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Hama Yoichiro - - 2010
Here we report a simple method for the structural analysis of red algal galactan containing 3,6-anhydrogalactose. Structural heterogeneity in the galactan was demonstrated by this method. For selective hydrolysis of 3,6-anhydrogalactosidic linkages in the galactan, conditions for reductive mild acid hydrolysis were examined by characterizing the resulting oligosaccharide alditols by ...
Luo Liqiang - - 2010
A simple and rapid method for the determination of ferulic acid in pharmaceutical formulations by didodecyldimethylammonium bromide (DDAB)/Nafion composite film-modified carbon paste electrode is presented. The electrochemical behavior of ferulic acid at the proposed electrode was investigated by cyclic voltammetry and a well-defined oxidation peak was observed at +0.44 V ...
Petacci Fernando - - 2010
Astilbin (5,7,3',4'-tetrahydroxy-2,3-dihydroflavonol-3-ß-o-rhamnoside), a flavonoid with a large range of biological activities, was isolated from Dimorphandra mollis, a shrub common to the Brazilian Cerrado. The purpose of this study is to verify the effects of astilbin on myeloperoxidase (MPO) and horseradish peroxidase (HRP), and its antioxidant activity against hypochlorous acid (HOCl) ...
Kim Jisun - - 2010
Dopamine (DA) is one of the most important catecholamine neurotransmitter molecules in the central nervous system (CNS). An abnormal level of DA in vivo can cause CNS diseases such as Parkinsonism and Schizophrenia. Thus, it is essential to develop an accurate and easy to use method for determining the level ...
Sun L M - - 2010
AIMS: To clarify the underlying synergistic antifungal mechanisms of retigeric acid B (RAB) in combination with azoles against Candida albicans. METHODS AND RESULTS: Increased accumulation of rhodamine 123 in C. albicans was measured by both spectrophotometric method and flow cytometry. The inhibitory properties to the drug efflux of C. albicans ...
Sugimoto Naoki - - 2010
A quantitative NMR (qNMR) method was applied for the determination of carminic acid. Carminic acid is the main component in cochineal dye that is widely used as a natural food colorant. Since several manufacturers only provide reagent-grade carminic acid, there is no reference material of established purity. To improve the ...
Kinumi Tomoya - - 2010
We have developed an accurate and traceable quantitation method of proteins and peptides by isotope-dilution mass spectrometry with the precolumn derivatization for hydrolyzed amino acid. This method utilized N-butylnicotinic acid N-hydroxysuccinimide ester iodide as the derivatization reagent and C-30 reversed phase column for the separation. Quantitative results of porcine insulin ...
Xiang Zheng - - 2010
The inhibitory effect of smallanthaditerpenic acids A, B, C and D previously isolated from leaves of Smallanthus sonchifolius (yacon) on alpha-glucosidase were examined and their IC50 were determined to be 0.48 mg/mL, 0.59 mg/mL, 1.00 mg/mL, and 1.17 mg/mL respectively. In addition, a rapid, reliable RP-HPLC method for the analysis ...
Nording Malin L - - 2010
Airway inflammation characterizing asthma and other airway diseases may be monitored through biomarker analysis of exhaled breath condensate (EBC). In an attempt to discover novel EBC biomarkers, a high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was used to analyze EBC from ten control non-asthmatics and one asthmatic ...
Komissarov Vsevolod V - - 2010
A novel one-pot method was developed for the synthesis of the title compounds starting from 4-chloro-1-aryl-1-butanones 1, phosphorus trichloride and acetic acid. The end products 2 were obtained in 20-94% yield. The cyclization step under acidic conditions probably occurs as a result of anchimeric assistance of the phosphonic acid group.
Huang Renliang - - 2010
A convenient and cost-efficient method featuring the integration of enzymatic and acid catalysis has been developed for the selective conversion of glucose into HMF, which provides a new strategy for HMF production from glucose.
Proskurnin Mikhail A - - 2010
As a primary aim, several approaches to photothermal (thermal-lens) and optoacoustic determination of exogenous pyrogens (lipopolysaccharides) based on photometric procedures for their determination at the microgram level and below are compared. The limits of detection of lipopolysaccharides by thermal-lens spectrometry and optoacoustic spectroscopy are at a level of 2-100 ng/mL, ...
