Search results for "nitriles"

showing 10 items of 177 documents

Preventive effect of risedronate on bone loss and frailty fractures in elderly women treated with anastrozole for early breast cancer.

2011

The aim of this study was to assess the effect of adjuvant anastrozole, alone or associated with risedronate, on BMD and bone fracture risk in women more than 70 years old with hormone receptor-positive early breast cancer (EBC). In a group of 51 elderly women (aged 76.4 ± 5.0 years) considered for adjuvant aromatase inhibitors for EBC, 24 patients with T-scores ≥ -2 and no prevalent fractures received anastrozole 1 mg/day (group A), and 27 patients with T-scores < -2, or with T-scores ≥ -2 and prevalent fractures (group B), received anastrozole (1 mg/day) plus risedronate (35 mg/week). Both groups received supplementation with 1 g calcium carbonate and 800 IU vitamin D per day. Differen…

Endocrinology Diabetes and MetabolismOsteoporosisSeverity of Illness IndexCohort StudiesEndocrinologyBone DensityOrthopedics and Sports MedicineVitamin DAromataseOsteoporosis PostmenopausalAged 80 and overBone Density Conservation AgentsbiologyAromatase InhibitorsEtidronic AcidGeneral MedicineCombined Modality Therapymedicine.anatomical_structureFemaleRisedronic Acidmedicine.drugmusculoskeletal diseasesmedicine.medical_specialtyAntineoplastic Agents HormonalUrologyAnastrozoleBreast NeoplasmsAnastrozoleCalcium CarbonateNitrilesmedicineVitamin D and neurologyHumansBone ResorptionAgedNeoplasm StagingFemoral neckTrochanterbusiness.industryBone fractureTriazolesmedicine.diseaseSurgeryEarly breast cancer Anastrozole Osteoporosis Vertebral fractures ElderlyDietary SupplementsOrthopedic surgerybiology.proteinbusinessOsteoporotic FracturesFollow-Up Studies
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Approaches to model the retention and peak profile in linear gradient reversed-phase liquid chromatography.

2012

Abstract The optimisation of the experimental conditions in gradient reversed-phase liquid chromatography requires reliable algorithms for the description of the retention and peak profile. As in isocratic elution, the linear relationship between the logarithm of the retention factor and the solvent contents is only acceptable in relatively small concentration ranges of modifier. However, more complex models may not allow an analytical integration of the general equation for gradient elution. Alternative approaches for modelling the retention in linear gradient elution are here proposed. Those based on the quadratic logarithmic model and a model proposed for normal liquid chromatography yie…

FlavonoidsChromatography Reverse-PhaseIsocratic elutionChromatographyAcetonitrilesLogarithmChemistryElutionOrganic ChemistryAnalytical chemistryWaterGeneral MedicineReversed-phase chromatographyBiochemistryAnalytical ChemistryLinear gradientSolventModels ChemicalGradient elutionDiureticsRetention timeAlgorithmsJournal of chromatography. A
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Estimation of formamide harmonic and anharmonic modes in the Kohn-Sham limit using the polarization consistent basis sets.

2010

Formamide harmonic and anharmonic frequencies of fundamental vibrations in the gas phase and in several solvents were successfully estimated in the B3LYP Kohn-Sham complete basis set limit (KS CBS). CBS results were obtained by extrapolating a power function (two-parameter formula) to the results calculated with polarization-consistent basis sets. Anharmonic corrections using the second order perturbation treatment (PT2) and hybrid B3LYP functional combined with polarization consistent pc-n (n = 0, 1, 2, 3, 4) and several Pople’s basis sets were analyzed for all fundamental formamide vibrational modes in the gas phase and solution. Solvent effects were modeled within a PCM method. The anhar…

