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1.
Hofmekler, Jonathan.
Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes.
Degree: MS, Chemistry and Biochemistry, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/42896 
► Fluorescence microscopy is a powerful analytical tool for visualizing biological processes at the subcellular level. In this regard, 1,3,5-triarylpyrazoline based fluorescent probes which act as…
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▼ Fluorescence microscopy is a powerful analytical tool for visualizing biological processes at the subcellular level. In this regard, 1,3,5-triarylpyrazoline based fluorescent probes which act as "turn-on" probes, have been extensively researched. These probes achieve their fluorescence "turn-on" response by inhibition of fluorescence quenching by acceptor-excited photoinduced electron transfer upon binding of an analyte. It has been recently shown that some fluorescent probes used in biological research form colloids composed of nanoparticles, due to their hydrophobic character. This hydrophobic character can also lead to partitioning of the probe into cellular membranes. Colloid formation and membrane partitioning may affect the probes' photophysical properties such as absorption and emission wavelength and quantum yields. Recently, a series of 1,3,5-triarylpyrazolines synthesized in our group by M. T. Morgan, showed no formation of aggregates in aqueous buffer. Surprisingly, these probes increased their fluorescence intensity in the presence of liposomes. The photoinduced electron transfer process is greatly affected by the polarity of the medium in which the probe is used. In this study, the effect of membrane proximity on the photoinduced electron transfer process for pyrazoline based "turn-on" probes has been investigated. A series of water soluble 1,3,5-triarylpyrazolines have been synthesized in which a N,N-dialkylaniline moiety acts as an electron donor and a proton acceptor and an alkylated sulfonamide moiety acts as a molecular anchor for interaction with neutral and anionic liposomes.
Advisors/Committee Members: Prof. Christoph J. Fahrni (Committee Chair), Dr. Adegboyega K. Oyelere (Committee Member), Dr. Wendy L. Kelly (Committee Member).
Subjects/Keywords: Pyrazoline; Liposomes; Photoinduced electron transfer; Fluorescence; Fluorescent probes; Fluorescence microscopy; Transition metals; Metal ions
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APA (6th Edition):
Hofmekler, J. (2011). Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/42896
Chicago Manual of Style (16th Edition):
Hofmekler, Jonathan. “Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes.” 2011. Masters Thesis, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/42896.
MLA Handbook (7th Edition):
Hofmekler, Jonathan. “Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes.” 2011. Web. 06 Mar 2021.
Vancouver:
Hofmekler J. Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes. [Internet] [Masters thesis]. Georgia Tech; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/42896.
Council of Science Editors:
Hofmekler J. Investigating the effect of membrane anchoring on photoinduced electron transfer pyrazoline based fluorescent probes. [Masters Thesis]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/42896
Georgia Tech
2.
Moore, Susanna.
Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse.
Degree: PhD, Chemistry and Biochemistry, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/5010
► Synthesis and Pharmacology of Potential Site-Directed Therapeutic Agents for Cocaine Abuse Susanna Moore 235 Pages Directed by Dr. David M. Collard and Dr. Howard M.…
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▼ Synthesis and Pharmacology of Potential Site-Directed Therapeutic
Agents for Cocaine Abuse
Susanna Moore
235 Pages
Directed by Dr. David M. Collard and Dr. Howard M. Deutsch
Stimulants such as cocaine continue to dominate the nations illicit drug problem. An effective medication for any aspect of cocaine addiction has not been developed. Cocaine binds, although not selectively, to the dopamine transporter (DAT) and disrupts normal dopamine (DA) neurotransmission between neurons. While the dopamine hypothesis for the mechanism of action of cocaine has been widely accepted, cocaine also possesses the ability to block the uptake of serotonin at the serotonin transporter (5-HTT) and norepinephrine at the norepinephrine transporter (NET). The purpose of the work described herein is directed towards synthesizing and testing compounds selective for the DAT, leading to the identification of candidates as potential pharmacotherapies for cocaine dependence.