Dubé Pascal - - 2009
Carbonyldiimidazole (CDI) was found to mediate the Lossen rearrangement of various hydroxamic acids to isocyanates. This process is experimentally simple and mild, with imidazole and CO(2) being the sole stoichiometric byproduct. Significant for large-scale application, the method avoids the use of hazardous reagents and thus represents a green alternative to ...
del Campo Gloria - - 2010
A quantitative method for the determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural (5-HMF) in soluble coffees by applying the proton nuclear magnetic resonance technique ((1)H NMR) is proposed. Each of these compounds records a singlet signal at the 7.6-9.5 ppm interval of the spectrum, and its area is used ...
Terasaki Masanori - - 2009
This study combined chemical analysis and bioassays of paper mill effluents and their components in order to determine their antiestrogenic activity. The bioassay comprised a yeast two-hybrid assay incorporating the estrogen receptor alpha (hERalpha) and an hERalpha competitive enzyme-linked immunosorbent assay (ELISA). Samples were fractionated by solid phase extraction (SPE) ...
Horák Tomás - - 2009
Solid-phase extraction (SPE), solid-phase microextraction (SPME) using carbowax/divinylbenzen fiber, and stir bar sorptive extraction (SBSE) followed by solvent back extraction have been used for the extraction of free fatty acids (caproic, caprylic, pelargonic, capric, lauric, myristic, palmitic, stearic, oleic, linoleic, and linolenic acids) from beer. Subsequent gas chromatographic analyses with ...
Granger Julie - - 2009
In environmental water samples that contain both nitrate (NO3-) and nitrite (NO2-), isotopic analysis of nitrate alone by all currently available methods requires pretreatment to remove nitrite. Sulfamic acid addition, used previously for this purpose (Wu JP, Calvert SE, Wong CS. Deep-Sea Research Part I - Oceanographic Research Papers 1997; ...
Alves Susana P - - 2009
The fatty acid (FA) analysis of grass and maize silages was studied by application of a direct transesterification method (DT) followed by purification by solid-phase extraction (SPE). The choice of the internal standard (IS) for quantification of FA by gas-liquid chromatography (GLC) was also studied. The acidic DT method applied ...
Mandalakis Manolis - - 2010
The analysis of amino acids by gas chromatography mass spectrometry (GC-MS) after their derivatization with N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide was investigated as an alternative approach for the determination of free (FAA) and combined amino acids (CAA) in aerosols. This technique showed excellent linearity with r(2) values ranging from 0.9029 to 0.9995 and instrumental ...
Tang Xiaofeng - - 2010
A novel and simple method for the direct and quantitative determination of L-tryptophan (Trp), L-tyrosine (Tyr) and L-cysteine (Cys) was proposed in this work. Carbon nanofibers (CNFs), made by electrospinning technique, were used to modify carbon paste electrode (CPE) without any treatment to study the electrochemical behaviors of the three ...
Zhang Wang-bing - - 2010
In this study we firstly report a new electrolytic cold vapor generation system for mercury determination on Pt/Ti cathode in the presence of organic acid catholyte. Comparing with the traditional inorganic acid, formic acid increased the signal intensity of Hg vapor from electrolytic generation on Pt cathode and reduced the ...
Haque Enamul - - 2009
A facile purification method for metal-organic frameworks (MOFs), especially the ones containing insoluble 1,4-benzenedicarboxylic acid (terephthalic acid) in the pore, has been suggested. The purification method consists of the treatment of the MOF with amides such as N,N-dimethylformamide, especially under ultrasound treatment. The purification is completed within 1 h at ...
Yu Jinghua - - 2009
A novel molecular imprinting-chemiluminescence (MI-CL) method for the determination of sorbic acid (SA) was established, taking the molecularly imprinted polymer (MIP) as recognition material and a novel rhodanine derivative as chemiluminescence reagent. The MIP was prepared by a self-assembly technique with SA as template molecule, methacrylic acid (MAA) as functional ...
Garrido-Delgado Rocio - - 2009
This article reports a method for determining organic acids by CE in order to obtain a characteristic fingerprint with a view to classifying white wine samples with the aid of multivariate statistics. The proposed method was optimized for the determination of the most abundant organic acids in wine (viz. succinic, ...
Caroprese Alessandro - - 2009
BACKGROUND/PURPOSE: Foot malodor is mostly due to short-chain fatty acids produced by bacterial metabolism of eccrine sweating. We aimed to develop a protocol for an objective (instrumental) efficacy evaluation of foot deodorant formulations. METHODS: Head-space solid-phase microextractions of target fatty acids from the feet of six healthy volunteers were analyzed ...
