Come check out the Seminar by our own Dr. Karver this Friday. She will be sharing work that has been done by DePaul students in her group and with collaborators. Her work will be especially interesting to those interested in biochemistry, medicinal chemistry, molecular biology, and diseases such as inflammation. She also does a lot of organic synthesis in her work. All majors/areas of interest welcome! See you there!
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We will discuss the inorganic chemistry applications of advanced paramagnetic resonance techniques. These techniques include electron paramagnetic resonance (EPR), but rather than being performed at a fixed, low frequency (typically X-band, ~9 – 9.5 GHz) and a modest field sweep (typically 0 – 600 mT), the technique of interest involves variable, high frequencies (up to 1 THz) and field sweeps from zero up to 36 T This technique is referred to as high-frequency and -field EPR (HFEPR). Another technique is far-infrared magnetic resonance (FIRMS), which involves fixed external fields from 0 – 7 T, with FIR frequencies in the range of 20 – 200 cm-1 (or higher using a conventional FTIR). HFEPR and FIRMS are applied to high-spin (defined here for EPR purposes as S > 1/2) mononuclear transition metal ion complexes. Particular emphasis will be placed on those ions that belong to the non-Kramers (integer-spin) class and are typically “EPR-silent” at X-band due to large magnitude zero-field splitting (zfs). Classic examples of this type include: V3+ (3d2, S = 1), Mn3+ (3d4, S = 2), Fe2+ (3d6, S = 2), and Ni2+ (3d8, S = 1). From among these ions, Mn3+ will be the primary example (see Figure 1). HFEPR is also useful for investigating high-spin Kramers-type (half integer-spin) ions characterized by large zero-field splitting. Examples of these are Cr3+ (3d3, S = 3/2), Fe3+ (3d5, S = 5/2), and Co2+ (3d7, S = 3/2), of which the last will be used for illustration. The meaning and utility of the parameters extracted by HFEPR/FIRMS will be explained. This information, in concert with quantum chemical theory, helps understand the electronic structure transition metal ion complexes both as models for enzymatic active sites and as building blocks for molecular (single ion) magnets.
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Mass spectrometry has emerged as a leading technology for biomarker discovery and to identify altered pathways in human diseases. Our laboratory studies Niemann-Pick Disease, Type C (NPC), a fatal, genetic, neurodegenerative disorders. Using combined approaches including mass spectrometry-based quantitative proteomics, lipidomics and lipid imaging, we have identified new markers of NPC and mapped altered lipids in brain tissue from the NPC mouse models. These markers provide insight into the biochemical alterations occurring following the primary genetic defect and can be used in future drug discovery studies.
Martin Conda-Sheridan
Assistant Professor
Pharmaceutical Sciences
University of Nebraska Medical Center
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Friday, September 14 at 1PM in McGowan South 103
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Hospital- and community-associated bacterial infections caused by pathogens such as methicillin-resistant staphylococcus aureus (MRSA) and escherichia coli (E. coli) are a reason of concern to people in the USA and around the world. These infections have become increasingly difficult to treat due to the tendency of bacteria to develop resistance and to form biofilms. Our lab is developing an antibacterial program using the phenazine natural products as active scaffolds. In this talk, we will introduce the total synthesis of two members of the endophenazine family. We will also present their biological activity against MRSA, E.coli and their toxicity towards human cells. In addition, we will present preliminary studies to unravel the mechanism of action of the molecules and the ability of bacteria to develop resistance to the molecules. Finally, we will present data regarding their metabolic stability.
The Catalyst 