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Dalmasso Pablo R - - 2012
We report for the first time the use of polyhistidine (Polyhis) to efficiently disperse multiwall carbon nanotubes (MWCNTs). The optimum dispersion MWCNT-Polyhis was obtained by sonicating for 30min 1.0mgmL(-1) MWCNTs in 0.25mgmL(-1) Polyhis solution prepared in 75:25 (v/v) ethanol/0.200M acetate buffer solution pH 5.00. The dispersion was characterized by scanning ...
Loeser Eric - - 2011
In this study, the tromethamine salt of an active pharmaceutical ingredient containing both a carboxylic acid and ethyl ester functionality was subjected to forced degradation conditions. Based on HPLC-MS analysis, it was found that tromethamine formed both amide and ester type condensation products with the API, with amide formation predominating ...
Tayama Eiji - - 2011
Asymmetric α-2-tosylethenylation of (S)-2-(pyrrolidin-1-yl)propanoic acid esters was shown to produce good yields with high enantioselectivities. The reaction proceeds via the formation of a non-racemic ammonium enolate without an external source of chirality.
Prasad K Sudhakara - - 2012
A simple procedure for the modification of carbon nanoparticles (CNPs) from castor oil soot using acid treatment was described herein. Characterization studies revealed the presence of edge plane sites and surface carbon-oxygen functionalities at the surface of the CNP material. Voltammetric studies revealed the increased electrochemical activity of the CNP-modified ...
Momiyama Norie - - 2011
Chiral bis-phosphoric acid 1 was designed to identify as a new class of structural features in chiral Brønsted acid catalysts, and evaluated in the Diels-Alder reaction of α,β-unsaturated aldehydes 4 with 1-N-acylamino-1,3-butadienes 3. X-ray diffraction analysis revealed the single atropisomer 1, bearing S axial chirality at 3,3'-biaryl substituents on (R)-binaphthyl ...
Simitzis J - - 2011
Copolyesters of glycolic acid (G) combined with sebacic acid (S) and ethylene glycol were synthesized in different molar ratios (G: 0-100% and S: 100-0%) and their hydrolytic degradation was studied and correlated with their structures. Based on the FTIR spectra of the homopolyesters and copolyesters and the normalized peak intensity ...
Jacobs Laura E - - 2011
The photolysis of caffeine was studied in solutions of fulvic acid isolated from Suwannee River, GA (SRFA) and Old Woman Creek Natural Estuarine Research Reserve, OH (OWCFA) with different chemical amendments (nitrate and iron). Caffeine degrades slowly by direct photolysis (>170h in artificial sunlight), but we observed enhanced photodegradation in ...
Hu Yufang - - 2011
A novel sensitive and selective imprinted electrochemical sensor for the determination of oleanic acid was constructed on a carbon electrode by stepwise modification of functional multi-walled carbon nanotubes, cobalt hexacyanoferrate nanoparticles and a thin imprinted sol-gel film. The fabrication of a homogeneous porous poly (sodium 4-styrenesulfonate-co-acrylic acid)-grafted multi-walled carbon nanotubes/SiO(2)-chitosan ...
Müller Steffen - - 2011
The first catalytic asymmetric Fischer indolization is reported. In the presence of a 5 mol % loading of a novel spirocyclic chiral phosphoric acid, 4-substituted cyclohexanone-derived phenylhydrazones undergo a highly enantioselective indolization. Efficient catalyst turnover was achieved by the addition of a weakly acidic cation exchange resin, which removes the ...
Mori Eiji - - 2011
Metabolic flux analysis using (13) C enrichment data of intracellular free amino acids (FAAs) can improve the time resolution of flux estimation compared to analysis of proteinogenic amino acid data owing to the faster turnover times of FAAs. The nature of the (13) C enrichment dynamics of FAAs remains obscure, ...
Noda Shuhei - - 2011
Transglutaminase from Streptoverticillium cinnamoneum (StvcMTG) was produced using recombinant Streptomyces lividans. When grown on glycerol and xylose as sole carbon sources, S. lividans/StvcMTG produced 360 and 530mg of StvcMTG per liter, respectively. With starch and xylan, the strain produced 230 and 400mg of StvcMTG per liter, respectively. Recombinant S. lividans/encP, ...
Wu Xiao-Feng - - 2011
A novel methodology for the direct nitration of arylboronic acids has been developed. By using inexpensive tert-butyl nitrite various aromatic nitro compounds are produced in moderate to good yields (45-87%) without the need of any catalyst.