Naseri Abdolhossein - - 2009
The net analyte preprocessing/classical least-squares (NAP/CLS) method is a simple chemometric method that has been used for the simultaneous spectrophotometric determination of benzoic acid, sorbic acid, and ascorbic acid. The obtained results indicated that the performances of the NAP/CLS and partial least-squares methods were almost identical. The net analyte signal ...
Harp Bhakti Petigara - - 2009
A reversed-phase LC method was developed to determine two manufacturing intermediates in the monosulfo monoazo color additive D&C Red No. 34 and its lakes. The analytes are 2-amino-1-naphthalenesulfonic acid (Tobias acid) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). This method can be used for batch certification of the color additives by the ...
Liu Shubin - - 2009
Accurate predictions of molecular acidity using ab initio and density functional approaches are still a daunting task. Using electronic and reactivity properties, one can quantitatively estimate pKa values of acids. In a recent paper [S. B. Liu and L. G. Pedersen, J. Phys. Chem. A 113, 3648 (2009)], we employed ...
Zhang Shanqing - - 2009
A photoelectrochemical probe for rapid determination of chemical oxygen demand (COD) is developed using a nanostructured mixed-phase TiO2 photoanode, namely PeCOD probe. A UV-LED light source and a USB mircroelectrochemical station are powered and controlled by a laptop computer, which makes the probe portable for onsite COD analyses. The photoelectrochemical ...
Bottein Marie-Yasmine Dechraoui - - 2010
Brevetoxins (BTXs) are a class of cyclic polyether toxins produced by the dinoflagellate Karenia brevis. These substances are subject to extensive conjugative metabolism in shellfish. BTX-B forms a conjugate with cysteine and is oxidized and reduced to yield BTX-B2, which is further modified by fatty acid addition via cysteine amide ...
Schwarz Lothar - - 2009
Analytical standards are needed in latent fingerprint detection for research and development as well as for quality control in routine work because normal fingerprints are too varied for comparison studies and tests. One way is to create latent fingerprints. For the amino acid sensitive detection method this can be achieved ...
Bazel Yaroslav - - 2009
A new sensitive and selective spectrophotometric method has been developed for the determination of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid in pharmaceuticals in the presence of nicotinic acid. The method is based on the reaction of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid with 1,3,3-trimethyl-5-phenyl-2-[3-(1,3,3-trimethyl-1,3-dihydro-indol-2-ylidene)-propenyl]-3H-indolium chloride (PIC) followed by the extraction of the formed ion associate into toluene and ...
Zhachkina Anna - - 2009
The gas phase acidity (DeltaH(acid) and DeltaG(acid)) and proton affinity (PA, and gas phase basicity (GB)) of adenine, guanine, and O(6)-methylguanine (OMG) have been examined using both theoretical (B3LYP/6-31+G*) and experimental (bracketing, Cooks kinetic) methods. We previously measured the acidity of adenine using bracketing methods; herein we measure the acidity ...
Crich David D Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, avenue de la Terrasse, 91198 Gif-sur-Yvette, France. - - 2009
A method for the synthesis of peptidyl thioacids is described on the basis of the use of the N-[9-(thiomethyl)-9H-fluoren-2-yl]succinamic acid and cross-linked aminomethyl polystyrene resin. The method employs standard Boc chemistry SPPS techniques in conjunction with 9-fluorenylmethyloxycarbonyl protection of side-chain alcohols and amines and 9-fluorenylmethyl protection of side-chain acids and ...
Underwood Robyn M - - 2009
Indoor fumigation of honey bees, Apis mellifera L., with formic acid to control varroa mites, Varroa destructor Anderson & Trueman, allows simultaneous fumigation of multiple colonies with little labor input and good efficacy. Several experiments were designed to test the efficacy of formic acid as a treatment for honey bee ...
Deng Yan - - 2009
Various alkyl-phenylboronic acids have been widely used in the fields of electronics, chemistry, medicine and biology, especially in glucose sensors and intermediates of medicines. In this paper, the syntheses of two or three different alkyl-phenylboronic acids and the improvement on synthesis processes were studied with Grignard reagent method in detail. ...
Kumari Sangeeta - - 2010
We determined the gas-phase acidities (DeltaH(acid)) of four deoxyribonucleosides, i.e., 2'-deoxyadenosine (dA), 2'-deoxyguanosine (dG), 2'-deoxycytidine (dC), and 2'-deoxythymidine (dT) by applying the extended kinetic method. The negatively charged proton-bound hetero-dimeric anions, [A - H - B](-) of the deoxyribonucleosides (A) and reference compounds (B) were generated under electrospray ionization conditions. ...
