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Full-Text Articles in Physical Sciences and Mathematics

Development Of Bifunctional Peptides As Scaffolds For Bifunctional Catalysis And A Novel Method Of Peptide Stapling Using Squaric Esters, Adam X. Wayment Mar 2024

Development Of Bifunctional Peptides As Scaffolds For Bifunctional Catalysis And A Novel Method Of Peptide Stapling Using Squaric Esters, Adam X. Wayment

Theses and Dissertations

Enzymes are some of nature's most powerful tools in chemical processes. However, their molecular complexity makes them difficult to synthesize and complicates their application in traditional organic synthesis. Peptides, a building block of enzymes, can be rapidly synthesized and have been used as a possible alternative in achieving enzyme-like catalysis. However, most peptide-based catalysts are limited in reaction-scope and are unable to incorporate traditional organic catalysts. We have designed a helical peptide scaffold capable of being functionalized with a wide variety of organocatalysts as well as transition-metal based catalysts. In order to understand how the peptide structure effects reactivity and …


Synthesis And Applications Of Α,Β-Dehydroamino Acid-Containing Peptides, Diego A. Moya Jun 2022

Synthesis And Applications Of Α,Β-Dehydroamino Acid-Containing Peptides, Diego A. Moya

Theses and Dissertations

Yaku’amide A (YA) is a linear anticancer peptide that is rich in bulky dehydroamino acids (ΔAAs) and β-hydroxyamino acids (β-OHAAs). In our recent total synthesis of YA, we featured a one-pot anti dehydration–azide reduction–O→N acyl transfer process for the stereospecific construction of Z- and E- ∆Ile residues. Despite previous total syntheses and our efforts, the synthesis of YA remains lengthy. Via computational studies, we identified two analogue peptides that closely resemble the conformation of YA. The use of simpler and symmetrical bulky ΔAAs such as dehydrovaline (ΔVal) and dehydroethylnorvaline (ΔEnv) as surrogates of ∆Ile, along with azlactone chemistry for their …


Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur Jun 2021

Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur

Undergraduate Honors Theses

This thesis explores the synthesis of fluorinated α,β-dehydroamino acids, specifically a fluorinated dehydrovaline derivative. Previous work has been done on the equivalent dehydrovaline derivative without fluorine present and this work builds toward the fluorinated version with the goal of comparing the two structurally. The synthesis presented here pulls from previous synthetic strategies employed for dehydrovaline while also exploring the synthetic impact of the electronegative fluorine atoms.


Novel Cinchona Alkoloid Derived Ammonium Salts As Phase-Transfer Catalysts For The Asymmetric Synthesis Of Beta-Hydroxy Alpha-Amino Acids Via Aldol Reactions And Total Synthesis Of Celogentin C., Bing Ma Jun 2009

Novel Cinchona Alkoloid Derived Ammonium Salts As Phase-Transfer Catalysts For The Asymmetric Synthesis Of Beta-Hydroxy Alpha-Amino Acids Via Aldol Reactions And Total Synthesis Of Celogentin C., Bing Ma

Theses and Dissertations

Project I. Cinchona alkaloid-derived quaternary ammonium salts have been successfully used as phase-transfer catalysts, particularly in asymmetric alkylations. Our group applied this type of catalyst in the synthesis of β-hydroxy α-amino acids via aldol reactions and discovered that the Park-Jew catalyst afforded good yields and good enantiomeric excess of the syn diasteromers, but negligible diastereoselectivity. This project was therefore focused on the synthesis of novel cinchonidine-derived catalysts with the Park-Jew catalyst as the lead structure. The C3 position of cinchonidine nucleus was modified to achieve dimers and catalysts possessing electron-deficient alkyne and alkene moieties. Synthesized catalysts were tested in the …


Development Of Polymer Monoliths For The Analysis Of Peptides And Proteins, Binghe Gu Dec 2006

Development Of Polymer Monoliths For The Analysis Of Peptides And Proteins, Binghe Gu

Theses and Dissertations

Several novel polymer monoliths for the analysis of peptides and proteins were synthesized using polyethylene glycol diacrylate (PEGDA) as crosslinker. Photo-initiated copolymerization of polyethylene glycol methyl ether acrylate and PEGDA yielded an inert monolith that could be used for size exclusion liquid chromatography of peptides and proteins. This macroscopically uniform monolith did not shrink or swell in either water or tetrahydrofuran. More importantly, it was found to resist adsorption of both acidic and basic proteins in aqueous buffer without any organic solvent additives. A strong cation-exchange polymer monolith was synthesized by copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and PEGDA. A ternary …


Polymer Microchips For Capillary Electrophoresis And Electric Field Gradient Focusing Of Biomolecules, Ryan Thomas Kelly Sep 2005

Polymer Microchips For Capillary Electrophoresis And Electric Field Gradient Focusing Of Biomolecules, Ryan Thomas Kelly

Theses and Dissertations

Polymeric materials have seen increasing use as microfluidic device substrates due to their low cost and the simplicity of templated fabrication procedures. I showed that poly(methyl methacrylate) (PMMA) microdevices could be enclosed in a boiling water bath, which allowed the seal to form more quickly than in conventional approaches, and enabled microchannels to remain hydrated throughout the bonding process. Microchip capillary electrophoresis (µ-CE) devices were fabricated using water-based enclosure, and a mixture of fluorescently labeled amino acids was separated in 30 s in these microchips. To create more robust capillary electrophoresis (CE) microdevices with improved separation performance, phase-changing sacrificial materials …