Chen Lei - - 2011
The presence of dissolved organic matter (DOM) in aquatic system has an important influence on the phototransformation of organic contaminants through the production of reactive substances, such as hydroxyl radicals (OH), singlet oxygen ((1)O(2)), and DOM triplet states ((3)DOM*) under solar irradiation. Addition of 5mg/L of Humic acid sodium (HA), ...
Ovchinnikova Olga G - - 2011
An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O48 and studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and (1)H,(13)C HSQC and HMBC experiments. It was found that the polysaccharide is acidic and has ...
Caschera F - - 2011
The self-assembly of cationic and anionic amphiphile mixtures into vesicles in aqueous media was studied using two different systems: (i) decanoic acid and trimethyldecylammonium bromide and (ii) hexadecanedioic acid (a simple bola-amphiphile) and trimethyldecylammonium bromide. The resulting vesicles with varying amphiphile ratios were characterized using parameters such as the critical ...
Tan Chaoliang - - 2011
An effective single-walled carbon nanotube (SWNT) covalently loaded with unsaturated terbium emissive material was designed for specific and rapid (2-3 s) detection of calcium dipicolinate (CaDPA) (detection limit 1 μM). The nanoprobe was successfully assembled onto electrodes and its sensing abilities were investigated through electrochemical measurement. Cyclic voltammetry curves were ...
Ji Pengju - - 2011
The acidities of various carbon acids in liquid ammonia (LNH(3)) at room temperature were determined by NMR and rates of D-exchange. There is a reasonable linear correlation of the pK(a)s in LNH(3) with those in water and DMSO of slope 0.7 and 0.8, respectively. Carbon acids with an aqueous pK(a) ...
Sponza Delia Teresa - - 2012
An anaerobic multichamber bed reactor (AMCBR) was effective in removing both molasses-chemical oxygen demand (COD), and the antibiotic oxytetracycline (OTC). The maximum COD and OTC removals were 99% in sequential AMCBR/completely stirred tank reactor (CSTR) at an OTC concentration of 300 mg L(-1). 51%, 29% and 9% of the total ...
Solovyev Andrey - - 2011
N,N'-Dialkyl and N,N'-diaryl imidazol-2-ylidene-boranes and trifluoroboranes are rapidly lithiated at C4 of the imidazole ring, and the resulting intermediates have been quenched with an assortment of electrophiles to provide ring-functionalized imidazol-2-ylidene-boranes. Further deprotonation and functionalization of C5 have been demonstrated. Deboronation of the products by treatment with triflic acid or ...
Erdem Beyhan - - 2011
Sulfonic acid functionalized poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole), poly(EGDMA-VTAZ-SO(3)H), is evaluated in the esterification of lactic acid with methanol. From nitrogen physisorption data, high surface area (220m(2)/g) and type IV isotherm are obtained. Conversion measurements indicate a stronger interaction of poly(EGDMA-VTAZ-20%SO(3)H) with water molecules than that occurring in poly(EGDMA-VTAZ-10%SO(3)H). Hence, the higher ...
Destaillats Frédéric - - 2011
Monochloropropanediol (MCPD) fatty acid esters are process contaminants generated during the deodorisation of edible oils. In particular, MCPD diesters are found in higher abundance in refined palm oil than other edible oils. In the present study, a series of model reactions mimicking palm oil deodorisation has been conducted with pure ...
Kushida Akira - - 2011
Sulfotransferase enzymes are known to regulate physiologically active substances such as steroids and catecholamines in mammals. Although invertebrates also express sulfotransferases, their biological function is mostly unclear. In a previous study, we reported that 4-nitrocatechol and the gallete ester are substrates for the silkworm sulfotransferase bmST1. The K(m) of bmST1 ...
McGrath John W - - 2011
Racemic (1R*,2R*)-1,2-dihydroxy-[1-(13) C(1) ]propylphosphonic acid and 1-hydroxy-[1-(13) C(1) ]acetone were synthesized and fed to R. huakuii PMY1. Alanine and a mixture of valine and methionine were isolated as their N-acetyl derivatives from the cell hydrolysate by reversed-phase HPLC and analyzed by NMR spectroscopy. It was found that the carbon atoms ...
Bi Mingda - - 2011
Enhancing and sustaining AMG 009 dissolution from a matrix tablet via microenvironmental pH modulation and supersaturation, where poorly soluble acidic AMG 009 molecule was intimately mixed and compressed together with a basic pH modifier (e.g., sodium carbonate) and nucleation inhibitor hydroxypropyl methylcellulose K100 LV (HPMC K100 LV), was demonstrated previously. ...
Hoffer L John - - 2011
It is commonly assumed that the weight of the amino acids in a parenteral amino acid mixture equals the amount of protein they provide. This assumption ignores the fact that the molecular weight of free amino acids is 18 mass units greater than when they are protein bound. The actual ...
