on these targets, showing several coincidences with co-crystal ligands. Compounds 1–3 were tested in vivo at an explorative 100 mg/kg dose, being 2 and 3 orally actives, reducing glucose levels in a non-insulin-dependent diabetes mice model. Compounds 2 and 3 displayed robust in vitro potency and in vivo efficacy, and could be considered as promising multitarget antidiabetic candidates. This is the first report of a single molecule with these four polypharmacological target action.
- Colín-Lozano, Blanca,Estrada-Soto, Samuel,Chávez-Silva, Fabiola,Gutiérrez-Hernández, Abraham,Cerón-Romero, Litzia,Giacoman-Martínez, Abraham,Almanza-Pérez, Julio Cesar,Hernández-Nú?ez, Emanuel,Wang, Zhilong,Xie, Xin,Cappiello, Mario,Balestri, Francesco,Mura, Umberto,Navarrete-Vazquez, Gabriel
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- Selective carboxylation of substituted phenols with engineered Escherichia coli whole-cells
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Selective carboxylation of substituted phenols is realized in the presence of bicarbonate under ambient pressure by engineered Escherichia coli whole-cells expressing various hydroxybenzoate decarboxylases, leading to their corresponding ortho-hydroxybenzoates. This process may be further developed as an efficient route to upgrade lignin-derived phenolic compounds as valuable building blocks.
- Peng, Chang,Liu, Yuxue,Guo, Xiaojia,Liu, Wujun,Li, Qing,Zhao, Zongbao K.
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p. 3810 - 3815
(2018/09/21)
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- Synthetic process of esmolol intermediate 3-(4-hydroxyphenyl) methyl propionate
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The invention belongs to the field of medicinal chemical industry, and particularly relates to a synthetic process of an esmolol intermediate 3-(4-hydroxyphenyl) methyl propionate. The synthetic process comprises the steps of: adopting p-methyl phenol and acetic anhydride as raw materials, performing an acylation reaction to obtain (4-methyl) phenol acetate, performing a halogenation reaction between the obtained (4-methyl) phenol acetate and a halogenating reagent, then carrying out a substitution reaction between the halogenated product and diethyl malonate, performing hydrolysis decarboxylation, and then carrying out an esterification reaction between the obtained product with methanol to obtain the 3-(4-hydroxyphenyl) methyl propionate. Through the route of the synthetic process, the process conditions are optimized, and the synthetic process has simple operation, easy and available raw materials and low cost; and the 3-(4-hydroxyphenyl) methyl propionate is obtained finally through acylation, halogenation, substitution, hydrolysis decarboxylation and the esterification reaction, and the synthetic process has a good industrial value and a total yield of 48.8%.
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Paragraph 0020; 0023; 0027; 0033
(2018/11/03)
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- The efficient and selective catalytic oxidation of para-substituted cinnamic acid derivatives by the cytochrome P450 monooxygenase, CYP199A4
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The cytochrome P450 enzyme, CYP199A4, demethylated 4-methoxybenzoic acid, but not 4-methoxyphenylacetic acid, with high product formation activity. The oxidative demethylation of 3-(4-methoxyphenyl)propionic acid was 8-fold more active than 4-methoxyphenylacetic acid and 4-methoxycinnamic acid was efficiently oxidised at a product formation rate of 180 nmol nmol-P450-1 min-1. Accordingly the oxidation of cinnamic acid derivatives was investigated in order to determine the potential of CYP199A4 to act as a biocatalyst for this important class of biological molecules. 4-Methoxy- and 4-methyl-cinnamic acids bound tightly to CYP199A4 and were better substrates for CYP199A4 than cinnamic acid itself. The oxidations of both 4-methoxy- and 4-methyl-cinnamic acids was 100% selective for attack at the para substituent. Certain dimethoxy substituted cinnamic acids were demethylated more efficiently than 4-methoxycinnamic acid and retained the selectivity for the para-methoxy substituent. Only very low product turnover was observed with 3,5-dimethoxycinnamic acid. 4-Isopropylcinnamic acid was hydroxylated and desaturated by CYP199A4 at the isopropyl group. Cinnamic acids with a para-substituted alkyl- and alkyloxy-cinnamic acid framework were a good fit for the active site of the CYP199A4 enzyme and as a consequence were efficiently and selectively oxidised. Whole-cell oxidations resulted in high yields of product and CYP199A4 could be developed for applications in the biocatalytic oxidation of cinnamic acid derivatives and related phenylpropanoids.
- Chao, Rebecca R.,De Voss, James J.,Bell, Stephen G.