FormamideAcetonitrilesMolecular ConformationAnharmonic vibrationSolvent effectMolecular physicsCatalysisInorganic ChemistryAcetonechemistry.chemical_compoundComputational chemistryScissoringHexanesComputer SimulationDimethyl SulfoxideHarmonic vibrationPhysical and Theoretical ChemistryPhysics::Chemical PhysicsCarbon TetrachlorideBasis setQuantitative Biology::BiomoleculesOriginal PaperFormamidesOrganic ChemistryAnharmonicityWaterComplete basis set limitFormamideComputer Science ApplicationsComputational Theory and MathematicschemistryModels ChemicalMolecular vibrationHarmonicSolventsThermodynamicsFermi resonanceChloroformGasesSolvent effectsJournal of molecular modeling
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Synthesis of Highly Functionalized Fluorinated Cispentacin Derivatives

2012

Fluorinated highly functionalized cispentacin derivatives were synthetised starting from an unsaturated bicyclic b-lactam through C¼C bond functionalization via the dipolar cycloaddition of a nitrile oxide, isoxazoline opening, and fluorination by OH/F exchange.

HalogenationBicyclic moleculeNitrileOxideOxidesBioengineeringCispentacinGeneral ChemistryGeneral Medicinebeta-LactamsBiochemistryCycloadditionchemistry.chemical_compoundchemistryCyclizationNitrilesMolecular MedicineSurface modificationOrganic chemistryCycloleucineta116Molecular BiologyChemistry & Biodiversity
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Partition Behavior of Anilines in Bulk‐Phase and High‐Performance Liquid Chromatographic Systems: Influence on Correlation with Biological Constants

1992

Abstract The partition behavior of a mixed series of ring‐substituted anilines in reversed‐phase high‐performance liquid chromatographic systems is substantially different from that observed in a classical bulk‐phase partition system with n ‐heptane as the aprotic reference solvent. On the basis of the equivalence of each ring substituent in the p ‐straight‐chain methylene groups (ν value) as a function of the fraction of organic solvent (acetonitrile or methanol) in the mobile phase, the biased partition behavior for imperfect homologues and heterologues is verified relative to that of perfect homologues. This behavior was tentatively attributed, mainly, to differences in the hydrogen bond…

HeptaneAcetonitrilesAniline CompoundsChromatographyChemistryMethanolSubstituentAnalytical chemistryPharmaceutical ScienceIntestinal absorptionSolventPartition coefficientchemistry.chemical_compoundReaction rate constantPartition (number theory)AcetonitrileChromatography High Pressure LiquidJournal of Pharmaceutical Sciences
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New Cathepsin Inhibitors to Explore the Fluorophilic Properties of the S 2 Pocket of Cathepsin B: Design, Synthesis, and Biological Evaluation

2011

5 páginas, 1 figura, 2 tablas -- PAGS nros. 5256-5260

Hydrocarbons FluorinatedStereochemistryStereoisomerismhydrolasesstereoselectivityCatalysisCathepsin BCathepsin BNitrilesinhibitorsCombinatorial Chemistry TechniquesHumansMoleculefluorinated ligandsBiological evaluationCathepsinMolecular StructureCombinatorial Chemistry TechniquesligandsChemistryOrganic ChemistryStereoisomerismDipeptidesGeneral Chemistryfluorinated fluorinatedDesign synthesisDrug DesignpeptidesStereoselectivityChemistry – A European Journal
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An efficient synthesis of new fluorinated uracil derivatives.

2003

A series of potentially biologically active fluorinated uracil derivatives has been prepared in three steps from oxazolines and fluorinated nitriles with good chemical yields. Fustero Lardies, Santos, Santos.Fustero@uv.es ; Sanz Cervera, Juan Francisco, Juan.F.Sanz@uv.es ; Asensio Martinez, Amparo, Amparo.Asensio@uv.es

Hydrocarbons FluorinatedSynthesis ; Fluorinated uracil derivatives ; Oxazolines ; Biologically activeAntimetabolitesUNESCO::QUÍMICABiologically active:QUÍMICA::Química orgánica [UNESCO]UracilGeneral MedicineOxazolines:QUÍMICA [UNESCO]Combinatorial chemistryFluorinated uracil derivativesSynthesischemistry.chemical_compoundchemistryNitrilesUNESCO::QUÍMICA::Química orgánicaUracilOxazolesChemical communications (Cambridge, England)
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Inhibition of the Cysteine Protease Human Cathepsin L by Triazine Nitriles: Amide⋅⋅⋅Heteroarene π-Stacking Interactions and Chalcogen Bonding in the …

