Mercury (Hg) is found in the environment in excess of historic baselines throughout the globe because of widespread atmospheric emissions of inorganic mercury (IHg) from anthropogenic sources such as coal-fired power plants and artisanal gold mines. In aquatic ecosystems, Ihg deposited from the atmosphere is converted by bacteria to methylmercury (MeHg), a bioavailable neurotoxin that adversely affects the health of vertebrates including humans and wildlife. Because IHg deposition varies across the landscape, it is necessary to monitor MeHg levels in aquatic food webs of individual waterbodies. This is a challenge because there are millions of river miles and lakes in the U.S. Shoreline spiders that feed on MeHg-contaminated emergent aquatic insects have been proposed as sentinel species to monitor MeHg contamination. Sentinel species are species which serve to map the bioavailable fraction of pollution in an ecosystem by retaining the pollutants in their tissue. The objective of this study was to test the hypothesis that shoreline spiders can be used as sentinels to evaluate MeHg contamination of river food webs. Our study focused on the Clear and West forks of the Trinity River. A pilot study in 2016 indicated the two forks have different levels of MeHg contamination. From June to August 2019, we collected over 1000 long-jawed orb weaver spiders (Tetragnathidae) along the shorelines of the two forks of the river. Spiders were preserved in 95% ethanol and sorted by leg length into different size categories. Mercury was analyzed using direct Hg analysis. Concentrations of Hg in spiders increased with spider size and was higher in the Clear Fork than the West Fork. A follow up study confirmed that fish in the Clear Fork had higher concentrations of MeHg than in the West Fork. This is one of the first studies to demonstrate that shoreline spiders can be used as sentinels of MeHg contamination in river ecosystems.

In recent years, macrocycles have emerged to be potential drug leads, as they show to have promise for targeting disease pathways, however their synthesis is quite difficult and has yet to be optimized. Utilizing glycine specifically in macrocycle synthesis was the objective, and this was done by stepwise reactions of successfully adding compounds onto glycine to prepare for cyclization. Cyanuric chloride, BOC-hydrazine, and morpholine were successfully added to glycine, as proven with thin layer chromatography and NMR. However, problems that arose came with purifying the compound for cyclization due to solubility issues. Many attempts utilized column chromatography, but there seems to be promise in utilizing an extraction to purify the compound and prepare for cyclization.

Organic dyes with photophysical properties affected by alterations in the properties of the media, including viscosity, temperature, and polarity, are known as environment-sensitive probes. These probes are widely used in various areas of analytical, biological and material sciences. This poster will describe our initial efforts on designing multi-responsive environment-sensitive probes based on squaric acid scaffolds. Specifically, the incorporation of aminoquinoline moieties produced small molecule viscometers, which have the ability to sense polarity variations of organic solvents. Multiplexing abilities, coupled with modular and facile synthesis, distinguishes these probes from other types.

Many drugs today are small molecules and function through a specific binding with their target. This has proved to be efficient, yet the idea of larger macromolecules being used as drugs has grown more popular because of their flexibility. The issue with these larger molecules is that they have been previously difficult to synthesize. The emphasis of the research is to find an efficient way to synthesize macrocycles, reducing purification processes and side products. All reactions are done in solution and column chromatography is used to purify. An important aspect is testing if this cyclization method is possible with all amino acids or if limitations are present based on the backbone of the molecule. Because macrocycles have proved difficult to synthesize in the past, they are overlooked in the field of drug design. However, with this rather basic process it is possible to create new rules associated with drug design and defy what was once believed about macrocycles.

Organic synthesis and research into the activity and uses for macrocycle compounds have increased in recent years. These compounds proved to be an interesting field of research due to their size and ability to orient in different ways depending on the environment. The synthesis of these molecules is done by using a stable foundation molecule, cyanuric chloride, which is subject to substitution. The compound can be built from there using nucleophilic substitution with various nitrogen-based compounds. Then, in the final steps of the synthesis, the compounds dimerize forming the macrocycle. The amino acid nucleophile used to build the molecule is being varied to build many different compounds. The challenge, however, is to find the most efficient route for synthesis. I have successfully managed to synthesize one macrocycle compound using lysine with a Z protecting group as the starting material. Throughout the synthesis there was great difficulty with the compound’s solubility, therefore the starting material was switched to a BOC protected lysine amino acid. This resulted in better solubility throughout the process and yielded another successful macrocycle. These results demonstrate how the synthesis pathway we used to build these macrocyclic dimers is successful, but the process can be variable, based on the properties of the amino acid. It is recognized how the synthesis of these compounds is only the first step and further research into the properties and actions of the compounds is necessary. However, a pure product and efficient synthesis in making the macrocycle is important to properly access its properties. My further research will specifically test the antibiotic properties, if any, the macrocycles possess.