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p. 55286 - 55297
(2016/07/06)
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- COMPOUNDS FOR INHIBITING LIPID OXIDATION AND A METHOD FOR PRODUCING THE SAME
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The present invention relates to a compound for inhibiting lipid oxidation, and a producing method thereof. The compound for inhibiting lipid oxidation is synthesized by a transesterification reaction though a vinyl reaction and a lipase-catalyzed reaction. The produced compound for inhibiting lipid oxidation has an excellent effect of inhibiting oxidation according to a total oxidation value (TOTOX) which is a combination of a P-anisidine value (P-AnV) and a peroxide value (PV) and an analysis of a thiobarbituric acid reaction substance (TBARS).COPYRIGHT KIPO 2016
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Paragraph 0135-0136; 0143
(2017/05/03)
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- METHOD OF PRODUCING 3-(4-HYDROXYPHENYL) PROPANOIC ACID AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a method of producing a 3-(4-hydroxyphenyl) propanoic acid amide compound which has excellent productivity, causes little by-product waste, and is inexpensive and ecological. SOLUTION: A method of producing 3-(4-hydroxyphenyl) propanoic acid amide compound represented by the general formula (2) comprises catalytic hydrogenation reduction of a side chain double bond of a p-hydroxycinnamic acid amide compound represented by the general formula (1) (where R is hydrogen, a hydroxy group, or a methoxy group) in the presence of a metal catalyst. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0062
(2018/10/27)
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- Computational and Experimental Studies of Phthaloyl Peroxide-Mediated Hydroxylation of Arenes Yield a More Reactive Derivative, 4,5-Dichlorophthaloyl Peroxide
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The oxidation of arenes by the reagent phthaloyl peroxide provides a new method for the synthesis of phenols. A new, more reactive arene oxidizing reagent, 4,5-dichlorophthaloyl peroxide, computationally predicted and experimentally determined to possess enhanced reactivity, has expanded the scope of the reaction while maintaining a high level of tolerance for diverse functional groups. The reaction proceeds through a novel "reverse-rebound" mechanism with diradical intermediates. Mechanistic insight was achieved through isolation and characterization of minor byproducts, determination of linear free energy correlations, and computational analysis of substituent effects of arenes, each of which provided additional support for the reaction proceeding through the diradical pathway.
- Camelio, Andrew M.,Liang, Yong,Eliasen, Anders M.,Johnson, Trevor C.,Yuan, Changxia,Schuppe, Alex W.,Houk,Siegel, Dionicio
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p. 8084 - 8095
(2015/09/01)
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- A biocompatible alkene hydrogenation merges organic synthesis with microbial metabolism
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Organic chemists and metabolic engineers use orthogonal technologies to construct essential small molecules such as pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small-molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Reported herein is a method for alkene hydrogenation which utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe, and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering. Reduction to practice: A hydrogenation reaction has been developed that employs hydrogen generated in situ by a microorganism and a biocompatible palladium catalyst to reduce alkenes on a synthetically useful scale. This type of transformation, which directly combines tools from organic chemistry with the metabolism of a living organism for small-molecule production, represents a new strategy for chemical synthesis.
- Sirasani, Gopal,Tong, Liuchuan,Balskus, Emily P.
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supporting information
p. 7785 - 7788
(2014/08/05)
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- Identification and cloning of an NADPH-dependent hydroxycinnamoyl-CoA double bond reductase involved in dihydrochalcone formation in Malus × domestica Borkh.
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The apple tree (Malus sp.) is an agriculturally and economically important source of food and beverages. Many of the health beneficial properties of apples are due to (poly)phenolic metabolites that they contain, including various dihydrochalcones. Although many of the genes and enzymes involved in polyphenol biosynthesis are known in many plant species, the specific reactions that lead to the biosynthesis of the dihydrochalcone precursor, p-dihydrocoumaroyl-CoA (3), are unknown. To identify genes involved in the synthesis of these metabolites, existing genome databases of the Rosaceae were screened for apple genes with significant sequence similarity to Arabidopsis alkenal double bond reductases. Herein described are the isolation and characterization of a Malus hydroxycinnamoyl-CoA double bond reductase, which catalyzed the NADPH-dependent reduction of p-coumaroyl-CoA and feruloyl-CoA to p-dihydrocoumaroyl-CoA and dihydroferuloyl-CoA, respectively. Its apparent Km values for p-coumaroyl-CoA, feruloyl-CoA and NADPH were 96.6, 92.9 and 101.3 μM, respectively. The Malus double bond reductase preferred feruloyl-CoA to p-coumaroyl-CoA as a substrate by a factor of 2.1 when comparing catalytic efficiencies in vitro. Expression analysis of the hydroxycinnamoyl-CoA double bond reductase gene revealed that its transcript levels showed significant variation in tissues of different developmental stages, but was expressed when expected for involvement in dihydrochalcone formation. Thus, the hydroxycinnamoyl-CoA double bond reductase appears to be responsible for the reduction of the α,β-unsaturated double bond of p-coumaroyl-CoA, the first step of dihydrochalcone biosynthesis in apple tissues, and may be involved in the production of these compounds.
