Search results for "compounds"

Exploring kainate receptor pharmacology using molecular dynamics simulations.

2010

Ionotropic glutamate receptors (iGluRs) are enticing targets for pharmaceutical research; however, the search for selective ligands is a laborious experimental process. Here we introduce a purely computational procedure as an approach to evaluate ligand–iGluR pharmacology. The ligands are docked into the closed ligand-binding domain and during the molecular dynamics (MD) simulation the bi-lobed interface either opens (partial agonist/antagonist) or stays closed (agonist) according to the properties of the ligand. The procedure is tested with closely related set of analogs of the marine toxin dysiherbaine bound to GluK1 kainate receptor. The modeling is set against the abundant binding data …

Synthesis and pharmacological characterization of beta2-adrenergic agonist enantiomers: zilpaterol.

2009

The beta-adrenergic agonist 1 (zilpaterol) is used as production enhancer in cattle. Binding experiments of separated enantiomers on recombinant human beta(2)-adrenergic and mu-opioid receptors and functional studies showed that the (-)-1 enantiomer accounts for essentially all the beta(2)-adrenergic agonist activity and that it exhibits less affinity toward the mu-opioid receptor than (+)-1, which is a mu-opioid receptor antagonist. X-ray crystallography revealed the absolute configuration of (-)-1 to be 6R,7R.

Altered atypical coupling of γ-aminobutyrate type A receptor agonist and convulsant binding sites in subunit-deficient mouse lines

2001

We searched for subunit correlations for GABA(A) receptor-associated atypically GABA-insensitive [35S]TBPS binding. The homomeric beta3 subunit receptors could be excluded, as GABA-insensitive [35S]TBPS binding was present in beta3-/- mice. Localization of GABA-insensitive [35S]TBPS binding correlated best with those of delta, alpha4 and alpha6 subunit mRNAs. The amounts of GABA-insensitive [35S]TBPS binding components were increased in delta-/- mice, but dramatically reduced in alpha6-/- mice, suggesting a role for alpha6 but excluding delta subunits.

Practical strategies for stable operation of HFF-QCM in continuous air flow

2013

Currently there are a few fields of application using quartz crystal microbalances (QCM). Because of environmental conditions and insufficient resolution of the microbalance, chemical sensing of volatile organic compounds in an open system was as yet not possible. In this study we present strategies on how to use 195 MHz fundamental quartz resonators for a mobile sensor platform to detect airborne analytes. Commonly the use of devices with a resonant frequency of about 10 MHz is standard. By increasing the frequency to 195 MHz the frequency shift increases by a factor of almost 400. Unfortunately, such kinds of quartz crystals tend to exhibit some challenges to obtain a reasonable signal-to…

Aspen Plus process-simulation model: Producing biogas from VOC emissions in an anaerobic bioscrubber

2018

A process-simulation model for a novel process consisted of an anaerobic bioscrubber was developed in Aspen Plus®. A novel approach was performed to implement the anaerobic reactor in the simulation, enabling it to be connected to the scrubber. The model was calibrated and validated using data from an industrial prototype that converted air emissions polluted with volatile organic compounds with an average daily concentration of 1129 mgC Nm−3 into bioenergy for more than one year. The scrubber, which showed a removal efficiency within 83-93%, was successfully predicted with an average absolute relative error of 5.2 ± 0.08% using an average height-to-theoretical-plate value of 1.05 ± 0.08 m …

Aminoacid zwitterions in solution : Geometric, energetic, and vibrational analysis using density functional theory-continuum model calculations

1998

Glycine and alanine aminoacids chemistry in solution is explored using a hybrid three parameters density functional (B3PW91) together with a continuum model. Geometries, energies, and vibrational spectra of glycine and alanine zwitterions are studied at the B3PW91/6-31+G∗∗ level and the results compared with those obtained at the HF and MP2/6-31+G∗∗ levels. Solvents effects are incorporated by means of an ellipsoidal cavity model with a multipolar expansion (up to sixth order) of the solute’s electrostatic potential. Our results confirm the validity of the B3PW91 functional for studying aminoacid chemistry in solution. Taking into account the more favorable scaling behavior of density funct…

Potential of microorganisms to decrease the "beany" off-flavor

2022

Synthesis of terpenoid unsaturated 1,4-dialdehydes. Pi-facial selectivity in the Diels-Alder reaction of the 1-vinyl-2-methylcyclohexene moiety of po…

2000

Catalytic Enantioselective Aza-Reformatsky Reaction with Cyclic Imines

2016

A catalytic highly enantioselective aza-Reformatsky reaction with cyclic aldimines and ketimines for the synthesis of chiral b-amino esters with good yields and excellent enantioselectivities is reported.Areadily available diaryl prolinol is used as a chiral ligand, ZnMe2 as a zinc source and ethyl iodoacetate as reagent in the presence of air atmosphere. The reaction with cyclic ketimines generates a quaternary stereocenter with excellent levels of enantioselectivity. Furthermore, five-membered N-sulfonyl ketimines were used as electrophiles with good enantiomeric excesses, under the optimized reaction conditions. Moreover, several chemical transformations were performed with the chiral b-…

Aqueous solubility diagrams for cementitious waste stabilization systems. 3. Mechanism of zinc immobilizaton by calcium silicate hydrate.

2002

Zinc oxide was added during hydration of alite (C3S) as an analogue for solidification/stabilization by cement of metal-bearing hazardous waste. Curing of samples was stopped at various intervals between 8 h and 100 d, and the reaction products were analyzed by both X-ray diffraction (XRD) and X-ray absorption spectroscopy (EXAFS at Zn, Ca, and Si K-edges). Calcium zincate hydrate (CaZn2(OH)6 x 2H2O) initially formed together with calcium silicate hydrate (CSH) vanishes from X-ray diffractograms after 14 d, and no other crystalline Zn-bearing phase could be detected thereafter. EXAFS Zn K-edge data analysis reveals that Zn(O,OH)4 tetrahedra continue to determine the first shell coordination…