A series of disubstituted and trisubstituted [2.2.2] and [2.2.1]bicycles were synthesized and tested for inhibitor potency in [3H]WIN 35,428 (WIN) binding at the DAT and for inhibition of [3H]DA uptake. Based on results from some of the pharmacology data new regio- and stereochemical isomers of bicyclic [2.2.1]heptanes and [2.2.2]octanes were synthesized. This will lead to further structure-activity-relationships, which will provide a better understanding of the structural requirements needed to bind at the DAT.
Advisors/Committee Members: Dr. David M. Collard (Committee Co-Chair), Dr. Howard M. Deutsch (Committee Co-Chair), Dr. Christoph J. Fahrni (Committee Member), Dr. Margaret M. Schweri (Committee Member), Dr. Suzy B. Shuker (Committee Member).
Subjects/Keywords: LR5182; Cocaine habit Treatment; Dopamine
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APA (6th Edition):
Moore, S. (2004). Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/5010
Chicago Manual of Style (16th Edition):
Moore, Susanna. “Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse.” 2004. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/5010.
MLA Handbook (7th Edition):
Moore, Susanna. “Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse.” 2004. Web. 06 Mar 2021.
Vancouver:
Moore S. Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/5010.
Council of Science Editors:
Moore S. Synthesis and Pharmacology of Potential Site-Specific Therapeutic Agents for Cocaine Abuse. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/5010
Georgia Tech
3.
Sommer, William J.
Supported catalysts, from polymers to gold nanoparticles supports.
Degree: PhD, Chemistry and Biochemistry, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/16140
► In today s world, the need to limit the use of nonrenewable resources and the importance of recycling has been recognized. One important contribution of…
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▼ In today s world, the need to limit the use of nonrenewable resources and the importance of recycling has been recognized. One important contribution of chemists toward the general goal of limiting their use is to find catalysts that can be reused and recycled thereby limiting the need for expensive metal precursors and metal waste. Strategies to recycle catalysts are multifold and range from the employment of soluble polymers as catalyst supports to the use of membrane-encapsulated catalyst. The use of soluble polymers as a support not only offers the advantage of being soluble under the catalytic reaction conditions but also, to be removable by changing the conditions of the surrounding media. Despite the great potential of these soluble supported catalysts, their use is very limited in today s synthesis. In addition, no set of rules have been established to guide the synthesis of efficient supported catalysts. In order to establish a tool box for the synthesis of supported catalysts, the study of several parameters such as the choice of the support and the choice and the stability of the catalyst are necessary. To establish this set of rules, a limited number of catalytic transformations, were studied. These catalytic reactions are the Heck-Mizoroki, Suzuki-Miyaura and Sonogashira coupling reactions. These transformations became fundamental for the synthesis of drugs and materials. The first and second chapters provide background information by describing and evaluating the main supports that were previously used for catalysts and the two main catalysts that are used in this thesis, the palladium pincer complex and the palladium N-heterocyclic complex. In chapter 3, the synthesis of a soluble polymer supported catalyst is described. The polymer chosen for the study is poly(norbornene), and the catalyst is a 1,3-disubstituted benzene ligand with sulfurs in the side-chains able to chelate to the metal center, better known as pincer ligand. These ligands are abbreviated by the three atoms that coordinate to the metal center, in this study, SCS. The metal used for the investigation of the activity of this supported pincer is palladium. The importance of the nature of the linkage on the stability of the Pd-SCS pincer complex has been reported in the literature, leading to the synthesis of Pd-SCS pincer complex tethered to the polymer via an ether and an amide linkage. The synthesized poly(norbornene) supported Pd-SCS pincer complexes were evaluated using the Heck transformation of iodobenzene with n-butyl acrylate. Kinetic studies and leaching tests using poly(vinyl pyridine) and mercury were carried out resulting in the conclusion that the active species during the catalysis is not the palladium pincer complex but a leached palladium (0) species. In chapter 4, Pd-PCP pincer complexes with the ether and amide tether were synthesized. Kinetic and poisoning studies were carried out resulting in a similar conclusion. Furthermore, 31P NMR experiments were conducted to investigate the unstability of the complex.…
Advisors/Committee Members: Marcus Weck (Committee Chair), Christoph J. Fahrni (Committee Member), Christopher W. Jones (Committee Member), E. Kent Barefield (Committee Member), Mostapha A. El-Sayed (Committee Member).
