Search Results
Results 51 - 100 of 2316
1 2 3 4 5 6 7 8 9 10 >
Kato Megumi - - 2012
Here, we describe an amino acid analysis that is based on the use of hydrophilic interaction liquid chromatography coupled with isotope dilution mass spectrometry for the accurate quantification of underivatized amino acids from hydrolyzed peptide/protein. Twelve underivatized amino acids were separated and detected during an 88-min runtime. The absolute limits ...
Farshdousti Hagh Majid - - 2012
Mechanism of zoledronic acid on osteoblastic differentiation of mesenchymal stem cells (MSCs) has not fully understood. With the knowledge of some drugs mechanism that alter methylation pattern of some genes, the present research sets out to evaluate osterix (OSX) promoter methylation pattern during zoledronic acid-induced osteoblastic differentiation of MSCs. In ...
Poppe László - - 2012
Ammonia-lyases catalyze a wide range of processes leading to α,β-unsaturated compounds by elimination of ammonia. In this chapter, ammonia-lyases are reviewed with major emphasis on their synthetic applications in stereoselective preparation of unnatural amino acids. Besides the synthesis of various unnatural α-amino acids with the aid of phenylalanine ammonia-lyases (PALs) ...
Ferreira Leandro De Santis Lde - - 2012
Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n(9); 18 : 2 Δ(9,12); 20 : 4; ...
Ekpeghere Kalu I - - 2012
The aim of this study was to apply loess balls containing effective microorganisms (EM) to the remediation of contaminated harbor sediments, and to thereby elucidate the functions of EM in remediation. Changes in physicochemical, biochemical, and microbiological parameters were measured to monitor the remediation process at a laboratory scale. Treatment ...
Clapés Pere - - 2012
An enzymatic methodology for the preparation of β-hydroxy-α-amino acid derivatives is described. The method consists of the stereoselective aldol addition reaction of glycine to N-Cbz-amino aldehydes furnishing 3-hydroxy-2,4-diaminobutyric derivatives.
D'Arrigo Paola - - 2012
The use of unnatural amino acids, particularly synthetic α-amino acids, for modern drug discovery research requires the availability of enantiomerically pure isomers. Starting from a racemate, one single enantiomer can be obtained using a deracemization process. The two more common strategies of deracemization are those obtained by stereoinversion and by ...
Friedman Mendel - - 2012
This paper describes a method for determining the nutritional value of D: -amino acids, D: -peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced ...
Zanini Cristina - - 2012
Formaldehyde (HCHO) is a gas (available as a 37% concentrated solution, stabilized with methanol). The 10% dilution (approximately 4% formaldehyde) has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, ...
Falade Olumuyiwa S - - 2011
OBJECTIVE: Two rat bioassay experiments are reported. The first investigated the first limiting amino acid in Acacia colei and the second experiment investigated the effect of S-carboxyethylcysteine (CEC; a compound present in acacia seed) on protein use. METHODS: In the first experiment, Wistar rats were fed A. colei seed supplemented ...
Isidorov V A - - 2011
Using headspace solid-phase microextraction (HS-SPME) followed by diethyl ether and methanol extraction, it was possible to isolate as many as 185 organic compounds out of 17 samples of crude royal jelly (RJ). Of the above compound number, 169 compounds were positively identified by means of gas chromatography-mass spectrometry. The volatile ...
Venkataramanan Keerthi P - - 2011
During the production of biodiesel, crude glycerol is produced as a byproduct at 10% (w/w). Clostridium pasteurianum has the inherent potential to grow on glycerol and produce 1,3-propanediol and butanol as the major products. Growth and product yields on crude glycerol were reported to be slower and lower, respectively, in ...
Christophe G - - 2011
The feasibility of the conversion of acetic acid, a metabolite commonly obtained during anaerobic fermentation processes, into oils using the yeast Cryptococcus curvatus was reported. This microorganism exhibited very slow growth rates on acetate as carbon source, which led to design a two-stage cultivation process. The first consisted of cell ...
Roy Madhumita - - 2011
Polycyclic aromatic hydrocarbons (PAHs) comprise of a group of priority organic pollutants that are toxic and/or carcinogenic. Phenanthrene, the simplest polyaromatic hydrocarbon among recognized priority pollutants, is commonly used as a model compound for the study of PAH biodegradation. Sphingobium sp. strain PNB, capable of degrading phenanthrene as a sole ...
