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Full-Text Articles in Medicinal-Pharmaceutical Chemistry

Synthesis, Structural Studies And Desilylation Reactions Of Some N-2-(Trimethylsilyl)Ethyl-N-Nitrosocarbamates, Arpitha Thakkalapally, Vladimir Benin May 2005

Synthesis, Structural Studies And Desilylation Reactions Of Some N-2-(Trimethylsilyl)Ethyl-N-Nitrosocarbamates, Arpitha Thakkalapally, Vladimir Benin

Chemistry Faculty Publications

The present report describes the preparation and characterization of several N-2-(trimethylsilyl)ethyl-N-nitrosocarbamates, designed as precursors to thermally unstable secondary N-nitrosocarbamate anions via fluoride-assisted cleavage. X-ray structural studies demonstrate that the core N-nitrosocarbamate moiety has a nearly planar geometry, with an s-E orientation at the N–N bond. DFT calculations (B3LYP/6-31+G(d)) reproduce accurately the structural features of the title compounds and detailed conformational analysis at the same level of theory addresses the long-standing issue of preferred geometries for three classes of related structures: N-nitrosocarbamates, N-nitrosoureas and N-nitrosoamides. Desilylation ...


Combining Structure-Based Drug Design And Pharmacophores, Renate Griffith, T. T. T. Luu, James A. Garner, Paul A. Keller Jan 2005

Combining Structure-Based Drug Design And Pharmacophores, Renate Griffith, T. T. T. Luu, James A. Garner, Paul A. Keller

Faculty of Science - Papers (Archive)

Development towards integrated computer-aided drug design methodologies is presented by utilising crystal structure complexes to produce structure-based pharmacophores. These novel pharmacophores represent the ligand features that are involved in interactions with the target protein, as well as the space around the ligand occupied by the protein. The protein-ligand complexes can also yield information about all interactions that ligands could potentially form with the binding site, as well as about the size of the binding cavity. Together, these describe a 'superligand', which can also be viewed as a pharmacophore. Various types of novel pharmacophores are discussed and compared, using HIV-1 Reverse ...


Modifications Of Human Βa1/Βa3-Crystallins Include S-Methylation, Glutathiolation, And Truncation, Veniamin N. Lapko, Ronald Cerny, David L. Smith, Jean B. Smith Jan 2005

Modifications Of Human Βa1/Βa3-Crystallins Include S-Methylation, Glutathiolation, And Truncation, Veniamin N. Lapko, Ronald Cerny, David L. Smith, Jean B. Smith

Ronald Cerny Publications

Disulfide bonding of lens crystallins contributes to the aggregation and insolubilization of these proteins that leads to cataract. A high concentration of reduced glutathione is believed to be key in preventing oxidation of crystallin sulfhydryls to form disulfide bonds. This protective role is decreased in aged lenses because of lower glutathione levels, especially in the nucleus. We recently found that human [1]-crystallins undergo S-methylation at exposed cysteine residues, a reaction that may prevent disulfide bonding. We report here that βA1/A3-crystallins are also methylated at specific cysteine residues and are the most heavily methylated of the human lens crystallins ...


Enantiomeric Chromatographic Separations And Ionic Liquids , Jie Ding Jan 2005

Enantiomeric Chromatographic Separations And Ionic Liquids , Jie Ding

Retrospective Theses and Dissertations

The chiral nature of compounds contributes to their bioactivity and their various pharmaceutical/industrial uses. As a result, the Food and Drug Administration (FDA) has implemented policies for analyzing the enantiomers of chiral compounds. Gas chromatography (GC) and liquid chromatography (LC) utilizing chiral stationary phases are the two most commonly used methods to achieve direct enantiomeric separations of chiral compounds. The first part of this dissertation includes a review of direct separation of enantiomers in gas and liquid chromatography, an example of the enantiomeric separation of various racemic sulfoxides and sulfinate esters on four derivatized cyclodextrin chiral stationary phases using ...


A Periplasmic Drug-Binding Site Of The Acrb Multidrug Efflux Pump: A Crystallographic And Site-Directed Mutagenesis Study, Edward Yu, Juilo R. Aires, Gerry Mcdermott, Hiroshi Nikaido Jan 2005

A Periplasmic Drug-Binding Site Of The Acrb Multidrug Efflux Pump: A Crystallographic And Site-Directed Mutagenesis Study, Edward Yu, Juilo R. Aires, Gerry Mcdermott, Hiroshi Nikaido

Physics and Astronomy Publications

The Escherichia coli AcrB multidrug efflux pump is a membrane protein that recognizes many structurally dissimilar toxic compounds. We previously reported the X-ray structures of four AcrB-ligand complexes in which the ligands were bound to the wall of the extremely large central cavity in the transmembrane domain of the pump. Genetic studies, however, suggested that discrimination between the substrates occurs mainly in the periplasmic domain rather than the transmembrane domain of the pump. We here describe the crystal structures of the AcrB mutant in which Asn109 was replaced by Ala, with five structurally diverse ligands, ethidium, rhodamine 6G, ciprofloxacin, nafcillin ...