Khodair Ahmed I - - 2011
N- and S-galactosylation was carried out via the reaction of 5-((Z)-arylidene)-2-thioxo-4-thiazolidinones with 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide under alkaline conditions or under silylation conditions. Deacetylation of the N-galactosylation products was performed with concentrated hydrochloric acid in methanol (3.5%) or sodium methoxide in methanol without cleavage of the 2-thioxo-4-thaizolidinone ring by means of acid ...
Marzo Matteo - - 2011
The hydrolysis of the three most important disaccharides: sucrose, maltose and cellobiose, has been comparatively studied in mild conditions (50-80°C) in water over several solid acid catalysts. Strong acidic resins (Amberlite A120 and A200), mixed oxides (silica-alumina and silica-zirconia), and niobium-containing solids (niobic acid, silica-niobia, and niobium phosphate) have been ...
Sen Gupta Susanta K - - 2011
A reverse ortho effect is observed for the (13)  C NMR chemical shifts of the carboxyl carbon (δ(co) ) in benzoic acids measured in aprotic solvents of varying polarity. The ortho effect on δ(co) is best described by a combination of the reverse field and steric accelerating effects of the ...
Gu Lin - - 2011
In this work, an humic acid adsorption with an enhanced Fenton oxidation was employed to treat the real effluent originating from the 1-diazo-2-naphthol-4-sulfonic acid (1,2,4-Acid) production plant. In a first step, humic acid with MgSO(4) was selected as adsorbent and precipitant for physicochemical pretreatment, the synergetic effect had led to ...
Yang Xue - - 2011
Organic matters in sewage sludge can be converted into volatile fatty acids (VFAs) as renewable carbon sources. This work for the first time applied anthraquinone-2,6-disulfonate (AQDS) for enhancing VFA production from sewage sludge. With 0.066 or 0.33g AQDSg(-1) dried solids (DS), the yields for VFAs peak at 403 or 563mgl(-1), ...
Wang Zhipeng - - 2011
The bare Pt electrode modified directly and simply by carbon nanosheets, which were synthesized by microwave plasma enhanced chemical vapor deposition at relatively low temperature, can be used to simultaneously and effectively detect dopamine, ascorbic acid and uric acid.
Downing Simoné - - 2011
β-N-Methylamino-L: -alanine (BMAA), a non-proteinogenic amino acid, has been detected in a range of cyanobacteria, including terrestrial, aquatic, free living and endosymbiotic species. The widespread occurrence of cyanobacteria in the environment raises concerns regarding the ecological and toxicological impact of BMAA, and consequently, studies have focussed extensively on the toxicity ...
Ohta Hidetoshi - - 2011
Carbon-supported Pt catalysts are highly active and reusable for the aqueous-phase hydrodeoxygenation of phenols as lignin models without adding any acids. It is suggested that Pt/carbon facilitates the hydrogenation of phenols and the hydrogenolysis of the resulting cyclohexanols.
Fröhlich Peter - - 2011
In the field of industrial biocatalysis, formate dehydrogenase (FDH) is well established, in particular for its broad application in cofactor regeneration. Further applications have been limited by the enzyme's narrow range of substrates. These restrictions have been overcome now by the finding, that the enzyme is capable of selectively cleaving ...
Wanninayake Udayanga - - 2011
A Taxus canadensis phenylalanine aminomutase (TcPAM) catalyzes the isomerization of (S)-α- to (R)-β-phenylalanine making (E)-cinnamate (~10 %) as a by-product at steady-state. A currently accepted mechanism for TcPAM suggests that the amino group is transferred from the substrate to a prosthetic group comprised of an amino acid triad in the ...
Ellis Lucas D - - 2011
Our lab and most others have not been able to close a carbon balance for fermentation by the thermophilic, cellulolytic anaerobe, Clostridium thermocellum. We undertook a detailed accounting of product formation in C. thermocellum ATCC 27405. Elemental analysis revealed that for both cellulose (Avicel) and cellobiose, >92% of the substrate ...
Amarasekara Ananda S - - 2011
The effects of adding D(2)SO(4), and p-toluenesulfonic acid-d to D-cellobiose dissolved in D(2)O were investigated at 23°C by plotting (13)C NMR chemical shift changes (Δδ) against the acid to D-cellobiose molar ratio. (13)C Chemical shifts of all 18 carbon signals from α and β anomers of D-cellobiose showed gradual decreases ...
