Physical Sciences and Mathematics Commons^™

Methyl Esterification Of Fatty Acids And Eicosanoids With A Novel Reagent Trimethylsilyldiazomethane For Analysis By Gas Chromatography-Mass Spectrometry, Aditi Munmun Sengupta

Master's Theses and Doctoral Dissertations

Fatty acids are compounds with limited water solubility that belong to the lipid class of bio-organic compounds and can be utilized as a source of energy by the body or as precursors to oxidized compounds that have roles in inflammation and in the regulation of vascular tone. The prostaglandins are naturally occurring 20-carbon cyclopentano fatty acid derivatives produced in mammalian tissue from polyunsaturated fatty acids (PUFAs) and are generated from endoperoxide precursors of arachidonic acid and related polyunsaturated fatty acids by the enzyme cyclo-oxygenase (COX). The lipoxygenase (LOX) enzymes convert arachidonic acid into hydroperoxy derivatives of PUFAs termed leukotrienes, which …

Synthesis And Solid State F-Nmr Studies On Fluorine-Labeled Antimicrobial Peptide Rk-21, Mahender Budarapu

Master's Theses and Doctoral Dissertations

Antimicrobial peptides act against bacteria by binding non-specifically and disrupting their outer membrane. LL-37 is the only member of the cathelicidin group of antimicrobial peptides present in humans and shows a broad range of antimicrobial activity. RK-21 is a fragment of human antimicrobial peptide LL-37, which is α-helical, cationic and amphipathic in nature. RK-21 displays similar antimicrobial activity to LL- 37. In order to understand the mechanism of lipid bilayer disruption, fluorine-labeled antimicrobial peptide RK-21 was chemically synthesized and 19F-NMR studies were done. NMR studies were done at various peptide concentrations, on different lipid bilayer compositions and temperatures. 31P-NMR studies …

Development Of A Microwave-Assisted Epoxide Aminolysis And Investigation Of The Aza-Cope Rearrangement--Mannich Cyclization For Alkaloid Synthesis, Brendan Roberto D'Souza

Master's Theses and Doctoral Dissertations

β-Amino alcohols are important organic compounds with numerous applications. Commonly β-amino alcohols are prepared by ring opening of epoxides using an amine nucleophile and a catalyst or promoter. Ring opening can take place by the SN1 pathway or the SN2 pathway, but no single catalyst or promoter consistently gives SN2 selectivity. Additionally, long reaction times are often required to obtain adequate yields. We have demonstrated that microwave heating reduces reaction times for the aminolysis of both reactive and unreactive, sterically hindered epoxides. These reactions were accomplished with various amines. In all cases, only one equivalent of amine and epoxide were …

Effect Of Counter Ion Concentration Added With Mixture Of Water And Ethylene Glycol On Krafft Temperature Of Sodium Dodecyl Sulfate, Sateesh Krishna Chand Chundru

Master's Theses and Doctoral Dissertations

Surfactants are amphiphilic organic compounds having both hydrophobic and hydrophilic groups. Surfactants in solution form aggregates known as micelles. The minimum temperature at which surfactants forms micelles is known as Krafft temperature. The Krafft temperature of sodium dodecyl sulfate (SDS) was measured at various counter ion concentrations in two solvent systems, water and 10% ethylene glycol. The Krafft temperature of sodium dodecyl sulfate increased in both water and 10% ethylene glycol with increasing counter ion concentration. The Krafft temperature of sodium dodecyl sulfate in 10% ethylene glycol was higher than the Krafft temperature of sodium dodecyl sulfate in water, at …

Characterization Of A Black Coating Overlying Rock Paintings Found In Little Lost River Cave, Idaho Using Thm-Gc-Ms, Jamie Brown-Sinha

Master's Theses and Doctoral Dissertations

A black coating overlies rock paintings found within Little Lost Rive Cave, Idaho. A calibrated radiocarbon date of 1390-1040 B.C. was obtained by Steelman et al.1 However, this relies on the assumption that the black coating was formed by some human activity. For further characterization and to verify that the coating is anthropogenic, THM-GC-MS was performed on various samples collected throughout the cave, including soil samples from inside, outside, and above the cave. Humic and fulvic acids, synthetic and natural melanin, and experimentally created cooking residues were also analyzed as standard materials. By comparing the resulting chromatograms and the compounds …

Kinetics Of The Ligand Exchange Reactions Between Bidentate Ligands And Rriethylenetetramine Nickelate (Ii) And Synthesis Of Boron (Iii) Subphthalocyanines With Various Boron Substitutions, Michael Christopher Cate