- Ibdah, Mwafaq,Berim, Anna,Martens, Stefan,Valderrama, Andrea Lorena Herrera,Palmieri, Luisa,Lewinsohn, Efraim,Gang, David R.
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- CYCLIC PEROXIDE OXIDATION OF AROMATIC COMPOUND PRODUCTION AND USE THEREOF
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The present invention provides a method for converting an aromatic hydrocarbon to a phenol by providing an aromatic hydrocarbon comprising one or more aromatic C-H bonds and one or more activated C-H bonds in a solvent; adding a phthaloyl peroxide to the solvent; converting the phthaloyl peroxide to a di-radical; contacting the di-radical with the one or more aromatic C-H bonds; oxidizing selectively one of the one or more aromatic C-H bonds in preference to the one or more activated C-H bonds; adding a hydroxyl group to the one of the one or more aromatic C-H bonds to form one or more phenols; and purifying the one or more phenols.
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Page/Page column 10
(2014/10/15)
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- A simple and straightforward approach toward selective C=C bond reduction by hydrazine
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A simple and straightforward method for reducing the C=C double bond with hydrazine is described. A number of representative C=C bonds in various steric and electronic environments were examined. Substituted alkenes can be selectively reduced in EtOH in the presence of hydrazine to give the corresponding products in up to 100% yields.
- Chen, Hao,Wang, Jianmin,Hong, Xuechuan,Zhou, Hai-Bing,Dong, Chune
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supporting information
p. 758 - 761
(2012/11/07)
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- Unusual isomeric corniculatolides from mangrove, Aegiceras corniculatum
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Four new isomeric macrolides of combretastatin D-2 congeners named isocorniculatolide A (1), 11-O-methylisocorniculatolide A (2), 11-O-methylcorniculatolide A (3), and 12-hydroxy-11-O-methylcorniculatolide A (4), and the known corniculatolide A (5), arjunolic acid, and maslinic acid were isolated from the CHCl3 extract of the bark of Aegiceras corniculatum. The structures of the new compounds (1-4) were elucidated by a combination of spectroscopic analysis (1-5), chemical modifications, and single-crystal X-ray analysis (1).
- Ponnapalli, M. Gowri,Annam, S. Ch. V. A. Rao,Ravirala, Saidulu,Sukki, Sushma,Ankireddy, Madhu,Tuniki, V. Raju
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supporting information; scheme or table
p. 275 - 279
(2012/05/05)
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- First synthesis, characterization, and evidence for the presence of hydroxycinnamic acid sulfate and glucuronide conjugates in human biological fluids as a result of coffee consumption
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A systematic investigation of the human metabolism of hydroxycinnamic acid conjugates was carried out. A set of 24 potential human metabolites of coffee polyphenols has been chemically prepared, and used as analytical standards for unequivocal identifications. These included glucuronide conjugates and sulfate esters of caffeic, ferulic, isoferulic, m-coumaric and p-coumaric acids as well as their dihydro derivatives. A particular focus has been made on caffeic and 3,4-dihydroxyphenylpropionic acid derivatives, especially the sulfate conjugates, for which regioselective preparation was particularly challenging, and have so far never been identified as human metabolites. Ten out of the 24 synthesized conjugates have been identified in human plasma and/or urine after coffee consumption. A number of these conjugates were synthesized, characterized and detected as hydroxycinnamic acid metabolites for the first time. This was the case of dihydroisoferulic acid 3′-O-glucuronide, caffeic acid 3′-sulfate, as well as the sulfate and glucuronide derivatives of 3,4-dihydroxyphenylpropionic acid.
