Chemistry

Rishi Chaudhuri and Rola Kolailat

Synthesis of Novel Nitrogen Containing Heterocyclic Systems

Modified four-quinazolinones have been widely patented for a variety of physiological activities. The modification explored in this work is annelation of a third ring onto the heterocyclic ring of the four-quinazolinones. Progress in the synthesis of annelated five, six and seven-membered ring derivatives, most of which have not been previously reported in the literature, will be discussed.

Session C - Noon - Room 330.

Michael Kallio

Kinetics of the Ligand Exchange Reaction between Ni(tren)2+ and 2,2'-Bipyridine

The ligand exchange reaction in which bipyridine replaces tren (tris(2-aminoethyl)amine) in its nickel(II) complex has been studied by following the formation of the product Ni(bipy)3 by absorption spectroscopy at 307 nm. The reaction is first-order in both [Ni(tren)2+] and [bipy] but the dependence on hydrogen ion concentration is a complex mathematical function. Mechanistic information is provided.

Session B - 10 a.m. - Room 304.

Ingrid Mèyè

Synthesis of Amylin Peptide: A Study of Amylin and its Role in Diabetes

Amylin, a 37-amino acid peptide hormone, is co-secreted with insulin from pancreatic islet _-cells. Human amylin forms aggregates known as amyloid fibers which may play a role in the destruction of islet _-cells, frequently found in individuals with Type II diabetes. However, rodent amylin does not form these same aggregates. The purpose of this study was to identify the amino acid fragments which influence amyloid aggregation, and investigate the mechanism of membrane destruction.

Session B - 10:15 a.m. - Room 304.

Nusibah Altayib, Miguel Perez and Hasina Saraha

Design and Synthesis of 1,2-Amino Alcohols as Antimalarial Agents

1,2-Amino alcohols have been shown to be potent inhibitors of Plasmodium falciparum, the most virulent material parasite in humans; however, few studies have been reported that investigate the importance of the relative and absolute stereochemistry of the inhibitors and the resulting effect on potency. The purpose of this research is to synthesize enantiomerically pure 1,2-amino alcohols of known stereochemistry in order to probe the structure-activity relationships against P. falciparum and determine the most effective stereoisomer.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Monica Bame

Acetylation of the A. aeolicus DHO-ATC Complex Disrupts the Oligomeric Structure

Aquifex aeolicus is an ancient, hyperthermophilic eubacteria that thrives at temperatures close to the boiling point of water. The enzymes that catalyze de novo pyrimidine biosynthesis are associated in multifunctional complexes. The activity of one of these enzymes, dihydroorotase, is entirely dependent on the formation of a complex with aspartate transcarbamoylase, another pathway enzyme. Here, we investigate the role of cysteine in the activation and oligomeric structure.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Brian Claxton

Development of an Environmentally-Friendly Procedure for Removal of a Common Protecting Group

Groups of removable atoms called protecting groups are often used to mask the reactivity of a particular atom. One common protecting group for nitrogen is the tert-butyl carbamate (Boc) group. Typically the Boc group is removed using excess strong acid and a halogenated solvent. By contrast, we have developed an environmentally-friendly method for Boc removal that involves a recyclable acid catalyst and a benign solvent. The scope and limitations of this procedure will be presented.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Andrea Dery

Mario Molina and the Discovery of Stratospheric Ozone Depletion

Mario J. Molina, Paul J. Crutzen and F. Sherwood Rowland shared the 1995 Nobel Prize in Chemistry for their pioneering efforts in atmospheric chemistry through which a catastrophic threat to Earth was identified at an early enough stage so as to allow corrective action to begin. This project in chemical education is presented from a multicultural viewpoint in a way to honor how Molina's scientific contributions benefited humanity.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Melissa Doolin

THM-GC-MS Analysis of Possible Binders in Rock Paintings

A vital step to radiocarbon dating rock paintings involves the characterization of organic material in the paint. In the past, rock paint samples have been radiocarbon dated with the assumptions that the paint contains carbon-based binders that are not affected by pretreatment. We are investigating these assumptions by analyzing synthetic paints with known organic binders, with and without pretreatment, by using thermally-assisted hydrolysis/methylation (THM)-GC-MS to compare to the composition of real paint. Results of these comparisons will be reported.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

James P. Grinias

Math Modeling of Length Tuning Effects on Gas Chromotography

In gas chromatography the ultimate goal is to resolve the components of interest in the shortest time possible. Length tuning involves the process of joining two different column segments together to maximize the efficiency of gas chromatography. The model we developed can be used to determine the best combination of two column segments and the highest carrier gas velocity that would still provide acceptable separation between the various compounds.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Benjamin F. Johnson

An Approach to the Synthesis of Amphorogynine D and Related Alkaloids

Amphorogynines are a group of naturally occurring compounds recently isolated from a Caledonian plant. They are of interest to the agricultural industry for their potential use as environmentally-benign insect antifeedants. Our research focuses on the development of a novel, microwave-assisted approach towards the synthesis of these compounds. The process represents a new technique that, with slight modifications, could be used to generate a wide variety of potentially useful molecules.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Andrew Livingston