Mossoba Magdi M - - 2009
Trans fatty acids are found in a variety of foods like dairy and meat products, but the major dietary sources are products that contain commercially hydrogenated fats. There has been a renewed need for accurate analytical methods for the quantitation of total trans fat since mandatory requirements to declare the ...
Golay Pierre-Alain - - 2009
To support labeling, claims, and authenticity of food products, industry needs reliable methods for the analysis of fatty acids, including trans fatty acids (TFA). In finished products, precise quantification of TFA can be problematic due to the occurrence of various positional and geometrical isomers originating from different sources, such as ...
Kanwal Shamsa - - 2009
A highly sensitive flow-injection chemiluminescent method for the direct determination of pyrogallol compounds has been developed. Proposed method is based on the enhanced effect of pyrogallol compounds on the chemiluminescence signals of KMnO(4)-H(2)O(2) system in slightly alkaline medium. Three important pyrogallol compounds, pyrogallic acid, gallic acid and tannic acid, have ...
Nurit Eric - - 2009
Biofortification programs in maize have led to the development of quality protein maize (QPM) with increased contents of the essential amino acids lysine and tryptophan, and increased nutritional value for protein deficient populations where maize is a staple food. Because multiple genetic systems control and modify the protein quality of ...
Zhu Shuyun - - 2009
Single-walled carbon nanohorn modified glassy carbon electrode (SWCNH-modified GCE) was first employed for the simultaneous determination of uric acid (UA), dopamine (DA), and ascorbic acid (AA). The SWCNH-modified GCE displayed excellent electrochemical catalytic activities. The oxidation overpotentials of UA, DA, and AA decrease significantly and their oxidation peak currents increase ...
Lee Bokyoung - - 2009
A method has been developed for the determination of the concentration of low molecular weight monocarboxylic acid gases in the atmosphere. The method involves quantitative collection of analyte gases using a parallel plate diffusion scrubber and subsequent ion analysis by ion chromatography. Among the gases are formic acid, acetic acid, ...
Gronert Scott - - 2009
The proton affinities of the 20 common amino acids have been computed at the G3MP2 level using structures derived from broad conformational searches at a variety of levels including G3MP2. In some cases, the conformational surveys identified more stable species than had been used in previous studies of proton affinities, ...
Liu Lin - - 2010
Diosgenin is an important starting material in the steroidal hormone industry. Traditionally, diosgenin is mainly produced by acid hydrolysis of Dioscorea zingiberensis C. H. Wright (DZW) tubers. This method yields numerous byproducts that can cause serious pollution. In this study, diosgenin was obtained by biotransformation of steroidal saponins in DZW ...
Vidal A - - 2009
The effect of cooking on the concentration and burden of domoic acid in two bivalve molluscs was studied. The Manila clam (Ruditapes philippinarum) and cockle (Cerastoderma edule) were subjected to steaming and boiling, respectively. In both cases, factorial plans were used to evaluate the effects of common cooking methods and ...
Seki Koh-ichi - - 2010
BACKGROUND, AIM, AND SCOPE: We recently developed a new isolation method for diesel exhaust particles (DEP), involving successive extraction with H(2)O, sodium bicarbonate, and sodium hydroxide, in which the sodium hydroxide extract was found to consist of phenolic components. Analysis of the extract revealed that vasodilative-active nitrophenols are in DEP ...
Elliott Douglas W - - 2009
The analysis of deuterium wideline NMR spectra has been an essential step in characterizing the dynamics of molecules in the solid-state. Although clearly important, the identification of quadrupolar coupling constants (QCCs) from the powder patterns is often complicated by poor sensitivity and/or spectral overlap. Previously, others have demonstrated the utility ...
Megdal Peter Andrew - - 2009
Mislabeling of farmed and wild salmon sold in markets has been reported. Since the fatty acid content of fish may influence human health and thus consumer behavior, a simplified method to identify wild and farmed salmon is necessary. Several studies have demonstrated differences in lipid profiles between farmed and wild ...
Huang Shan - - 2009
In this contribution, a simple and sensitive method for L-cysteine detection was established based on the increment of the fluorescence intensity of mercaptoacetic acid-capped CdSe/ZnS quantum dots (QDs) in aqueous solution. Meanwhile, the fluorescence characteristics and the optimal conditions were investigated in detail. Under the optimized conditions, the linear range ...
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