- Fumeaux, Rene,Menozzi-Smarrito, Candice,Stalmach, Angelique,Munari, Caroline,Kraehenbuehl, Karin,Steiling, Heike,Crozier, Alan,Williamson, Gary,Barron, Denis
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supporting information; experimental part
p. 5199 - 5211
(2010/12/25)
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- Tyrosinase inhibitory activities of cinnamic acid analogues
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The aim of this study was to show how tyrosinase inhibitory activity is correlated with the structure of cinnamic acid derivatives. We synthesized cinnamic acid derivatives, and investigated their tyrosinase inhibitory and DPPH radical scavenging activities. The results show that reduction of C=C double bonds and the substituent group of cinnamic acid derivatives have an effect on antioxidant activity and tyrosinase inhibitory activity. Among these compounds, compounds 2, 6 and 6a showed a potent tyrosinase inhibitory activity with IC50 (50% inhibitory concentration) values of 115.6 μM, 114.9 μM and 195.7 μM, respectively. The results obtained provide a useful clue for the design and development of new tyrosinase inhibitors.
- Takahashi,Miyazawa, Mitsuo
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p. 913 - 918
(2011/08/06)
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- New approaches to the synthesis of aromatic polyesters
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A new method of the synthesis of high molecular polybutylene terephthalate (PBT) is developed with the use of Irganox 1010, tris(nonylphenyl) phosphite and hypophosphite as stabilizers and boron nitride or boron oxide as a catalyst is proposed.
- Mikitaev,Bedanokov, A. Yu.,Mikitaev
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body text
p. 1998 - 2005
(2010/02/16)
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- Antileukotrienic phenethylamido derivatives of arylalkanoic acids in the treatment of ulcerative colitis
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A series of arylalkanoic acid derivatives bearing methyl(phenethyl)amino groups were prepared and their inhibition of LTB4 biosynthesis was evaluated. Regression analysis showed the slightly different parabolic dependences of this activity on lipophilicity of α-methyl and α-unsubstituted alkanoic acid derivatives. The relationship derived for α-unsubstituted alkanoic acids was extended by previously prepared group of similar derivatives of arylacetic acids without any change of regression coefficients and statistical criteria. It was concluded that the most active compounds belong to 2-arylpropanoic acid derivatives with lipophilicity close to log Popt (=6.97). But generally, the structural changes in the acidic part of compounds under study did not yield the substantial improvement of LTB4 biosynthesis inhibition in comparison with the previously prepared series of derivatives IV. The anti-inflammatory effect of the compounds under study was evaluated in three animal models of inflammation and their possible utilization in the treatment of ulcerative colitis (UC) was followed. From 12 evaluated compounds, 4 compounds are more active in UC inhibition than the standard sulfasalazine but it can be stated that the change of connecting chain between aromatic ring and carboxyl did not bring about the important improvement of this activity in comparison with previous derivatives of arylacetic acids. Possible relation between LTB4 biosynthesis inhibition and ulcerative colitis is seriously broken by the compound 8a with carbonyl as the additional functional group on the connecting chain between carboxyl and aromatic ring.
- Junek, Richard,Kverka, Miloslav,Jandera, Antonin,Panajotova, Vladimira,Satinsky, Dalibor,Machacek, Milos,Kuchar, Miroslav
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experimental part
p. 332 - 344
(2009/04/06)
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- Inherently radiopaque bioresorbable polymers for multiple uses
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Preferred embodiments of the present invention relate to polymeric medical devices, such as stents. More particularly, the compositions disclosed herein comprise halogen-containing phenol moeities, that may be used for medical devices and other uses whereby bioresorbable and radiopaque and physicomechanical properties are desired.
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- TETRACYCLIC INHIBITORS OF FATTY ACID AMIDE HYDROLASE
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Certain tetracyclic compounds are described, which may be used in pharmaceutical compositions and methods for treating disease states, disorders, and conditions mediated by fatty acid amide hydrolase (FAAH) activity. Thus, the compounds may be administered to treat, e.g., anxiety, pain, inflammation, sleep disorders, eating disorders, or movement disorders (such as multiple sclerosis).
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Page/Page column 25
(2009/01/20)
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- 1,4-Cyclohexadiene with Pd/C as a rapid, safe transfer hydrogenation system with microwave heating
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A method for the rapid, safe hydrogenation of alkenes and deprotection of benzyl ethers and carboxybenzyl amides is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In general, the reactions are complete within five minutes at 100 °C.
- Quinn, John F.,Razzano, Dana A.,Golden, Kathryn C.,Gregg, Brian T.
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scheme or table
p. 6137 - 6140
(2009/04/05)
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- Interaction of functionally-substituted 4-alkyl-2,6-di-tert-butylphenols with hydrohalic acids
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Reactions of 4-alkyl-2,6-di-tert-butylphenols containing OH, SH, COOH, and COOMe groups in their para substituents with hydrogen chloride and hydrohalic acids were studied. One-step transformations of 2,6-di-tert-butyl-4-(ω- hydroxyalkyl)phenols to the corresponding 4-(ω-halogenoalkyl)phenols, as well as of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and its esters to phloretic acid were proposed. 4-(3-Mercaptopropyl)phenol upon heating with conc. HBr undergoes condensation to 3-(4-hydroxyphenyl)propyl 4-(3-mercaptopropyl)phenyl sulfide as the main product.