Tzocheva Sylvia S - - 2011
The limiting solubility of fatty acids in micellar solutions of the anionic surfactant sodium laurylethersulfate (SLES) and the zwitterionic surfactant cocamidopropyl betaine (CAPB) is experimentally determined. Saturated straight-chain fatty acids with n=10, 12, 14, 16, and 18 carbon atoms were investigated at working temperatures of 25, 30, 35, and 40°C. ...
Schuster Judith - - 2012
Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as ...
Hadibarata Tony - - 2011
Armillaria sp. F022, a white-rot fungus isolated from a tropical rain forest in Samarinda, Indonesia, was used to biodegrade benzo[a]pyrene (BaP). Transformation of BaP, a 5-ring polycyclic aromatic hydrocarbon (PAH), by Armillaria sp. F022, which uses BaP as a source of carbon and energy, was investigated. However, biodegradation of BaP ...
Harris William S - - 2011
PURPOSE OF REVIEW: ω-3 Fatty acids continue to be promoted as cardioprotective, generating an increased demand for these nutrients. Ocean-based supplies are limited, and so land-based sources are being sought. Stearidonic acid-fortified soybean oil may help to meet this demand. RECENT FINDINGS: Stearidonic acid has been shown in animal and ...
Hvattum Erlend - - 2011
The polysorbate species in polysorbate 80 (PS 80) have been characterized with (1)H NMR, LC-UV/MS and MS/MS. The MS was operated with both negative and positive electrospray ionization (ESI). PS 80 was found to contain mono- and di-fatty acid esters of polyoxyethylene (POE) sorbitan, POE isosorbide and of POE. In ...
Abe Lucile T - - 2011
BACKGROUND: The objectives of this study were (1) to evaluate the content of ellagic acid in fruits consumed by the Brazilian population, including native ones; (2) to further characterize rich sources in relation to ascorbic acid, phenolics contents and in vitro antioxidant capacity; and (3) to study the distribution and ...
Adewuyi Adewale - - 2011
Proximate composition of the seeds and chemical analysis of the oils of Lonchocarpus sericeus and Lonchocarpus cyanescens were determined. The oil content of the seed of L. cyanescens is 29.71 ± 0.20% while that of L. sericeus is 28.00 ± 0.50%. The seeds as well as the oils of L. cyanescens and L. sericeus ...
Poh Hwee Ling - - 2011
Nanoporous carbon materials are highly important materials for a wide array of applications. Here we show that nanoporous carbon can act as highly active materials for electrochemical sensing. We observed that nanoporous carbon material exhibits a faster heterogeneous electron transfer than graphite and pure carbon nanotubes. Nanoporous carbon exhibits a ...
Figueroa Félix L - - 2011
The biofiltration capacity, biomass-yield and accumulation of N- and C-compounds of Hydropuntia cornea were analyzed. Algae were grown in different conditions for 28d: outdoor and indoor, with or without fishpond effluents. N-uptake efficiency of these effluents was higher than 95% after 7d both outdoors and indoors. N-enriched conditions reduced the ...
Fujioka Hiromichi - - 2011
Mild substitution reactions of acetals with carbon nucleophiles via the pyridinium-type salts generated by the treatment of acetals with TESOTf-2,4,6-collidine or 2,2'-bipyridyl have been developed. Various carbon nucleophiles, such as organocuprates, silyl enol ethers, enamines, etc., reacted with the pyridinium-type salts to give the corresponding substituted products in good yields. ...
Pasteris Daniel R - - 2011
The acid content of ice core samples provides information regarding the history of volcanism, biogenic activity, windblown dust, forest fires, and pollution induced acid rain. A continuous ice core analysis enables the collection of high time-resolution data in a very efficient manner, however this technique has not been readily applied ...
Monroig Oscar - - 2011
Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due, in part, to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval ...