THM-GC-MS Analysis of Rock Paintings from Casa de Las Golondrinas, Guatemala: Implications for Radiocarbon Dating

Rock paintings from Guatemala were prepared using plasma-chemical oxidation (PCO) and radiocarbon dated. Carbon extracted by the plasma, presumed to be a binder in the paint, was examined using GC-MS. No binder compounds were observed in a sample yielding an unexpectedly ancient date. Compounds from this sample correspond to compounds observed in the site's soil indicating the dated carbon is from a geologic, not anthropogenic, source. This work aids in understanding and refining the PCO technique.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Mark Lukowski

Substrate Binding and Kinetic Aspects of the Oxygenation Reaction Mechanism in COX-1

Polyunsaturated fatty acids (PUFAs) exhibit very different rates of oxygenation in the cyclooxygenase (COX) active site of prostaglandin endoperoxide H synthase-1. This work is a theoretical investigation of the interaction between substrate and enzyme, aimed at explaining the observed activity differences. Results of the calculations provide insight into the reasons why arachidonic acid is the preferred substrate for COX-1.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Edwin L. Marrero

Influencing Diastereoselectivity in the Synthesis of Acylpyrrolidines via an Aza-Cope Rearrangement-Mannich Cyclization

We have explored microwave heating to accelerate the aza-Cope rearrangement, Mannich cyclization, a reaction that is used in the synthesis of five-membered nitrogen-containing rings. These molecules have potential for both physiological and agricultural applications. We have demonstrated that the three-dimensional structure of these rings may be altered by varying the size of certain removable groups of atoms in the reactants. Discussion of the effects of microwave versus conventional heating on product structures will also be presented.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Geneve M. Maxwell

GC-MS for Quantitative Analysis of Lipids in a Coating Associated with Rock Paintings in Idaho

Rock paintings in Little Lost Cave, Idaho contain a black coating of unknown origin consisting of organic materials. We are using gas chromatography-mass spectrometry to carry out quantitative analysis of the fatty acids. Lipids were extracted using chloroform:methanol and derivatized to their methyl esters using tetramethylammonium hydroxide, which was mixed with the sample just prior to insertion into the Varian Chromatoprobe inlet system. The results of this new method will be presented.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Amanda Mortensen

A Chemical Education Experiment in Lipstick Chromatography

A "crime scene investigation" experiment for high school students is described in which students must identify the guilty person in a group of suspects by determining unique lipstick chromatograms and comparing the suspect's results to those found at the crime scene. The experiment is described in detail from both chemical and pedagogical viewpoints.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Bryan Perria

Synthesis of an Aza-Analogue of the Cocaine Molecule

Cocaine is a great anesthetic, but it is terribly addictive. Quite modest structural changes often produce dramatic changes in physiological activity so it is conceivable that modified cocaine could retain the anesthetic properties without the addictive character. The major change investigated in this work is the introduction of an extra nitrogen atom into the cocaine skeleton at the bridgehead position. Progress towards this objective will be described.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Allison Rogalski and Carrie Bowen

Synthesis and Kinetic Analysis of an _-Amylase Inhibitor

The enzyme _-amylase breaks down starch into glucose subunits and is important in controlling blood sugar levels. Inhibiting _-amylase activity is a beneficial treatment for patients with insulin-dependent diabetes mellitus. Naturally occurring Tendamistat has inhibitory effects, but there are several drawbacks to this large molecule. A smaller synthesized variation of Tendamistat was created and analyzed to mimic its inhibitory effects, and several modifications were made to alter pKa, testing for the importance of hydrogen bonding.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .

Claire Tornow

Mechanism of Lipid Peroxidation of Arachidonic Acid: A Theoretical Investigation

The mechanism of lipid peroxidation of polyunsaturated fatty acids (PUFA) is well established, yet it is difficult to predict the ratio of aldehydes produced, which is a marker of biological activity. Molecular orbital calculations using density functional theory are used to study the thermodynamic aspects of the mechanism of lipid peroxidation of arachidonic acid. The relative stability of resulting radical species is analyzed with respect to position in the chain and stereochemistry of double bonds.

Group 2 - 10:45 a.m. to 12:30 p.m.- Room 310A/B .

Janine Van Gemert

Characterization of Copal Incense from Mesoamerica: Identification of Residues by GC-MS

The presence of copal incense residues in archaeological materials may help to place archaeological sites of unknown cultural affiliation into specific Mesoamerican contexts. We have undertaken GC-MS analysis of extracts from modern copal resins from Mexico and Guatemala to determine if burned residues of these materials retain the terpenoid marker compounds. While many of the terpenoids were observed, burning occasionally induced significant changes. Further studies are needed to apply this method to archaeological materials.

Group 1 - 8:30 a.m. - 10:15 a.m. - Room 310A/B .