- Prosenko,Skorobogatov,Dyubchenko,Pinko,Kandalintseva,Shakirov,Pokrovsky
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p. 1119 - 1124
(2008/09/18)
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- Structure-activity relationships of α-ketooxazole inhibitors of fatty acid amide hydrolase
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A systematic study of the structure-activity relationships of 2b (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the C2 acyl side chain. A series of aryl replacements or substituents for the terminal phenyl group provided effective inhibitors (e.g., 5c, aryl = 1-napthyl, K, - 2.6 nM), with 5hh (aryl -3-ClPh, Ki = 900 pM) being 5-fold more potent than 2b. Conformationally restricted C2 side chains were examined, and many provided exceptionally potent inhibitors, of which 11j (ethylbiphenyl side chain) was established to be a 750 pM inhibitor. A systematic series of heteroatoms (O, NMe, S), electron-withdrawing groups (SO, SO2), and amides positioned within and hydroxyl substitutions on the linking side chain were investigated, which typically led to a loss in potency. The most tolerant positions provided effective inhibitors (12p, 6-position S, Ki = 3 nM, or 13d, 2-position OH, Ki = 8 nM) comparable in potency to 2b. Proteome-wide screening of selected inhibitors from the systematic series of >100 candidates prepared revealed that they are selective for FAAH over all other mammalian serine proteases.
- Hardouin, Christophe,Kelso, Michael J.,Romero, F. Anthony,Rayl, Thomas J.,Leung, Donmienne,Hwang, Inkyu,Cravatt, Benjamin F.,Boger, Dale L.
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p. 3359 - 3368
(2008/02/13)
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- Structural modification of phenylpropanoid-derived compounds and the effects on their participation in redox processes
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Oxidation and reduction processes are fundamental to many of the proposed mechanisms by which dietary phytochemicals are thought to exert protective effects against cardiovascular disease and some cancers. An understanding of the redox chemistry of these compounds is essential in assessing their potential to participate in these processes. Phenylpropanoid-derived compounds were selected and synthesised where required to represent many of the structural features found in this important group of compounds. Using electron paramagnetic resonance spectroscopy and computational chemistry a structure-redox activity relationship was obtained. Good correlation of computational and experimental results was observed for the mono-hydroxylated compounds. This demonstrated the value of computational chemistry in obtaining information about compounds, not readily available and the effect of electron delocalisation on parent radical stability. For compounds containing more than one hydroxyl, the relationship was found to be more complex. The importance of quinone formation in compounds containing more than one hydroxyl substituent was highlighted, as this was found to have a significant effect on stabilisation and therefore, their participation in redox processes.
- Russell, Wendy R.,Scobbie, Lorraine,Chesson, Andrew
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p. 2537 - 2546
(2007/10/03)
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- P-hydroxyphenyl propionic acid derivatives as antiproliferative agents
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Derivatives of the compound p-hydroxyphenyl propionic acid characterised by those derivatives having the general formulas (I) and (Ia), where n can take the values 1,2,3; R can be H or CH3 and R1 can be CH3 or H with pharmacological activity and their application in medicine for the treatment of disorders of the immunological system.
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- Fluorescence studies on nyctinasty which suggest the existence of genus-specific receptors for leaf-movement factor.
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Periodic leaf-movement of legumes is called nyctinasty and has been known since the age of Alexander the Great. We found that nyctinasty is controlled by a periodic change of the internal concentration of leaf-opening and leaf-closing substances in the plant body. Now, we have developed novel fluorescent probes (1) based on the structure of cis-p-coumaroylagmatine (3), which was isolated as a leaf-opening substance of Albizzia juribrissin Durazz. Binding experiments using probe 1 showed that Albizza plants have receptors for a leaf-opening substance in their motor cells. By using probes 1 we then found that genus-specific receptors are involved in nyctinasty.