Subjects/Keywords: Kinetic study; Heck reaction; Coupling chemistry; Poisoning; Suzuki reaction; Catalysts; Supported catalysts; Polymers; Gold nanoparticles; Polymers Synthesis; Water-soluble polymers; Catalysts Recycling
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APA (6th Edition):
Sommer, W. J. (2007). Supported catalysts, from polymers to gold nanoparticles supports. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/16140
Chicago Manual of Style (16th Edition):
Sommer, William J. “Supported catalysts, from polymers to gold nanoparticles supports.” 2007. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/16140.
MLA Handbook (7th Edition):
Sommer, William J. “Supported catalysts, from polymers to gold nanoparticles supports.” 2007. Web. 06 Mar 2021.
Vancouver:
Sommer WJ. Supported catalysts, from polymers to gold nanoparticles supports. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/16140.
Council of Science Editors:
Sommer WJ. Supported catalysts, from polymers to gold nanoparticles supports. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/16140
4.
Ovat, Asli.
Design, synthesis and evaluation of cysteine protease inhibitors.
Degree: PhD, Chemistry and Biochemistry, 2009, Georgia Tech
URL: http://hdl.handle.net/1853/33822
► Cysteine proteases are important drug targets due to their involvement in many biological processes such as protein turnover, digestion, blood coagulation, apoptosis, cell differentiation, cell…
(more)
▼ Cysteine proteases are important drug targets due to their involvement in many biological processes such as protein turnover, digestion, blood coagulation, apoptosis, cell differentiation, cell signaling, and the immune response. In this thesis, we have reported the design, synthesis and evaluation of clan CA and clan CD cysteine protease inhibitors.
Aza-peptidyl Michael acceptor and epoxide inhibitors for asparaginyl endopeptidases (legumains) from the bloodfluke, Schistosoma mansoni (SmAE) and the hard tick, Ixodes ricinus (IrAE) were designed and synthesized. SARs were similar, but with some notable exceptions. Both enzymes prefer disubstituted amides to monosubstituted amides in the P1' position and potency increased as we increased the hydrophobicity of the inhibitor in this position. Extending the inhibitor to P5 resulted in increased inhibitory potency, especially against IrAE, and both enzymes prefer small over large hydrophobic residues in the P2 position. Aza-peptide Michael acceptor inhibitors are more potent than aza-peptide epoxide inhibitors and, for some of these compounds, second order inhibition rate constants are the fastest yet discovered.
We have also synthesized aza-peptidyl Michael acceptor and epoxide inhibitors for the parasitic cysteine proteases; cruzain, rhodesain. We have found that monosubstituted amides were favored over disubstituted amides indicating the involvement of the amide hydrogen in a H-bond network. We have shown that aza-peptide epoxides were as potent as Michael acceptors and we have obtained compounds with IC50 values as low as 20 nM.
We have worked on the synthesis of heterocyclic peptidyl α-ketoamides, peptidyl ketones and aza-peptidyl ketones as calpain inhibitors. We have synthesized peptidyl α-ketoamides with nucleotide bases in the primed region to create compounds that can cross the blood-brain barrier. We have improved the potency by introducing a hydrophobic group on the adenine ring. We have obtained compounds with Ki values in the nanomolar range. We have designed peptidyl aminoketones as a new class of inhibitors for calpain. Peptidyl aminoketones were less potent than peptidyl α-ketoamides but still reasonable inhibitors of calpain that have the potential to cross the BBB.