Master's Theses and Doctoral Dissertations

Part 1. The kinetics of the ligand exchange reaction between 5-methyl-1,10-phenanthroline and triethylenetetramine nickel (II) were studied spectrophotometrically over the pH range of 5.2 to 8.0 at 25oC. A ternary complex Ni(Trien)(5MP) forms within a few seconds and subsequently reacts with 5MP to form Ni(5MP)3. The reaction is first-order with respect to: [5MP], [Ni(Trien)(5MP)] and [H+]. The rate law is given by:

k dt d[Ni(trien)] = ( − MP Ni(trien)(5MP) + kH, 5MP Ni(trien)(5MP) [H+]) [Ni(trien)][5mp]

where: 5MP is 5-methyl-1,10-phenanthroline and k is the first order rate constant that has units of 1/time.

kH, 5mp Ni(trien)(5mp) = 9.78 X 104 …

Membrane Fragmentation By A 20-29 Fragment Of Human Islet Amyloid Polypeptide And Rat Amyloid Polypeptide, Shyamprasad Samisetti

Master's Theses and Doctoral Dissertations

A key factor in the development of type II diabetes is the loss of insulin-producing pancreatic beta cells. The amyloidogenic human Islet Amyloid Polypeptide (hIAPP, also known as human amylin) is believed to play a crucial role in this biological process. Previous studies have shown that hIAPP forms small aggregates that kill β-cells by disrupting the cellular membrane. In this study we report membrane fragmentation by hIAPP20-29 and the rat version, rIAPP20-29, using solid-state NMR experiments on nanotube arrays of anodic aluminum oxide containing aligned phospholipid membranes.

31P NMR results suggest that membrane fragmentation by hIAPP is related to peptide …

Synthesis Of An Isotopically Labelled Analog Of The Antimicrobial Peptide Ll-37, Rajesh Penumatcha

Master's Theses and Doctoral Dissertations

LL-37 is a cationic cathelin-associated broad spectrum antibiotic peptide of human neutrophils. Its mechanism of action is by disruption of the bacterial cell membrane structure. LL-21 is a simplified form of the peptide that contains only the core portion of LL-37, which retains antimicrobial activity and is easier to synthesize. We synthesized an 15N –Val-labeled LL-21 peptide which allows us to perform antimicrobial assays to know the antimicrobial activity of the new peptide LL-21 on various gram positive and gram negative bacteria. We found that our new peptide LL-21 shows good minimum inhibitory concentrations on various gram positive and gram …

Kinetic Studies Of The Hydrolysis Reactions Of Ruthenium (Iii) Complexes Him Trans-[Rucl₄(Im)₂] And Hind Trans-[Rucl₄(Ind)₂] By Uv-Visible Spectrophotometry, Pramod K. Nangunuri

Master's Theses and Doctoral Dissertations

The ruthenium complexes have gained importance in cancer research in recent times, as several cancers have developed resistance towards platinum compounds. Platinum compounds have severe adverse effects that limited their use towards a wide range of tumors.

Ruthenium complexes are considered as pro-drugs, as they transform into antitumor active species in the body by hydrolysis, redox reactions, and reactions with biologically occurring nucleophiles. My project involved the synthesis of two ruthenium complexes with different ligands and the study of the hydrolysis reactions under different pH at room temperature using UV-visible spectrophotometry.

These studies will enable us to understand how structural …

The Effect Of The Reducing Agent Triphenylphosphine On Arachidonic Acid Metabolism By Prostaglandin H2 Synthase, Lalini Ailaboina

Master's Theses and Doctoral Dissertations

Prostaglandin H2 synthase (PGHS) catalyzes the conversion of arachidonic acid to prostaglandin endoperoxide (PGH2), which is a precursor to a variety of prostaglandins that function as hormones. Gas chromatography combined with mass spectrometry is employed to look for the novel products produced by reaction of triphenylphosphine with arachidonic acid prior to and during the PGHS reaction. Triphenylphosphine (TPP) is known to reduce hydro peroxides to alcohols and is used in the present study to ascertain the extent to which hydroperoxides in arachidonic acid preparations and in PGHS contribute to enzyme activity. Incubation of PGHS with arachidonic acid that was treated …

Controlling The Diastereoselectivity In The Microwave-Assisted Aza-Cope Rearrangement--Mannich Cyclization, Wesley A. Turley

Master's Theses and Doctoral Dissertations

No abstract provided.