- Nagano, Hideharu,Kato, Eisuke,Yamamura, Shosuke,Ueda, Minoru
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p. 3186 - 3192
(2007/10/03)
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- Differentiation of natural and synthetic phenylalanine and tyrosine through natural abundance 2H nuclear magnetic resonance
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The natural abundance deuterium NMR characterization of samples of the amino acids tyrosine (1) and phenylalanine (2), examined as the acetylated methyl esters 4 and 6, has been performed with the aim to identify by these means the contribution in animals of the hydroxylation of the diet L-phenylalanine (2) to the formation of L-tyrosine (1), a feature previously revealed on the same samples through the determination of the phenolic δ18O values. The study, which includes also the NMR examination of benzoic acid (5) from 2 and of tyrosol (7) from 1, substantially fails in providing the required information because the mode of deuterium labeling of tyrosine samples of different origins is quite similar but indicates a dramatic difference in the deuterium labeling pattern of the two amino acids 1 and 2. The most relevant variation is with regard to the deuterium enrichments at the CH2 and CH positions, which are inverted in the two amino acids of natural derivation. Moreover, whereas the diastereotopic benzylic hydrogen atoms of L-tyrosine (1) appear to be equally deuterium enriched, in L-phenylalanine (2) the (D/H)3R > (D/H)3S. Similarly, benzoic acid (5) shows separate signals for the aromatic deuterium nuclei, which are quite indicative of the natural or synthetic derivation. The mode of deuterium labeling of the side chain of 1 and 2 is tentatively correlated to the different origins of the two amino acids, natural from animal sources for L-tyrosine and biotechnological probably from genetically modified microorganisms for L-phenylalanine.
- Brenna, Elisabetta,Fronza, Giovanni,Fuganti, Claudio,Pinciroli, Matteo
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p. 4866 - 4872
(2007/10/03)
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- Biocatalytic deprotection of a cetraxate ester by Microbacterium sp. strain 7-1W cells
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Enzymatic deprotection of the terminal ester bond of a cetraxate methyl ester was done with resting cells of Microbacterium sp. strain 7-1W, which produces an esterase catalyzing a regioselective hydrolysis reaction, as the catalyst. When 20 g of cetraxate methyl ester in 50 ml of a reaction mixture was incubated with 5 g of wet cells for 17 h, 96% of the substrate was converted to the desired product, cetraxate, quantitatively.
- Honda, Kohsuke,Sakamoto, Keiji,Kita, Shinji,Kataoka, Michihiko,Shimizu, Sakayu
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p. 192 - 194
(2007/10/03)
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- Melanin-concentrating hormone antagonist
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A melanin-concentrating hormone antagonist comprising a compound of the formula: wherein R is hydrogen atom or a cyclic group which may be substituted; X is a bond or a spacer having a main chain of 1 to 10 atoms; Y is a spacer having a main chain of 1 to 6 atoms; ring A is benzene ring which may be further substituted; ring B is a 5- to 9-membered nitrogen-containing non-aromatic heterocyclic ring which may be further substituted; R1 and R2 are the same or different and are hydrogen atom, a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted; or R1 and R2, together with the adjacent nitrogen atom, may form a nitrogen-containing heterocyclic ring which may be substituted; or R2, together with the adjacent nitrogen atom and Y, may form a nitrogen-containing heterocyclic ring which may be substituted; or a salt thereof is useful as a preventive or therapeutic agent for obesity, etc.
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- Development and evaluation of an immunoassay for biological monitoring chlorophenols in urine as potential indicators of occupational exposure
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Trichlorophenols (TCP) eliminated by the urine can be considered as potential biomarkers of exposure of many chemicals (chlorophenols, chlorophenoxy acid herbicides, prochloraz, lindane, hexachlorobenzene, etc). Highthroughput screening methods are necessary to carry out efficient monitoring programs that may help to prevent certain occupational health diseases. For this purpose, an indirect enzyme-linked immunosorbent assay (ELISA) for 2,4,6-trichlorophenol detection has been developed using polyclonal antisera raised against 3-(3-hydroxy-2,4,6-trichlorophenyl)propanoic acid (hapten 5) covalently coupled by the mixed anhydride (MA) method to keyhole limpet hemocyanin (KLH). The indirect ELISA uses a heterologous coating antigen prepared by conjugation of 3-(2-hydroxy-3,6-dichlorophenyl)propanoic acid (hapten 4) to bovine serum albumin (BSA) using the active ester (AE) method. The optimum hapten density for the coating antigen was found to be 3 mol of hapten/mol of protein. The assay shows a limit of detection of 0.245 ± 0.116 μg L-1, and it is performed on 96-well microtiter plates in about 1.5 h. The ELISA reported recognizes on a much less extent other chlorinated phenols, such as 2,3,4,6-tetrachlorophenol (2,3,4,6-TtCP, 21%), 2,4,5-TCP (12%) and 2,3,5-TCP (15%); however, brominated phenols (BP) are even more recognized than the corresponding chlorinated analogues (ex. 2,4,6-TBP, 710%; 2,4-DBP, 119%). With the aim of finding an explanation for this behavior, theoretical calculations have been performed for those and other halogenated phenols (2,4,6-triiodophenol and 2,4,6-trifluorophenol) to clarify which physicochemical parameter can explain better the recognition pattern observed. Finally, the assay has been adapted to the analysis of urine samples. The studies have shown that a limit of detection of 1 μg L-1 can be accomplished on this biological matrix by combining the ELISA procedure with a C18 solid-phase extraction method.
