Search results for "Propionate"
showing 10 items of 144 documents
Catalytic Functionalization of Methane and Light Alkanes in Supercritical Carbon Dioxide
2014
International audience; The development of catalytic methods for the effective functionalization of methane yet remains a challenge. The best system known to date is the so-called Catalytica Process based on the use of platinum catalysts to convert methane into methyl bisulfate with a TOF rate of 10−3 s. In this contribution, we report a series of silver complexes containing perfluorinated tris(indazolyl)borate ligands that catalyze the functionalization of methane into ethyl propionate upon reaction with ethyl diazoacetate (EDA) by using supercritical carbon dioxide (scCO2) as the reaction medium. The employment of this reaction medium has also allowed the functionalization of ethane, prop…
CCDC 838945: Experimental Crystal Structure Determination
2012
Related Article: A.Kirste, B.Elsler, G.Schnakenburg, S.R.Waldvogel|2012|J.Am.Chem.Soc.|134|3571|doi:10.1021/ja211005g
Determination of aerobic-anaerobic metabolism-related compounds in aChaoborus flavicans population by infusion ion trap mass spectrometry of extracts…
2006
In a daily migration, the aquatic larvae of Chaoborus flavicans (a phantom midge) alternate oxygen-saturated and anoxic lake strata. To investigate this cycle, larvae were collected at a natural environment, and acetate, propionate, pyruvate, lactate, glycerol, phosphate, maleate, succinate, glucose and citrate were determined. Each larva was homogenized with 200 microL water and deproteinized with a spin-filter; 50 microL aliquots were mixed with 50 microL of a buffer containing 80 mM propylamine, 20 mM HCl and 0.06 mM 2,4-dihydroxybenzoic acid (internal standard) in methanol. The extracts were infused in an electrospray ionization ion-trap mass spectrometer. The limits of detection for th…
A POLYCARBOXYLIC/AMINO FUNCTIONALIZED HYALURONIC ACID DERIVATIVE FOR THE PRODUCTION OF pH SENSIBLE HYDROGELS IN THE PREVENTION OF BACTERIAL ADHESION …
2014
A graft copolymer derivative of hyaluronic acid bearing pendant amino and short polymethacrylate portions (HA-EDA-BMP-MANa) has been employed for the production of a pH sensible vancomycin releasing hydrogel and studied in vitro to test its potential anti adhesive property against Staphylococcus aureus colonization. The copolymer obtained through atom transfer radical polymerization bears chargeable (carboxyl and amino groups) portions and it could be formulated as a hydrogel at a concentration of 10% w/v. The HA-EDA-BMP-MANa hydrogels, produced at three different pH values (5, 6 and 7, respectively), were formulated with or without the addition of vancomycin (2% w/v). The vancomycin releas…
Main individual and product characteristics influencing in-mouth flavour release during eating masticated food products with different textures: mech…
2013
Research Areas: Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; A mechanistic model predicting flavour release during oral processing of masticated foods was developed. The description of main physiological steps (product mastication and swallowing) and physical mechanisms (mass transfer, product breakdown and dissolution) occurring while eating allowed satisfactory simulation of in vivo release profiles of ethyl propanoate and 2-nonanone, measured by Atmospheric Pressure Chemical Ionization Mass Spectrometry on ten representative subjects during the consumption of four cheeses with different textures. Model sensitivity analysis showed that the main paramet…
Antibodies directed to drug epitopes to investigate the structure of drug-protein photoadducts. Recognition of a common photobound substructure in ti…
2001
Drug-induced photoallergy is an immune adverse reaction to the combined effect of drugs and light. From the mechanistic point of view, it first involves covalent binding of drug to protein resulting in the formation of a photoantigen. Hence, determination of the structures of drug-protein photoadducts is of great relevance to understand the molecular basis of photoallergy and cross-immunoreactivity among drugs. Looking for new strategies to investigate the covalent photobinding of drugs to proteins, we generated highly specific antibodies to drug chemical substructures. The availability of such antibodies has allowed us to discriminate between the different modes by which tiaprofenic acid (…
Resolution of mixtures of steroidal hormones with micellar eluents of sodium dodecyl sulphate and acetonitrile or pentanol
2000
An optimization strategy was applied to explore the capability of hybrid micellar eluents of sodium dodecyl sulphate (SDS), using acetonitrile or pentanol as modifiers, to resolve mixtures of eleven steroids showing a wide range of hydrophobicity (clostebol acetate, dehydrotestosterone, dydrogesterone, medroxyprogesterone, medroxyprogesterone acetate, methandienone, methyltestosterone, progesterone, testosterone, testosterone enanthate and testosterone propionate). The accurate prediction of the retention behaviour of the steroids, with relative errors in the 0.8–1.7% and 0.4–2.9% ranges for SDS-acetonitrile and SDS-pentanol eluents, respectively, demonstrated the reliability of the methodo…
Retention-structure relationship studies for some steroidal hormones in micellar liquid chromatography
2000
The retention behavior in a C18 column of fourteen steroidal hormones (clostebol acetate, dehydrotestosterone, dydrogesterone, medroxyprogesterone, medroxyprogesterone acetate, methandienone, methyltestosterone, nandrolone, nandrolone decanoate, progesterone, testosterone, testosterone enanthate, testosterone propionate and, stanozolol) with pure micellar mobile phases prepared from sodium dodecyl sulfate (SDS), and hybrid mobile phases comprising SDS-acetonitrile and SDS-pentanol, was correlated with their octanol-water partition coefficients. Similar correlations were found with retention data obtained by other authors in gas chromatography, conventional reversed-phase liquid chromatograp…
DETERMINATION OF STEROIDAL HORMONES IN URINE SAMPLES BY MICELLAR LIQUID CHROMATOGRAPHY FOLLOWING SOLID-PHASE EXTRACTION
2001
Steroidal hormones were determined in spiked urine samples using micellar mobile phases of sodium dodecyl sulphate (SDS)-pentanol, solid-phase extraction (SPE), and detection in the UV region. In the optimized procedure, a 10 mL aliquot of urine sample is loaded into a C18 cartridge and washed with 2 mL of 50:50 (v/v) methanol-water, followed by 200 μL of 70:30 (v/v) methanol-water. The retained steroids are eluted with 2 mL of methanol and the eluate evaporated to dryness under nitrogen at 50°C. The residue is redissolved with 200 μL of the micellar mobile phase used in the chromatographic separation and injected into the chromatograph. The performance of the procedure was checked for 13 s…
SENSITIZED LANTHANIDE FLUORESCENCE DETECTION OF STEROIDAL HORMONES
2000
Several steroidal hormones with an α,β-unsaturated carbonyl group sensitized the fluorescence of terbium(III) ions: medroxyprogesterone, medroxyprogesterone acetate, methyltestosterone, nandrolone, nandrolone decanoate, progesterone, testosterone, testosterone enanthate, and testosterone propionate, but other steroids which have this chromophore did not give any signal: clostebol acetate, dehydrotestosterone, dydrogesterone, methandienone, and methenolone enanthate. Sensitized fluorescence was used to detect the steroids when eluted with micellar mobile phases of sodium dodecyl sulphate (SDS)-acetonitrile and SDS-pentanol containing 0.01 M Tb(III), with 245 nm and 545 nm as excitation and e…