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Showing 1 to 20 of 87 for “"enantiomer"”.
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Surface Acoustic Wave-Actuated Cell Sorting and Enantiomer Separation
… channel through the other outflow boundary. Enantiomers are chiral objects such as chemical molecules that can be distinguished by their handedness. They typically occur as racemic compounds of left- and right-handed species which may have completely different properties. Therefore, in …
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Part I--studies toward the synthesis of sesbanimide A : Part II--total synthesis of the natural enantiomer of olvin
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1988.
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Chiral resolution control in batch and continuous crystallization processes for a conglomerate forming compound
… Each of these mirror image forms is known as an enantiomer. Such molecules exist throughout nature, from amino acid and sugar molecules, to the complex helical structure of our own DNA. However, the separation of enantiomers (resolution) is extremely important in the pharmaceutical industry due …
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A novel GC-MS/MS assay for the measurement of 2-hg enantiomers and the utility of 2-hg enantiomer levels as a biomarker for IDH mutant gliomas
… due to the lack of discrimination from the enantiomer of R-2-hg and (S)-2-hydroxyglutarate (S-2-hg). S-2-hg is also normally made in the body but can increase to levels comparable to R-2-hg during hypoxic and acidic conditions. Thus, it is important to differentiate between R-2-hg and S-2-hg …
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Separation of enantiomers of Baclofen
… in the solid state and in solution. The (-) enantiomer of the lactam and the ( +) enantiomer of the glutaramide were found to cocrystallise selectively with (2R,3R)-( +)-tartaric acid and (S)-(-)-a.-Methylbenzylamine respectively. Both these dissociable diastereomers Vere analysed by X-ray …
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Precursors to the potent odorant wine lactone.
… carried out on wine extracts to confirm which enantiomers of menthiafolic acid and wine lactone are present in real wine samples. Bioconversion of the glucose ester of menthiafolic acid utilising three different microorganisms was evaluated in order to determine if menthiafolic acid is produced …
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Untersuchungen von Einschlusskomplexen aus Cyclodextrinen mit Aminosäuren und Dipeptiden
… Jena systematische Studien über die Trennung von Enantiomeren verschiedener Dipeptide mit einer Vielzahl von nativen und derivatisierten Cyclodextrinen bei verschiedenen pH-Werten durchgeführt. Bei der Trennung der Enantiomere von z. B. Ala-Phe oder Ala-Tyr mit beta-Cyclodextrin wurde eine Umkehr …
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New routes to enantioenriched substances through small organic molecules
… trans-chrysanthemic acid (trans-ChA) and pure enantiomers of threo-2-dimethylamino-1-phenyl-1,3-propanediol (DMPP). The occurrence of p1,n1 salt formation can have profound effects on enantiomer separation of scalemic (non-racemic) mixtures. This phenomenon when accompanied by substrate …
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A microscopic model of signal transduction mechanisms: olfaction
… in particular the apparent paradox of enantiomer discrimination. The apparent paradox is shown to be obsolete. A correlation between a certain type of flexibility and whether enantiomer pairs smell the same is found. A rule is established: The members of an enantiomer pair will smell …
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A new cyclohexyl-based chiral auxiliary: application in the total synthesis of (+)-linalool oxide
… classical resolution was achieved and the enantiomer (–)-TTC was obtained in excellent yield and enantiopurity (99 % ee). The stereochemistry of the obtained enantiomer was defined as (1S,2R) from the X-ray structure of its Mosher ester derivative 2.76. (–)-TTC was used in the total …
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The interactions of Propafenone and its enantiomers with the major human forms of cytochrome P450 in terms of inhibition and metabolic rates
… and pharmacokinetic properties of the separate enantiomeric forms of the drug can exist. Propafenone enantiomers have been shown to have similar pharmacological properties, but studies are limited with regards to their disposition and interaction with drug metabolising enzymes. The aim of the …
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STEREOCHEMICAL STUDIES OF 1,2-DIAMINOCYCLOHEXANE AND SOME OF ITS DERIVATIVES
… by the condensation of benzil and (-)-(R,R)-DACH enantiomer. Optically active N,N'-dibenzyl-1,2-diaminocyclohexane (DBDACH) was prepared by the NaBH(,4) reduction of the diimine obtained by the condensation of benzaldehyde and (-)-(R,R)-DACH enantiomer.</p><p>Three diamines were added to …
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Utilization of Rationally Designed Small Molecule Chiral Selectors in Novel Enantioselective Processes
… run in the presence of a chiral selector, one enantiomer is effectively shielded from reaction. The methodology is extended to enantioselective nucleophilic aromatic substitution, reactions known to proceed through the intermediacy of a Meisenheimer adduct.
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Synthesis and evaluation of β-fluoro-γ-aminobutyric acid enantiomers
… the enantioselective synthesis of 3-fluoro-GABA enantiomers. This was achieved from L- and D- phenylalanine in six steps and in an overall yield of 31%. The preferred conformations of 3-fluoro-GABA in solution are then explored by NMR analysis and ab initio calculations. The biological evaluation …
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Wirkung der Enantiomere der alpha- Liponsäure auf die Widerstandsfähigkeit von Erythrozytenkonzentraten auf oxidativen Stress bei Kryokonservierung
… Antioxidans ebenfalls bekannten a-Liponsäure (R-Enantiomer und Razemat) in einer wesentlichen Qualitätsverbesserung sowohl hinsichtlich der quantitativen Ausbeute als auch der biochemischen Eigenschaften der gelagerten Eryhtrozyten resultiert. Die Erythrozytenkonzentrate wurden vor der …
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Stretching Collagen: Using Fluorophores in Collagen Mimetic Peptides as a Proposed Enantiomeric Sorting Technique
… These pairs of molecules are known as enantiomers, and for medications, one enantiomer is typically biologically active for a specific function (eutomer), while the other (distomer) is not. A problem presents itself when the distomer is biologically active in another part of the body, …
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The optical resolution of albuterol
… and di-0-toluoyltartaric acid, with the (2S,3S)enantiomer of the acid selectively co-crystallising with the desired (R)-albuterol acetonide. High performance liquid chromatography on a chiral stationary phase, and 1H NMR experiments using a chiral shift reagent were used to assess the optical …
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The Kinetic Resolution of Secondary Alcohols Through A Tandem Enantioselective Silylation and the Synthesis of Bis(Oxazolidinyl)Pyridine Metal-Organic Complexes
… to a kinetic resolution which targets the minor enantiomer, thereby increasing the e.e.of the products which were generated in the first reaction. This design was realized when we were able to increase the e.e.of a homoallylic alcohol generated through the allylboration of benzaldehyde, which …
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The stereoselective synthesis of a novel aromatic peptide nucleic acid (APNA) oligomer
… thymine derivative (S)-50, was achieved in high enantiomeric purity (98% ee). The (R) enhanced enantiomer was also synthesized with moderate enantiomeric purity (46% ee). This acyclic pyrimidine analog ((S)-50) is a useful building block for the synthesis of a novel class of oligomers, the …
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Side Chain Functionalized Hexestrols and Norhexestrols as Probes for the Estrogen Receptor
… receptor in four possible binding modes--two per enantiomer. Several side chain functionalized hexestrol and norhexestrol derivatives have been synthesized and resolved into pure enantiomers. Binding studies with lamb uterine estrogen receptor indicate that there is no appreciable difference in …
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