- Galve, Roger,Nichkova, Mikaela,Camps, Francisco,Sanchez-Baeza, Francisco,Marco, M.-Pilar
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p. 468 - 478
(2007/10/03)
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- NOVEL OPIATE COMPOUNDS, METHODS OF MAKING AND METHODS OF USE
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The present application relates to novel opioid receptor antagonists and agonists, methods of making these compounds, and methods of use thereof.
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- Antioxidative properties of phenolic antioxidants isolated from corn steep liquor
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With the immersion of corn into dilute sulfur oxide during starch-manufacturing processes, corn steep liquor (CSL) remains as leftover material. CSL is often used for fermentation, but its components are not fully understood. To determine the properties of CSL, 12 p-coumaric acid-related compounds were isolated from an ethyl acetate extract of CSL with the guidance of antioxidative activity on the rabbit erythrocyte membrane ghost system. The activity of these compounds was compared against oxidative damages, and it was elucidated that the activity of p-coumaric acid derivatives was mainly affected by their functional groups at the 3-position and less, by the conjugated side chain. Moreover, p-coumaric acid derivatives exhibited inhibitory activity stronger than that of tocopherols and ascorbic acid on peroxynitrite-mediated lipoprotein nitration. These findings that p-coumaric acid derivatives, which might play a beneficial role against oxidative damage, exist in CSL suggest this byproduct might be a useful resource of phenolic antioxidants.
- Niwa, Toshio,Dpi, Umeyuki,Kato, Yoji,Osawa, Toshihiko
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p. 177 - 182
(2007/10/03)
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- Hapten Synthesis for a Monoclonal Antibody Based ELISA for Deltamethrin
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An enzyme-linked immunosorbent assay (ELISA) was developed for the insecticide deltamethrin. Two haptens were synthesized: the first one was a derivative of the whole molecule with a spacer arm bound to the aromatic ring; the second one was a derivative of deltamethric acid. Twelve monoclonal antibodies were obtained. A competitive ELISA using monoclonal antibody Del 01 yielded the most sensitive assay. The IC50 value for deltamethrin was estimated to be 0.5 μg mL-1 with a detection limit of 0.08,μg mL-1. Monoclonal antibody Del 01 seems to be deltamethrin specific since 1% cross-reactivity with other pyrethroid analogues was observed.
- Queffelec, Anne-Laurence,Nodet, Patrice,Haelters, Jean-Pierre,Thouvenot, Daniel,Corbel, Bernard
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p. 1670 - 1676
(2007/10/03)
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- Kinetics and Mechanism of the Alkaline Hydrolysis of Pentachlorophenyl ω-(p-Hydroxyphenyl)alkanoates
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A kinetic study of the alkaline hydrolysis of pentachlorophenyl esters of ω-(p-hydroxyphenyl)alkanoic acids 3 shows that the dissociative route involving a spirodienone intermediate is not a feasible alternative to the normal associative BAC2 pathway.
- Cevasco, Giorgio,Thea, Sergio
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p. 269 - 272
(2007/10/03)
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- Palladium-catalyzed cross-coupling reaction of organostannoates with aryl halides in aqueous medium
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Water-soluble hydroxycomplexes 2, easily formed from organotin trihalides 1 in aqueous alkaline solution, react readily with aryl halides in the same medium in the presence of palladium complexes to give cross-coupled products 3 in high yields.
- Roshchin, Alexander I.,Bumagin, Nikolai A.,Beletskaya, Irina P.
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p. 125 - 128
(2007/10/02)
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- Alumina-mediated microwave thermolysis: A new approach to deprotection of benzyl esters
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A simple and high yielding method for deprotection of benzyl esters is described which occurs under mild and solvent-free conditions on alumina surface using microwave irradiation.