Ho Shih-Hsin - - 2011
Engineering strategies were applied to improve the CO(2) fixation rate and carbohydrate/lipid production of a Scenedesmus obliquus CNW-N isolate. The light intensity that promotes cell growth, carbohydrate/lipid productivity, and CO(2) fixation efficiency was identified. Nitrogen starvation was also employed to trigger the accumulation of lipid and carbohydrate. The highest productivity ...
Wawrik Boris - - 2011
The bioconversion of coal to methane in the San Juan Basin, New Mexico, was investigated. Production waters were analyzed via enrichment studies, metabolite-profiling, and culture-independent methods. Analysis of 16S rRNA gene sequences indicated the presence of methanogens potentially capable of acetoclastic, hydrogenotrophic, and methylotrophic metabolisms, predominantly belonging to the Methanosarcinales ...
Quade Nick - - 2011
Polyketides are structurally diverse and medically important natural products that have various biological activities. During biosynthesis, chain elongation uses activated dicarboxylic acid building blocks, and their availability therefore limits side chain variation in polyketides. Recently, the crotonyl-CoA carboxylase-reductase (CCR) class of enzymes was identified in primary metabolism and was found ...
Parker Eric T - - 2011
Stanley Miller's 1958 H(2)S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH(4)), ammonia (NH(3)), carbon dioxide (CO(2)), and hydrogen sulfide (H(2)S) produced several alkyl amino acids, including the α-, β-, and γ-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark ...
Treviño-Quintanilla Luis G - - 2011
Pentachlorophenol is the most toxic and recalcitrant chlorophenol because both aspects are directly proportional to the halogenation degree. Biological and abiotic pentachlorophenol degradation generates p-chloranil, which in neutral to lightly alkaline environmental conditions is hydrolyzed to chloranilic acid that present a violet-reddish coloration in aqueous solution. Several genes of the ...
Yu S Y - - 2011
Myrmecia incisa Reisigl H4301 is a green coccoid freshwater microalga that is rich in arachidonic acid (20:4n-6, ArA) especially grown under a nitrogen starvation stress. A fatty acid elongase gene, MiFAE, was cloned based on a selected expressed sequence tag (EST) from a M. incisa cDNA library. To examine the ...
Saga Linda C - - 2011
The oxidative stability of mixtures of edible oils containing polyunsaturated fatty acids (PUFA) and microcrystalline cellulose (MCC) was investigated. The mixtures studied consisted of oils of either camelina (CAM), cod liver (CLO), or salmon (SO) mixed with either colloidal or powdered MCC. A 50:50 (w/w) ratio of oil:MCC resulted in ...
Antruejo A - - 2011
1. Diets high in total lipids, saturated fatty acids, trans fatty acids, and having high ω-6:ω-3 fatty acid ratios, have been shown to be related to increased instances of coronary heart disease, while diets high in ω-3 fatty acids have been shown to decrease the risk. 2. Feeding ω-3 fatty ...
Awano Tomotsugu - - 2011
The stereochemical course of the stereospecific Suzuki-Miyaura coupling of enantioenriched α-(acetylamino)benzylboronic esters with aryl bromides can be switched by the choice of acidic additives in the presence of a Pd/XPhos catalyst system. Highly enantiospecific, invertive C-C bond formation takes place with the use of phenol as an additive. In contrast, ...
Salwiczek Mario - - 2011
Fluorinated analogues of the canonical α-l-amino acids have gained widespread attention as building blocks that may endow peptides and proteins with advantageous biophysical, chemical and biological properties. This critical review covers the literature dealing with investigations of peptides and proteins containing fluorinated analogues of the canonical amino acids published over ...
Inoue Yoshiyuki - - 2011
Carp (Cyprinus carpio L.) was exposed to perfluorinated compounds (PFCs)-perfluoroalkyl carboxylic acids (number of carbon atoms, C = 8, 11, 12, 14, 16, and 18) and perfluorooctane sulfonate (PFOS)-in bioconcentration tests to compare the bioconcentration factors (BCFs) and physicochemical properties of each specific compound. Despite having the same number of carbon atoms ...
Allen C Liana - - 2011
The direct coupling of unactivated carboxylic acids with amines can be performed in toluene 110 °C in the absence of catalyst. The use of simple zirconium catalysts at 5 mol% loading gave amide formation in as little as 4 h.