2016

We report an extensive "heteroarene scan" of triazine nitrile ligands of the cysteine protease human cathepsin L (hCatL) to investigate π-stacking on the peptide amide bond Gly67-Gly68 at the entrance of the S3 pocket. This heteroarene⋅⋅⋅peptide bond stacking was supported by a co-crystal structure of an imidazopyridine ligand with hCatL. Inhibitory constants (Ki ) are strongly influenced by the diverse nature of the heterocycles and specific interactions with the local environment of the S3 pocket. Binding affinities vary by three orders of magnitude. All heteroaromatic ligands feature enhanced binding by comparison with hydrocarbon analogues. Predicted energetic contributions from the ori…

ImidazopyridineNitrileStereochemistryCathepsin LPeptideMolecular Dynamics Simulation010402 general chemistryCrystallography X-RayLigands01 natural sciencesBiochemistrychemistry.chemical_compoundAmideDrug DiscoveryHydrolaseNitrilesPeptide bondHumansGeneral Pharmacology Toxicology and PharmaceuticsTriazinePharmacologychemistry.chemical_classificationBinding Sites010405 organic chemistryChemistryLigandTriazinesOrganic ChemistryAmides0104 chemical sciencesProtein Structure TertiaryMolecular MedicineChalcogensQuantum TheoryProtein BindingChemMedChem
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Kinetics of the lipoperoxyl radical-scavenging activity of indicaxanthin in solution and unilamellar liposomes

2007

Abstract The reaction of the phytochemical indicaxanthin with lipoperoxyl radicals generated in methyl linoleate methanol solution by 2,20-azobis(2,4-dimethylvaleronitrile), and in aqueous soybean phosphatidylcholine unilamellar liposomes by 2,20-azobis(2- amidinopropane)hydrochloride, was studied. The molecule acts as a chain-terminating lipoperoxyl radical scavenger in solution, with a calculated inhibition constant of 3.63 £ 105M21 s21, and a stoichiometric factor approaching 2. Indicaxanthin incorporated in liposomes prevented lipid oxidation, inducing clear-cut lag periods and decrease of the propagation rate. Both effects were concentration-dependent, but not linearly related to the p…

Indicaxanthin membranes radical scavenger liposomesLipid PeroxidesAntioxidant12-DipalmitoylphosphatidylcholinePyridinesmedicine.medical_treatmentRadicalLipid Bilayersalpha-TocopherolAmidinesContext (language use)In Vitro TechniquesBiochemistryAntioxidantsLipid peroxidationchemistry.chemical_compoundLipid oxidationSuspensionsPhosphatidylcholineNitrilesmedicineOrganic chemistryLiposomeDose-Response Relationship DrugMolecular StructureMethanolDrug SynergismGeneral MedicineFree Radical ScavengersBetaxanthinsSolutionsKineticschemistryLinoleic AcidsLiposomesPhosphatidylcholinesSolventsLipid PeroxidationIndicaxanthinAzo CompoundsOxidation-ReductionNuclear chemistry
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A synthetic approach to new polycyclic ring system of biological interest through domino reaction: indolo[2,3-e][1,2,3]triazolo[1,5-a]pyrimidine

2006

Abstract The title indolo-triazolo-pyrimidines were obtained from 3-azidoindoles and can be used as models for the design of DNA-interactive compounds. Hetero-domino reaction of azidoindoles/pyrroles and acetonitriles constitutes the synthetic entry to annelated 1,2,3-triazolo[1,5- a ]pyrimidines.

Indolo-triazolo-pyrimidinechemistry.chemical_compoundAcetonitrilesPyrimidinechemistryCascade reactionDocking (molecular)StereochemistryOrganic ChemistryDrug DiscoveryDomino reactionBiochemistryDockingTetrahedron Letters
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