Physical Sciences and Mathematics Commons^™

Resolution Modeling Of Length Tuning In Gas Chromatography, James P. Grinias

Senior Honors Theses and Projects

Tunable selectivity provides a relatively simple and inexpensive way to manipulate peak positions and gain resolution in chromatographic separations. Length tuning utilizes two columns of different polarities connected in series. Selectivity is manipulated by changing the relative lengths of the two columns. However, a direct correlation is not seen between relative length and effective contribution due to gas compression effects. Rather, a direct correlation is observed between the carrier gas transport time through a segment of column (relative to the total carrier gas transport time) and the effective contribution of that segment. This relationship has been used to predict retention …

A Density Functional Study Of The Relative Stability Of Intermediates In A Mcmurry Coupling Reaction, Andrew Jozef Livingston

Senior Honors Theses and Projects

Reductive cyclization via McMurry coupling is a common way to form pyrrolizidine rings. In this work we investigate the titanium-catalyzed McMurry coupling reaction leading to a pyrrolizidine alkaloid using density functional methods. Specifically, we compare the relative energies of all possible pinacolate intermediates at the UB3LYP/6-31G level of theory. The most stable intermediate is found to be the one resulting from C-O bond insertion in the ester group. The McMurry product is not predicted to form.

Qualitative Thm-Gc-Ms Analysis Of Proteins And Amino Acids In Rock Painting Binders, Melissa Doolin

Senior Honors Theses and Projects

A vital step to radiocarbon dating rock paintings involves the characterization of organic material in the paint. Using THM-GC-MS we have created a library of mass spectrometric data on possible organic binders, to compare to authentic paint samples. To reduce interference from contaminants and the mineral background, we are developing a simple purification technique to extract proteins and carbohydrates from these samples. Separating the organics can greatly enhance our results for GC-MS identification and subsequent radiocarbon analysis by accelerator mass spectroscopy.

Role Of Aromatic Pi-Stacking On The Aggregation Of Human Islet Amyloid Polypeptide (Hiapp), Srikanth Reddy Konda

Master's Theses and Doctoral Dissertations

Human islet amyloid polypeptide (hIAPP) is secreted in the β-cells of the pancreas, which also secretes insulin. In type 2 diabetes mellitus, hIAPP undergoes self-aggregation, forming fibrils. This self-aggregation is cytotoxic and is thought to be linked to type 2 diabetes mellitus by causing β-cell membrane destruction. The N-terminus of hIAPP (1-19) contains a binding site (residues 14-18) for self-aggregation. Aggregation is thought to be mediated by pistacking interactions between phenylalanine residues of hIAPP. In this study, the hIAPP 1-19 sequence was modified by replacing phenylalanine with alanine and naphthylalanine, to study if the modification of the aromatic side chain …

An Improved Synthesis Of The Hdac Inhibitor Trichostatin A, Joseph Colombo

Master's Theses and Doctoral Dissertations

Histone deacetylase inhibitors (HDIs) have found a wide variety of medicinal uses and are most noted for their specific apoptotic action towards cancer cells. Several hydroxamate HDIs have since been moved on to phase 1 and 2 clinical drug trials, with one having already been approved for treatment of advanced cutaneous T-cell lymphoma. Trichostatin A is one of the most potent known naturally-occurring inhibitors of histone deacetylase. Unfortunately for researchers, the syntheses that have been reported are both long and difficult, which leads to a low overall yield and therefore to a prohibitively expensive product, limiting its medicinal potential. This …

Synthesis Of The Bicyclic Core Of Pyrrolizidine Alkaloids, Fatmagul Tuluoglu

Master's Theses and Doctoral Dissertations

Pyrrolizidine alkaloids are a large class of natural products whose members exhibit a variety of biological properties including potential applications toward the treatment of cancer, diabetes, and viral infections such as HIV. In addition, some of these compounds exhibit insect antifeedant activity, and so have potential applications in the agricultural industry for the protection of crops.

