Gas chromatographic separatio of substituted pyridines

Premecz, J.E.; Ford, Michael E.

doi:10.1016/s0021-9673(01)94463-2

Cited by 17 publications

(2 citation statements)

References 13 publications

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“…(A) Cytidine analogues used for Brønsted analysis. Solution p K a ’s for N3 (indicated in bold) of each analogue are included. − (B) Brønsted analysis of the dependence of reaction rate on the acidity of the N3 imino nitrogen of C76. The x -axis represents the reaction p K a for each mutant ribozyme, and the y -axis represents proton-transfer-specific electronic effects of each mutation, as described in the Experimental Section.…”

Section: Resultsmentioning

confidence: 99%

Transition State Features in the Hepatitis Delta Virus Ribozyme Reaction Revealed by Atomic Perturbations

Koo

Lü

et al. 2015

J. Am. Chem. Soc.

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Endonucleolytic ribozymes constitute a class of non-coding RNAs that catalyze single strand RNA scission. With crystal structures available for all of the known ribozymes, a major challenge involves relating functional data to the physically observed RNA architecture. In the case of the HDV ribozyme, there are three high-resolution crystal structures, the product state of the reaction and two precursor variants, with distinct mechanistic implications. Here, we develop new strategies to probe the structure and catalytic mechanism of a ribozyme. First, we use double mutant cycles to distinguish differences in functional group proximity implicated by the crystal structures. Second, we use a corrected form of the Brønsted equation to assess the functional significance of general acid catalysis in the system. Our results delineate the functional relevance of atomic interactions inferred from structure, and suggest that the HDV ribozyme transition state resembles the cleavage product in the degree of proton transfer to the leaving group.

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Section: Resultsmentioning

confidence: 99%

Transition State Features in the Hepatitis Delta Virus Ribozyme Reaction Revealed by Atomic Perturbations

Koo

Lü

et al. 2015

J. Am. Chem. Soc.

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“…(5.38) was demonstrated with experimentally found (T Char ,q Char ) pairs for about 200 solutes and two types of stationary phase polymers [11,64,71]. The database was compiled from published thermodynamic data [51][52][53][54][55][56][57][58][59][60][61][62][64][65][66] and from experimental results developed by the software vendor [74]. A large database of thermodynamic parameters of solute-liquid interaction in GC is compiled in commercial Pro ezGC software [73] covering more than 3000 soluteseach in several liquid polymers widely used for making stationary phases in GC columns [74].…”

Section: Fixed Dimensionless Film Thicknessmentioning

confidence: 80%

Solute–Liquid Interaction in Gas Chromatography

Blumberg¹

2010

Temperature‐Programmed Gas Chromatography

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Solute separation in GC results from the difference in their migration velocities in a column. That difference, in turn, is a result of the difference in the solute interaction with the columns stationary phase. The stronger is the interaction, the lower is the migration velocity. Depending on the stationary phase typesolid or liquida solute can be adsorbed on the solid surface, or it can be absorbed by the liquid (dissolved in it). This chapter focuses on the GC-related parameters of interaction of solutes with liquid stationary phases. Distribution Constant and Retention FactorConsider a layer of a liquid (the liquid phase) and a layer of an inert gas (the gas phase) that are in contact with each other, Figure 5.1. In this chapter, the layers represent organic liquid polymer film and a carrier gas in a capillary (open tubular) column, respectively, Figure 2.1a. Suppose that a solute was added to the gas, and the entire three-component system was sealed. A fraction of the solute added to the gas can be absorbed by the liquid (dissolved in it). Of the primary concern for this chapter is a chromatographically meaningful description of equilibrium of a solute solvationevaporation (solvation in the liquid and evaporation into the gas) or, in broader terms, equilibrium of a solute-liquid interaction. The equilibrium takes place at a certain distribution of a solute between the gas and the liquid. The gas is inert and has no effect on the equilibrium distribution of a solute between the two phases. This means that replacement of one gas with another has no effect on the equilibrium.The equilibrium distribution of a solute between a gas and a liquid, Figure 5.1, can be described by the distribution constant [1] (partition coefficient [2-8]), K c , defined as [2][3][4][5][6][7]9] K c ¼ C sol;f C sol;g ð5:1Þwhere C sol,g and C sol,f are concentrations (mass per volume, mole per volume, and so forth) of the solute in a liquid film and a gas, respectively.Temperature-Programmed Gas Chromatography. Leonid M. Blumberg

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The Need for Two-Dimensional Gas Chromatography: Extent of Overlap in One-Dimensional Gas Chromatograms

Davis

Samuel

2000

J. High Resol. Chromatogr.

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Gas chromatographic separatio of substituted pyridines

Cited by 17 publications

References 13 publications

Transition State Features in the Hepatitis Delta Virus Ribozyme Reaction Revealed by Atomic Perturbations

Transition State Features in the Hepatitis Delta Virus Ribozyme Reaction Revealed by Atomic Perturbations

Solute–Liquid Interaction in Gas Chromatography

The Need for Two-Dimensional Gas Chromatography: Extent of Overlap in One-Dimensional Gas Chromatograms

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