- Varma, Rajender S.,Chatterjee, Arnab K.,Varma, Manju
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p. 4603 - 4606
(2007/10/02)
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- CINNAMIC ACID BRIDGES BETWEEN CELL WALL POLYMERS IN WHEAT AND PHALARIS INTERNODES
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A method has been devised for the quantitative determination of cinnamic acids participating in ester-ether bridges between cell wall polymers based on the different reactivities of free carboxylic acids and their esters towards borohydride reductants and the different susceptibilities of cinnamic acid ester and benzyl ether linkages to alkaline treatments.Lignin-poylsaccharide containing fractions extracted with dioxane-H2O from cell walls of wheat (Triticum aestivum) and phalaris (phalaris aquatica) internodes are hydrogenated using a Pd/C catalyst at room temperature to convert cinnamic acids to their corresponding dihydrocinnamic acids.The sample is subsequently reduced with LiBH4 in ether-toluene to convert ester-linked dihydrocinnamates to their corresponding alcohols, hydrolysed with 4 M NaOH at 170 deg, and the dihydrocinnamic acid derivatives released from their etherified forms determined by GC.Using model compounds it was shown that these reactions proceeded quantitatively.The results indicate that all of the etherified ferulic acid in the dioxane-H2O-soluble fractions of walls of wheat and phalaris internodes is also ester-linked.It has been calculated that there are nine to 10 ferulic acid ester-ether bridges for every 100 C6-C3 lignin monomers. p-Coumaric acid is not involved in ester-ether bridges. Key Word Index - Triticum aestivum; Phalaris aquatica; Gramineae; lignin; polysaccharide; p-coumaric acid; ferulic acid; esterified cinnamic acid; etherified cinnamic acid.
- Lam, Thi Bach Tuyet,Iiyama, Kenji,Stone, Bruce A.
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p. 1179 - 1184
(2007/10/02)
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- Process for the preparation of omega-arylalkanoic acids
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The present inventon pertains to a process for the preparation of omega-arylalkanoic acids of the genral formula wherein R is hydrogen, hydroxy, C1 -C8 alkyl, C1 -C8 alkoxy, or aryl; wherein R1 is C1 -C4 alkyl; and wherein Ar is an aryl group which can be further substituted with at least one of hydroxy, C1 -C8 alkyl, C1 -C8 alkoxy, aryl, halide, amino, or acetamido. The omega arylalkanoic acids of the given formula are prepared using catalysts which provide an improvement over the known Willgerodt-Kindler reaction. The present invention also pertains to methods for removing sulfur during the above-described process for the preparation of the omega-arylalkanoic acids.
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- The Effect of Carbonyl Containing Terminal Chains on Mesomorphic Properties in 4,4'-Disubstituted Phenylbenzoates and Phenylthiobenzoates. 4. Phenylbenzoates Containing A (CH2)nCO2R' Group (n = 0-2) on the Phenolic End
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The effect of a (CH2)nCO2R' group on the mesomorphic properties of the esters where X = alkyl or alkoxy, Y = (CH2)nCO2R'(R' = C7 and C9) and n = 0-2 has been studied by synthesizing these esters and determining their mesomorphic properties by hot-stage polarizing microscopy.The starting phenols were prepared by esterification of 4-hydroxybenzoic, phenylacetic or phenylpropionic acids.Both the benzyl and methoxycarbonyl protecting groups were tried with the latter giving higher yields when n = 0 because of better solubility of the protected acid.No mesophases were observed in the esters when n = 1, nematic and smectic A phases occurred when n = 2 and smectic A and C phases when n = 0.A few 1,4-cyclohexane diesters were also prepared using these phenols.The mesomorphic properties of these esters followed the same trend observed in the phenylbenzoates escept no C phases were observed.Comparisons of the transition temperatures for these esters with those for Y = R' showed that both small increases or decreases were observed for Y = CO2R'.However, the addition of a spacer methylene group (n = 1 and 2) always gave lower temperatures with the amount of lowering being much greater for n = 2 than n = 1.A comparison of transition temperatures for Y = CO2R', OCOR', COR' and OR' indicated that these temperatures were higher when Y = COR' as expected from dipole moment considerations but were lower when Y = CO2R' than when Y = OCOR', the opposite expected from these considerations.This trend was also observed in the cyclohexane diesters.Transition temperatures were always higher for the esters when Y has an oxygen atom adjacent to the benzene ring.Therefore, esters with Y = O(CH2)nCO2R', n = 1 and 2 were also synthesized.The phenols were prepared by alkylation of 4-benzyloxyphenol with the bromo esters followed by hydrogenolysis.However, these esters showed no mesophases except the cyclohexane diester with n = 2.
- Neubert, M. E.,Leung, K.,Jirousek, M. R.,Ezenylimba, M. C.,Sabol-Keast, S.,et al.
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