Advisors/Committee Members: Powers, James C. (Committee Chair), Christoph J. Fahrni (Committee Member), Jonathan D. Glass (Committee Member), Nicholas V. Hud (Committee Member), Sheldon W. May (Committee Member).
Subjects/Keywords: Legumain; Calpain; Protease; Cysteine; Cysteine proteinases; Cysteine proteinases Inhibitors; Protease inhibitors; Biosynthesis; Epoxy compounds
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APA (6th Edition):
Ovat, A. (2009). Design, synthesis and evaluation of cysteine protease inhibitors. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/33822
Chicago Manual of Style (16th Edition):
Ovat, Asli. “Design, synthesis and evaluation of cysteine protease inhibitors.” 2009. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/33822.
MLA Handbook (7th Edition):
Ovat, Asli. “Design, synthesis and evaluation of cysteine protease inhibitors.” 2009. Web. 06 Mar 2021.
Vancouver:
Ovat A. Design, synthesis and evaluation of cysteine protease inhibitors. [Internet] [Doctoral dissertation]. Georgia Tech; 2009. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/33822.
Council of Science Editors:
Ovat A. Design, synthesis and evaluation of cysteine protease inhibitors. [Doctoral Dissertation]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/33822
Georgia Tech
5.
McRae, Reagan.
Investigating metal homeostasis in mammalian cells using high resolution imaging techniques.
Degree: PhD, Chemistry and Biochemistry, 2010, Georgia Tech
URL: http://hdl.handle.net/1853/41197
► The primary aim of the work presented in this thesis is to elucidate novel information regarding the uptake, storage, distributions, and functions of both copper…
(more)
▼ The primary aim of the work presented in this thesis is to elucidate novel information regarding the uptake, storage, distributions, and functions of both copper and zinc in mammalian cells by predominantly using a combination of the high resolution imaging modalities, synchrotron radiation X-ray fluorescence microscopy (SXRF) and standard fluorescence imaging. Results from studies using cell permeable, metal ion selective fluorescent probes suggested the presence of labile pools of copper and zinc localized within the mitochondria and Golgi apparatus. Furthermore, SXRF imaging of a cell line defective in the copper transporter, Atox1, revealed intriguing differences in the Cu distribution of Atox1-/- cells compared to the corresponding wild-type cells. Finally, spatially well-resolved SXRF elemental maps of single, adherent mouse cells revealed remarkable changes in the distributions of both zinc and copper as the cells progressed through the cell cycle. Taken together, findings suggested major roles for copper and zinc within a native biological setting.
Advisors/Committee Members: Christoph J. Fahrni (Committee Chair), Donald Doyle (Committee Member), Jake Soper (Committee Member), Nael A. McCarty (Committee Member), Uwe Bunz (Committee Member).
Subjects/Keywords: Microscopy; Imaging; Synchrotron based X-ray fluorescence; Copper; Zinc; Synchrotron radiation
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APA ·
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APA (6th Edition):
McRae, R. (2010). Investigating metal homeostasis in mammalian cells using high resolution imaging techniques. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/41197
Chicago Manual of Style (16th Edition):
McRae, Reagan. “Investigating metal homeostasis in mammalian cells using high resolution imaging techniques.” 2010. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/41197.
MLA Handbook (7th Edition):
McRae, Reagan. “Investigating metal homeostasis in mammalian cells using high resolution imaging techniques.” 2010. Web. 06 Mar 2021.
Vancouver:
McRae R. Investigating metal homeostasis in mammalian cells using high resolution imaging techniques. [Internet] [Doctoral dissertation]. Georgia Tech; 2010. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/41197.
