Chemistry Commons^™

Application Of Mass Spectrometry For The Characterization Of Synthetic Oligomers And Natural Lignin, Poorya Kamali

Theses and Dissertations--Chemistry

As part of the ongoing effort to substitute finite fuel and chemical resources with renewable ones, biomass is emerging as one of the most promising sources. Biomass consists of three main components of cellulose, hemicellulose, and lignin. Traditionally, cellulose has been used extensively in pulping industry, while lignin has been considered waste and is burned to generate heat. Lignin, a complex aromatic polymer component of biomass, has the potential to be used as a source of aromatic chemicals and pharmaceutical synthons. The recalcitrant nature of lignin, the lack of effective lignin breakdown methods and analytical techniques to analyze it are …

Investigation Of The Analytical Utility Of The Inductively Coupled Plasma Mass Spectrometer (Icp-Ms) For The Quantification Of Proteins Via Lanthanide Labeling, Caitlin Elizabeth Dunlap

Undergraduate Honors Thesis Collection

The discovery and ability to provide an absolute concentration of biomarkers in the body can facilitate early diagnoses of diseases. This information can also be used for more accurate and unique treatments for those patients. While major advances in molecular mass spectrometry allows for a sensitive identification of these biomarkers, they are limited to only four orders of magnitude in their dynamic ranges. Due to this, detection and quantitation of low abundant proteins, which tend to make up these vital biomarkers, is very difficult. On the other hand, ICP-MS offers a wider dynamic range (up to 12 orders of magnitude) …

Mechanisms And Applications Of Improved Protein Analysis By Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Roshan Javanshad

Dissertations

Electrospray ionization mass spectrometry (ESI-MS) is a soft ionization technique that allows detection of macromolecules, such as intact proteins, by the formation of multiply charged ions from solutions. Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient ionization technique that directly samples analyte from a surface during ESI-MS analysis. Although DESI-MS is highly accomplished at the analyses of metabolites, lipids, and other small molecules, it is far more limited when it comes to protein analysis. While most of the field in ambient ionization MS has moved towards primarily applications, our approach has been to explore the use of DESI-MS and …

Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski

Dissertations, Theses, and Capstone Projects

Recent genomic studies of microbiomes have revealed an overwhelming number of biosynthetic genes of unknown function. Most of these “cryptic” biosynthetic genes are not expressed in laboratory monocultures of individual microbes. Thus, there remains tremendous untapped potential for natural products discovery. Here we employ mixed microbial culture (MMC) as a simple yet powerful approach to awaken cryptic biosynthetic gene clusters. Our preliminary studies demonstrated that arrays of metabolites could be induced in MMCs upon environmental cues, such as surface adhesion. Using this system, we have screened, identified, and isolated bioactive bacterial metabolites, which were characterized structurally and biologically. Of the …

Protein Detection And Structural Characterization By Mass Spectrometry Using Supramolecular Assemblies And Small Molecules, Bo Zhao

Doctoral Dissertations

Mass spectrometry (MS) has played an increasingly prominent role in proteomics and structure biology because it shows superior capabilities in identification, quantification and structural characterization of proteins. To realize its full potential in protein analysis, significant progress has been made in developing innovative techniques and reagents that can couple to MS detection. This dissertation demonstrates the use of polymeric supramolecular assemblies for enhanced protein detection in complex biological mixtures by MS. An amphiphilic random co-polymer scaffold is developed to form functional supramolecular assemblies for protein/ peptide enrichment. The influences of charge density and functional group pK_a on host-guest interactions …

Analytical Methods To Support Design And Optimization Of Protein Drug Conjugate: Focusing On Haptoglobin-Hemoglobin Complex As A Drug Carrier, Shengsheng Xu

Doctoral Dissertations

Acquired immunodeficiency syndrome (AIDS) remains one of the most serious public health challenges and a significant cause of mortality for certain populations. Despite the large number of antiretrovirals (mostly nucleotide and nucleoside analogs) developed in the past two decades, the inability of small molecule therapeutics to target HIV reservoirs directly creates a significant obstacle to their effective utilization. Indeed, achieving the desired therapeutic effect in the absence of the effective targeted delivery must rely on dosage escalation, which frequently causes severe toxicity. This problem may be solved by conjugation of antiretroviral agents to endogenous proteins (e.g., hemoglobin haptoglobin complex) that …

Application Of Electrospray Ionization Mass Spectrometry For Ionic Liquids And Their Biodegradation Products, Sepideh Rahbarirad

Masters Theses

Ionic liquids (ILs) are organic salts with unique physico-chemical properties and are used as green alternatives to volatile organic solvents. ESI-MS is a sensitive technique to detect these stable, permanent ions. My research focused on (1) Identification of biodegradation products of ionic liquids and (2) Multiplexed tandem MS by modulation of ionization efficiency.

Studies, have demonstrated that ILs are toxic to the environment, which makes their biodegradability an important consideration. In this work, metabolites generated during the biodegradation of 1-butyl-3-methylimidazolium chloride (BMIM), a degradation resistant and commonly used ionic liquid, are identified using high performance liquid chromatography-mass spectrometry (LC-MS).

Multiplexed …

Enzyme, Cosolvent, And Substrate Interactions In Ple Hydrolysis Reactions And Evaluation Of The Stability Of An Unnatural Glutathione Analogue, Maureen Elizabeth Smith

Dissertations

Prochiral diester malonates have been hydrolyzed in the presence of Pig Liver Esterase (PLE). Several of the diesters produced the respective half-ester in moderate to high enantioselectivity. A series of cosolvent assays were performed to evaluate the ability of the cosolvent to influence the enantioselective outcome of the hydrolysis reactions. Ethanol produced the largest changes in enantioselectivity of all solvents evaluated. The isoenzymes of PLE were also evaluated and provided very different enantioselective outcomes than that of crude PLE. A series of NMR titrations was performed to explore the interactions between the substrates and ethanol cosolvents.

Improvements to our previously …

Fundamental Studies Of Protein Ionization For Improved Analysis By Electrospray Ionization Mass Spectrometry And Related Methods, Kevin A. Douglass

Dissertations

Mass spectrometry (MS) is an analytical technique in which a sample is converted to gas-phase ions that are subsequently separated and detected. It offers great speed, selectivity, and sensitivity during analysis, characteristics which have enabled it to become a leading method for the study of proteins. The applications of MS for these biologically significant macromolecules range from accurately determining identity and sequence to shedding light on post-translational modifications and protein-molecule interactions. As a first step towards analysis by MS, gas-phase protein ions must be formed. A common method for ionization is electrospray ionization (ESI), where a liquid sample including the …

New Applications Of Mass Spectrometry For Drug And Lipid Analysis, Elizabeth Lauren Emerson

Graduate Theses and Dissertations

Mass spectrometry is an important tool used in many different disciplines and settings that include forensics, drug discovery, environmental analysis, and proteomics. Gas chromatography - mass spectrometry (GC-MS) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI - TOF MS) are two of the most important instruments used for analysis of compounds. Chapters 1 and 2 of this discussion use GC-MS for the investigation of synthetic cannabinoids in `K2' incense products and the detection of metabolites in urine samples from individuals suspected of consuming these mixtures. Analytical standards were synthesized and used for identification and confirmation of structures. Detection of …