Johnson Richard J RJ Department of Biological Sciences, University of Essex, Colchester, Essex, - - 2012
Naphthenic acids (NAs) are complex mixtures of carboxylic acids found in weathered crude oils and oil sands, and are toxic, corrosive and persistent. However, little is known about the microorganisms and mechanisms involved in NA degradation. We isolated a sediment bacterium (designated strain IS2.3), with 100% 16S rRNA gene sequence ...
Baransi Katie - - 2011
The photocatalytic degradation of two phenolic compounds, p-coumaric acid and caffeic acid, was performed with a suspended mixture of TiO(2) and powdered activated carbon (PAC) (at pH=3.4 and 8). Adsorption, direct photolysis and photocatalytic degradation were studied under different pH and UV light sources (sunlight vs. 365nm UV lamps). The ...
Qiao Xue - - 2011
Bile acids are steroids with a pentanoic acid substituent at C-17. They are the terminal products of cholesterol excretion, and play critical physiological roles in human and animals. Bile acids are easy to detect but difficult to identify by using mass spectrometry due to their poly-ring structure and various hydroxylation ...
Michalczyk Magdalena - - 2011
This study examined the effect of adding essential oils of hyssop and coriander at the highest concentration (0.02% v/w) sensorially acceptable to a panel of assessors on the microbiological and biochemical characteristics of stored ground beef. Vacuum-packed meat was stored at 0.5±0.5°C and 6±1°C for 15days. The greatest beneficial effect ...
Turner Glenn W - - 2012
The repeated removal of flower, fruit, or vegetative buds is a common treatment to simulate sink limitation. These experiments usually lead to the accumulation of specific proteins, which are degraded during later stages of seed development, and have thus been designated as vegetative storage proteins. We used oligonucleotide microarrays to ...
Jehmlich Nico - - 2011
We introduce a universal metabolic labeling strategy using elemental heavy (36) Sulphur ((36) S) called (36) Sulphur stable isotope labeling of amino acids for quantification (SULAQ). In the proof of principle experiment, Pseudomonas putida KT2440 was grown in defined minimal medium with sodium benzoate or sodium succinate as sole carbon ...
Aissaoui Regadia - - 2011
Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good-to-excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO2H) group. This novel nucleophilic aromatic substitution is ...
Santa Cruz Chavez Grace - - 2011
In our previous study, we investigated the setting time, mechanical properties and microstructure of dicalcium phosphate dihydrate cements prepared using monocalcium phosphate monohydrate (MCPM) and hydroxyapatite (HA). Despite the use of sodium citrate as a setting regulator, setting occurs rapidly in the MCPM/HA system and further studies on other retardants ...
Erythropel Hanno C - - 2011
The plasticizer di (2-ethylhexyl) phthalate (DEHP) and its metabolites are considered ubiquitous contaminants, which have a range of implications on the environment and human health. This work considered several alternative compounds with structural features similar to DEHP. This added to the understanding of why DEHP is so poorly biodegraded once ...
Liu Shugen - - 2011
Batch experiment was carried out in a simulated thermophilic aerobic digester to investigate the digestion process of one-stage autothermal thermophilic aerobic digester and to explore the sludge stabilization mechanism. Volatile solids removal was 38.4% at 408h and 45.0% at 552h. Chemical oxidation demand, total nitrogen, and ammonia nitrogen in supernatant ...
Wang Cuihong - - 2011
We investigated the adsorption of three aromatic amino acids-phenylalanine, tyrosine, and tryptophan-on the sidewalls of a number of representative single-walled carbon nanotubes (SWNTs) using density-functional tight-binding calculations, complemented by an empirical dispersion correction. The armchair (n, n) SWNTs (n = 3-12) and zigzag (n, 0) SWNTs (n = 4-12) were ...
Long Bo - - 2011
The formic acid catalyzed gas-phase reaction between H(2) O and SO(3) and its reverse reaction are respectively investigated by means of quantum chemical calculations at the CCSD(T)//B3LYP/cc-pv(T+d)z and CCSD(T)//MP2/aug-cc-pv(T+d)z levels of theory. Remarkably, the activation energy relative to the reactants for the reaction of H(2) O with SO(3) is lowered ...
1 2 3 4 5 6 7 8 9 10 >