Ionic liquids could solve a major problem with evaporation based solvent waste in laboratories and industry. However, scientists must understand how ionic liquids behave as co-solvents to determine their usefulness. This project studied intermolecular interactions in liquid-liquid solutions of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C2N) and co-solvent 1-propanol. Raman spectra were collected as a function of composition. Shifts of up to 3.5 cm-1 in the C-O and O-H regions of 1-propanol were observed as system composition changed. These shifts are indicative of a change in the symmetry of the solvation shell of 1-propanol in C2N as the number of hydrogen-bonded 1-propanol molecules decrease.
Faculty Sponsor: Chuck Williamson
Discipline: Chemistry
The study of liquid mixtures yields insight into components’ co-miscibility behavior. Previous work has shown that replacing a component’s hydrogen atoms with deuterium causes a shift in coexistence temperatures for a binary liquid mixture. In this work, we have investigated the degree to which naturally abundant carbon-13 isotopologues shift coexistence temperatures in liquid mixtures through measurements of the benzyl alcohol + heptane and benzyl alcohol + tetradecane systems. Coexistence temperatures for forty samples were determined from changes in laser light scattering. The asymmetries of the resultant coexistence curves were evaluated regarding expected isotopologue contributions.
Faculty Sponsor: Chuck Williamson
Discipline: Chemistry
Many approved medical drugs suffer from poor solubility and toxicity resulting in poor absorption from the body and side effects. The macrocycle Cucurbit 7 Uril has been shown to increase drug solubility upon encapsulation. Although guest-host complex chemistry has promising applications, detection of complex formation involves substantial work to characterize, often relying on expensive equipment that also fail to detect high binding interactions that many macrocycles like CB7 produce. Here we present a naphthalene derived sensor that is modifiable, PH independent, and measures high binding interactions via a sensitive solution derived assay based on fluorescence.
Faculty Sponsor: Cooper Battle
Discipline: Chemistry
Quadruplex molecular beacons (QMBs) are DNA strands that have shown promise in research for cancer screening. This project focuses on assessing quadruplex stability and structure, as both play an important role in the functionality of the sensor. We are specifically interested in looking at the effects of FRET pairs and how their location affects the quadruplex. Stability analysis was done looking at both melting temperatures and thermodynamic values, with structural analysis being done in collaboration with Dr. Mike Harms at the University of Oregon.
Faculty Sponsor: Cooper Battle
Discipline: Chemistry
Estrogens are pervasive endocrine-disrupting chemicals released into aquatic environments. These include the potent synthetic estrogen 17ɑ-ethynylestradiol (EE2), found in birth control. Reported EE2 concentrations in aquatic environments are often orders of magnitude higher than population demographics predict. Our research, utilizing ultra-high resolution mass spectrometry, identified six potential interferences co-eluting with EE2. Among them were several common surfactants. This discovery highlights the importance of designing standardized methods to enhance the accuracy of measuring synthetic estrogens. Our study enhances understanding of interferences, contributing to improved measurement precision in assessing the impact of these chemicals on aquatic ecosystems.
Faculty Sponsor: David Griffith
Discipline: Chemistry
Plants produce a large amount of methyl halides which contribute to the destruction of the ozone layer. In Arabidopsis thaliana, the HARMLESS TO OZONE LAYER (HOL) gene was found to be responsible for the production of methyl halides. This gene codes for a S-Adenosyl-L-Methionine (SAM) thiol/halide methyltransferase enzyme, which catalyzes the methylation of numerous halide ion and pseudohalide ion substrates. We characterized the kinetics of AtHOL1 from Arabidopsis thaliana, with the substrates KBr and KSCN, to compare to literature values. We determined enzymatic activity using a High-Performance-Liquid Chromatography enzyme assay and applied Michaelis-Menten kinetic theory to find kinetic constants.
Faculty Sponsor: Alison Fisher
Discipline: Chemistry
When a methyl halide is introduced into the atmosphere, it catalyzes the destruction of the ozone layer through a chain reaction initiated by UV radiation. Methyl halide production is catalyzed by a SAM-dependent methyltransferase and encoded by HARMLESS TO OZONE LAYER (HOL) genes. We developed an enzymatic assay to characterize the enzymatic activity of AtHOL1 from Arabidopsis Thaliana using High-Performance Liquid Chromatography (HPLC). The substrates of focus in this study are chloride and iodide. Our methodology was adapted from Nagatoshi and Nakamura (2009), who also found thiocyanate to be the preferred substrate for AtHOL1.
Faculty Sponsor: Alison Fisher
Discipline: Chemistry
Oxidative stress, stemming from reactive oxygen and nitrogen species (ROS, RNS), poses significant health risks. Polyphenols like caffeic acid exhibit therapeutic potential but suffer from poor water solubility. Conjugating lipophilic polyphenols to soluble polymers, like Poly-(Acetyl, Arginyl)-Glucosamine (PAAG), enhances their bioavailability. Previous conjugation experiments were successful but faced limitations, such as insolubility of more heavily functionalized polymer strands, prompting the exploration of alternative counter anions. This study explores the solubility effects of substituting PAAG-CA associated chloride counteranions with alternatives, such as phosphate, citrate, and lactate with the aim to create highly functionalized water-soluble conjugates.
Faculty Sponsor: Andrew Duncan
Discipline: Chemistry
Free radicals are reactive compounds that can harm human health. Antioxidants suppress free radicals by scavenging and neutralizing their reactivity but suffer from limited aqueous solubility and bioavailability. Here, we covalently attach ferulic acid (FA) antioxidants to a biocompatible drug-delivery polymer, Poly(Acetyl, Arginyl)Glucosamine (PAAG). The resulting PAAG-FA conjugates exhibit solubility issues above 30 mg antioxidant loading, which we attempt to stabilize using citrate, phosphate, and lactate ions. Stabilization with phosphate exhibits promising solubility improvements, while citrate-stabilized conjugates show a decrease. Antioxidant capabilities are evaluated through a DPPH scavenging assay, offering insights into the potential of PAAG-FA conjugates as bioactive formulations.
Faculty Sponsor: Andrew Duncan
Discipline: Chemistry
Understanding the phylogenetic relationships and morphological variations within bee species is essential for conservation efforts and ecological studies. In this study, we investigated the phylogenies and morphology of bees within the Melissodes genus, utilizing a multi-faceted approach. Previous DNA sequencing provided phylogenetic insights into 10 specimens collected from the Willamette Valley. Morphological analysis, employing the DiscoverLife and LaBerge keys, supplemented the genetic data. Additionally, Barcode of Life Database sequences facilitated comparison, revealing congruence between molecular and morphological classifications. Our findings shed light on the taxonomic organization of Melissodes species and underscore the importance of integrating multiple methodologies in species research.
Faculty Sponsor: Briana Lindh
Discipline: Biology