Council of Science Editors:
McRae R. Investigating metal homeostasis in mammalian cells using high resolution imaging techniques. [Doctoral Dissertation]. Georgia Tech; 2010. Available from: http://hdl.handle.net/1853/41197
Georgia Tech
6.
Cody, John W., Jr.
Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture.
Degree: PhD, Chemistry and Biochemistry, 2006, Georgia Tech
URL: http://hdl.handle.net/1853/13962
► Copper is an essential trace element present in all living systems and is important for the function of many cellular enzymes. It ranks third in…
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▼ Copper is an essential trace element present in all living systems and is important for the function of many cellular enzymes. It ranks third in intracellular abundance behind only zinc and iron and plays a very important role as a catalytic cofactor in various cellular processes such as mitochondrial respiration, iron uptake, and the redox processes of a number of enzymes, including superoxide dismutase, lysyl oxidase, or tyrosinase. Any abnormality in copper trafficking pathways can lead to serious diseases such as Wilsons disease, Menkes syndrome and has been implicated in the neurodegenerative diseases amyotropic lateral sclerosis (ALS) and Alzheimers disease. While free copper in the cytoplasm would prove toxic, there is compelling evidence for the existence of a labile pool of copper that remains kinetically accessible. In order to investigate the existence of such a pool the development of Cu(I) selective probes is necessary.
Chapter I provides the background for the role of copper in biology and elucidates the main trafficking pathways discovered to date. This chapter also provides recent developments of fluorescent sensors for selective visualization of biologically relevant metals.
Chapter II discusses the exploration of a phenanthroline-based ligand for the selective detection of Cu(I). A series of derivatives incorporating chelating substituents in the 2- and 9-positions to enforce a 1:1 binding stoichiometry were synthesized and the properties of their respective Cu(I) complexes were characterized by x-ray structural analysis, and their photophysical properties were investigated by absorption and emission spectroscopy. Visible light excitation yielded metal-to-ligand charge-transfer (MLCT) excited states with luminescence lifetimes up to 155 ns. Electrochemical measurements further indicate that coordinative rearrangements are involved in nonradiative deactivation of the excited states. According to time-dependent density functional theory calculations (B3LYP/6-31G**), the major MLCT transitions are polarized along the C2 axis of the complex and originate predominantly from the dxz orbital.
In chapter III, the development of a ratiometric Cu(I) sensor based on a donor-acceptor functionalized biphenyl fluorophore platform is discussed. The fluorescence emission energy for such fluorophores is highly dependent upon the interannular twist angle and this property was harnessed to provide a ratiometric sensor selective for Cu(I). Coordination of Cu(I) leads to a flattening of the biphenyl backbone and was confirmed by absorbance and emission spectroscopy as well as 2D NOESY experiments. The peak emission energy was shifted by 39 nm towards higher energy upon metal cation binding with a concomitant 7 bathochromic shift in absorption energy. The photophysical data accompanied by 1H NMR analysis confirms a well-defined 1:1 binding stoichiometry between metal and ligand. The findings from this study showed ratiometric behavior for this probe, albeit with a lowered quantum yield.
While…
Advisors/Committee Members: Christoph J. Fahrni (Committee Chair), James C. Powers (Committee Member), John Zhang (Committee Member), Julia Kubanek (Committee Member), Suzanne Beckham (Committee Member).
Subjects/Keywords: Donor-acceptor; Cu(I); Sensors; Charge transfer
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APA (6th Edition):
Cody, John W., J. (2006). Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/13962
Chicago Manual of Style (16th Edition):
Cody, John W., Jr. “Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture.” 2006. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/13962.
MLA Handbook (7th Edition):
Cody, John W., Jr. “Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture.” 2006. Web. 06 Mar 2021.
Vancouver:
Cody, John W. J. Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/13962.
Council of Science Editors:
Cody, John W. J. Design, Synthesis, and Evaluation of Metal Cation Sensors with Donor-Acceptor Architecture. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/13962
. 
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