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Acid Components (acid + component)
Selected AbstractsTruncated Diastereoselective Passerini Reaction, a Rapid Construction of Polysubstituted Oxazole and Peptides Having an ,-Hydroxy-,-amino Acid Component.CHEMINFORM, Issue 38 2004Guylaine Cuny Abstract For Abstract see ChemInform Abstract in Full Text. [source] Production of a Polyester Degrading Extracellular Hydrolase from Thermomonospora fuscaBIOTECHNOLOGY PROGRESS, Issue 5 2002Mona K. Gouda The production of a polyester-degrading hydrolase from the thermophilic actinomycete Thermomonospora fusca was investigated with regard to its potential technical application. Only in the presence of a polyester (random aliphatic-aromatic copolyester from 1,4-butanediol, terephthalic acid, and adipic acid with around 40,50 mol % terephthalic acid in the acid component), the excretion of the extracellular enzyme could be achieved with an optimized synthetic medium using pectin and NH4Cl as nitrogen source. Compared to complex media, a significantly higher specific activity at comparable volumetric yields could be obtained, thus reducing the expenditure for purification. The activity profile in the medium is controlled by a complex process involving (1) induction of enzyme excretion, (2) enzyme adsorption on the hydrophobic polyester surface, (3) inhibition of enzyme generation by monomers produced by polyester cleavage, and (4) enzyme denaturation. Diafiltration with cellulose acetate membranes as the sole downstream processing step led to a product of high purity and with sufficient yield (60% of total activity). Scaling-up from shaking flasks to a fermentor scale of 100 L revealed no specific problems. However, the excretion of the hydrolase by the actinomycete turned out to be inhibited by the degradation products (monomers) of the aliphatic-aromatic copolyester used as inductor for the enzyme production. The crude enzyme exhibited generally similar properties (temperature and pH optimum) as the highly purified hydrolase described previously; however, the storage capability and thermal stability is improved when the crude enzyme solution is diafiltrated. [source] A double blind, randomized, controlled clinical trial to assess the efficacy of a new coal tar preparation (Exorex) in the treatment of chronic, plaque type psoriasisCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 8 2000C. H. Smith Exorex is a new topical formulation for the treatment of psoriasis; it contains 1% coal tar and a synthetic analogue resembling components identified in banana skin (a complex of esterified essential fatty acids). To determine whether the esterified essential fatty acid complex confers any therapeutic advantage over coal tar alone, patients with chronic plaque psoriasis (n = 20) were entered into a double-blind, randomized, right/left comparison of Exorex, and Exorex without the essential fatty acid component (known hereafter as coal tar control) for 8 weeks. Target plaques were scored (0,4) for erythema, desquamation and infiltration at day 0 and at 2 week intervals throughout the study. No significant differences were detected between Exorex and coal tar control with respect to changes in the summed scores at baseline and following 8 weeks of treatment (mean difference in summed score changes from baseline between Exorex and coal tar control 0.2, 95% confidence interval ,,0.44 to 0.84; P = 0.52) or in the area under the response,time curve (P = 0.16). Mean percentage improvement in summed scores of target plaques were 53.9% (SE = 4%) and 56.1% (SE = 4.9%) for Exorex and coal tar control, respectively. Results suggest that the complex of esterified essential fatty acids is not exerting any clinically important therapeutic effect in the treatment of chronic plaque psoriasis. [source] Green Approaches to Field Nitrate Analysis: An Electroanalytical PerspectiveELECTROANALYSIS, Issue 7 2009Radha Desai Abstract The different approaches that have been taken in the development of analytical methods for the determination of nitrate within the field are reviewed. The emphasis has been placed on providing a critical appraisal of the chemistry that underpins current commercial systems and the need to remove the dependence on heavy metal and concentrated acid components. The search for more environmentally acceptable and user friendly systems has long been pursued and the present communication seeks to explore the recent development in portable testing technologies and how they might evolve in the future. In particular, the role of electrochemical techniques in the latter are investigated and their potential application compared and contrasted with the more traditional wet chemical detection strategies. [source] ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLISJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009ALI OSMAN SARIKAYA ABSTRACT This study describes the constituents of phenolic acids and antioxidant activities of chestnut (Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin,Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA. PRACTICAL APPLICATIONS In this study, some phenolic acid components and antioxidant capacity of chestnut (Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins. [source] Rapid characterization of edible oils by direct matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis using triacylglycerolsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2006Jackson O. Lay Jr. Direct matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOFMS) analysis of solutions of edible fats/oils yielded spectra useful for their rapid differentiation and classification. Results also reflected the individual fatty acid components and their degree of unsaturation. After dissolution in hexane, MALDI-MS analysis revealed spectra showing characteristic triacylglycerols (TAGs), the main fat/oil components, as sodium adduct ions. The Euclidean distances calculated using the mass and intensity values for 20 TAGs were used to evaluate and compare spectra. With cluster analysis, animal fats grouped together differently than vegetable oils and the individual oils grouped together by type. The ion abundances for the individual TAGs and their presumed compositions were used to approximate the overall fatty acid composition of canola, soybean, corn, olive and peanut oil, as well as lard. Using this approach the calculated fatty acid compositions and degree of unsaturation generally fell within about 4% of literature values. When the degree of saturation was compared with values calculated from the package labeling the differences were about 7%. Copyright © 2006 John Wiley & Sons, Ltd. [source] Hydrogen-bond-directed supramolecular arrays in 4,4,-bipyridinium tetrachloroterephthalate dihydrate and bis(1,10-phenanthrolinium) tetrachloroterephthalate tetrachloroterephthalic acid trihydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Ming-Yang He The title compounds, C10H10N22+·C8Cl4O42,·2H2O, (I), and 2C12H9N2+·C8Cl4O42,·C8H2Cl4O4·3H2O, (II), both crystallize as charge-transfer organic salts with the dianionic or neutral acid components lying on inversion centres. The acid and base subunits in (I) arrange alternately to generate a linear tape motif via N,H...O hydrogen bonds; these tapes are further combined into a three-dimensional architecture through multiple O,H...O and C,H...O interactions involving solvent water molecules. In contrast, the neutral and anionic acid components in (II) are linked to form a zigzag chain by means of O,H...O hydrogen bonds between acid groups, with dangling 1,10-phenanthrolinium units connected to these chains by carboxylate,pyridinium interactions with R22(7) hydrogen-bond notation. Adjacent chains are further extended to result in a two-dimensional corrugated layer network via,,, interactions. Inter-ion Cl...O interactions are also found in both (I) and (II). [source] Interaction of Cytidine 5,-Monophosphate with Au(111): An In Situ Infrared Spectroscopic StudyCHEMPHYSCHEM, Issue 9-10 2009Thomas Doneux Dr. Abstract Attracted to gold: The interaction of cytidine 5,-monophosphate (CMP) with gold surfaces is studied at the Au(111) | aqueous solution interface. In situ infrared spectroscopy studies show that cytidine 5,-monophosphate is chemisorbed on Au(111) through the N3 atom of the pyrimidine ring (see picture). The interaction of cytidine 5,-monophosphate (CMP) with gold surfaces is studied by means of in situ infrared spectroscopy and cyclic voltammetry at the Au(111) | aqueous solution interface. Similar to other nucleic acid components, cytidine 5,-monophosphate is chemisorbed on the surface at positive potentials, and the amount of adsorbed CMP increases with the potential. Subtractively normalized interfacial Fourier-transform infrared spectroscopy (SNIFTIRS) is used to identify the adsorbed and desorbed species. Upon electrochemical desorption, the molecules released in solution are unprotonated on the N3 atom. Striking similarities are found between the spectrum of adsorbed CMP and the solution spectrum of protonated CMP. The origin of such similarities is discussed. The results strongly suggest that chemisorption occurs through the N3 atom of the pyrimidine ring. A comparison is drawn with cytidine, whose electrochemical and spectroscopic behaviors are also investigated. [source] The potential interactions between polyunsaturated fatty acids and colonic inflammatory processesCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2005S C. Mills Summary n- 3 Polyunsaturated fatty acids (PUFAs) are recognized as having an anti-inflammatory effect, which is initiated and propagated via a number of mechanisms involving the cells of the immune system. These include: eicosanoid profiles, membrane fluidity and lipid rafts, signal transduction, gene expression and antigen presentation. The wide-range of mechanisms of action of n- 3 PUFAs offer a number of potential therapeutic tools with which to treat inflammatory diseases. In this review we discuss the molecular, animal model and clinical evidence for manipulation of the immune profile by n- 3 PUFAs with respect to inflammatory bowel disease. In addition to providing a potential therapy for inflammatory bowel disease there is also recent evidence that abnormalities in fatty acid profiles, both in the plasma phospholipid membrane and in perinodal adipose tissue, may be a key component in the multi-factorial aetiology of inflammatory bowel disease. Such abnormalities are likely to be the result of a genetic susceptibility to the changing ratios of n- 3 : n- 6 fatty acids in the western diet. Evidence that the fatty acid components of perinodal adipose are fuelling the pro- or anti-inflammatory bias of the immune response is also reviewed. [source] | |||||||||||||