For these reasons, we were interested in developing a method to form the bicyclic alkaloid core that could be functionalized to generate many pyrrolizidine alkaloids. Specifically, our goal was to synthesize the pyrrolizidine B-ring by a novel McMurry cyclization strategy (Scheme 1). The synthesis …

Insulin Based Inhibitors Of Human Islet Amyloid Polypeptide (Hiapp) And Their Effect On Hiapp- Mediated Membrane Damage In Type 2 Diabetes Mellitus, Durgaprasad Peddi

Master's Theses and Doctoral Dissertations

Amylin (Islet Amyloid Polypeptide, IAPP) is a 37 amino acid polypeptide, co-secreted with insulin from pancreatic beta cells, that plays a role in the damage of cell membranes by forming amyloid fibrils in Type 2 diabetes. Insulin has been found to inhibit hIAPP (Human Islet Amyloid Polypeptide) aggregation. The HLVEALYLVC amino acid region of insulin contacts hIAPP near the N-terminus. Truncated and modified analogs of insulin containing the binding region (VEALYLV, VEALFLV and EALYLV) were synthesized and purified, and their actions were studied on model lipid membranes in the presence of hIAPP 1-19 and hIAPP 1-37.

Development Of Methodology For The Use Of Multi-Bed Sorbent Traps With Gas Chromatography Time Of Flight Mass Spectrometry, Siva Maheswara Reddy Anna Pareddy

Master's Theses and Doctoral Dissertations

The lipid peroxidation of unsaturated fatty acids in cellular membranes leads to the formation of alkanes, aldehydes, alkanals, alk-2-enals, and hydroxyl alkenals. The free radicals formed during the process of lipid peroxidation can react with and damage cellular components. Lipid peroxidation is known to cause a number of diseases such as cancer, diabetes, and heart disease. Various analytical methods that include spectrometric assays and chromatographic analyses of derivatized products are available for the detection of the lipid peroxidation products.

The development of rapid, non-invasive monitoring of reactions occurring in biological systems, such as cell cultures, is highly desirable, as such …

Identification Of Changes In The Surface Of Textiles Subjected To Plasma Chemical Treatment Using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy, Joslyn Diana Kirkland

Master's Theses and Doctoral Dissertations

Plasma chemical oxidation has been proposed as a “nondestructive” method for preparing samples from archaeological materials for radiocarbon dating using accelerator mass spectrometry. However, the chemical effects of low-temperature, low-pressure plasma discharges on fragile archaeological materials are not understood. It is believed that reactions only occur at the surface of the treated samples. Therefore, we have used Fourier transform infrared spectroscopy with attenuated total reflectance sampling (ATR-FTIR) to examine changes in the chemical nature of the surface of representative modern and archaeological samples upon plasma treatment. Samples that were treated with destructive wet chemical methods, e.g., treatment with sodium hydroxide …

Isolation And Analysis Of Cyanobacterial Dna, Tiffany Crosby

Senior Honors Theses and Projects

Cyanobacteria are a phylum of bacteria that possess a diverse number of biological characteristics. One of the evolutionary innovations of the cyanobacteria are its ability to perform oxygenating photosynthesis, which all cyanobacteria are able to perform. It is believed that a form of metabolism became the dominant method for producting fixed carbon from carbon dioxide (CO₂) at around 3.5 billion years ago. Instead of using hydrogen sulfide, whose generated waste products were difficult to eliminate, the photosynthetic cyanobacteria used water as their hydrogen source (1). Many cyanobacteria are also capable of fixing atmospheric nitrogen (2). Cyanobacteria are present …

Development Of A Headspace Solid-Phase Microextraction (Hs-Spme) Procedure For The Determination Of Short-Chain Fatty Acids (Scfas) In Activated Sludge By Gc-Fid, Shiyan Cheng

Master's Theses and Doctoral Dissertations

The process of wastewater treatment includes the removal of inorganic solids such as sand and gravel as well as organic materials, phosphorus, and nitrogen. Activated sludge, containing a variety of living organisms, is added into the wastewater treatment system. Short-chain fatty acids (SCFAs), an energy source of the bioorganisms, are produced during activated sludge digestion, and play a significant role in phosphorus and nitrogen removal as well as the removal of organic materials during the process of wastewater treatment. Extensive research has been carried out recently in search of optimized conditions to increase the level of fatty acids in the …