Li Yanhong - - 2011
Cytidine 5'-monophosphate (CMP)-sialic acid synthetases (CSSs) catalyze the formation of CMP-sialic acid from CTP and sialic acid, a key step for sialyltransferase-catalyzed biosynthesis of sialic acid-containing oligosaccharides and glycoconjugates. More than 50 different sialic acid forms have been identified in nature. To facilitate the enzymatic synthesis of sialosides with diverse ...
Vilanova Mar - - 2011
BACKGROUND: Early defoliation is a very innovative technique in viticulture used for yield management. The effects of early leaf removal performed manually and mechanically at two different phenological stages, pre-bloom and fruit set, on the volatile composition of Tempranillo (Vitis vinifera L.) wines were studied. Volatiles were identified and quantified ...
Cho Sunja - - 2011
In order to investigate and generalize the effects of carbon and nitrogen sources on the growth of and lipid production in Chlorella sp. 227, several nutritional combinations consisting of different carbon and nitrogen sources and concentrations were given to the media for cultivation of Chlorella sp. 227, respectively. The growth ...
Vatsala T M - - 2011
Rhodospirillum rubrum was grown under light anaerobic conditions with phycocyanin (C-pc) extracted from Spirulina platensis as the sole source of carbon and nitrogen. When grown under these conditions cellular components like lipids, carbohydrates, protein, carotenoids, bacteriochlorophyll were similar to the one grown with malic acid and ammonium chloride. Growth of ...
Hong Won-Kyung - - 2011
We examined the growth of a novel oleaginous microalga, Aurantiochytrium sp. KRS101, using cellulosic materials as nutrients, and the resultant production of lipids containing high levels of docosahexaenoic acid (DHA). The microalgal strain could grow using either carboxymethylcellulose or cellobiose as a carbon source, and produced lipids containing high levels ...
Slatnar Ana - - 2011
Fresh figs were subjected to two different drying processes: sun-drying and oven drying. To assess their effect on the nutritional and health-related properties of figs, sugars, organic acids, single phenolics, total phenolics and antioxidant activity were determined before and after processing. Samples were analyzed 3 times in a year and ...
Bonnett Shilah A - - 2011
OleD is shown to play a key reductive role in the generation of alkenes (olefins) from acyl thioesters in Stenotrophomonas maltophilia. The gene coding for OleD clusters with three other genes, oleABC, and all appear to be transcribed in the same direction as an operon in various olefin producing bacteria. ...
Ben-Gal Alon - - 2011
Five rates of water application (30, 50, 75, 100 and 125% of potential evapotranspiration) were applied in a four year study on olive (Olea europaea) varieties Barnea and Souri. Increased irrigation rate lead to increased tree-scale oil yields, lower polyphenol content and, frequently, to higher oil acidity. These effects were ...
Krähenbühl Barbara - - 2011
A four-dimensional (4D) APSY (automated projection spectroscopy)-HBCB(CG)CDHD experiment is presented. This 4D experiment correlates aromatic with aliphatic carbon and proton resonances from the same amino acid side chain of proteins in aqueous solution. It thus allows unambiguous sequence-specific assignment of aromatic amino acid ring signals based on backbone assignments. Compared ...
Katagiri Toshimasa - - 2011
The preparation of optically pure alpha-trifluoromethyl-alpha-amino acids from N-tosyl-2- trifluoromethyl-2-alkyloxycarbonylaziridine is described. Optically pure aziridine was prepared with a 60% yield via 3 steps from optically pure 2,3-epoxy-1,1,1-trifluoropropane (TFPO). Ring opening reactions of the aziridine with a variety of nucleophiles and subsequent deprotection of the N-tosyl moieties gave the optically ...
O'Reilly Robert J - - 2011
Quantum chemistry computations have been used to investigate hydrogen-atom abstraction by chlorine atom from protonated and N-acetylated amino acids. The results are consistent with the decreased reactivity at the backbone α-carbon and adjacent side-chain positions that is observed experimentally. The individual effects of NH(3)(+), COOH, and NHAc substituents have been ...
Ozeir Mohammad - - 2011
Coenzyme Q (Q), an essential component of eukaryotic cells, is synthesized by several enzymes from the precursor 4-hydroxybenzoic acid. Mutations in six of the Q biosynthesis genes cause diseases that can sometimes be ameliorated by oral Q supplementation. We establish here that Coq6, a predicted flavin-dependent monooxygenase, is involved exclusively in ...
Amador-Noguez Daniel - - 2011
The fermentation carried out by the biofuel producer Clostridium acetobutylicum is characterized by two distinct phases. Acidogenesis occurs during exponential growth and involves the rapid production of acids (acetate and butyrate). Solventogenesis initiates as cell growth slows down and involves the production of solvents (butanol, acetone, and ethanol). Using metabolomics, ...
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