http://hdl.handle.net/10177/1077 http://libmedia.willamette.edu:8080/xmlui/retrieve/7118 http://hdl.handle.net/10177/1077 http://hdl.handle.net/10177/2126 A Novel Method for the Determination of Phospholipid Phase Transitions Werst, Nathan The objective of this research is to develop a novel method for measuring phospholipid phase transition temperatures. Preliminary experimentation has shown that both the main chain melting transitions as well as pre-transitions are observable as changes in laser light scattering (λ = 635 nm) in response to sample turbidity. Measurements on phosphatidylcholine multilamellar liposomes indicate that the phase transition is best detected in 30mM KCl , with lipid concentration between 250 and 500 µM. The addition of 4% anionic lipid (dicetyl phosphate) did not improve the ease of transition measurement. Finally, preparation of sample solutions at 70° C increased the reproducibility of subsequent measurements, compared to samples prepared and measured starting at room temperature. Thu, 09 Jul 2009 21:45:40 GMT http://hdl.handle.net/10177/2102 Raman Investigation of the Aquation Reactions Involving the Anti-Cancer Compound NAMI-A Currie, Simon Ruthenium-based compounds have been widely studied as potential complements to transition metal-based drugs currently in use, such as cisplatinum. In particular, NAMI-A has exhibited promising anti-cancer properties in clinical trials. This study used Raman spectroscopy to detect ruthenium-ligand bonds in NAMI-A, and to monitor these bonds during the progression of aquation reactions. Peak assignments were made for ν(Ru-Cl), ν(Ru-S), ν(Ru-O), and ν(Ru-N). These peaks were tracked over time and showed that for NAMI-A at 25 °C and pH 7.4, a chloride ligand is the first to be replaced with water in an aquation reaction. Additionally, this study demonstrated that NAMI-A is accelerated through its aquation processes due to exposure to the argon ion laser. Thu, 14 May 2009 19:06:57 GMT http://hdl.handle.net/10177/2097 Construction of a Synthetic Octapeptide to Investigate the Effects of Ene-Allene Ring-Closing Metathesis (RCM) Reactions on 310-Helical Peptides Costantino, Corey The stabilization of helical peptide structures through the cross-linking of amino acid side chains has been shown in some cases to increase protein activity and biostability. Recent research has demonstrated that Grubbs-catalyzed ring-closing metathesis (RCM) reactions can stabilize synthetic 310-helical peptides without disrupting the helicity of the structure. In addition, the RCM reactions proceeded rapidly and E-selectively in the 310-helical framework. This research details the design and synthesis of a 310-helical octapeptide containing both alkene and allene side-chain functionalities. The substrate described herein provides an ideal template for future investigations of novel ene-allene RCM reactions as a potential methodology for synthesizing covalently cross-linked helical peptides. Wed, 13 May 2009 19:50:24 GMT http://hdl.handle.net/10177/2095 Soil Retention of Phosphorus from Phos-Chek® LC-95A, a Long-Term Fire Retardant Kehr, Alissa Each year thousands of gallons of long-term fire retardant, mainly comprised of ammonium phosphate salts, are dropped from the air in an attempt to suppress wildland fires. The impact of ammonium ions on ecosystems has been investigated in depth but the interaction of the phosphates with the environment has been neglected. In this study, the interactions of phosphorus from the long-term fire retardant, Phos-Chek® LC-95A, with soil from the Fremont-Winema National Forest were investigated using a graphite furnace atomic absorption spectrometer. A method was created for measuring phosphorus concentration on the instrument with a La(NO3)3 chemical modifier. The concentration of phosphorus in Phos-Chek® LC-95A was determined to be 48900 ± 2400 ppm phosphorus. Distribution coefficients were calculated to determine the partitioning of the retardant between water and soil. When the retardant was added to soil that had already experienced a fire-like environment the distribution coefficient was calculated to be 4.2 ± 0.4. When retardant was added to dried soil simulating fire-like conditions the distribution coefficient for phosphorus was calculated to be 9.1 ± 1.2. Wed, 13 May 2009 17:22:41 GMT