Chemistry

Dave Cordes

Project 1: Asymmetric Organic Synthesis

Asymmetric synthesis is the art of selectively synthesizing only one of the two possible enantiomers, or basic forms, which can exist for a particular chiral compound. Ordinarily, under standard, traditional ways of producing compounds in the lab, both possible enantiomers are formed together. These two enantiomers are very difficult to separate from one another. Often, pharmaceutical and life science products require the use of only one of the two enantiomers for a medicine or therapeutic agent. Our research is geared towards meeting this challenge of selective synthesis by using Lewis acid-catalyzed transformations to obtain enantiomerically enriched products.

Students who have successfully completed at least one course in Organic Chemistry will be considered for this project.

Project 2: Fluorescent Sensors and Materials

There is considerable interest in using chemistry to better understand systems of biomedical, industrial, and environmental significance. One way to explore these systems is using fluorescent light as a probe to determine the presence, concentration, or activity of different chemicals. We are working to develop fluorescence-based sensing systems using very small fluorescent crystals called “quantum dots”. We plan to synthesize and evaluate these materials for use in the detection of metal ions in aqueous solutions. 

Students who have successfully completed two semesters of General Chemistry will be considered for this project.

Kevin Johnson

Project 1: The chemistry an acidic surface: A scanning tunneling microscopy study of self-assembled monolayers

Chemists are all familiar with the behavior of weak acids in a solution. The protonation/deprotonation state of a molecule can be probed by measuring pH in a titration curve. When the molecular weak acid is bound to a surface in a self-assembled monolayer (SAM) the acid/base chemistry of the molecule changes due to its proximity to other molecules. This project utilizes scanning tunneling microscopy to investigate the structural changes to surfaces with an acid-terminated SAM under varying pH in solution.

Students who have successfully completed general chemistry and beyond will be considered for this project.

Project 2: Computational studies of compounds exhibiting nonlinear optical absorbance

Compounds with the property of nonlinear optical absorption have multiple potential applications, including passive optical limiters, optical data storage, optical switching, and photodynamic therapies. Molecules exhibiting sequential two-photon nonlinear absorption will be investigated using Time-Dependent Density-Functional methodologies to calculate ground and excited state spectral characteristics. This approach will serve as a means to better understand and predict nonlinear optical behavior. A student researcher will learn to use molecular modeling software and interpret results of calculations.  This project stems from a collaboration with James Butler on a funded MRI proposal (major research instrumentation) and is the basis of a proposal submitted to the National Science Foundation in November 2007.

Students who have successfully completed general chemistry and beyond will be considered for this project.

Jeannine Chan: Deducing roles of amino acid residues in the function of proteins involved in the global nitrogen cycle

The goal of these projects is to determine the roles of specific amino acid residues in proteins that participate in the global nitrogen cycle. One protein that will be investigated is the enzyme, nitrogenase, which catalyzes the conversion of nitrogen gas to ammonia. This enzyme consists of two component proteins that must associate and dissociate during the catalytic cycle. By using site-directed mutagenesis, we can assess the importance of certain amino acid residues in this protein-protein interaction. A student researcher will use standard molecular biology techniques to construct the site-specific mutations, express and purify the altered forms of the enzyme, and determine the in vitro activity using GC and UV-vis. A second possible project focuses on the biosynthesis of the novel copper-containing active site of the enzyme, nitrous oxide reductase, which converts nitrous oxide to nitrogen gas. The protein, NosL, is thought to be involved in the assembly of this active site. To try to determine the function of NosL, a student researcher will express, purify, and characterize NosL and site-specifically altered forms of NosL. The results of these projects are expected to contribute to an understanding of the global nitrogen cycle at the molecular level, with potential implications in agriculture and in water and air quality. Students will ideally have taken Biol 204 and either Chem 240 or Chem 320, however students who have completed general chemistry will also be considered.

Pharmacy

Amber Buhler:  Pain Processing Circuitry in the Brain

One student will learn and use immunohistochemistry techniques in order to map the anatomy of pain processing neurons in rat brain tissue. These neurons play a role in chronic pain conditions, and are a potential target for future analgesic drug therapies. Student should have had general chemistry and biology. No contact with animals will occur.

Sigrid Roberts: Identifying potential therapeutic targets in the human parasite Leishmania

Parasites of the genus Leishmania cause a variety of devastating and often fatal diseases in humans and domestic animals worldwide. Due to the absence of effective vaccines, chemotherapy has offered the only avenue of defense for the treatment of leishmaniasis and other parasitic diseases. Unfortunately, the currently available drugs are far from ideal because of toxic side effects due to a lack of specificity, i.e. these drugs harm not only the parasite but also the human host. A better and more directed approach in the design of selective and efficacious drugs is to study parasite biology and biochemistry in order to identify new therapeutic targets. The ideal paradigm would be a metabolic pathway or cellular process that is vital to the parasite but exhibits considerable differences compared to the biology of the human host.

My research focuses on the polyamine biosynthetic pathway in Leishmania, an essential pathway that is significantly disparate from the host’s mechanism of polyamine production. The proposed summer research project is to characterize two putative Leishmania deoxyhypusine synthase (DHS) proteins biochemically and to determine whether they indeed function as DHS enzymes. The experimental approach is to 1. subclone the genes into appropriate expression vectors, 2. produce and purify recombinant enzymes in bacteria (E.coli) or Leishmania, and 3. investigate their function in an in vitro assay. These studies will be carried out at Oregon Health & Science University.

Rajesh Vadlapatla:  Examination of Oxidative Metabolites of Arachidonic Acid and Low Birth Weight Associated Disease

Recent epidemiological studies suggest a strong correlation between low birth weight and high incidence of metabolic syndrome diseases such as hypertension, hyperlipidemia, and diabetes. It is hypothesized in our laboratory that the cardiovascular abnormalities in low birth weight subjects is mediated by oxidative metabolites of arachidonic acid (AA) such as epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids (HETEs).

In the current project, we embark on examining the rate and extent of formation of EETs and HETEs in livers of rodents. The rodent model to study low birth weight associated diseases has been established by one of our collaborator at Oregon Health & Science University/ Oregon State University. The collaborator’s laboratory will provide rodent tissues to examine the status of EETs and HETEs. The objectives this summer are to (1) setup and validate a newly acquired HPLC instrument in the laboratory, (2) develop an analytical method to separate, identify, and quantify EETs, HETEs, and AA, and (3) examine the rate and extent of formation of EETs and HETEs in low birth weight subjects using the rodent model.